MAY/JUNE 2022 VOL 33 NO 3 • Fascial plane regional anaesthesia techniques • Epicardial fat thickness assessment • Response to ibut i l ide af ter catheter ablat ion for AF • Aort ic cross-clamp techniques in CABG • Tetralogy of Fal lot in south-west Niger ia • Strain-gauge plethysmography in chronic venous disease • Management of acute coronary syndromes in Cape Town • Effect of di fferent block techniques on open-heart surgery • Acute coronary syndrome compl icated by cardiogenic shock • Successful retr ieval of an entrapped and uncoi led guide wi re CardioVascular Journal of Afr ica (off icial journal for PASCAR) www.cvja.co.za
NEW INTRODUCING OUR IMPROVE QUALITY OF LIFE IVABRADINE Versus placebo, Ivabradine has shown1 : 18% reduction in primary endpoint, driven by • a reduction in hospitalisation for HF • a reduction in death due to HF For further product information contact PHARMA DYNAMICS Email info@pharmadynamics.co.za CUSTOMER CARE LINE +27 21 707 7000 www.mydynamics.co.za IVOLAN 5 mg. Each tablet contains Ivabradine oxalate equivalent to 5 mg Ivabradine base. S3 51/7.1.4/0921. For full prescribing information, refer to the professional information approved by SAHPRA, March 2021. 1) K Swedberg et al. Ivabradine and outcomes in chronic heart failure (SHIFT): a randomised placebo-controlled study. Lancet 2010; 376: 875-85. IVNA842/05/2022
ISSN 1995-1892 (print) ISSN 1680-0745 (online) Cardiovascular Journal of Afr ica www.cvja.co.za CONTENTS INDEXED AT SCISEARCH (SCI), PUBMED, PUBMED CENTRAL AND SABINET Vol 33, No 3, MAY/JUNE 2022 EDITORS Editor-in-Chief (South Africa) PROF PAT COMMERFORD Assistant Editor PROF JAMES KER (JUN) Regional Editor DR A DZUDIE Regional Editor (Kenya) DR F BUKACHI Regional Editor (South Africa) PROF R DELPORT EDITORIAL BOARD PROF PA BRINK Experimental & Laboratory Cardiology PROF R DELPORT Chemical Pathology PROF MR ESSOP Haemodynamics, Heart Failure & Valvular Heart Disease DR OB FAMILONI Clinical Cardiology DR V GRIGOROV Invasive Cardiology & Heart Failure PROF J KER (SEN) Hypertension, Cardiomyopathy, Cardiovascular Physiology DR J LAWRENSON Paediatric Heart Disease PROF A LOCHNER Biochemistry/Laboratory Science DR MT MPE Cardiomyopathy PROF DP NAIDOO Echocardiography PROF B RAYNER Hypertension/Society PROF MM SATHEKGE Nuclear Medicine/Society PROF YK SEEDAT Diabetes & Hypertension PROF H DU T THERON Invasive Cardiology INTERNATIONAL ADVISORY BOARD PROF DAVID CELEMAJER Australia (Clinical Cardiology) PROF KEITH COPELIN FERDINAND USA (General Cardiology) DR SAMUEL KINGUE Cameroon (General Cardiology) DR GEORGE A MENSAH USA (General Cardiology) PROF WILLIAM NELSON USA (Electrocardiology) DR ULRICH VON OPPEL Wales (Cardiovascular Surgery) PROF PETER SCHWARTZ Italy (Dysrhythmias) PROF ERNST VON SCHWARZ USA (Interventional Cardiology) SUBJECT EDITORS Nuclear Medicine and Imaging DR MM SATHEKGE Heart Failure DR G VISAGIE Paediatric DR S BROWN Paediatric Surgery DR DARSHAN REDDY Renal Hypertension DR BRIAN RAYNER Surgical DR F AZIZ Adult Surgery DR J ROSSOUW Epidemiology and Preventionist DR AP KENGNE Pregnancy-associated Heart Disease PROF K SLIWA-HAHNLE EDITORIAL 103 Fascial plane regional anaesthesia techniques R Verbeek • F Montoya • JLC Swanevelder CARDIOVASCULAR TOPICS 108 Epicardial fat thickness assessment by multi-slice computed tomography for predicting cardiac outcomes in patients undergoing transcatheter aortic valve implantation G Er taş • A Ekmekçi • S Şahin • A Murat • N Bakhshaliyev • HB Erer • TS Güvenç • M Eren 112 Response to ibutilide and the long-term outcome after catheter ablation for non-paroxysmal atrial fibrillation Y Wu • P Gao • Y Liu, Q Fang 117 The effect of single aortic cross-clamp technique versus multiple clamp technique on postoperative stroke in octogenarians undergoing coronary artery bypass grafting EE Tekin • M Balli • MA Yesiltas • A Uysal 122 Tetralogy of Fallot in the nascent open-heart surgical era in a tertiary hospital in south-west Nigeria: lessons learnt OT Bamigboye-Taiwo • B Adeyefa • UU Onakpoya • OO Ojo • JO Eyekpegha • A Oguns • JAO Okeniyi 128 The use of strain-gauge plethysmography in the functional assessment of chronic venous disease: five-year experience at a single centre HS Başbuğ • H Göçer • K Özışık 138 Profile and management of acute coronary syndromes at primary- and secondary-level healthcare facilities in Cape Town F Uys • AT Beeton • S van der Walt • M Lamprecht • M Verryn • Y Vallie • D Stokes • RS Millar • CA Viljoen
CONTENTS Vol 33, No 3, MAY/JUNE 2022 FINANCIAL & PRODUCTION CO-ORDINATOR ELSABÉ BURMEISTER Tel: 021 976 8129 Fax: 086 664 4202 Cell: 082 775 6808 e-mail: elsabe@clinicscardive.com PRODUCTION EDITOR SHAUNA GERMISHUIZEN Tel: 021 785 7178 Cell: 083 460 8535 e-mail: shauna@clinicscardive.com CONTENT MANAGER MICHAEL MEADON (Design Connection) Tel: 021 976 8129 Fax: 0866 557 149 e-mail: michael@clinicscardive.com The Cardiovascular Journal of Africa, incorporating the Cardiovascular Journal of South Africa, is published 10 times a year, the publication date being the third week of the designated month. COPYRIGHT: Clinics Cardive Publishing (Pty) Ltd. LAYOUT: Jeanine Fourie – TextWrap PRINTER: Tandym Print/Castle Graphics ONLINE PUBLISHING & CODING SERVICES: Design Connection & Active-XML.com All submissions to CVJA are to be made online via www.cvja.co.za Electronic submission by means of an e-mail attachment may be considered under exceptional circumstances. Postal address: PO Box 1013, Durbanville, RSA, 7551 Tel: 021 976 8129 Fax: 0866 644 202 Int.: +27 21 976 8129 e-mail: info@clinicscardive.com Electronic abstracts available on Pubmed Audited circulation Full text articles available on: www.cvja. co.za or via www.sabinet.co.za; for access codes contact elsabe@clinicscardive.com Subscription: To subscribe to the online PDF version of the journal, e-mail elsabe@clinicscardive.com • R500 per issue (excl VAT) • R2 500 for 1-year subscription (excl VAT) The views and opinions expressed in the articles and reviews published are those of the authors and do not necessarily reflect those of the editors of the Journal or its sponsors. In all clinical instances, medical practitioners are referred to the product insert documentation as approved by the relevant control authorities. 145 Pre-operative neurodevelopmental assessment in young children undergoing cardiac surgery in central South Africa: feasibility and clinical value R Smith • V Ntsiea • S Brown • J Potter ton 153 Evaluation of the effect of different block techniques on open-heart surgery in the postoperative period: a prospective observational study S Turkmen • M Mutlu CASE REPORTS 157 Acute coronary syndrome complicated by cardiogenic shock in a young adult: a case report from Dakar, Senegal SCT Ndao • MM Ka • K Dia • PD Fall • MC Mboup 162 Successful retrieval of an entrapped and uncoiled guide wire using a wire-cutting technique W Tian • L Cui • CJ Nicholson • R Malhotra PUBLISHED ONLINE (Available on www.cvja.co.za and in PubMed)
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 103 Editorial Fascial plane regional anaesthesia techniques Renier Verbeek, Felipe Montoya, Justiaan LC Swanevelder 10.5830/CVJA-2022-034 Peri-operative pain management and a reduction in stress response to cardiac surgery has traditionally been accomplished with opioids, but these agents also have a negative effect on enhanced recovery after surgery (ERAS). Techniques based on reducing opioid use is associated with fewer side effects and earlier patient recovery. Increasing pressure to provide efficient patient care while improving patient outcomes has led to a recent surge in administering regional techniques for cardiac surgery as part of a multimodal pain management concept, with the overall goal to provide effective and safe patient care during cardiac surgery procedures.1,2 Inadequate control of surgical pain can lead to chronic pain in up to 20% of post-sternotomy and 25 to 60% of postthoracotomy patients. Regional techniques may help to reduce acute postoperative pain, including opioid-induced hyperalgesia and the development of chronic pain by reducing noxious sensitisation. Poorly controlled pain is associated with sympathetic nervous system activation and an increased hormonal stress response. This response may contribute to multiple adverse postoperative events, including myocardial ischaemia, cardiac arrhythmias, hypercoagulability, pulmonary complications and increased rates of delirium and wound infection.3 Huang et al. reviewed the incidence of pain at two months after cardiac surgery and found that out of 244 patients, 30% had persistent sternal pain, 29% had continued chest pain after mini-thoracotomy, 17% had shoulder pain and 15.9% had back pain after cardiac surgery.4 Fascial plane blocks involve the deposition of local anaesthetic (LA) between the fascial layers, thereby blocking sensory nerve fibres that pass through the fascial planes and pierce different muscle layers to finally supply cutaneous sensory innervation. The nerve often gives off sensory and motor branches to the muscle layers along its course. With ultrasound guidance, the procedure is relatively simple with a low risk profile. Neuraxial regional anaesthesia, like spinals or epidurals, carries an uncomfortably high perceived risk in terms of nerve injury due to compressive haematoma in a fully heparinised patient. With these techniques, there is also the risk of potential haemodynamic instability at the spinal analgesia level, which is required. Pectoral blocks (PECS I and PECS II) have been used in breast surgery, as described by Blanco, and more recently introduced to cardiac surgery (Fig. 1).5 The medial (C8–T1) and lateral (C5–C7) pectoral, long thoracic (C5–C7) and thoracodorsal (C6–C8) nerves originate from the brachial plexus and provide primarily motor innervation to the muscles of the chest wall, but also carry sensory nerve fibres. Segmental thoracic sensory innervation of the chest wall extends from the spinal nerve root level T1 to T11. The spinal nerve exits the intervertebral foramen and divides into a dorsal and ventral ramus within the paravertebral space, which communicate with the sympathetic trunc via the white and gray rami communicantes. Dorsal rami supply the muscles, bone, joints and skin of the midback. Ventral rami travel alongside blood vessels between pleura and endothoracic fascia, then between internal and innermost intercostal muscles, supplying the lateral and anterior chest wall. At the mid-axillary level, a branch pierces the internal and external intercostal muscles and serratus anterior muscle (SAM), becoming the lateral cutaneous branches providing sensory innervation to the lateral chest wall. The rest of the nerve courses anteriorly towards the sternum and pierces the internal intercostal muscle, external intercostal membrane and pectoralis major muscle, providing sensory innervation for the anterior chest wall. The intercostal nerves provide segmental innervation with an overlap between the adjacent nerves, requiring blockade of at least the nerve above and below. The PECS I block is performed by injecting LA between the pectoralis major and minor muscle at Morheim’s pouch. The ultrasound probe is first placed below the mid-clavicle and moved inferolaterally to the level of the third rib. The thoraco-acromial artery may be seen between the pectoralis major and minor Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa Renier Verbeek, MD Felipe Montoya, MD Justiaan LC Swanevelder, MD, Justiaan.swanevelder@uct.ac.za Fig. 1. Transverse chest anatomy.
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 104 AFRICA muscles. Tilting the probe helps to identify fascial planes. The needle is inserted in the plane, in a craniocaudal direction. The shaded area (Fig. 2) illustrates approximate interfascial LA spread between the pectoralis major and pectoralis minor muscles. The PECS II block is performed by injecting LA between the pectoralis minor muscle and SAM. PECS I and II blocks are frequently performed with a single skin puncture site by first injecting the LA in the PECS II plane, followed by needle withdrawal and injection into the PECS I plane. The site of PECS I injection affects the distribution of the block, with a more lateral injection spreading towards the axilla and blocking the intercostobrachial nerve, and a more medial injection spreading toward the midline, potentially blocking the anterior intercostal nerve branches. The PECS II blocks the long thoracic and thoracodorsal nerves and lateral cutaneous branches of the intercostal nerves, providing innervation to the SAM and lateral chest wall (Fig. 3). A recent case report discusses the use of PECS II with a continuous catheter for two patients undergoing trans-apical aortic valve implantations (TAVI).6 Randomised studies in breast surgery patients comparing PECS I/II blocks to placebo consistently demonstrate improved analgesia with the blocks. Randomised studies comparing PECS I/II blocks to the paravertebral blocks in similar patient populations show conflicting results, which differ in terms of analgesia duration and quality. This may be due to differences in the extent of surgical dissection, techniques used when performing the blocks, and the type and amount of LA injected. PECS II will block the thoracodorsal and long thoracic nerves, but spare the anterior branches of the intercostal nerves. The serratus anterior plane (SAP) block anaesthetises primarily the thoracic intercostal nerves and provides analgesia of the lateral thorax. The SAP block can be considered an extension of the PECS II block, with a more inferolateral level of injection and a wider spread. It can block the spinal nerve root at level T2 to T9, including the anterior, lateral and posterior chest wall. The efficacy is partly influenced by the volume of LA injected, as well as the injection site being deep or superficial to the SAM. Better anterior spread of the block occurs with deep injection, while the superficial injection may be preferred for a more posterior spread. Anaesthetising T1 to T8 requires a LA volume greater than 40 ml (Fig. 4). The efficacy and duration of an SAP block, PECS II block and intercostal nerve block (ICNB) for the management of postthoracotomy pain was examined in paediatric cardiac surgery patients and was found to be equally efficacious, but longest Fig. 3. Pectoral II block anatomy. Fig. 2. Pectoral I block anatomy. Fig. 4. Serratus anterior block anatomy.
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 105 lasting with the SAP block (more than 12 hours), followed by the PECS II block (8–12 hours) and then the ICNB (4–6 hours).7 While their use is relatively safe, we must be cognisant of their potential complications, which include infection, thoraco-acromial artery injury, haematoma, pneumothorax and intravenous injection with subsequent LA toxicity. Anterior cutaneous branches can be anaesthetised by injecting LA in the fascial planes of the anterior chest wall. The intercostal nerves run between the innermost and inner intercostal muscles. As they reach the most anterior part of the chest wall, they run between the transverse thoracic (deeper) and internal intercostal (superficial) muscles in the same plane as the internal mammary artery. They then pierce through the internal intercostal muscle and external intercostal membrane anteriorly to give medial and lateral cutaneous branches, innervating superficial tissues in the parasternal area. The target anterior branches of the intercostal nerves are from T2 to T6. An ultrasound-guided pecto-intercostal fascial (PIF) block was introduced as an adjunct to PECS blocks, providing analgesia to the anterior chest wall with an injection placed 2 cm lateral from the sternum between the pectoralis major and (internal) intercostal muscles (Fig. 5). With a transverse thoracic muscle plane (TTMP) block, the injection is performed between the internal intercostal and transverse thoracic muscles (Fig. 6). However, the transverse thoracic muscle is a very thin structure lying posterior to the sternum and can be difficult to visualise with ultrasound. The TTMP and PIF blocks are useful for patients undergoing median sternotomies and patients with anterior chest wall trauma.8,9 Potential complications include infection, haematoma, pneumothorax and internal mammary artery injury. The PIF, compared to the TTMP block, avoids the plane of the internal mammary artery. In a prospective, randomised study, 108 patients undergoing open cardiac surgery received either bilateral PIF blocks or nothing. The primary endpoint was postoperative pain, with secondary endpoints being analgesia consumption, time to extubation, the presence of ileus, intensive care unit (ICU) length of stay, insulin resistance and interleukin-6 (IL-6) levels. The PIF block group consumed less sufentanil and parecoxib than the control group. Compared to the PIF block group, the control group had higher numerical rating scale (NRS) pain scores at 24 hours after operation, both at rest and during coughing. The time to extubation, length of stay in ICU and length of hospital stay were significantly decreased in the PIF block group compared with the control group. The PIF block group had lower insulin, glucose, IL-6 and HOMA-IR levels than the control group at three days after surgery. This study demonstrates that bilateral PIF blocks provide effective analgesia and accelerate recovery in patients undergoing open cardiac surgery.10 In a prospective, double-blind, randomised study investigating TTMP blocks, Aydin et al.11 showed good efficacy and a reduction in opioid requirements. They investigated 48 adult patients having cardiac surgery with median sternotomy. Patients were randomly assigned to receive pre-operative ultrasoundguided TTMP block with either 20 ml of 0.25% bupivacaine or saline bilaterally. Postoperative analgesia was administered intravenously in the two groups four times a day with 1 000 mg of paracetamol and patient-controlled analgesia with fentanyl. They demonstrated a reduction in postoperative 24-hour opioid consumption (p < 0.001). Pain scores were significantly lower in the TTMP group compared with the control group up to 12 hours after surgery, both at rest and during active movement (p < 0.001). Compared with the TTMP group, the proportion of postoperative nausea and pruritus was statistically higher in the control group (p < 0.001). Interestingly, the median fentanyl use in the control group was 465 µg, while it was only 255 µg in the TTMP group. A recent prospective, randomised, placebo-controlled trial investigated by Khera et al.12 determined the effect of PIF block on postoperative opioid requirements, pain scores, lengths of ICU and hospital stays, as well as the incidence of postoperative delirium in cardiac surgical patients at a single tertiary centre. The study investigated 80 adult cardiac surgical patients (age > 18 years) requiring median sternotomy. Patients were randomly assigned to receive ultrasound-guided PIF block, with either 0.25% bupivacaine or placebo. On postoperative days zero and one, patients receiving PIF block with 0.25% bupivacaine showed a statistically significant reduction in visual analog scale (VAS) scores (4.8 ± 2.7 vs 5.1 ± 2.6; p < 0.001) and 48-hour cumulative opioid requirement. A low incidence of complications and an improvement in VAS pain scores suggested that PIF block can be performed safely in this population and it warrants additional studies.12 The erector spinae plane (ESP) block was initially described for the treatment of chronic thoracic neuropathic pain. It can be used for acute postoperative analgesia involving chest, thoracic, cardiac and abdominal surgeries. LA is injected ventral to the erector spine muscle along thoracic levels 5–9, within the costotransverse foramen region, providing analgesia to the ventral and dorsal rami of the spinal nerves. The erector spinae muscle is the main component of the paraspinal muscles that stabilise the torso, but there is also Fig. 5. Pecto-intercostal fascial block (PIF). Fig. 6. Transverse thoracic muscle plane block (TTMP).
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 106 AFRICA a transvers spinalis muscle group that lies deep to the spinalis and immediately adjacent to the bony vertebrae, and includes multifidus, rotators and intertransverse muscles. The rotators and intertransverse muscles, together with several ligamentous structures, such as the superior costotransverse ligament, span the gap between adjacent vertebral transverse processes. This ‘intertransverse tissue complex’ is a permeable posterior boundary of the paravertebral space (Fig. 7). The ESP block is performed under ultrasound guidance with the patient sitting, prone or in the lateral decubitus position. Using an aseptic technique, a high-frequency (12–15 MHz) linear-array transducer is placed in the parasagittal plane and moved from a lateral to medial direction until the ribs are no longer visualised and the transverse processes of T3 to T5 with overlying trapezius, rhomboid major and erector spine muscles are identified. The most caudal vertebral attachment of the rhomboid major muscle is the T5 spinous process, and tapering out of the rhomboid at this level may be useful confirmation of the desired probe position. An in-plane needle is inserted in the craniocaudal direction and advanced below the erector spine muscle, with the tip contacting the T5 transverse process. This block can be used with rib fractures, chest wall surgery and cardiac surgery (Fig. 8). Significant variations among cadaver studies have been found regarding injectate spread into the ventral rami after magnetic resonance imaging and dissection assessment, but all studies report significant distribution along the craniocaudal plane and the lateral cutaneous branches of the intercostal nerves. Schwarzmann et al.13 report radiological confirmation of notable craniocaudal spread with a single ESP injection. Athar et al.14 conducted a randomised, double-blind, controlled trial assessing the efficacy of an ESP block in cardiac surgery. Their study included 30 patients aged 18 to 60 years, body mass index ranging between 19 and 30 kg/m2, undergoing elective on-pump, single-vessel coronary artery bypass grafting or valve replacement under general anaesthesia. Patients were randomly categorised into two groups of 15 patients each receiving bilateral ESP blocks with 20 ml of 0.25% levobupivacaine per side, or placebo blocks with 20 ml of normal saline per side. Endpoints included total opioid dose in 24 hours, time-to-rescue analgesia, duration of mechanical ventilation, Ramsay sedation score (one of the most commonly used measures of sedation) six-hour post-extubation, postoperative nausea and vomiting, pruritus and the incidence of pneumothorax. According to their study, a single-shot ESP block provided superior analgesia compared with a placebo block. It decreased the first 24-hour postoperative analgesic consumption by 64.5% and risk of pain by five times in the authors’ population. It also reduced the duration of mechanical ventilation (88 vs 103 hours) in their postcardiac surgery patients.14 In this edition of the journal, Turkmen and Mutlu15 (page 153) compared the efficacy of ultrasound-guided PECS II block with a parasternal (PS) block in 100 patients undergoing open-heart surgery through midline sternotomy. This is the first study comparing two blocks between two groups after openheart surgery via sternotomy. For postoperative analgesia, 50 patients received a PECS II block and 50 a PS block at the end of surgery. They were then compared in terms of sedation scores, ventilation duration, and pain scores at rest after extubation as first endpoints. Block duration and cumulative morphine consumption were secondary endpoints, while complications such as postoperative nausea and vomiting were also compared. Interestingly in this study, the VAS scores at rest, a tool widely used to measure pain, were higher in the PECS II block group over the first six hours than in the PS group (p < 0.01). This was associated with a block duration that lasted longer in the PS block group. The cumulative morphine consumption (p < 0.01) and the Richmond agitation–sedation scale scores (RASS, a medical scale used to measure the agitation or sedation level of a person) (p < 0.01) were also higher in the PECS II block group than in the PS block group over the first four hours. There was no difference in the ventilation duration, block durations, pain and sedation scores over the first two hours. The final conclusion from the authors was that a PS block provides longer block duration with lower postoperative pain and sedation scores, as well as lower cumulative morphine consumption than a PECS II block for patients receiving a heart operation via median sternotomy. We must keep in mind that there is a strong trend towards performing cardiac surgery via a minimally invasive and minimal-access approach. This is usually performed through a mini-thoracotomy, which makes these procedures also amenable to other thoracic plane blocks. The discussion about analgesia for thoracotomy procedures is however not comprehensively covered in this editorial. Fig. 8. Erector spinae plane block anatomy. Fig. 7. Erector spinae plane block anatomy.
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 107 The relatively low risk of complications, with the potential beneficial effects on opioid consumption, duration of ventilation and ICU length of stay, make fascial plane analgesia techniques an exciting field of research. More research is necessary to validate fascial plane blocks. We expect them to become part of our daily cardiac anaesthesia techniques and part of any cardiac ERAS programme. References 1. Kelava M, Alfirevic A, Bustamante S, Hargrave J, Marciniak D. Regional anaesthesia in cardiac surgery: an overview of fascial plane chest wall blocks. Anesth Analg 2020; 131(1): 127–135. 2. Alexander JC. Regional techniques for cardiac and cardiac-related procedures. J Cardiothorac Vasc Anesth 2019; 33(2): 532–546. 3. Mazzeffi M, Khelemsky Y. Poststernotomy pain: a clinical review. J Cardiothorac Vasc Anesth 2011; 25(6): 1163–1178. 4. Huang APS, Rioko RK. Dor após esternotomia – revisão. Pain after sternotomy – review. Brazilian J Anesth 2016; 66(4): 395–401. 5. Blanco R. The ‘pecs block’: a novel technique for providing analgesia after breast surgery. Anaesthesia 2011; 66(9): 847–848. 6. Shakuo T, Kakumoto S, Kuribayashi J, Oe K, Seo K. Continuous PECS II block for postoperative analgesia in patients undergoing transapical transcatheter aortic valve implantation. JA Clin Rep 2017; 3(1): 65. 7. Kaushal B. Comparison of the efficacy of ultrasound-guided serratus anterior plane block, pectoral nerves II block, and intercostal nerve block for the management of postoperative thoracotomy pain after pediatric cardiac surgery. J Cardiothorac Vasc Anesth 2019; 33(2): 418–425. 8. Ueshima H, Kitamura A. Clinical experiences of ultrasound-guided transversus thoracic muscle plane block: a clinical experience. J Clin Anesth 2015; 27: 428–429. 9. Ueshima H, Otake H. Continuous transversus thoracic muscle plane block is effective for the median sternotomy. J Clin Anesth 2017; 37: 174. 10. Zhang Y, Gong H, Zhan B, Chen S. Effects of bilateral pecto-intercostal fascial block for perioperative pain management in patients undergoing open cardiac surgery: a prospective randomized study. BMC Anesthesiology 2021; 21: 175. 11. Aydin ME, Ahiskalioglu A, Ates Ihttps://pubmed.ncbi.nlm.nih. gov/32665179/ - affiliation-3, Tor IH, Borulu F, Erguney OD, et al. Efficacy of ultrasound-guided transversus thoracic muscle plane block on postoperative opioid consumption after cardiac surgery: a prospective, randomized, double-blind study. J Cardiothorac Vasc Anesth 2020; 34(11): 2996–3003. 12. Khera T, Murugappan KR, Leibowitz A, Bareli N, Shankar P, Scott Gilleland S, et al. Ultrasound-guided pecto-intercostal fascial block for postoperative pain management in cardiac surgery: a prospective, randomized, placebo-controlled trial. J Cardiothorac Vasc Anesth 2020; 35(3): 896–903. 13. Schwartzmann A, Peng P, Maciel MA, Ferero M. Mechanisms of erector spinae plane block: insights from a magnetic resonance imaging study. Can J Anesth 2018; 65: 1165–1166. 14. Athar M, Parveen S, Yadav M, Siddiqui OA, Nasreen F, Ali S, et al. A randomized double-blind controlled trial to assess the efficacy of ultrasoundguided erector spinae plane block in cardiac surgery. J Cardiothorac Vasc Anesth 2021; 35(12): 3574–3580. 15. Turkmen S, Mutlu M. Evaluation of the effect of different block techniques on open-heart surgery in the postoperative period: a prospective observational study. Cardiovasc J Afr 2022; 33: 153–156.
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 108 AFRICA Cardiovascular Topics Epicardial fat thickness assessment by multi-slice computed tomography for predicting cardiac outcomes in patients undergoing transcatheter aortic valve implantation Gökhan Ertaş, Ahmet Ekmekçi, Sinan Şahin, Ahmet Murat, Nijad Bakhshaliyev, Hatice Betül Erer, Tolga Sinan Güvenç, Mehmet Eren Abstract Introduction: Chronic inflammation promotes aortic valve calcification. It is known that epicardial fat is a source of inflammation. The aim of this study was to investigate the relationship between epicardial fat thickness, cardiac conduction disorders and outcomes in patients undergoing transcatheter aortic valve implantation (TAVI). Methods: During a three-year period, 45 patients with severe aortic stenosis who underwent TAVI were recruited to the study. Data were collected retrospectively. Epicardial fat was defined as the adipose tissue between the epicardium and the visceral pericardium. Mean epicardial fat thickness was determined by multi-slice computed tomography, which was performed before the procedure. Results: The average thickness of epicardial fat was 13.06 ± 3.29 mm. This study failed to reveal a significant correlation between epicardial fat thickness and post-procedural left bundle branch block, right bundle branch block, paravalvular aortic regurgitation and pacemaker implantation rates (p > 0.05). Conclusion: The results of this study failed to show a significant relationship between epicardial fat thickness, cardiac conduction disorders and outcomes, however further studies with larger sample numbers are required to explore the relationship. Keywords: epicardial fat thickness, calcific aortic stenosis, transcatheter aortic valve implantation, multi-slice computed tomography Submitted 17/11/20; accepted 13/9/21 Published online 15/10/21 Cardiovasc J Afr 2022; 33: 108–111 www.cvja.co.za DOI: 10.5830/CVJA-2021-043 Epicardial fat is a metabolically active visceral fat that has paracrine and endocrine functions. It surrounds the heart between the pericardium and myocardium and can be found in highest concentration in the atrioventricular and interventricular grooves and in direct contact with the major coronary arteries and their branches.1 Epicardial fat may also act as an endocrine organ due to its adipocytokine production.2,3 Epicardial fat thicknesses and volumes can be accurately evaluated by non-invasive imaging modalities such as echocardiography, computed tomography (CT) or magnetic resonance imaging (MRI).4 Recent studies indicate that epicardial fat may contribute to the progression of coronary atherosclerosis due to its proximity to the coronary arteries.3,5 Epicardial fat is independently associated with coronary atherosclerosis, adverse cardiovascular events and myocardial ischaemia.5-7 However, the exact underlying mechanisms are still not fully understood. The association between epicardial fat and atrial fibrillation has been demonstrated.8 Interestingly, an association between epicardial fat thickness and valvular heart disease has been found.9 The authors revealed that epicardial adipose tissue has an increased thickness in patients with calcific aortic stenosis. The aim of this study was to evaluate the epicardial fat thickness for predicting cardiac conduction disorders and outcomes in patients undergoing transcatheter aortic valve implantation (TAVI). As far as we know, this is the first study to address the potential association between epicardial fat thickness and outcomes in patients undergoing TAVI. Department of Cardiology, Memorial Sisli Hospital, Istanbul, Turkey Gökhan Ertaş, MD, drgokhanertas@yahoo.com.tr Ahmet Murat, MD Department of Cardiology, Medical Park Pendik Hospital, Istanbul, Turkey Ahmet Ekmekçi, MD Hatice Betül Erer, MD Tolga Sinan Güvenç, MD Department of Radiology, Dr Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey Sinan Şahin, MD Department of Cardiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey Nijad Bakhshaliyev, MD Department of Cardiology, Dr Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey Mehmet Eren, MD
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 109 Methods We performed a retrospective analysis of 45 consecutive patients with severe symptomatic calcific aortic stenosis who underwent TAVI at Siyami Ersek Hospital from 2013 to 2015. Pre-procedural coronary angiography was performed to assess the need for revascularisation. Pre-TAVI assessment was initially done with transthoracic echocardiography, followed by an electrocardiography-gated, multi-slice CT study. Severe aortic stenosis was defined as: peak transvalvular gradient of ≥ 40 mmHg on transthoracic echocardiography or transoesophageal echocardiography or dobutamine stress echocardiography (DSE), and an aortic valve area ≤ 1.0 cm2. Each case was considered by a multidisciplinary cardiovascular team. The patient was accepted for TAVI if he/she was deemed unable to undergo open-heart surgery due to excessive risk [Society of Thoracic Surgeons (STS) score ≥ 10 or logistic EuroSCORE ≥ 20] or was unsuitable for surgical aortic valve replacement because of medical co-morbidities or because of technical considerations (for example if the patient had a calcified aorta or scarring from previous cardiac surgery). TAVI was performed under general anaesthetic, or under local anaesthetic with sedation. The procedure was performed via the transfemoral approach. A temporary pacemaker was placed in the right ventricular apex, and a balloon valvuloplasty was performed under rapid ventricular pacing, followed by implantation of the valve. Electrocardiographic and echocardiographic parameters after TAVI were recorded. The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki as reflected in a priori approval by our institution’s human research committee. All CT examinations were performed with a 64-slice CT scanner (Toshiba Aquilion 64, Otawara, Japan). Image acquisition occurred using a detector collimation of 64 × 0.5 mm, tube current of 120 kVp and rotation time of 400 msn. Scanning time varied between 5.7 and 8.4 seconds. Retrospective ECG gating was used for data reconstruction. Image reconstructions were performed at 70–80% RR intervals. An intravenous dose of 100 ml non-ionic contrast agent Iopromide (Schering AG, Berlin, Germany) was administered at an infusion rate of 4 ml/s, followed by 30 ml saline infusion. Post-processing was performed on an Aquarius workstation (TeraRecon, Inc). All images were read by two experienced physicians. Intra- and inter-observer reproducibility for quantification of epicardial fat was greater than 0.95. Epicardial fat was defined as the adipose tissue between the epicardium and the visceral pericardium. Epicardial fat tissue was identified with voxels between –30 and –190 Hounsfield units. Measurement was performed at the basal level of the short-axis images. Three measurements were performed at the superior, mid and inferior levels (75, 50 and 25% level of full length, respectively) of the right ventricle. The average of three separate measurements was used for the analysis10 (Fig. 1). Statistical analysis Statistical analyses were performed with NCSS (Number Cruncher statistical system) 2007 (NCSS, LLC Kaysville, Utah, USA). Data were analysed using descriptive statistical methods (mean, standard deviation, median, frequency and rate). The Kruskal–Wallis test was used for the comparison of normally distributed variables and two-group assessment was done with the Mann–Whitney U-test. Comparison of numerical data for before and after measurements was performed with the pairedsamples test. The McNemar test was used for comparison of qualitative data. A p-value of < 0.05 was considered statistically significant. A 95% confidence interval reflected a significance level of 0.05. Results The patient demographics and clinical characteristics are shown in Table 1. A total of 45 patients, including 37.8% (n = 17) male and 62.2% (n = 28) female were included in the study. The mean age of the study population was 79.07 ± 6.18 years (age range 60–89). Baseline laboratory data characteristics are shown in Table 2. Two patients died during the procedure prior to valve implantation (4.4%). The overall in-hospital mortality rate was 11.4% (five patients). Pre-procedural echocardiographic and CT data are shown in Table 3. The mean valve area was 0.78 ± 0.15 cm2. The mean STS score was 5.15 ± 3.54, and the mean logistic EuroSCORE was 11.91 ± 9.14. Seven patients (18.9%) underwent permanent pacemaker implantation after the TAVI procedure, mostly due to high-degree atrioventricular block. The rate of stroke was 9.3% (four patients). Twelve patients (27.3%) had minor vascular complications, according to the VARC definition.11 The average thickness of epicardial fat was 13.06 ± 3.29 mm. We did not find a significant correlation between epicardial fat thickness and post-procedural left bundle branch block (LBBB), right bundle branch block (RBBB), paravalvular aortic regurgitation and pacemaker implantation rates (p > 0.05) (Tables 4, 5). Fig. 1. Epicardial fat and pericardium appearance on computed tomography.
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 110 AFRICA Discussion This study is the first clinical study that evaluated the potential association between epicardial fat thickness and outcomes in patients undergoing TAVI. Our results failed to show a significant correlation between epicardial fat thickness and postprocedural LBBB, RBBB, paravalvular aortic regurgitation and pacemaker implantation rates. Obesity is an important determinant of cardiovascular disease. Previous studies have revealed that epicardial fat is strongly correlated with other visceral fat deposits.12 Higher epicardial fat volumes independently predicted major adverse cardiac events in a healthy population.13 Epicardial fat thickness has also been Table 1. Baseline demographic characteristics Characteristics Min–Max Mean ± SD Age (years) 60–89 79.07 ± 6.18 Weight (kg) 50–91 69.65 ± 10.74 Height (m) 1.50–1.78 1.64 ± 10.74 Body mass index (kg/m2) 20.52–33.06 25.78 ± 3.48 Number Percent Gender Female 28 62.2 Male 17 37.8 Hypertension 33 73.3 Diabetes mellitus 18 40.0 Coronary artery disease 20 44.4 Smoking 7 15.6 Previous heart surgery history 11 24.4 Chronic obstructive pulmonary disease 10 22.2 Sinus rhythm before TAVI 32 71.1 TAVI: transcatheter aortic valve implantation. Table 2. Baseline laboratory characteristics Characteristics Min–Max Mean ± SD Mean platelet volume (fl) 5.9–13.3 8.61 ± 1.31 Neutrophil (k/µl) 2–11.8 4.54 ± 2.04 Lymphocytes (k/µl) 0.3–3.2 1.58 ± 0.58 Creatinine (mg/dl) 0.5–11.3 1.23 ± 1.57 Haemoglobin (gr/dl) 8.2–14.8 11.25 ± 1.39 Haematocrit (%) 24.7–42.7 33.81 ± 4.16 Table 3. Pre-procedural data Variables Min–Max Mean ± SD STS score 1.06–19 5.15 ± 3.54 Logistic EuroSCORE 2.37–56.92 11.91 ± 9.14 Echocardiography data Aortic valve area (cm2) 0.6–1.1 0.78 ± 0.15 Aortic mean gradient (mmHg) 27–75 46.26 ± .77 Aortic max gradient (mmHg) 54–120 77.47 ± 14.40 Aortic velocity (m/s) 3.6–5,5 4.33 ± 0.38 Ascending aorta diameter (mm) 25–43 35.21 ± 4.24 Sinotubular junction diameter 18–38 27.95 ± 5.39 Aortic annulus diameter (TEE, mm) 20–29 20.79 ± 5.52 CT data Epicardial fat thickness (mm) 7.5–24.1 13.06 ± 3.29 MAD of iliac artery (mm) 8–16 11.43 ± 2.29 MAD of femoral artery (mm) 6–13 8.65 ± 1.81 Aortic annulus diameter (CT, mm) 18–33 23.79 ± 3.77 Pre-procedural valve data Number Percent Mitral valve stenosis 6 13.3 Coronary stent implantation before procedure 5 11.1 Mitral regurgitation 0 (none) 8 17.8 1 (mild) 25 55.6 2 (moderate) 12 26.7 Aortic regurgitation 0 (none) 14 31.1 1 (mild) 21 46.7 2 (moderate) 10 22.2 TEE: transesophageal echocardiography, CT: computed tomography, MAD: minimal artery diameter, STS: Society of Thoracic Surgeons, TAVI: transcatheter aortic valve implantation. Table 4. Post-procedural data Variables Number Percent Pacemaker implantation 7 18.9 Blood transfusion 12 27.3 Death 5 11.4 Heart failure 3 7.0 Rehospitalisation 7 16.3 Stroke 4 9.3 Paravalvular AR (aortography) 0 (none) 18 41.9 1 (mild) 18 41.9 2 (moderate) 7 16.3 Paravalvular AR (echocardiography) 0 (none) 18 40.9 1 (mild) 20 45.5 2 (moderate) 6 13.6 Valve diameter (mm) 23 13 30.2 26 24 55.8 29 6 14.0 Type of valve Core-valve 4 9.3 Edwards Sapien 39 90.7 AR: aortic regurgitation. Table 5. Association of epicardial fat thickness with post-procedural data Variables Epicardial fat thickness p-value Min–Max (median) Mean ± SD LBBB No 7.5–16.4 (12.7) 12.63 ± 2.78 0.709a Yes (n = 5) 9.1–18.5 (14.6) 13.40 ± 3.95 RBBB No 7.5–18.5 (13.5) 12.83 ± 2.94 0.743a Yes (n = 2) 9.0–15.8 (12.4) 12.40 ± 4.80 Pacemaker implantation No 9.0–18.5 (13.3) 13.16 ± 2.79 0.525a Yes (n = 7) 7.5–15.8 (13.5) 12.38 ± 3.08 Paravalvular AR (aortography) 0 9.7–24.1 (13.3) 13.94 ± 3.69 0.619b 1 7.5–16.4 (12.0) 12.32 ± 2.96 2 9.1–18.5 (14.6) 13.86 ± 3.48 Paravalvular AR (echocardiography) 0 9.0–24.1 (13.0) 13.10 ± 4.08 0.781b 1 9.2–16.4 (12.4) 12.74 ± 2.77 2 9.1–18.5 (14.6) 13.86 ± 3.48 aMann–Whitney U-test, bKruskall–Wallis test. LBBB: left bundle branch block, RBBB: right bundle branch block, AR: aortic regurgitation.
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 111 found to be significantly correlated with the severity of coronary artery disease in patients with known coronary artery disease.14 Epicardial adipose tissue has been shown to be a source of inflammatory mediators such as interleukin (IL)-1β, IL-6 and tumour necrosis factor.15 Inflammatory mediators have been shown to play a role in the pathogenesis of calcific aortic stenosis as well.16,17 A significant correlation between epicardial fat thickness and levels of pro-inflammatory cytokines and calcific aortic stenosis has been described.9 The authors indicated a strong association between epicardial fat thickness and aortic stenosis.9 Epicardial adipose tissue is an important source of several pro-inflammatory mediators and it may play a role in promoting aortic valve degeneration and calcification. Mancio et al. reported that low body mass index (BMI) was paradoxically associated with aortic valve calcification and mortality in elderly aortic stenosis patients submitted for TAVI.18 Koifman et al. also concluded that patients with BMI < 20 kg/ m2 were associated with a higher risk of mortality.19 Interestingly, in another study, the authors revealed that patients with larger epicardial adipose tissue volume had an increased all-cause one-, two- and three-year mortality rate after TAVI.20 In our study, we aimed to evaluate the association of epicardial fat thickness with post-procedural outcomes of TAVI. To the best of our knowledge, our study is the first report to focus on the relationship between epicardial fat thickness and outcomes of patients who underwent TAVI. Our results failed to reveal any significant relationship. The limitations of this study are the small sample size and retrospective design. There is no consensus on the gold standard for an in vivo quantification of epicardial adipose tissue. Volume measurement could be more accurate in the assessment of epicardial adipose tissue, however, epicardial fat thickness measurement is less time consuming and easier. Conclusion Larger trials are needed to evaluate whether epicardial fat thickness might have predictive properties and become a routine way of assessing cardiovascular risk in a clinical setting of TAVI. References 1. Iacobellis G, Corradi D, Sharma AM. Epicardial adipose tissue: anatomic, biomolecular and clinical relationships with the heart. Nat Clin Pract Cardiovasc Med 2005; 2: 536–543. 2. Jazet IM, Pijl H, Meinders AE. Adipose tissue as an endocrine organ: impact on insulin resistance. Neth J Med 2003; 61: 194–212. 3. Demircelik MB, Yilmaz OC, Gurel OM, Selcoki Y, Atar IA, Bozkurt A, et al. Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease. Clinics (Sao Paulo) 2014; 69: 388–392. 4. Dey D, Nakazato R, Li D, Berman DS. Epicardial and thoracic fat – noninvasive measurement and clinical implications. Cardiovasc Diagn Ther 2012; 2: 85-93. 5. Alexopoulos N, McLean DS, Janik M, Arepalli CD, Stillman AE, Raggi P. Epicardial adipose tissue and coronary artery plaque characteristics. Atherosclerosis 2010; 210: 150–154. 6. Cheng VY, Dey D, Tamarappoo B, Nakazato R, Gransar H, MirandaPeats R, et al. Pericardial fat burden on ECG-gated noncontrast CT in asymptomatic patients who subsequently experience adverse cardiovascular events. J Am Coll Cardiol Cardiovasc Imaging 2010; 3: 352–360. 7. Tamarappoo B, Dey D, Shmilovich H, Nakazato R, Gransar H, Cheng VY, et al. Increased pericardial fat volume measured from noncontrast CT predicts myocardial ischemia by SPECT. J Am Coll Cardiol Cardiovasc Imaging 2010; 3: 1104–1112. 8. Al Chekakie MO, Welles CC, Metoyer R, Ibrahim A, Shapira AR, Cytron J, et al. Pericardial fat is independently associated with human atrial fibrillation. J Am Coll Cardiol 2010; 56: 784–788. 9. Parisi V, Rengo G, Pagano G, D’Esposito V, Passaretti F, Caruso A, et al. Epicardial adipose tissue has an increased thickness and is a source of inflammatory mediators in patients with calcific aortic stenosis. Int J Cardiol 2015; 186: 167–169. 10. Wang TD, Lee WJ, Chen MF. Epicardial adipose tissue measured by multidetector computed tomography: Practical tips and clinical implications. Acta Cardiol Sin 2010; 26: 55–68. 11. Kappetein AP, Head SJ, Généreux P, Piazza N, van Mieghem NM, Blackstone EH, et al; Valve Academic Research Consortium-2. Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document. J Thorac Cardiovasc Surg 2013; 145: 6–23. 12. Iacobellis G, Ribaudo MC, Assael F, Vecci E, Tiberti C, Zappaterreno A, et al. Echocardiographic epicardial adipose tissue is related to anthropometric and clinical parameters of metabolic syndrome: A new indicator of cardiovascular risk. J Clin Endocrinol Metab 2003; 88: 5163–5168. 13. Shmilovich H, Dey D, Cheng VY, Rajani R, Nakazato R, Otaki Y, et al. Threshold for the upper normal limit of indexed epicardial fat volume: Derivation in a healthy population and validation in an outcome-based study. Am J Cardiol 2011; 108: 1680–1685. 14. Jeong JW, Jeong MH, Yun KH, Oh SK, Park EM, Kim YK, et al. Echocardiographic epicardial fat thickness and coronary artery disease. Circulation J 2007; 71: 536–539. 15. Mazurek T, Zhang L, Zalewski A, Mannion JD, Diehl JT, Arafat H, et al. Human epicardial adipose tissue is a source of inflammatory mediators. Circulation 2003; 108: 2460–2466. 16. Yetkin E, Waltenberger J. Molecular and cellular mechanisms of aortic stenosis. Int J Cardiol 2009; 135: 4–13. 17. Helske S, Kupari M, Lindstedt KA, Kovanen PT. Aortic valve stenosis: an active atheroinflammatory process. Curr Opin Lipidol 2007; 18: 483–491. 18. Mancio J, Fonseca P, Figueiredo B, Ferreira W, Carvalho M, Ferreira N, et al. Association of body mass index and visceral fat with aortic valve calcification and mortality after transcatheter aortic valve replacement: the obesity paradox in severe aortic stenosis. Diabetol Metab Syndr 2017; 9: 86. 19. Koifman E, Kiramijyan S, Negi SI, Didier R, Escarcega RO, Minha S, et al. Body mass index association with survival in severe aortic stenosis patients undergoing transcatheter aortic valve replacement. Catheter Cardiovasc Interv 2016; 88(1): 118–124. 20. Eberhard M, Stocker D, Meyer M, Kebernik J, Stähli BE, Frauenfelder T, et al. Epicardial adipose tissue volume is associated with adverse outcomes after transcatheter aortic valve replacement. Int J Cardiol 2019; 286: 29–35.
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 112 AFRICA Response to ibutilide and the long-term outcome after catheter ablation for non-paroxysmal atrial fibrillation Yanfang Wu, Peng Gao, Yongtai Liu, Quan Fang Abstract Purpose: This study aimed to assess the relationship between the cardiac rhythm response to ibutilide infusion after pulmonary vein isolation and the recurrence of long-term atrial arrhythmias. Methods: One hundred and thirty-eight patients with nonparoxysmal atrial fibrillation who had had their first catheter ablation were retrospectively included. All patients whose atrial fibrillation did not terminate after pulmonary vein isolation were administered intravenous ibutilide (1.0 mg). Those with termination of atrial fibrillation after ibutilide administration were defined as responders (n = 86); those without termination of atrial fibrillation, as non-responders (n = 52). The primary endpoint was any documented recurrence of atrial arrhythmia lasting more than 30 seconds after the initial catheter ablation. Results: Conversion of atrial fibrillation to sinus rhythm, directly or via atrial flutter, with ibutilide administration was achieved in 62.3% of patients. A longer duration of atrial fibrillation was associated with failed termination of atrial fibrillation (odds ratio 1.009, 95% confidence interval 1.002–1.017, p = 0.011). During a median follow-up period of 610 days (interquartile range 475–1 106) post ablation, non-responders (n = 24, 46.2%) had a higher recurrence rate of atrial arrhythmia than the responders (n = 26, 30.2%; log-rank, p = 0.011) after the initial catheter ablation. Multivariate Cox regression analysis revealed that non-responders (hazard ratio 1.994, 95% confidence interval 1.117–3.561, p = 0.020) was significantly correlated with recurrence of atrial arrhythmias. Conclusion: In patients whose atrial fibrillation persisted after pulmonary vein isolation, the response to ibutilide administration could predict the recurrence of atrial arrhythmias after catheter ablation, which may be useful for risk stratification for recurrence of atrial fibrillation and individualised management of atrial fibrillation. Keywords: ibutilide, atrial fibrillation, catheter ablation, prognosis Submitted 5/2/21; accepted 13/9/21 Published online 15/10/21 Cardiovasc J Afr 2022; 33: 112–116 www.cvja.co.za DOI: 10.5830/CVJA-2021-044 Atrial fibrillation (AF) is the most common clinical arrhythmia, with a prevalence of 3.0% in persons aged over 21 years.1 Since over 90% of the triggering factors of AF are found in the pulmonary veins (PVs), electrical isolation of the PVs has been the cornerstone of AF ablation.2-4 However, AF termination during or upon completion of pulmonary vein isolation (PVI) occurs in only a minority of patients with persistent AF. During catheter ablation (CA) of persistent AF, antiarrhythmic drug (AAD) administration is a common practice to facilitate the ablation. Ibutilide, which is a class III AAD, can block the rapidly outward delayed rectifier potassium (K+) current to prolong the atrial refractory period, subsequently terminating AF.5 In some previous studies, ibutilide showed a 50.5 to 56% cardioversion rate for AF in patients without ablation.6,7 After PVI completion, the re-entrant wave fronts between the PV and the left atrium are interrupted, which could in turn facilitate a higher AF termination rate after ibutilide administration. However, studies reporting the efficacy of ibutilide in the termination of AF after PVI completion are limited. In patients with non-paroxysmal AF, there was a 31% recurrence rate of AF after catheter ablation, which was associated with a poor prognosis, such as stroke.8 The prediction of AF recurrence could help optimise individualised AF management. The approach employed for AF termination was reported to be associated with AF recurrence after ablation.9 As mentioned, ibutilide can be used for AF termination, while patients with different clinical characteristics had different responses to ibutilide. Currently, studies about intraprocedural ibutilide mostly focus on low-dose application and the difference in ablation strategy may influence the judgement of the effect of ibutilide on the prognosis.10,11 In patients with persistent AF after PVI, it remains to be established whether the heart rhythm response to ibutilide infusion with a standard dose is associated with ablation outcome. The use of ibutilide in non-paroxysmal AF treatment is unknown. This study therefore aimed to assess the relationship between the cardiac rhythm response to ibutilide infusion after PVI and recurrence of long-term atrial arrhythmias (AAs), which may provide a useful tool for prediction of AF recurrence. We hypothesised that AF termination with ibutilide infusion after PVI indicates good rhythm control during a long-term follow up. Methods A total of 193 consecutive patients with non-paroxysmal AF who underwent CA for the first time between January 2014 and December 2018 at our institution were retrospectively included. Patients with valvular heart disease, a history of hyperthyroidism or cardiac surgery, or failed intraprocedural cardioversion were excluded. Of the remaining patients, seven had sinus rhythm (SR) before CA, 11 had AF conversion to SR during or Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China Yanfang Wu, MD Peng Gao, MD Yongtai Liu, MD Quan Fang, MD, dr_cardio@163.com
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