CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 3, April 2012
e4
AFRICA
Discussion
SCAD is a rare cause of myocardial infarction. The incidence
of SCAD has been estimated to vary from 0.1 to 1.1%.
1
SCAD
usually occurs as a consequence of haemorrhage within the
outer third of the media or between the media and the external
elastic lamina of a coronary artery. Expansion of the false lumen
by further bleeding and separation of the dissected layers leads
to compression of the true lumen, with subsequent myocardial
ischaemia or infarction.
2
Disruption and bleeding from the
vasa vasorum has been suggested as a possible mechanism. An
underlying inflammatory process has been discussed by several
authors.
3
In patients with atherosclerosis, plaque rupture that disrupts
the intima–media junction, with the formation of an intramural
haematoma is believed to be the underlying cause. In women
who develop dissection during pregnancy or puerperium,
hormonal changes are thought to impair collagen synthesis,
loosen the ground substance, and cause changes in the media of
the coronary walls.
1-3
Clinically, SCAD may present with the entire spectrum of
coronary syndromes, varying from unstable angina to myocardial
infarction. The pattern and severity of presentation are primarily
related to the vessel involved, the extent of dissection, its rate of
development and the presence of coronary artery disease.
1
SCAD has been described in healthy young women,
4
among
whom 25–30% were pregnant or in the peripartum period.
4
SCAD probably accounts for up to 30% of the myocardial
infarctions during pregnancy or during the early postpartum
period.
4
SCAD has been described in the setting of atherosclerotic
coronary artery disease,
5
isolated fibromuscular dysplasia
of the coronary arteries,
6
hypertrophic cardiomyopathy,
7
oral
contraceptive use,
8
cocaine abuse,
9
cyclosporine use,
10
Marfan or
Ehlers–Danlos syndrome,
11
and sarcoidosis.
12
In rare cases, the
occurrence of SCAD is a cause of acute myocardial infarction
after heavy lifting in male patients who have coronary risk
factors. However, SCAD associated with Leriche syndrome has
not been reported before.
Leriche’s syndrome
13
is an aorto-iliac occlusive disease in men,
with associated signs and symptoms of intermittent claudication,
atrophy of the leg muscles, impotence and reduced femoral
pulses. The main cause of this syndrome is an atherosclerotic
obstruction of the aorto-iliac arteries. It typically begins at the
origin of the distal aorta or common iliac artery. The progression
is quite variable, but it may ultimately extend to the level of
the renal arteries or result in total aortic occlusion. Surgical
treatment is important for these patients.
14
SCAD predominantly occurs as single-vessel disease, and
the LAD is most often involved (in 75% of cases), followed by
the RCA, and the left main and circumflex arteries.
1-12
Only a
few cases of multi-vessel dissection have been reported.
15
The
majority of patients with left coronary artery dissection sustain
myocardial infarction (vs only 50% of patients with RCA
dissection).
15
Several treatment modalities (coronary artery bypass grafting,
PTCA and/or stenting) have been reported with variable
success.
15
Medical therapy alone in patients who completed
their infarctions after dissections and without residual ischaemic
symptoms produced good long-term outcomes.
15
To the best of our knowledge, this is the first reported
case with the concomitant presence of SCAD and Leriche
syndrome. Although our patient presented with a recent
myocardial infarction, he was discharged with anti-anginal and
anti-ischaemic medication without percutaneous or surgical
interventions because no viable myocardium was detected.
Aorto-bifemoral bypass was planned for the Leriche syndrome.
Conclusion
SCAD is a rare cause of acute coronary artery syndrome but
should be considered in the differential diagnosis of patients at
risk, especially pregnant women who present with chest pain in
the peripartum period.
References
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2.
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3.
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Fig. 2. Occlusion at the infra-renal level of the abdominal
aorta.
