Case:
A 40-year-old male with no significant history presented to our
institution with acute chest pain. His electrocardiogram (ECG)
demonstrated incomplete right bundle branch block and no acute ischemic
changes. His initial troponin-I was elevated to 1.02 ng/mL. He was
diagnosed with a non-ST segment elevation myocardial infarction and
admitted to the hospital. Transthoracic echocardiogram showed a
preserved biventricular function and no regional wall motion
abnormalities. Other echocardiographic parameters were normal as well.
Patient was placed on current guideline based medical therapy for acute
coronary syndrome with subsequent symptomatic relief.
Coronary angiography revealed an anomalous left main coronary artery
(LMCA) arising from the right coronary cusp (Figure 1A). Given
the high suspicion for a malignant LMCA course, cardiac computed
tomography was performed demonstrating an extramural and inter-arterial
LMCA trajectory between the ascending aorta and the pulmonary trunk
before reaching the anterior sulcus (Figure 1B). Furthermore the
LMCA appeared to experience notable compression of 37% during systole,
with caliber reduction from 2.41mm in diastole (Figure 1C) to
1.53 mm in systole (Figure 1D). Cardiothoracic surgery recommended
coronary bypass graft to left anterior descending artery to prevent
further complications. Patient decided to defer surgery for later. He
was recommended to avoid strenuous physical activities and discharged on
treatment with aspirin 81 mg daily, metoprolol succinate 50 mg daily and
sublingual nitroglycerin for occasional acute chest pain. He agreed to
follow up closely in the outpatient cardiology clinic.
Anomalous coronary artery from the opposite sinus (ACAOS) congenital
disorders entails a diverse group with varied clinical characteristics
and outcomes. Left-ACAOS has been described as the most dangerous
occurrence. Indeed, in a continuous young population series from the
American Armed Forces Institute of Pathology, 33% of all
cardiac-related deaths were related to ACAOS and specifically to the
LMCA with no other anomalies resulting in adverse outcomes1. Diverse retrospective studies have determined
left-ACAOSs low incidence, including the largest one to date reporting
0.017% of all cardiac angiographies reviewed 2. Most
ACAOS patients either die suddenly associated with strenuous exercise or
have an indolent course with atypical chest pain presentation where
diagnosis is made later in life 3. Treatment options
for symptomatic ACAOS patients involve medical treatment, coronary
angioplasty with stent deployment and surgical correction3. In cases of left-ACAOS with malignant course,
surgery is usually recommended; nevertheless, multidisciplinary heart
team discussion and share decision making with the patient and family
members is crucial.