Acute Left Main Coronary Artery Occlusion: A Catastrophic Problem with Poor Prognosis

Left main coronary artery occlusion is a rare occurrence that is often fatal. It usually manifests as an acute myocardial infarction with cardiogenic shock and/or fatal arrhythmias. This circumstance is rarely observed, as most patients affected die before seeking medical attention. Case Report. A 47-year-old male with no known coronary artery disease presented to our hospital one hour after sudden-onset chest pain and dyspnea. The pain occurred while the patient was working on a construction site. The patient’s past medical history included poorly-controlled hypertension, diabetes mellitus type II, obesity and smoking. On presentation, the patient was dyspneic, agitated and had cold diaphoresis. His blood pressure was 90/50, heart rate was 140 b.p.m., and his oxygen saturation was 86%. Heart examination showed marked tachycardia with very distant heart sounds. Chest examination revealed bilateral diffuse crackles with marked wheezing. Twelve-lead electrocardiography (Figure 1) showed sinus tachycardia, marked ST-elevation and hyperacute T-waves in all precordial leads, and reciprocal ST-depressions in the inferior leads. Mechanical ventilation was initiated through oral-tracheal intubation and the patient was then immediately transferred to the cardiac catheterization laboratory. An intra-aortic balloon pump was inserted. Diagnostic left heart catheterization showed a totally occluded left main coronary artery (Figure 2) with high-grade stenosis of the posterior descending artery which arose from the right coronary artery. A temporary pacemaker was placed, and a 0.014-inch guidewire was passed beyond the occlusion to the left anterior descending artery. The AngioJet® (Possis Medical, Inc., Minneapolis, Minnesota) was used to reduce the clot burden, and a series of balloon inflations were done in the left main coronary artery, the proximal left anterior descending artery and the proximal left circumflex artery (Figures 3, 4 and 5). Subsequently, TIMI 3 flow was restored in the left coronary circulation. The patient’s left ventricular ejection fraction was 35%, with anterior, apical and lateral akinesis. The patient was transferred to the cardiovascular intensive care unit and was scheduled for coronary artery bypass graft when hemodynamically stable. A follow-up ECG showed marked improvement in ST-segment changes in all leads (Figure 6). Ventilatory support and the intra-aortic balloon were continued, and the patient remained hypotensive and required inotropic support. The patient’s course was complicated by aspiration pneumonia, acute renal failure, liver failure and bilateral lower extremities gangrene. Two weeks later, the patient died from overwhelming multiple organ failure. Discussion. Cardiogenic shock remains a very challenging syndrome in medical practice. It carries a high rate of morbidity and mortality despite advances in therapeutics. Emergency revascularization has proven to be beneficial in patients presenting with acute coronary syndrome and cardiogenic shock, and mortality has decreased from 60% to 48%. Left main coronary thrombosis is rarely observed and mortality is very high, even when appropriate treatment is administered, as most patients die before seeking medical attention. Prompt revascularization is the key to possible survival. Coronary artery bypass grafting remains the main treatment for left main coronary disease, but percutaneous revascularization is a potential option, especially when acute thrombosis is diagnosed. It provides quick reperfusion of the cardiac muscle by re-establishing the patency of the vessel. Although our patient received appropriate, prompt treatment and TIMI 3 flow was restored, his survival was limited by multiple organ failure which was induced by cardiogenic shock.

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