Acute total occlusion of the unprotected left main coronary artery: Patient characteristics and outcomes.

INTRODUCTION AND OBJECTIVES: Acute total occlusion of the unprotected left main coronary artery (LMCA) is a dramatic event. There are limited data regarding this population. We aimed to describe the clinical presentation and outcomes of patients and to determine predictors of in-hospital mortality.

METHODS: This retrospective study included patients presenting with acute (<12 h) myocardial infarction due to total occlusion of the LMCA (TIMI flow 0) between January 2008 and December 2020 in three tertiary hospitals.

RESULTS: During this period, 11 036 emergent coronary angiographies were performed, 59 (0.5%) of which revealed acute total occlusion of the LMCA. Patients' mean age was 61.2 (SD±12.2) years and 73% were male. No patients had left dominance. At presentation, 73% were in cardiogenic shock, aborted cardiac arrest occurred in 27% and 97% underwent myocardial revascularization. Primary percutaneous coronary intervention was performed in 90% of cases and angiographic success was achieved in 56% of procedures, while 7% of patients underwent surgical revascularization. In-hospital mortality was 58%. Among survivors, 92% and 67% were alive after one and five years, respectively. After multivariate analysis, only cardiogenic shock and angiographic success were independent predictors of in-hospital mortality. Use of mechanical circulatory support and presence of well-developed collateral circulation were not predictive of short-term prognosis.

CONCLUSION: Acute total occlusion of the LMCA is associated with a dismal prognosis. Cardiogenic shock and angiographic success play a major role in predicting the prognosis of these patients. The effect of mechanical circulatory support on patient prognosis remains to be determined.