A systematic review and meta-analysis on primary percutaneous coronary intervention of an unprotected left main coronary artery culprit lesion in the setting of acute myocardial infarction.

OBJECTIVES: This study sought to evaluate 30-day all-cause mortality of patients treated with primary percutaneous coronary intervention (PCI) presenting with an acute myocardial infarction (AMI) due to an unprotected left main coronary artery (ULMCA) culprit lesion. In addition, an average estimated mortality rate was extrapolated from the available data.

BACKGROUND: There are limited data available on clinical outcome after primary PCI in patients presenting with AMI with unprotected left main as the infarct-related coronary artery.

METHODS: Medical literature databases were searched to identify cohort studies reporting on primary PCI for unprotected left main-related AMI. A total of 13 retrospective studies meeting all pre-specified criteria were included in the meta-analysis. No randomized trials were available. The primary endpoint for the meta-analysis was 30-day all-cause mortality.

RESULTS: This meta-analysis comprises a total of 977 patients, of which 252 (26%) presented in cardiogenic shock. Thirty-day all-cause mortality was evaluated using a forest plot analysis and showed higher event rates in patients presenting with cardiogenic shock among all subgroups. The average estimated 30-day all-cause mortality was 15% in patients presenting without signs of cardiogenic shock and 55% in patients presenting with cardiogenic shock (relative risk: 3.74, 95% confidence interval [CI]: 2.95 to 4.76, p < 0.001).

CONCLUSIONS: In this large meta-analysis of patients treated with primary PCI for AMI due to an ULMCA culprit lesion, the 30-day all-cause mortality in patients presenting with shock is much higher than in patients not presenting with shock. The estimated all-cause mortality data may serve as a benchmark for future reference.