Characteristics and long term outcomes of patients with acute coronary syndromes due to culprit left main coronary artery disease treated with percutaneous coronary intervention

Background: Patients with acute coronary syndrome (ACS) due to unprotected culprit left main coronary artery disease (LMCAD) treated with percutaneous coronary intervention (PCI) are rare, high-risk, and not represented in trials. Data regarding long term outcome after PCI are limited. Methods: Between January 2000 and December 2014, there were 8,794 patients hospitalized with unstable angina/non-ST elevation myocardial infarction (UA/NSTEMI) or ST-elevation myocardial infarction (STEMI) treated with PCI at our institution; of these, 83 (0.94%) patients were identified as having culprit LMCAD ACS. Results: Of the 83 patients with unprotected LMCAD ACS, 40 patients presented with STEMI and 43 patients presented with UA/NSTEMI. As compared to LM UA/NSTEMI, LM STEMI patients were younger and had less hypertension, with a trend towards greater frequency of cardiogenic shock. Distal LM involvement was common in both groups and did not differ by ACS type. In-hospital mortality was 33% in LM STEMI and 9% in LM UA/NSTEMI (P =.009). Over median follow up of 6.3 years, long term survival rates in both groups were similar (46% for STEMI vs 51% for UA/NSTEMI; P =.50 by log-rank). Conclusions: Unprotected culprit LMCAD ACS necessitating PCI is uncommon, occurring in <1% of cases, but is associated with reduced survival, with long term follow-up noting continued and similar risk of death regardless of index ACS type.