Background:
Patients with ST-segment elevation myocardial infarction (STEMI) due to left main coronary artery occlusion (LMCAO) represent a rare group of patients with poor prognosis. They often present with cardiogenic shock (CS). Despite the lack evidence, percutaneous coronary intervention (PCI) is the preferred strategy of myocardial revascularization in an acute setting. The goal of our single center registry was to evaluate in-hospital outcomes of patients with STEMI undergoing emergency PCI due to LMCAO.

Methods and results:
We analyzed the in hospital mortality of patients with STEMI (or equivalent) undergoing emergency PCI due to LMCAO at our center between march 2020 and march 2022.

2,281 consecutive patients undergoing PCI were recorded in this period. Of those, 29 patients had STEMI or a STEMI equivalent ECG pattern and LMCAO treated by primary PCI. 75.9% were male, mean age was 73.55 ± 13.48 years. Prehospital and intrahospital cardiopulmonary resuscitation (CPR) was necessary in 27.6% (62.5 % of those longer than 30 minutes) and 6.8 % of the patients, respectively. 58.6% of patients had CS on admission and 20.6 % required left ventricular circulatory support using the coaxial Impella®pump or extracorporeal membrane oxygenation (ECMO). Primary PCI was successful in 82.7% of the patients. In-hospital mortality was 48.3%. 90% of the CPR patients and 76.5% of the CS patients died during hospitalization.

Conclusions:
Patients with STEMI and LMCA occlusion as the culprit lesion require emergency cardiac catheterization. Mortality of patients with STEMI due to LMCAO is high. Moreover, mortality increased in our analysis with the presence of CPR or CS despite the frequent use of mechanical left ventricular circulatory support systems.