Characteristics and Outcomes of ST-Segment Elevation Myocardial Infarction due to Left Main Coronary Artery Stenosis.

There is limited data on the incidence and outcomes of ST-segment elevation myocardial infarction (STEMI) due to the left main coronary artery (LMCA) lesions. We aimed to examine the trends and outcomes of STEMI due to LMCA lesions. The Nationwide Readmissions Database was utilized to identify hospitalizations with LMCA STEMI between January 2016 and December 2022. The primary outcome was all-cause in-hospital mortality during index admission. Among 1,528,764 weighted hospitalizations with STEMI from 2016 to 2022, 4,885 (0.3%) were due to LMCA lesions, of which 2,156 (44.1%) had cardiogenic shock (CS). The number of LMCA STEMI hospitalizations and the incidence of CS increased over time. Mechanical circulatory support was used in 78.8% of the patients with LMCA STEMI and CS, with intra-aortic balloon pump being the most common modality (63%). Impella utilization increased from 4.5% in Q1 2016 to 34% in Q4 2022. Revascularization was performed in 78.2% of cases, with percutaneous coronary intervention (PCI) being the most common revascularization modality (62.1%). Among those who had PCI, intravascular imaging (IVI) was used in 18.3%, with a significant increase from 9.6% in Q1 2016 to 26.3% in Q4 2022. All-cause in-hospital mortality was 25.5% and was significantly higher among CS patients (43.4% vs. 11.4%, P<0.001). In conclusion, the incidence of LMCA STEMI increased from 2016 to 2022 with nearly half of the patients developing CS. IVI use in LMCA PCI was low (18.3%) but increased over time. More than 1 in 4 patients with LMCA STEMI died during the index hospitalization.