# Outcome of contemporary unprotected left main percutaneous coronary intervention in patients with acute myocardial infarction

## TL;DR

This study compares outcomes of left main coronary artery interventions in patients with and without heart attacks, finding higher risks and worse outcomes in heart attack cases.

## Contribution

The study provides contemporary insights into treatment patterns and outcomes for left main coronary artery stenosis in STEMI and non-STEMI patients.

## Key findings

- STEMI patients with culprit LMCA stenosis had higher cardiogenic shock and mortality rates than non-STEMI patients.
- Intravascular ultrasound improved outcomes for culprit LMCA stenosis in STEMI patients.
- Concurrent PCI for non-culprit LMCA stenosis in STEMI did not improve MACCE.

## Abstract

Limited data are available on clinical characteristics and outcomes in patients with culprit or non-culprit left main coronary artery (LMCA) stenosis between ST-segment elevation myocardial infarction (STEMI) and non-STEMI.

This study aimed to compare treatment pattern and outcome between STEMI and non-STEMI according to culprit and non-culprit LMCA stenosis. We examined 572 patients with LMCA stenosis from the Korean Acute Myocardial Infarction Registry–National Institute of Health database. Major adverse cardiac and cerebrovascular events (MACCE) were defined as all-cause death, nonfatal myocardial infarction (MI), repeat revascularization, cerebrovascular accident, rehospitalizations, and stent thrombosis.

In patients with culprit LMCA stenosis, cardiogenic shock (50.5% vs. 12.1%; P < 0.001) and use of mechanical hemodynamic support (48.5% vs. 11.0%; P < 0.001) were significantly greater in STEMI than in non-STEMI. In-hospital mortality (32.3% vs. 8.1%, P < 0.001) and 3-year MACCE (56.6% vs. 42.2%; log-rank P = 0.003) were significantly higher in STEMI. Intravascular ultrasound improved outcomes of culprit LMCA stenosis (23.1% vs. 68.1%, log-rank P = 0.001). Acute kidney injury, multiple organ failure, and cardiopulmonary resuscitation were independently associated with MACCE in STEMI. In patients with non-culprit LMCA stenosis, there were no significant differences in MACCE between STEMI and non-STEMI (31.3% vs. 34.8%, log-rank P = 0.530). Concurrent percutaneous coronary intervention (PCI) for non-culprit LMCA stenosis during PCI for other culprit vessel segments did not improve MACCE in STEMI (29.5% vs. 32.9%; log-rank P = 0.660).

PCI for culprit LMCA stenosis is challenging in both STEMI and non-STEMI despite appropriate mechanical hemodynamic support. Concurrent PCI for non-culprit LMCA stenosis in STEMI does not improve MACCE.

Graphic comparing cardiac complications, hemodynamic support, and outcomes across four clinical scenarios: culprit LMCA stenosis with STEMI and non-STEMI, and non-culprit LMCA stenosis with STEMI and non-STEMI. Illustrations show coronary artery involvement and ECG patterns. Severity of complications and interventions is denoted by plus signs, with highest rates of cardiogenic shock, CPR, and mortality in culprit LMCA STEMI. Definitions and abbreviations are provided below the table.