Aims: Unprotected left main (ULM) coronary artery disease is encountered in 3%-10% of coronary angiograms and is associated with high mortality. The survival of patients with ULM disease presenting with acute coronary syndromes (ACS) depends on different variables and is lowest in those with cardiogenic shock (CS). The aim of the present study was to estimate the impact of baseline characteristics on the subsequent clinical outcome in patients treated by percutaneous coronary intervention (PCI) of ULM for ACS.
Methods and results: One hundred and thirty-four patients were retrieved from our database and followed by phone or physician visit. Patients were classified into two groups according to their presentation (CS/STEMI group: patients presenting with CS or ST-elevation myocardial infarction; NSTEMI/UA group: patients with non-STEMI or unstable angina). Data collected were baseline characteristics, procedural information, and clinical outcome. The primary endpoint was all-cause mortality at 6-month follow-up. The secondary end point was a composite of cardiac death, myocardial infarction, and any repeat revascularisation, i.e., major adverse cardiac events (MACE). Kaplan-Meier curves were computed for survival. Logistic regression determined that hypercholesterolaemia (OR 6.22, p=0.03), high pre-procedural TIMI score (OR 3.89, p=0.01), preserved left ventricular ejection fraction (OR 1.07, p=0.01) and LM as culprit lesion (OR 8.57, p=0.01) protected against development of CS. Primary outcome occurred in 44% of patients in the CS/STEMI group compared to 6% in the NSTEMI/UA group (p<0.001). MACE were observed in 30 patients (48%) of the CS/STEMI group and in 12 patients (19%) of the NSTEMI/UA group (p=0.001).
Conclusions: Acute coronary syndrome due to critical ULM stenosis is associated with high mortality even after successful PCI. Patients presenting with CS or STEMI are at particular risk.