Objectives Acute myocardial infarction (AMI) due to unprotected left main coronary artery (ULMCA) occlusion has a poor prognosis. There is limited results in patients undergoing primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) caused by ULMCA stenosis. Previous studies have reported in-hospital mortality rates of 50%–60%. The purpose of this study was to determine the clinical features and in-hospital outcomes of patients who underwent primary PCI for AMI due to ULMCA lesions.

Methods Between July 2002 and August 2012, a total of 86 AMI patients (65 male, 75.6%) underwent primary PCI on ULMCA lesions. Among them, 72 (83.7%) patients presented with acute ST elevation myocardial infarction and 14 (16.3%) patients with acute non-ST elevation myocardial infarction. The culprit lesions in all patients located in ULMCA diagnosed by angiography. The target lesion included de novo lesion located in ostial, shaft and distal bifurcation. The indexes of clinical, in-stent thrombosis and major adverse cardiac events (MACE) including death, myocardial infarction or target lesion revascularisation were evaluated.

Results The mean age of patients was 67.6 ± 13.9 years. Cardiogenic shock was observed in 66 (76.7%) patients and cardiac arrest in 16 (18.6%). Prior to commencing PCI, 61 (70.9%) patients received the intra-aortic balloon pump. Angiographic success was achieved in all patients. Lesion location was ostial in 13 (15.2%), body in 25 (29.1%) and distal in 48 (55.8%). After PCI procedure, TIMI III flow were achieved in 79 (91.9%) patients. All patients had the ULMCA successfully dilated. Stent were deployed in 82 (95.3%) patients with drug eluting stent used in 72 (83.7%) patients. In-hospital death occurred in 7 (8.1%) patients [the mortality rate was 10.6% (7/66) in patients with cardiogenic shock]. On univariate analysis, age > 75yeas (P < 0.01), cardiogenic shock (P < 0.0001), and stenting failure (P < 0.01) were associated with in-hospital mortality.

Conclusions Despite the high mortality rate in patients with cardiogenic shock, our data have shown that primary PCI is a valuable therapeutic strategy for ULMCA in the setting of AMI. But the long-term outcomes should be observed by follow-up.