Outcomes following primary percutaneous coronary intervention for unprotected left main-related ST-segment elevation myocardial infarction.

INTRODUCTION: Unprotected left main (ULM) related ST-segment elevation myocardial infarction (STEMI) is a severe event, often leading to circulatory failure and/or sudden cardiac death. Although high-risk ULM thrombosis populations treated by primary percutaneous coronary intervention (PPCI) have been previously described, very little is known regarding the outcomes following PPCI for ULM-related STEMI in a hospital without on-site surgical back-up.

METHODS: A retrospective cohort analysis was performed on all consecutive patients who underwent PPCI for ULM-related STEMI in a single center. The primary end-point was to assess in-hospital mortality in the overall population and according to the presence/absence of cardiogenic shock at admission.

RESULTS: Between October 2006 and December 2012, 1094 patients underwent PPCI for STEMI. PPCI for ULM-related STEMI was performed in 34 (3.1%) patients. Among these, 22 (64.7%) were in cardiogenic shock at admission. Baseline mean ejection fraction was lower (P = 0.008), whereas the prevalence of patients with pre-procedural cardiac arrest and Killip Class III-IV was significantly higher in the cardiogenic shock (P = 0.05 and P < 0.001, respectively) compared with non-cardiogenic shock group. Furthermore, patients with cardiogenic shock had a higher prevalence of pre-procedural thrombolysis in myocardial infarction flow 0-1 (P = 0.05) and associated other vessel chronic total occlusion (P = 0.05) compared with non-cardiogenic shock group. Procedural success rate was lower in the cardiogenic shock compared with non-cardiogenic shock group (77.3 vs. 100%, P = 0.09), whereas in-hospital mortality rate was significantly higher in the cardiogenic shock compared with non-cardiogenic shock group (36.4 vs. 0%, P = 0.02). No deaths were reported among survivors of the acute phase at mid-term follow-up, whereas target lesion revascularization rate was 7.6%.

CONCLUSIONS: PPCI for ULM-related STEMI in a hospital without on-site surgical back-up was technically feasible in most of the cases. Although the procedural success and in-hospital mortality rates were influenced by cardiogenic shock at admission, an excellent mid-term outcome among patients who survived the hospitalization was reported independently by the severity of clinical presentation.