Prasugrel versus clopidogrel in acute coronary syndromes treated with PCI: Effects on clinical outcome according to culprit artery location.

Background: Acute coronary syndrome (ACS) mortality increases when the culprit lesion is in the left anterior descending (LAD) artery. We investigated the effects of prasugrel versus clopidogrel according to site of culprit lesion causing ACS treated with percutaneous coronary intervention (PCI) in the TRITON-TIMI 38 study.

Methods: Patients were divided into three groups based on the native coronary artery culprit lesion location. The LAD artery group included also patients with the culprit lesion in the left main (LM) artery.

Results: In the whole ACS population, prasugrel recipients had lower rates of the primary endpoint that included cardiovascular (CV) death, non-fatal myocardial infarction (MI) or non-fatal stroke without significant differences across vessel groups. CV death was significantly decreased with prasugrel in the whole ACS population (p=0.03) and in ST-elevation MI (STEMI) patients undergoing primary PCI (p=0.04), with pronounced differences in favour of prasugrel versus clopidogrel when the LAD-LM was the culprit vessel (relative risk reduction 50% in the whole ACS population, 57% in STEMI treated with primary PCI, p for interaction 0.07 and 0.08 respectively).

Conclusions: Prasugrel effects were particularly favourable when LAD-LM was the culprit vessel, resulting in CV mortality reduction in the whole ACS population and in STEMI patients when treated with primary PCI.