Outcome of poor initial TIMI flow in patients presenting with acute coronary syndrome.

Objectives. We explored the predictors and outcome of poor, versus good, initial TIMI flow in patients with acute coronary syndrome (ACS). Design. We performed post-hoc analysis of a randomized trial of patients presenting with ACS who received 2 comparative stents. Poor initial TIMI flow was defined as baseline TIMI flow grade 0/1 at the initial coronary angiography. The primary endpoint was major adverse cardiac events (MACE): a composite of cardiac death, non-fatal myocardial infarction or ischemia-driven target lesion revascularization. Stent thrombosis (ST) was adjudicated according to the criteria of definite ST described by the Academic Research Consortium. Propensity score-matched analysis was performed. We report data after 5-year follow-up. Results. Of 827 patients enrolled, 279 (33.7%) had initial TIMI 0/1 flow. Median follow-up duration was 5.0 years. Presentation by ST-elevation myocardial infarction and target vessel other than left anterior descending artery predicted initial TIMI 0/1 flow. MACE rate was comparable between the 2 subgroups (14% versus 15.9%, in patients with poor versus good initial TIMI flow, respectively, p=.46). Individual endpoints were comparable (p>.05 for all). Definite ST was more frequent in patients with initial TIMI 0/1 flow (3.6% versus 1.5%, respectively, p=.048). This was driven by more frequent early events (30 days) (p=.036); late/very late events were comparable (p=1.0). Conclusions. Predictors of poor initial TIMI flow included presentation by ST-elevation myocardial infarction, and target vessel other than left anterior descending artery. Definite ST occurred more in patients with poor, versus good, initial TIMI flow, mainly driven by difference in early events.