Implications of pre-procedural TIMI flow in patients with non ST-segment elevation acute coronary syndromes undergoing percutaneous coronary revascularization: Insights from the ACUITY trial

Objectives: The purpose of this study was to evaluate the prognostic implications of preprocedural TIMI flow in ACS patients undergoing early invasive management. Background: Although the negative prognostic impact of reduced Thrombolysis in Myocardial Infarction (TIMI) flow before percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) has been well described, whether this relationship holds in patients with acute coronary syndromes (ACS; unstable angina and non-STEMI) has not been examined. Methods: We evaluated 3582 moderate and high-risk patients with ACS undergoing PCI enrolled in the ACUITY trial. Patients were divided in 3 groups according to pre-procedural culprit vessel TIMI flow (TIMI 0/1, TIMI 2 and TIMI 3 flows), determined by an independent angiographic core laboratory. Results: Baseline culprit vessel flow was absent (TIMI 0/1) in 453 patients (12.6%), reduced (TIMI 2) in 389 patients (10.9%) and normal (TIMI 3) in 2740 patients (76.5%) patients. Post-PCI TIMI 3 flow was achieved in 87.2%, 86.8% and 98.8% of the 3 groups, respectively (P < 0.0001). At 1 year, mortality occurred in 2.7%, 2.4% and 3.0% of patients with baseline TIMI 0/1, 2 and 3 flows, respectively (P = 0.82). By multivariable analysis, pre-PCI TIMI flow 0/1 (vs. TIMI 3) was not an independent predictor of 1-year mortality (P = 0.61). Conclusions: Reduced baseline TIMI flow in moderate and high-risk patients with ACS undergoing PCI does not appear to affect survival at 1 year, in contrast to that described in patients with STEMI.