Timing of and risk factors for myocardial ischemic events after percutaneous coronary intervention (IMPACT-II)

We studied both the time course and risk factors for adverse clinical event s after percutaneous coronary intervention (PCI). Such information is criti cal to clinical decision-making, but scant quantitative data exist to descr ibe the time course of these adverse outcomes. Patients enrolled in the Int egrilin to Minimize Platelet Aggregation and Coronary Thrombosis-ii (IMPACT -II) trial were analyzed. Patients undergoing elective, urgent, or emergenc y PCI (n = 4,010) were randomized to receive either placebo or 1 of 2 eptif ibatide regimens during intervention. We evaluated the time to the primary end point of the trial, the 30-day composite of death, myocardial infarctio n, repeat nonelective PCI, nonelective bypass surgery, or stenting for abru pt closure. Adverse events occurred in 407 patients (10.1%). Because the ri sk of events declined substantially between 6 and 9 hours (66% occurred wit hin b hours), events were classified as occurring before or after 6 hours. Independent predictors of "early" events included dissection, pre- and post procedural coronary blood flow, side-branch occlusion, procedural thromboly tic use, previous bypass, presentation with unstable angina, absence of dia betes, and hyperlipidemia. The predictors of "late" events included lower w eight, increased baseline heart rate, coronary dissection, and procedural t hrombolytic use. The risk of ischemic events were greatest immediately afte r PCI and rapidly declined, so that by 9 hours the hazard function plot was flat; 66% of events occurred within 6 hours of PCI. Knowledge of the risk factors for early and late events help risk-stratify patients before and af ter intervention for myocardial ischemic events. (C) 2000 by Excerpta Medic o, Inc.