Prediction of Mortality After Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

OBJECTIVES: We sought to develop a simple risk score for predicting mortality after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). BACKGROUND: Accurate risk stratification after primary PCI is important. Previous risk scores after reperfusion therapy have incorporated clinical +/- angiographic variables but have not considered baseline left ventricular function. Moreover, prior studies have not been validated against independent databases or studies. METHODS: The databases from the two largest multicenter, randomized AMI trials of primary PCI were utilized for score derivation (the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications CADILLAC trial, n = 2,082) and subsequent validation (the Stent-Primary Angioplasty in Myocardial Infarction Stent-PAMI trial, n = 900). Logistic regression and the jackknife procedure were used to select correlates of one-year mortality that were subsequently weighted and integrated into an integer scoring system. RESULTS: Seven variables selected from the initial multivariate model were weighted proportionally to their respective odds ratio for one-year mortality (age >65 years 2 points, Killip class 2/3 3 points, baseline left ventricular ejection fraction /=6) with excellent prognostic accuracy for survival in the derivation and validation sets (c statistics = 0.83 and 0.81 for 30-day mortality and 0.79 and 0.78 for 1-year mortality, respectively). CONCLUSIONS: In AMI patients treated with primary PCI, seven risk factors readily available at the time of intervention accurately predict short- and long-term mortality. Of note, measurement of baseline left ventricular function is the single most powerful predictor of survival and should be incorporated into risk score models.