Abstract 17338: Development of a TIMI Risk Score for Stable Ischemic Heart Disease

Abstract

Patients (pts) with stable ischemic heart disease (SIHD) who have had a prior myocardial infarction (MI) demonstrate a range of residual risk for recurrent CV events. A risk prediction tool may be useful to identify high risk pts who have the greatest potential for benefit from intensive treatment. Methods: The integer-based TIMI Risk Score for SIHD (Prior MI) was derived in 8,200 placebo-treated pts who were stable with a history of MI (2 wks to 12 mo) in the TRA 2°P-TIMI 50 trial. The score was developed to predict CV death, MI or ischemic stroke (CVD/MI/iCVA; n=676 events, median 2.5y follow-up). The score was validated in 8,274 vorapaxar-treated pts from the trial. Differential efficacy and safety (GUSTO severe bleeding) response to randomized treatment was assessed among pts with prior MI without a history of TIA or stroke for whom there is a clinical indication for vorapaxar. Results: The risk score predictors were age, CHF, smoking, diabetes mellitus, hypertension, prior stroke, peripheral arterial disease, family history of CAD, prior CABG, and eGFR (Fig 1a). The TIMI Risk Score showed a strong graded relationship with the rate of CVD/MI/iCVA as well as the individual components (p-trend<0.001 for all), a pattern that was confirmed in the validation cohort (p<0.001). In pts eligible for clinical use, those at intermediate (score 2-3) and high (score ≥4) risk had a 2.4% and 3.6% absolute risk reduction in CVD/MI/iCVA with vorapaxar, translating to a number needed to treat (NNT) of 41 and 28 in the intermediate and high risk groups (Fig 1b). Bleeding increased across risk groups (Fig 1b); however, net clinical outcome was increasingly favorable with vorapaxar with an increasing TIMI Risk Score. ICH was 0.5 vs 0.6% and fatal bleeding was 0.3 vs 0.5% with vorapaxar vs placebo in those with a score ≥4. Conclusions: The TIMI Risk Score for SIHD (Prior MI) identifies a strong gradient of increasing risk for recurrent CV events and may be useful as a basis for therapeutic decision-making.