Results:

Among DAPT Study patients (derivation cohort; mean age, 61.3 years; women, 25.1%), ischemia occurred in 348 patients (3.0%) and bleeding in 215 (1.8%). Derivation cohort models predicting ischemia and bleeding had c-statistics of 0.70 and 0.68, respectively. The prediction rule assigned 1 point each for myocardial infarction at presentation, prior myocardial infarction or PCI, diabetes, stent diameter <3 mm, smoking, and paclitaxel-eluting stent; 2 points each for history of congestive heart failure/low ejection fraction and vein graft intervention; −1 point for age 65 to <75 years; and −2 points for age ≥75 years. Among the high score group (score ≥2, n = 5,917), continued thienopyridine versus placebo was associated with reduced ischemic events (2.7% vs. 5.7%; risk difference [RD], −3.0%; 95% confidence interval [CI], −4.1% to −2.0%; p < 0.001) compared with the low score group (score <2, n = 5,731; 1.7% vs. 2.3%; RD, −0.7%; 95% CI, −1.4% to 0.09%; p = 0.07; interaction p < 0.001). Conversely, continued thienopyridine was associated with smaller increases in bleeding among the high score group (1.8% vs. 1.4%; RD, 0.4%; 95% CI, −0.3% to 1.0%; p = 0.26) compared with the low score group (3.0% vs. 1.4%; RD, 1.5%; 95% CI, 0.8% to 2.3%; p < 0.001; interaction p = 0.02). Among PROTECT patients (validation cohort; mean age, 62 years; women, 23.7%), ischemia occurred in 79 patients (1.0%) and bleeding in 37 (0.5%), with a c-statistic of 0.64 for ischemia and 0.64 for bleeding. In this cohort, the high-score patients (n = 2,848) had increased ischemic events compared with the low-score patients, and no significant difference in bleeding.