Use of the Dual-Antiplatelet Therapy Score to Guide Treatment Duration After Percutaneous Coronary Intervention

Background The dual-antiplatelet therapy (DAPT) score was developed to identify patients more likely to derive harm (score <2) or benefit (score ≥2) from prolonged DAPT after percutaneous coronary intervention (PCI). Objective To evaluate the safety and efficacy of DAPT duration according to DAPT score. Design Retrospective assessment of DAPT score-guided treatment duration in a randomized clinical trial. (ClinicalTrials.gov: NCT00611286). Setting PCI patients. Patients 1970 patients undergoing PCI. Intervention DAPT (aspirin and clopidogrel) for 24 versus 6 months. Measurements Primary efficacy outcomes were death, myocardial infarction, or cerebrovascular accident. The primary safety outcome was type 3 or 5 bleeding according to the Bleeding Academic Research Consortium definition. Outcomes were assessed between 6 and 24 months. Results 884 patients (44.9%) had a DAPT score of at least 2, and 1086 (55.1%) had a score less than 2. The reduction in the primary efficacy outcome with 24- versus 6-month DAPT was greater in patients with high scores (risk difference [RD] for score ≥2, -2.05 percentage points [95% CI, -5.04 to 0.95 percentage points]; RD for score <2, 2.91 percentage points [CI, -0.43 to 6.25 percentage points]; P = 0.030). However, the difference by score for the primary efficacy outcome varied by stent type; prolonged DAPT with high scores was effective only in patients receiving paclitaxel-eluting stents (RD, -7.55 percentage points [CI, -12.85 to -2.25 percentage points]). The increase in the primary safety outcome with 24- versus 6-month DAPT was greater in patients with low scores (RD for score ≥2, 0.20 percentage point [CI, -1.20 to 1.60 percentage points]; RD for score <2, 2.58 percentage points [CI, 0.71 to 4.46 percentage points]; P = 0.046). Limitation Retrospective calculation of the DAPT score. Conclusion Prolonged DAPT resulted in harm in patients with low DAPT scores undergoing PCI but reduced risk for ischemic events in patients with high scores receiving paclitaxel-eluting stents. Whether prolonged DAPT benefits patients with high scores treated with contemporary drug-eluting stents requires further study. Primary Funding Source None.