Ischaemic and bleeding outcomes in elderly patients undergoing a prolonged versus shortened duration of dual antiplatelet therapy after percutaneous coronary intervention: Insights from the PRODIGY randomised trial

Aims: The aim of this study was to evaluate the efficacy and safety of 24-month vs. six-month dual antiplatelet therapy (DAPT) among elderly (≥75 years) and non-elderly patients (>75 years) undergoing percutaneous coronary intervention.
Methods and results: The primary efficacy endpoint of the PRODIGY trial was the composite of death, myocardial infarction, or cerebrovascular accident at 24-month follow-up. The key safety endpoint was type 2, 3 or 5 bleeding according to the BARC criteria. Of 1,970 participants, 587 (29.8%) were elderly and had a higher risk of adverse events compared with younger patients. The risk of the primary endpoint was not significantly reduced with 24-month compared to six-month DAPT among both elderly (HR 0.80, 95% CI: 0.55-1.16, p=0.24) and non-elderly patients (HR 1.48, 95% CI: 0.95-2.30, p=0.08), although interaction testing was significant (p=0.036). A 24-month versus six-month DAPT significantly increased the risk of BARC type 2, 3 or 5 bleeding in both older (HR 1.90, 95% CI: 1.06-3.38, p=0.03) and younger patients (HR 2.54, 95% CI: 1.43-4.53, p=0.002, p-interaction=0.48). However, measures of absolute risk difference indicated a less favourable safety profile of prolonged DAPT for older rather than younger patients.
Conclusions: In the PRODIGY trial, prolonging clopidogrel-based DAPT beyond six months in elderly patients increased the risk of bleeding, without affording a significant prevention of ischaemic events.