Optimal dual antiplatelet therapy duration for bioresorbable scaffolds: an individual patient data pooled analysis of the ABSORB trials

Background: Compared with everolimus-eluting metallic stents, the Absorb bioresorbable scaffold (BRS) results in increased rates of myocardial infarction (MI) and scaffold thrombosis (ST) during its three-year bioresorption phase. It is unknown whether prolonged dual antiplatelet therapy (DAPT) duration might decrease the risk of ischaemic events. Aims: We sought to evaluate the impact of DAPT duration on ischaemic and bleeding outcomes following BRS implantation. Methods: We conducted an individual patient data pooled analysis from four ABSORB randomised trials and one prospective ABSORB registry. Study endpoints were MI, ST, bleeding, and death up to three-year follow-up. Propensity score-adjusted Cox regression analysis was used to account for baseline differences related to DAPT duration. Results: The five ABSORB studies included 2,973 patients. DAPT use was 91.7%, 53.2%, and 48.0% at 1, 2, and 3 years, respectively. DAPT use within the first year after BRS implantation was associated with markedly lower risks of MI (adjusted hazard ratio [aHR] 0.17, 95% CI: 0.10-0.32; p<0.0001) and ST (aHR 0.08, 95% CI: 0.03-0.19; p<0.0001). Conversely, DAPT use between 1 and 3 years did not significantly affect the risk of MI (aHR 1.04, 95% CI: 0.70-1.55; p=0.84) or ST (aHR 0.86, 95% CI: 0.42-1.75; p=0.67). DAPT did not have major effects upon bleeding or death in either period. Conclusions: DAPT use during the first year after BRS implantation was strongly associated with lower risks of ST and MI. However, a benefit of ongoing DAPT use between 1 and 3 years after BRS implantation was not apparent.