Stent Thrombosis and Dual Antiplatelet Therapy Interruption With Everolimus-Eluting Stents

BACKGROUND: Whether premature dual antiplatelet therapy (DAPT) interruption is safe in patients receiving cobalt chromium everolimus-eluting stents remains controversial. We sought to examine the relationship between DAPT discontinuation and stent thrombosis (ST) after cobalt chromium everolimus-eluting stents. METHODS AND RESULTS: Outcomes from 11,219 patients were pooled from 3 randomized trials and 4 registries with 2-year follow-up period after cobalt chromium everolimus-eluting stent implantation. Rates of definite/probable ST were analyzed according to DAPT discontinuation in the following time intervals: 0 to 30, 30 to 90, 90 to 180, 180 to 365, and 365 to 730 days. Eighty-five cases of ST (0.75%) occurred in 83 patients during 2 years, with 41 (48.2%) events occurring within 30 days. The 2-year ST rate in patients interrupting DAPT at any time was similar to that in patients never interrupting DAPT through 2 years (25/4067 [0.63%] versus 58/7152 [0.83%] respectively; P=0.27]. By propensity and DAPT usage-adjusted multivariable analysis, permanent DAPT discontinuation before 30 days was independently associated with the occurrence of ST (hazard ratio [95% confidence interval], 26.8 [8.4-85.4]; P<0.0001), whereas permanent DAPT discontinuation in any interval after 90 days was not associated with ST. Only 2 ST events occurred after DAPT discontinuation between 30 and 90 days (both between 30 and 60 days), and the association between permanent DAPT discontinuation and ST during this period is unclear (hazard ratio [95% confidence interval], 8.7 [2.0-37.3]; P=0.004 for adjusted analysis and 3.4 [0.8-13.8]; P=0.07 for the unadjusted analysis). CONCLUSIONS: In this large pooled experience, permanent DAPT discontinuation before 30 days after cobalt chromium everolimus-eluting stent implantation was strongly associated with ST, whereas DAPT discontinuation beyond 90 days appeared safe. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180310, NCT00180479, NCT00307047, NCT00402272, NCT00496938, NCT00676520, and NCT00631228.