In patients with diabetes, long-term dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) and stent implantation may not improve cardiovascular outcomes and may increase bleeding risk compared with short-term therapy, according to a recent meta-analysis.
Researchers pooled data from 6 randomized controlled trials of nearly 11,500 patients with and without diabetes to assess the impact of diabetes status on outcomes after implantation of drug-eluting stents in those receiving short-term (≤6 months) or long-term (12 months) DAPT. Participants with diabetes made up about one-third of the cohort. Results were published online on Nov. 3 by The BMJ.
The number of participants randomized to long-term versus short-term DAPT were, respectively, 1,853 and 1,828 in the group with diabetes and 3,848 and 3,860 in the group without diabetes. Compared to those without diabetes, participants with diabetes were older, were more likely to be women, and had higher rates of cardiovascular disease.
The primary endpoint was the 1-year rate of major adverse cardiac events (MACE), and secondary endpoints included the 1-year rate of major and minor bleeding. Of the 6 studies, 2 compared 3-month and 12-month DAPT, 2 compared 6-month and 12-month DAPT, and 2 compared 6-month and 24-month DAPT.
Patients with diabetes had significantly higher rates of MACE than those without diabetes (adjusted hazard ratio [HR], 2.30; P=0.048). Rates of MACE at 1 year were similar among those receiving long-term or short-term DAPT in each subgroup (HR in patients with diabetes, 1.05 [P=0.86]; HR in patients without diabetes, 0.97 [P=0.85]).
There were no significant differences in bleeding between patients with or without diabetes (adjusted HR, 0.62; P=0.43). However, in patients with diabetes, long-term DAPT was associated with a higher rate of major or minor bleeding compared with short-term DAPT (HR, 1.89; P=0.02). There was a nonsignificant increase in those without diabetes (HR, 1.43; P=0.08).
The study should be considered hypothesis-generating because of the limitations of subgroup analyses, the study authors wrote. They noted other limitations, such as that data by diabetes type were not available and that the results may not be applicable to all types of drug-eluting stents or to antiplatelet agents other than clopidogrel.
Despite these limitations, the study “highlights the fact that having diabetes itself does not necessarily equate to a requirement for longer duration of DAPT and that this can actually do more harm than good,” according to an accompanying editorial. If confirmed in future studies, these results could change clinical practice and management guidelines for the optimal duration of DAPT after PCI and drug-eluting stent implantation, the editorialist wrote.