Current guidelines recommend 12 months of dual antiplatelet
therapy (
DAPT) after
drug-eluting stent (DES) implantation in the absence of increased
bleeding risk. Studies have suggested that early discontinuation of
DAPT can result in an increased risk of
stent thrombosis. However, given the potential for major
bleeding, the optimal duration of
DAPT after DES implantation remains uncertain. We searched PubMed, EMBASE, Scopus, and ClinicalTrials.gov databases from inception until October 2013 for randomized controlled trials that compared shorter versus longer
DAPT duration after DES implantation. Four randomized controlled trials were included. A total of 4,081 patients received
DAPT for 3 to 6 months, and 4,076 patients were treated with
DAPT for 12 to 24 months. Oral
DAPT consisted of
aspirin and
clopidogrel. There was no significant difference in the rate of the composite outcome of
cardiac death or
myocardial infarction between the short (3.3%) and prolonged (3.0%)
DAPT groups (odds ratio 1.11, 95% confidence interval 0.87 to 1.43, p=0.41). A landmark analysis performed at the time of discontinuation of
DAPT in the short
DAPT group demonstrated a nonsignificant higher rate of
stent thrombosis in patients treated with a short course of
DAPT (0.35% vs 0.20%, p=0.22). Major
bleeding was significantly higher in the group of patients treated with prolonged
DAPT (0.29% vs 0.71%, p=0.01). In conclusion, prolonged
DAPT compared with short-term treatment is associated with increased major
bleeding but is not associated with a decrease in the composite rates of death or
myocardial infarction.