Longer DAPT courses not more effective at preventing adverse outcomes

Prolonged dual antiplatelet therapy (DAPT) in acute myocardial infarction (MI) patients treated with drug-eluting stents (DES) does not appear to be particularly advantageous to shorter treatment durations, a recent study has found.

Researchers enrolled 6,199 acute MI patients who were given 12 months of DAPT after percutaneous coronary intervention with DES. The primary study endpoint was the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE), defined as a composite of MI, ischaemic stroke and all-cause death.

Participants were divided into two groups according to the duration of DAPT: 4,802 (mean age, 62.1±12.1 years; 78.3 percent male) received a prolonged regimen of >12 months, while 1,397 (mean age, 60.9±11.7 years; 79.9 percent male) took the medication for 12 months. Second-generation DES saw predominant use in either treatment group.

After inverse probability treatment-weighted adjustment, the incidence rate of MACCE was comparable between those who received the longer vs shorter DAPT course (1.3 percent vs 1.0 percent; hazard ratio [HR], 1.32, 95 percent confidence interval [CI], 0.71–2.45; p=0.378).

The same was true for the corresponding rates of the individual components of the composite outcome: death from any cause (0.1 percent vs 0.1 percent; HR, 1.02, 95 percent CI, 0.19–5.41; p=0.983), MI (0.8 percent vs 0.6 percent; p=0.650) and ischaemic stroke (0.4 percent vs 0.2 percent; p=0.229). The incidence of net adverse clinical events was likewise similar between groups (1.4 percent vs 1.1 percent; p=0.466).