Three-month DAPT post MI may suffice

Although guidelines recommend 12 months of dual antiplatelet therapy (DAPT) following a heart attack, results from the DUAL-ACS* trial appear to show otherwise.

“Compared with 12-month DAPT, the 3-month regimen was not associated with demonstrable differences in all-cause death and cardiovascular (CV) outcomes, but there were trends for lower rates of fatal or major bleeding,” said Professor David Newby from the University of Edinburgh, UK, at ESC 2025.

At 15 months, there were fewer incidences of the primary efficacy endpoint of all-cause mortality with 3- vs 12-month DAPT (2.7 percent vs 3.4 percent; hazard ratio [HR], 0.78; p=0.1232). A similar pattern was observed for CV death (1.6 percent vs 2.2 percent; HR, 0.71; p=0.1020).

However, as the study population was below the target sample, the comparisons did not achieve statistical significance, noted Newby.

Looking at CV death or non-fatal MI, event rates were similar between 3- and 12-month DAPT (9.3 percent vs 8.9 percent; HR, 1.04; p=0.6149). The same applies for fatal or non-fatal MI (8.7 percent vs 8 percent; HR, 1.09; p=0.3623) and stent thrombosis (1.3 percent for both; HR, 1.06; p=0.8102). [Newby, et al, ESC 2025]

For the secondary safety endpoints, non-CV death or non-fatal major bleeding event rate was slightly lower with 3 vs 12 months of DAPT (4.1 percent vs 5 percent; HR, 0.81; p=0.1220), as was fatal or non-fatal major bleeding (3.2 percent vs 4 percent; HR, 0.78; p=0.0977).

Supporting data

In the CURE trial comparing clopidogrel against placebo on top of aspirin, nearly all the benefit was observed during the first 3 months. In the 3–12 month period, there was only 0.3-percent absolute risk reduction as opposed to 2 percent in the first 3 months. [Lancet 2001;345:494-502]

“The CURE trial explicitly stated that the benefit was seen in the first 3 months and beyond that, there was no demonstrable benefit and that there was a bleeding hazard. The optimal duration of treatment has never been formally established,” Newby pointed out.

In a meta-analysis, longer DAPT durations were associated with harm, while shorter durations demonstrated a lower mortality and bleeding risk. [Lancet 2015;385:2371-2378]

“In the real world, patients have a higher [CV] and bleeding risk,” Newby noted. Hence, the team evaluated DAPT (aspirin and a P2Y₁₂ inhibitor) duration in a real-world population of individuals who had a recent (<3 months) type 1 MI and had already been prescribed DAPT.

A total of 5,052 patients (mean age 63 years, 73 percent men) were randomized 1:1 to either 3 or 12 months of DAPT. After index admission, 23 percent of participants received medical management only, 70 percent underwent percutaneous coronary intervention, and 6 percent had coronary artery bypass graft surgery. About 60 percent had hypertension and 41 percent had hyperlipidaemia. The most frequently used P2Y₁₂ receptor antagonist was clopidogrel (53 percent), followed by ticagrelor (43 percent).

Takeaways

According to Newby and colleagues, this all-comer, real-world trial only recruited 30 percent of the planned participants and was unable to address the primary question definitively. However, there was no evidence that DAPT given for 12 months conferred any additional benefit.

“Why give [DAPT] for 12 months when there is no evidence of efficacy and there are signals of harm? Whilst we did not see any statistically significant differences [between 3- and 12-month DAPT], the trends are very consistent with what we know today in terms of the effects of prolonged DAPT,” Newby said.

“We do need to revisit our very old and stated claim that we should be giving DAPT for 12 months. [Our findings suggest that] we should give DAPT for 3 months,” he concluded.