Results of a meta-analysis support short-term dual antiplatelet therapy (DAPT) for most patients who have a drug-eluting stent (DES), according to investigators.
The research showed that shorter-duration DAPT was associated with a decrease in all-cause mortality and major bleeding.
On the other hand, patients who received DAPT for a shorter period also had an increase in myocardial infarction (MI) and definite or probable stent thrombosis.
The results appear in The Lancet.
Study investigators examined 31,666 patients with DES from 10 randomized trials that compared different durations of DAPT. DAPT duration was categorized in each study as “shorter” vs “longer,” and ≤6 months vs 1 year vs >1 year.
The study’s primary endpoint was all-cause mortality. Secondary pre-specified endpoints included cardiac death, non-cardiac death, MI, stroke, stent thrombosis (definite or probable), major bleeding, and any bleeding.
A shorter DAPT duration was associated with significantly lower rates of all-cause mortality compared to longer DAPT (hazard ratio [HR]=0.82, P=0.02).
This difference was driven by a significant reduction in non-cardiac mortality with shorter DAPT (HR=0.67, P=0.006). There was no significant difference in cardiac mortality between the shorter and longer strategies (HR=0.93, P=0.52).
“[L]onger DAPT was associated with a 22% increased rate of all-cause mortality due to a 49% increased rate in non-cardiac mortality . . . ,” said study author Gregg W. Stone, MD, of Columbia University Medical Center in New York, New York.
“These results support a short-term (3 or 6 months) DAPT strategy in most patients, especially those at low risk of recurrent coronary events and stent thrombosis, and at high risk of bleeding.”
“However, an extended DAPT strategy (longer than 1 year) may still be appropriate in selected patients in whom prevention of stent- and non-stent-related coronary events are likely to offset the adverse events associated with extended-duration antiplatelet therapy.”
Dr Stone and his colleagues found that shorter-duration DAPT was associated with significantly lower rates of major bleeding (HR=0.58, P<0.0001) and any bleeding (HR=0.56, P<0.0001) compared to longer-duration DAPT.
However, shorter DAPT was also associated with significantly higher rates of MI (HR=1.51, P<0.0001) and definite or probable stent thrombosis (HR=2.04, P<0.0001), with moderate heterogeneity across trials. Stroke rates did not vary significantly with DAPT duration (HR=1.03, P=0.86).
Additional subgroup analyses showed that patients treated with DAPT for 6 months or less and those treated for 1 year had a higher risk of MI and stent thrombosis but a lower risk of mortality than patients who received DAPT for more than 1 year.
Patients treated with DAPT for 6 months or less had similar rates of mortality, MI, and stent thrombosis as patients who received DAPT for 1 year. But the 6-months-or-less patients had lower rates of major bleeding.
“Establishing the optimal duration of DAPT after DES implantation is extremely important in balancing the risks of ischemic and bleeding complications,” Dr Stone said. “Therefore, an individualized approach in which the benefit-risk profile for each patient should be carefully considered.”
“Further studies are required to model the demographic, laboratory-based, and genetic variables that affect the benefit-vs-risk balance of prolonged DAPT that might remove the guesswork from this equation.”
