Optimal antiplatelet duration varies according to clinical presentation
medwireNews: The optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation differs depending on clinical presentation, researchers report.
In an individual patient data pairwise and network meta-analysis, the study authors collated data from 11,473 participants of six randomized trials investigating the safety and efficacy of shortening the duration of DAPT with aspirin and clopidogrel following DES placement in patients with and without acute coronary syndromes (ACS).
Among patients with ACS, 2.43% of 2383 patients treated with short-term (≤6 months) DAPT experienced myocardial infarction (MI) or stent thrombosis (ST) at 1 year, compared with 1.67% of 2375 ACS patients treated with 1-year DAPT, translating into a nonsignificant hazard ratio (HR) of 1.48.
Conversely, 1.67% of 3347 patients with stable coronary artery disease (CAD) treated with short-term DAPT versus 1.79% of 3367 CAD patients treated with 1-year DAPT experienced MI or ST events (HR=0.93).
These findings suggest “a borderline interaction between DAPT duration and clinical presentation,” Gregg Stone (Columbia University, New York, USA) and colleagues write in the European Heart Journal.
By network meta-analysis, the team found that ACS patients treated with 3-month, but not 6-month, DAPT experienced higher rates of MI or ST events than those receiving 1-year DAPT (HR=2.08 and 1.28, respectively). However, these differences were not observed among patients with stable CAD.
In accordance with current evidence, patients treated with 3- and 6-month DAPT had lower rates of bleeding compared with those who received 1-year DAPT, confirming “that prolonging DAPT carries a substantial risk of major bleeding and any bleeding,” say the authors.
Stone and colleagues acknowledge that the majority of patients with ACS had biomarker-negative unstable angina and few had experienced acute ST-segment elevation MI, indicating that the study represents “a relatively low-risk cohort,” and note that the study is limited by the use of first-generation DES in many of the participants.
“However, as second generation DES are safer than first generation DES, the balance between risk and benefit would likely favour shorter DAPT duration to an even greater degree with contemporary DES,” they add.
And the researchers conclude: “These data suggest that the optimal DAPT duration after DES placement should be tailored in individual patients after carefully balancing the risks of ischaemic versus bleeding events.”
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