Dual Antiplatelet Therapy After DES in Patients With or Without ACS

Study Questions:

What is the safety and efficacy of shortening dual antiplatelet therapy (DAPT) to <1 year after drug-eluting stent (DES) implantation in patients with and without acute coronary syndrome (ACS)?

Methods:

The investigators performed an individual patient data pairwise and network meta-analysis comparing short-term (≤6 months) versus long-term (1 year) DAPT as well as 3-month vs. 6-month vs. 1-year DAPT. The primary study outcome was the 1-year composite risk of myocardial infarction (MI) or definite/probable stent thrombosis (ST). Six trials were included, in which DAPT after DES consisted of aspirin and clopidogrel. For the network meta-analysis treatment effect, estimates for short versus long DAPT were obtained as log hazard ratio (HR) and standard error from individual randomized controlled trials. These estimates were then used to obtain head-to-head comparison estimates between different DAPT regimens (3 months vs. 6 months vs. 1 year).

Results:

Among 11,473 randomized patients, 6,714 (58.5%) had stable coronary artery disease (CAD) and 4,758 (41.5%) presented with ACS, the majority of whom (67.0%) had unstable angina. In ACS patients, ≤6-month DAPT was associated with nonsignificantly higher 1-year rates of MI or ST compared with 1-year DAPT (HR, 1.48; 95% confidence interval [CI], 0.98-2.22; p = 0.059), whereas in stable patients, rates of MI and ST were similar between the two DAPT strategies (HR, 0.93; 95% CI, 0.65-1.35; p = 0.71; Pinteraction = 0.09). By network meta-analysis, 3-month DAPT, but not 6-month DAPT, was associated with higher rates of MI or ST in ACS, whereas no significant differences were apparent in stable patients. Short DAPT was associated with lower rates of major bleeding compared with 1-year DAPT, irrespective of clinical presentation. All-cause mortality was not significantly different with short versus long DAPT in both patients with stable CAD and ACS.

Conclusions:

The authors concluded that optimal DAPT duration after DES differs according to clinical presentation.

Perspective:

This study reports that a strategy of short-term DAPT (3 or 6 months) after DES implantation is associated with similar 1-year composite rates of MI or definite/probable ST compared with 1-year DAPT, with a borderline interaction between DAPT duration and clinical presentation. Furthermore, in patients with ACS, 3-month but not 6-month DAPT was associated with higher rates of MI or ST compared with 1-year DAPT, whereas in stable CAD, no such difference was apparent. Additional studies are needed to individualize the optimal duration of DAPT after DES in patients at varying degrees of ischemic and bleeding risk with use of different P2Y12 inhibitors.

Keywords: Acute Coronary Syndrome, Angina, Unstable, Aspirin, Coronary Artery Disease, Drug-Eluting Stents, Hemorrhage, Myocardial Infarction, Platelet Aggregation Inhibitors, Thrombosis, Ticlopidine


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