Six Versus Twelve Months of Dual Antiplatelet Therapy After Drug-Eluting Stent Implantation in ST-Elevation Myocardial Infarction - DAPT-STEMI
Contribution To Literature:
The DAPT-STEMI trial showed that among patients who remain event-free at 6 months following PPCI with a ZES for STEMI, cessation of DAPT at the 6-month mark vs. continuing for an additional 6 months (12 months total from stent implantation) is noninferior for clinical outcomes at 2 years.
The goal of the trial was to assess the safety and efficacy of 6 vs. 12 months of dual antiplatelet therapy (DAPT) in patients presenting with ST-segment elevation myocardial infarction (STEMI) and undergoing primary percutaneous coronary intervention (PPCI) with a second-generation drug-eluting stent (DES).
Patients with STEMI and undergoing PPCI with a second-generation DES (zotarolimus-eluting stent [ZES]) were randomized in a 1:1 fashion to either 6 months (n = 433) or 12 months of DAPT (n = 437).
- Total number of enrollees: 1,496
- Duration of follow-up: 1 year
- Mean patient age: 60 years
- Percentage female: 23%
- Percentage with diabetes: 14%
- Age 20-85 years
- PPCI with second-generation ZES
- Event free at 6 months (no MI, stent thrombosis, target vessel or lesion revascularization, or stroke/bleeding requiring DAPT discontinuation)
- Intolerance to aspirin, prasugrel, ticagrelor, heparin, bivalirudin, zotarolimus, or everolimus
- Planned elective surgical procedure necessitating interruption of DAPT during the first 6 months after the procedure
- Need for oral anticoagulation
- History of stent thrombosis
- DES in main left coronary artery
- Active bleeding, known bleeding diathesis, or known coagulopathy
- Oral anticoagulant therapy with Coumadin derivative
- Malignancies or other comorbidity
Other salient features/characteristics:
- Prior MI: 5%
- P2Y12 inhibitor at start of trial: clopidogrel: 42%, prasugrel: 30%, ticagrelor 29%
- Infarct vessel: left anterior descending: 41%, right coronary artery: 41%
- Average number of treated vessels: 1.08
- Total stented length: 29 mm
The primary outcome, all-cause mortality, MI, revascularization, stroke, and TIMI major bleeding at 18 months for 6-month vs. 12-month DAPT, was 4.8% vs. 6.6%, p for noninferiority = 0.004, p for superiority = 0.26.
- All-cause mortality: 0.7% vs. 1.4%, p = 0.33
- MI: 1.8% vs. 1.8%, p = 0.97
- TIMI major bleeding: 0.2% vs. 0.5%, p = 0.58
Secondary outcomes for 6-month vs. 12-month DAPT:
- Stent thrombosis: 0.7% vs. 0.9%, p = 0.72
- Target lesion failure: 1.2% vs. 1.8%, p = 0.42
The results of this trial indicate that among patients who remained event free at 6 months following PPCI with a ZES for STEMI, cessation of DAPT at the 6-month mark vs. continuing for an additional 6 months (12 months total from stent implantation) is noninferior for clinical outcomes at 2 years. The trial was underpowered to assess individual safety endpoints. These are thought-provoking results, and while they may not change practice or guidelines immediately, they indicate the need for additional clinical trials in this area. The most recent American College of Cardiology/American Heart Association DAPT guidelines indicate that a 6-month duration may be reasonable among patients undergoing PCI for stable angina.
Presented by Dr. Elvin Kedhi at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2017), Denver, CO, November 1, 2017.
< Back to Listings