Safety of 6-Month Duration of Dual Antiplatelet Therapy After Percutaneous Coronary Intervention in Patients With Acute Coronary Syndromes - SMART-DATE

Contribution To Literature:

The SMART-DATE trial showed that a 6-month duration of DAPT is noninferior for MACCE, but inferior for MI compared with a ≥12-month duration among patients with ACS undergoing PCI with a second-generation DES.

Description:

The goal of the trial was to assess the safety and efficacy of a 6-month duration of dual antiplatelet therapy (DAPT) compared with ≥12 months among patients undergoing drug-eluting stent (DES) percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS).

Study Design

Patients with ACS undergoing PCI with a second-generation DES were randomized in a 1:1 fashion to either DAPT for either short-term (6 months) (n = 1,357) or long-term (≥12 months) (n = 1,355) DAPT. In a factorial design, three different DES were tested: everolimus-eluting stent (EES), zotarolimus-eluting stent (ZES), and biolimus-eluting stent (BES).

  • Total number of enrollees: 2,712
  • Duration of follow-up: 18 months
  • Mean patient age: 62.1 years
  • Percentage female: 24%

Inclusion criteria:

  • ACS patients with target lesion(s) in native coronary artery
  • Amenable for PCI with DES implantation

Exclusion criteria:

  • Recent major bleeding
  • History of bleeding diathesis
  • DES implantation within 12 months
  • Life expectancy <1 year
  • Planned elective surgery within 12 months

Other salient features/characteristics:

  • Diabetes: 28%, prior myocardial infarction (MI): 2%
  • Mean Ejection fraction: 55.5%
  • Presentation: ST-segment elevation MI (STEMI): 38%, NSTEMI: 31%
  • Multivessel disease: 45%; left main/left anterior descending artery treated: 70%
  • Mean stents per patient: 1.5

At 12 months, use of P2Y12 inhibitor among short-term vs. long-term DAPT was 20% vs. 96%.

Principal Findings:

The primary outcome, major adverse cardiac and cerebrovascular events (MACCE) at 18 months, for short- vs. long-term DAPT, was 4.7% vs. 4.2%, p for noninferiority = 0.027; p for superiority = 0.51.

On landmark analysis at 6 months, hazard ratio for MACE in the short-term arm compared with the long-term arm, was 1.69, 95% confidence interval 0.97-2.94, p = 0.07.

Secondary outcomes for short- vs. long-term DAPT:

  • Death: 4.7% vs. 4.2%, p = 0.9
  • MI: 1.8% vs. 0.8%, p = 0.02; nontarget vessel MI: 0.8% vs. 0.2%, p = 0.07
  • Stent thrombosis 1.1% vs. 0.7%, p = 0.32
  • Bleeding Academic Research Consortium (BARC) 2-5 bleeding: 2.7% vs. 3.9%, p = 0.09

Interpretation:

The results of this important trial indicate that a 6-month duration of DAPT is noninferior to a ≥12-month duration among patients with ACS undergoing PCI with a second-generation DES. However, there is a higher risk of MI with shorter durations. On landmark analysis at 6 months, the shorter duration strategy also resulted in a trend towards harm for the composite endpoint. There was also a high rate of crossover to longer durations (~20%) in the 6-month duration DAPT arm.

References:

Hahn JY, Song YB, Oh JH, et al., on behalf of the SMART-DATE Investigators. 6-month versus 12-month or longer dual antiplatelet therapy after percutaneous coronary intervention in patients with acute coronary syndrome (SMART-DATE): a randomised, open-label, non-inferiority trial. Lancet 2018;Mar 12:[Epub ahead of print].

Editorial Comment: Motovska Z, Bhatt DL. 12 months of DAPT after acute coronary syndrome still beats 6 months. Lancet 2018;Mar 12:[Epub ahead of print].

Presented by Dr. Hyeon-Cheol Gwon at the American College of Cardiology Annual Scientific Session (ACC 2018), Orlando, FL, March 12, 2018.

Clinical Topics: Acute Coronary Syndromes, Invasive Cardiovascular Angiography and Intervention, Interventions and ACS

Keywords: ACC18, ACC Annual Scientific Session, Acute Coronary Syndrome, Drug-Eluting Stents, Hemorrhage, Myocardial Infarction, Percutaneous Coronary Intervention, Platelet Aggregation Inhibitors, Stents, Thrombosis


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