Shortening the duration of dual-antiplatelet therapy (DAPT) and continuing with a P2Y12 inhibitor alone after percutaneous coronary intervention (PCI) was associated with a similar rate of ischemic events but with less bleeding than prolonged DAPT after 3 years of follow-up in the SMART-CHOICE trial.
“The current the investigators, with lead author Ki Hong Choi, MD, division of cardiology, department of medicine, Samsung Medical Center, Sungkyunkwan University, Seoul, South Korea, conclude.
The 3-year results from the study were published online in JAMA Cardiology.
The authors explain that although dual therapy with aspirin and a P2Y12 inhibitor after PCI with a drug-eluting stent (DES) is crucial to reduce the risk of ischemic events, it raises concerns about increased risk of bleeding, and the antiplatelet strategy after PCI is currently shifting to reduce the duration of DAPT.
Several recent randomized studies have consistently shown that a short duration of DAPT (1-3 months) followed by P2Y12 inhibitor monotherapy had ischemia protection effects comparable with that of DAPT of longer duration, and it was associated with a significantly reduced risk of bleeding events in patients who underwent PCI, they note. However, these studies have so far reported only 1-year outcomes, and long-term results are not yet available.
The SMART-CHOICE trial compared two antiplatelet strategies – 3 months of DAPT followed by long-term P2Y12 inhibitor monotherapy (mainly with clopidogrel) or prolonged DAPT for 12 months or longer – in 2,993 patients who had undergone PCI with a drug-eluting stent. Results at 12 months showed a similar rate of ischemic events with both strategies but a lower rate of bleeding in the group that received shortened DAPT.
The SMART-CHOICE investigators now report the 3-year results showing similar outcomes.
At 3 years, the primary endpoint, a composite of all-cause death, myocardial infarction, or stroke, had occurred in 6.3% of the shortened DAPT group and 6.1% in the prolonged DAPT group, giving a hazard ratio of 1.06 (95% confidence interval, 0.79-1.44).
But in the shortened DAPT group, the risk of bleeding was reduced. Bleeding Academic Research Consortium (BARC) types 2-5 bleeding had occurred in 3.2% of the shortened DAPT group and in 8.2% of the prolonged DAPT group (hazard ratio, 0.39; 95% CI, 0.28-0.55). Major bleeding, BARC types 3-5, occurred in 1.2% of the shortened DAPT group and in 2.4% of the prolonged DAPT group (HR, 0.56; 95% CI 0.31-0.99).
The landmark analyses between 3 months and 3 years and per-protocol analyses showed consistent results.
The researchers point out that this is the first trial to report on the long-term safety and efficacy of P2Y12-inhibitor monotherapy as long-term maintenance therapy for stable patients treated with PCI.
“Especially considering that extended DAPT significantly reduced the risks of ischemic events compared with aspirin monotherapy in a couple of trials, comparison between P2Y12-inhibitor monotherapy and prolonged DAPT for recurrent ischemic events over a longer period beyond 1 year is of great importance,” they say.
They cite two other trials – HOST-EXAM and GLOBAL LEADERS – which have shown P2Y12-inhibitor monotherapy to be superior to aspirin monotherapy in preventing both ischemic and bleeding events during the long-term maintenance period after PCI.
“Combining the results of the current study, HOST-EXAM trial, and landmark analysis of the GLOBAL LEADERS trial, long-term P2Y12-inhibitor monotherapy after a minimum period of DAPT might be the most reliable option from among aspirin monotherapy, P2Y12 monotherapy, and extended DAPT for maintenance therapy after stabilizing patients who have undergone PCI with a current-generation DES,” they conclude.
They note that the American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions guidelines for coronary artery revascularization newly recommends a shorter course of DAPT followed by P2Y12 monotherapy as a class IIa indication. The recommendation is based on results of five large, randomized clinical trials, including SMART-CHOICE, TWILIGHT, STOPDAPT-2, TICO, and GLOBAL LEADERS.
“The current results of extended follow-up from the SMART-CHOICE trial support evidence of aspirin-dropping strategy with indefinite use of P2Y12 inhibitor after minimum use of DAPT in patients who underwent PCI,” they say.
They point out that two further trials, A-CLOSE in high-risk patients and SMART-CHOICE III, will be helpful to confirm these findings.