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 results of extended follow-up from the SMART-CHOICE trial support evidence of an aspirin dropping strategy with indefinite use of P2Y12 inhibitor after minimum use of DAPT in patients who underwent PCI,” the investigators, with lead author Ki Hong Choi, MD, Division of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, conclude.
The 3-year results from the study were published online on September 28 in JAMA Cardiology.
The authors explain that although dual therapy with aspirin and a P2Y12 inhibitor after PCI with a drug-eluting stent 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 to 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 2993 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 (MI), 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% CI, 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 (HR, 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 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 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.
P2Y12 Inhibitor Monotherapy “Attractive Concept”
In an accompanying editor’s note, Ajay Kirtane, MD, Columbia University Irving Medical Center/New York–Presbyterian Hospital, New York, and Roxana Mehran, MD, Icahn School of Medicine at Mount Sinai and the Cardiovascular Research Foundation, New York, note that current guidelines recommend 3 to 6 months of DAPT following PCI with current-generation drug-eluting stents in stable patients and 6 to 12 months or longer for those with acute coronary syndromes. For patients at higher risk of bleeding, even shorter DAPT durations can be considered on a case-by-case basis.
Historically, the component of DAPT subject to discontinuation decisions was the P2Y12 inhibitor (clopidogrel, prasugrel, or ticagrelor), but more recent trials have further explored whether discontinuation of the aspirin component of DAPT can mitigate bleeding while preserving anti-ischemic efficacy.
The editorialists explain that the concept of P2Y12 inhibitor monotherapy is attractive because it may optimize antiplatelet effects through a single agent that can avoid the gastrointestinal toxicity of aspirin as well as the increased bleeding that comes with combing multiple antithrombotic agents.
They suggest that the long-term results from the SMART-CHOICE trial “should lead clinicians to consider a strategy of monotherapy after a short period of DAPT as a viable one to mitigate bleeding risk,” although they also point out that SMART-CHOICE was underpowered to rigorously assess ischemic differences, so caution is warranted.
“For patients at greatest risk for recurrent ischemic events, the role of continued DAPT is always an option, but these data (and other consistent trials) give clinicians more options to pursue individualized treatment decisions,” they write.
“To some, the continually moving field of post-PCI antiplatelet therapy has provided too many choices, which can at times be dizzying. To us, every patient is different, and thoughtful evidence-based consideration is increasingly possible for many of our treatment decisions,” they conclude.
The SMART-CHOICE study was supported by unrestricted grants from the Korean Society of Interventional Cardiology, Abbott Vascular, Biotronik, and Boston Scientific.
JAMA Cardiol. Published online September 28. Abstract, Editor’s note
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