Abbreviated DAPT beneficial after PCI in high-risk patients regardless of MI status
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In a subgroup analysis of MASTER-DAPT, regardless of whether patients had a history of MI, 1-month DAPT after PCI was noninferior to 3-month or longer DAPT for ischemic events and conferred a reduction in bleeding events.
“The optimal duration of antiplatelet therapy after coronary stenting in high bleeding risk with patients with acute coronary syndrome remains unclear. Specifically, these high ischemic and bleeding, so-called 'bi-risk' patients present with a clinical dilemma,” Pieter C. Smits, MD, PhD, director of the interventional cardiology department at Maasstad Hospital Rotterdam and board member of the Dutch Heart Registration, the Netherlands, said during a press conference at TCT 2021. “This study reports the results of a prespecified and stratified subgroup analysis of the MASTER-DAPT trial, in which we investigated patients with or without a prior acute MI within 12 months of baseline PCI.”
The initial MASTER-DAPT trial included 4,579 patients (mean age, 76 years; 69% men) at high bleeding risk who underwent PCI with an ultrathin stent (Ultimaster, Terumo). At 30 days post index PCI, participants were randomly assigned to either halt DAPT, which consisted of aspirin and a P2Y12 inhibitor, or continue DAPT for at least 2 more months. Single antiplatelet therapy of either aspirin or a P2Y12 inhibitor was continued up to 11 months, if indicated.
As Healio previously reported, in the main results, 1-month short-term DAPT after PCI lowered the incidence of bleeding events and was noninferior for ischemic events compared with 3-month longer-term DAPT.
For the present analysis, researchers evaluated the 1-year outcomes of MASTER-DAPT participants. The researchers compared the DAPT strategies in those who had acute MI within the prior 12 months or presented with acute MI, and in those who did not.
As was seen in the main MASTER-DAPT results, the rates of net adverse clinical events and MACCE did not differ between arms on short-term or long term DAPT.
At 1 year, net adverse clinical events, defined as all-cause death, MI, stroke and BARC 3 or 5 bleeding, did not differ by DAPT strategy in those who had prior MI (HR = 0.83; 95% CI, 0.61-1.12; P = .22) and in those who did not (HR = 1.03; 95% CI, 0.77-1.38; P = .85; P for interaction = .3), Smits said during the press conference.
MACCE, defined as all-cause death, MI or stroke, at 1 year also not differ by DAPT strategy in those who had prior MI (HR = 0.86; 95% CI, 0.62-1.19; P = .36) and in those who did not (HR = 1.13; 95% CI, 0.8-1.59; P = .48; P for interaction = .25), he said.
Moreover, the reductions in BARC 2, 3 or 5 bleeding events were consistent with the initial findings and were similar regardless of whether patients had experienced a MI in the prior 12 months or not (HR for prior MI = 0.65; 95% CI, 0.46-1.91; P = .01; HR for no MI = 0.71; 95% CI, 0.54-0.92; P = .01; P for interaction = .72).
“In this predefined and stratified MASTER-DAPT subgroup analysis in high-bleeding-risk patients presenting with acute or recent myocardial infarction, we found that at 1-year follow-up, NACE and MACCE rates did not differ between the abbreviated and non-abbreviated DAPT strategy,” Smits said during the presentation. “In fact, there was no signal towards an increased ischemic risk in your abbreviated DAPT population presenting with a recent or acute myocardial infarction. Second, an abbreviated antiplatelet therapy strategy significantly reduced clinically relevant bleeding risk in these bi-risk patients. Thirdly, the abbreviated antiplatelet therapy effect was consistent between patients with or without a recent or acute myocardial infarction.”
Perspective
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These results build a strong case that longer DAPT does not decrease ischemic risk but does increase bleeding risk, and that we need to reframe our thoughts about the length of DAPT in our patients after PCI.
The researchers looked at higher-ischemic-risk groupings, ie, patients with MI in the past 12 months, and showed that longer DAPT did not reduce ischemic complications or do anything favorable over shorter DAPT. It’s important that reducing bleeding risk does not mean we are increasing ischemic risk, particularly with later-generation, smaller, thinner stents.
These results will lead us down the pathway of shorter DAPT and less bleeding, not only in patients who are stable and at low risk, but also in patients with recent ACS at higher risk.
This trial population is similar to the PCI population in the U.S. and worldwide. Currently, 25% to 50% of the patients we treat with PCI have ACS or recent MI, which is the exact group in the MASTER-DAPT and STOPDAPT-2 trials.
The study has increased the enthusiasm for continuing to try to answer the question of DAPT duration. The answer may be that we have to tailor our therapy more for our individual patients, weighing the bleeding risk against the ischemic risk. MASTER-DAPT and STOPDAPT-2 give us confidence that it is not a 1-for-1 tradeoff — reducing bleeding risk does not necessarily mean increasing ischemic risk, as was the case 5 or 10 years ago. Perhaps we can reduce the amount of time patients are on DAPT, and reduce the bleeding risk from those agents, regardless of risk category.
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Smits PC, et al. Late-Breaking Clinical Trials Session II, in Collaboration with JAMA. Presented at: TCT Scientific Symposium; Nov. 4-6, 2021; Orlando, Florida (hybrid meeting).
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