Fifteen-month results from the MASTER DAPT trial have shown that the preserved ischaemic benefits and reduced bleeding risk seen with one month of dual antiplatelet therapy (DAPT) among high-bleeding risk patients undergoing percutaneous coronary intervention (PCI) continue beyond one year.
Marco Valgimigli (Cardiocentro Ticino Foundation, Lugano, Switzerland) delivered the 15-month data during a hot line session at the annual congress of the European Society of Cardiology (ESC; 26–29 August, Barcelona, Spain), having presented the trial’s 12-month findings a year earlier at the virtual ESC 2021. There, Valgimigli reported that that in high-bleeding risk patients, after intervention using the Ultimaster (Terumo) stent, one month of DAPT was shown to be non-inferior when compared with more than two months of DAPT for the net and major adverse clinical events and was superior for reducing major and clinically relevant non-major bleeding.
At ESC 2022, Valgimigli reported that following the initial 12-month trial period, patients in both the abbreviated and standard DAPT treatment groups received routine clinical care at the discretion of their physician. The MASTER DAPT researchers recorded medications and adverse events during the following three months, and the results of the prespecified 15-month final analysis were shared for the first time by Valgimigli.
Of 2,295 and 2,284 patients randomised to abbreviated versus standard DAPT, 2,205 and 2,186 patients started routine care at 12 months, respectively. Complete follow-up at 15 months was available for 99.8% and 99.9% of patients in the abbreviated and standard arms, respectively.
For routine care, physicians tended to continue the treatment assigned in the trial, Valgimigli noted in his presentation. Though guidelines recommend that patients not on oral anticoagulation (OAC) should discontinue DAPT, more than 15% of non-OAC patients were still on DAPT at 15 months in the standard DAPT arm of the MASTER DAPT trial, which was three times higher than the corresponding figure in the abbreviated arm, figures shared by Valgimigli revealed—with the presenter describing this as a “carry over reflex” from the trial.
Furthermore, though guidelines recommend that OAC patients, if free from recurrent ischaemic events or repeat interventions, should discontinue single antiplatelet therapy (SAPT), more than one fourth were still on SAPT in the standard DAPT arm compared with 14% of the abbreviated treatment group, Valgimigli reported. In multivariate modelling, prior allocation to abbreviated treatment was a strong independent predictor of SAPT versus DAPT in non-OAC patients and no antiplatelet versus SAPT in OAC patients.
The researchers reported 15-month results according to original treatment assignment for the three co-primary outcomes of the main trial: net adverse clinical events (NACE; composite of all-cause death, myocardial infarction, stroke, and major or clinically relevant nonmajor bleeding); major adverse cardiac and cerebral events (MACCE; composite of all-cause death, myocardial infarction, and stroke); and major or clinically relevant nonmajor bleeding (Bleeding Academic Research Consortium type 2, 3 or 5 bleeding).
NACE occurred in 199 (8.7%) and 214 (9.5%) patients in the abbreviated and standard DAPT groups, respectively, for a hazard ratio (HR) of 0.92 (95% confidence interval [CI] 0.76–1.12; p=0.399) and a risk difference of −0.75 percentage points (95% CI −2.42 to 0.93). MACCE occurred in 158 (6.9%) and 167 (7.4%) patients in the abbreviated and standard DAPT arms, respectively (HR 0.94; 95% CI 0.76– 1.17; p=0.579), for a risk difference of −0.51 percentage points (95% CI −2.01 to 1.00). Major or clinically relevant nonmajor bleeding remained lower in the abbreviated compared with the standard therapy arm (167 [7.4%] versus 239 [10.7%]; HR 0.68; 95% CI 0.56–0.83; p=0.0001), for a risk difference of −3.25 percentage points (95% CI −4.93 to -1.58).