SAN FRANCISCO – Stopping aspirin within 1 month of implanting a drug-eluting stent (DES) for acute coronary syndrome (ACS) followed by ticagrelor monotherapy was shown to be noninferior to 12 months of dual antiplatelet therapy (DAPT) in net adverse cardiovascular and bleeding events in the T-PASS trial.
of death, myocardial infarction, stent thrombosis, stroke, and major bleeding, primarily due to a significant reduction in bleeding events,” senior author Myeong-Ki Hong, MD, PhD, Yonsei University, Seoul, Korea, told attendees at the Transcatheter Cardiovascular Therapeutics annual meeting, sponsored by the Cardiovascular Research Foundation.
“This study provides evidence that stopping aspirin within 1 month after implantation of drug-eluting stents for ticagrelor monotherapy is a reasonable alternative to 12-month DAPT as for adverse cardiovascular and bleeding events,” Dr. Hong concluded.
The study was published in Circulation ahead of print to coincide with the presentation.
Three months to 1 month
Previous trials (TICO and TWILIGHT) have shown that ticagrelor monotherapy after 3 months of DAPT can be safe and effectively prevent ischemic events after percutaneous coronary intervention (PCI) in ACS or high-risk PCI patients.
The current study aimed to investigate whether ticagrelor monotherapy after less than 1 month of DAPT was noninferior to 12 months of ticagrelor-based DAPT for preventing adverse cardiovascular and bleeding events in patients with ACS undergoing PCI with a DES implant.
T-PASS, carried out at 24 centers in Korea, enrolled ACS patients aged 19 years or older who received an ultrathin, bioresorbable polymer sirolimus-eluting stent (Orsiro, Biotronik). They were randomized 1:1 to ticagrelor monotherapy after less than 1 month of DAPT (n = 1,426) or to ticagrelor-based DAPT for 12 months (n = 1,424).
The primary outcome measure was net adverse clinical events (NACE) at 12 months, consisting of major bleeding plus major adverse cardiovascular events. All patients were included in the intention-to-treat analysis.
The study could enroll patients aged 19-80 years. It excluded anyone with active bleeding, at increased risk for bleeding, with anemia (hemoglobin ≤ 8 g/dL), platelets less than 100,000/mcL, need for oral anticoagulation therapy, current or potential pregnancy, or a life expectancy less than 1 year.
Baseline characteristics of the two groups were well balanced. The extended monotherapy and DAPT arms had an average age of 61 ± 10 years, were 84% and 83% male and had diabetes mellitus in 30% and 29%, respectively, with 74% of each group admitted via the emergency room. ST-elevation myocardial infarction occurred in 40% and 41% of patients in each group, respectively.
Results showed that stopping aspirin early was noninferior and possibly superior to 12 months of DAPT.
For the 12-month clinical outcome, fewer patients in the less than 1 month DAPT followed by ticagrelor monotherapy arm reached the primary clinical endpoint of NACE versus the ticagrelor-based 12-month DAPT arm, both in terms of noninferiority (P < .001) and superiority (P = .002). Similar results were found for the 1-month landmark analyses.
For both the 12-month clinical outcome and the 1-month landmark analyses, the curves for the two arms began to diverge at about 150 days, with the one for ticagrelor monotherapy essentially flattening out just after that and the one for the 12-month DAPT therapy continuing to rise out to the 1-year point.
In the less than 1 month DAPT arm, aspirin was stopped at a median of 16 days. Panelist Adnan Kastrati, MD, Deutsches Herzzentrum München, Technische Universität, Munich, Germany, asked Dr. Hong about the criteria for the point at which aspirin was stopped in the less than 1 month arm.
Dr. Hong replied: “Actually, we recommend less than 1 month, so therefore in some patients, it was the operator’s decision,” depending on risk factors for stopping or continuing aspirin. He said that in some patients it may be reasonable to stop aspirin even in 7-10 days. Fewer than 10% of patients in the less than 1 month arm continued on aspirin past 30 days, but a few continued on it to the 1-year point.
There was no difference between the less than 1 month DAPT followed by ticagrelor monotherapy arm and the 12-month DAPT arm in terms of major adverse cardiac and cerebrovascular events at 1 year (1.8% vs. 2.2%, respectively; hazard ratio, 0.84; 95% confidence interval, 0.50-1.41; log-rank, P = .51).
However, the 12-month DAPT arm showed a significantly greater incidence of major bleeding at 1 year: 3.4% versus 1.2% for less than 1 month aspirin arm (HR, 0.35; 95% CI, 0.20-0.61; log-rank, P < .001).
Dr. Hong said that a limitation of the study was that it was open label and not placebo controlled. However, an independent clinical event adjudication committee assessed all clinical outcomes.
Lead discussant Marco Valgimigli, MD, PhD, Cardiocentro Ticino Foundation, Lugano, Switzerland, noted that T-PASS is the fifth study to investigate ticagrelor monotherapy versus a DAPT, giving randomized data on almost 22,000 patients.
“T-PASS showed very consistently with the prior four studies that by dropping aspirin and continuation with ticagrelor therapy, compared with the standard DAPT regimen, is associated with no penalty ... and in fact leading to a very significant and clinically very convincing risk reduction, and I would like to underline major bleeding risk reduction,” he said, pointing out that this study comes from the same research group that carried out the TICO trial.
Dr. Hong has received institutional research grants from Samjin Pharmaceutical and Chong Kun Dang Pharmaceutical, and speaker’s fees from Medtronic and Edwards Lifesciences. Dr. Kastrati has disclosed no relevant financial relationships. Dr. Valgimigli has received grant support/research contracts from Terumo Medical and AstraZeneca; consultant fees/honoraria/speaker’s bureau for Terumo Medical Corporation, Bayer, Daiichi Sankyo/Eli Lilly, Amgen, Alvimedica, AstraZenca, Idorsia, Coreflow, Vifor, Bristol-Myers Squibb, and iVascular. The study was funded by Biotronik.
A version of this article first appeared on Medscape.com.