Shorter outshines longer DAPT for ACS patients following DES implantation

In patients treated with drug-eluting stents (DES) for acute coronary syndrome (ACS), stopping aspirin within a month of dual antiplatelet therapy (DAPT) and continuing with ticagrelor alone outdid a 12-month DAPT regimen with ticagrelor and aspirin, findings from the T-PASS trial have shown.

“In [ACS patients] treated with ultrathin biodegradable polymer sirolimus-eluting stents, less than 1 month of DAPT followed by ticagrelor monotherapy met a noninferiority threshold and provided evidence of superiority to 12 months of ticagrelor-based DAPT for the 1-year composite outcome,” said Professor Myeong-Ki Hong from the Yonsei University College of Medicine, Severance Hospital, Seoul, Republic of Korea, at TCT 2023.

There was a lower incidence of the primary composite outcome of net adverse clinical events (NACE) including all-cause death, MI, definite or probable stent thrombosis, stroke, and major bleeding at 1 year after the index procedure among patients on ticagrelor monotherapy after <1 month DAPT vs those on the ticagrelor-based 12-month DAPT (2.8 percent vs 5.2 percent; HR, 0.54, 95 percent confidence interval [CI], 0.37–0.80; p<0.001 for noninferiority; p=0.002 for superiority).

The rate of major bleeding (Bleeding Academic Research Consortium [BARC] type 3 or 5) was also markedly lower in the shorter vs longer DAPT arm (1.2 percent vs 3.4 percent; HR, 0.35, 95 percent CI, 0.20–0.61; p log-rank<0.001). A similar trend was seen in terms of any bleeding (BARC type ≥2; 2.0 percent vs 4.5 percent; HR, 0.43, 95 percent CI, 0.28–0.68; p log-rank<0.001).

Results of the subgroup analyses for the primary outcome generally favoured the shorter DAPT regimen over the longer one, with HRs ranging between 0.42 and 0.87.

A game-changer

“Stopping aspirin less than a month after DES implantation for ticagrelor monotherapy has not been sufficiently evaluated for ACS patients,” Hong pointed out. As such, Hong and colleagues sought to evaluate whether ticagrelor monotherapy after less than 1 month of DAPT is noninferior to a 12-month ticagrelor-based DAPT regimen for NACE in this group of patients.

They enrolled 2,850 ACS patients who underwent percutaneous coronary intervention (PCI; mean age 61 years, 84 percent male, 40 percent with ST-elevation MI). Participants were randomized 1:1 to receive either ticagrelor alone at a dose of 90 mg BID after <1 month of DAPT or 12 months of ticagrelor-based DAPT. In the ticagrelor alone arm, aspirin was stopped at a median of 16 days.

Of note, as the study was powered to evaluate the incidence of NACE, comparisons of the incidence of each component, particularly major adverse cardiovascular events, could have been underpowered, Hong said.

Nonetheless, T-PASS provides evidence that dropping aspirin within a month after DES placement and continuing with ticagrelor alone is a reasonable alternative to the conventional 12-month DAPT regimen in terms of adverse cardiovascular and bleeding events, Hong concluded.

In a press conference, Dr John Messenger from the University of Colorado School of Medicine, Aurora, Colorado, US, commented that the findings provide encouragement to modify guidelines and to “really push the envelope on shortening DAPT [owing to] the safety of the third- and fourth-generation DES.”

The findings also correlate with previous studies favouring a shorter DAPT regimen. In two studies, ticagrelor monotherapy after 3 months of DAPT cut the risk of bleeding without increasing ischaemic events following PCI in ACS or high-risk PCI patients. [JAMA 2020;323:2407-2416; N Engl J Med 2019;381:2032-2042]

“I really think this is a game-changer in terms of changing the impact on patients,” Messenger said.