Optimal duration of DAPT after stenting in high and low bleeding risk populations

ACC.25 – In the Korean HOST-BR study, 3-month DAPT was superior to 1-month DAPT regarding NACE or MACCE in patients with high bleeding risk, without increasing the risk of bleeding. In low bleeding risk patients, 3-month DAPT was non-inferior to 12-month DAPT for NACE or MACCE and reduced the risk of bleeding.

This summary is based on the presentation of Hyo-Soo Kim, MD, PhD (Seoul, South Korea) at the ACC.25 Scientific Session - Stratified Randomization Study To Compare Different Duration Of Dual Antiplatelet Therapy After Coronary Stenting In Either High Or Low Bleeding Risk Population.

Introduction and methods

The optimal duration of dual antiplatelet therapy (DAPT) after coronary stent implantation according to bleeding risk remains unclear. General recommendation is 1 to 3 months DAPT for patients with high bleeding risk (HBR) and 3 to 12 months DAPT for patients with low bleeding risk (LBR). The HOST-BR trial evaluated the optimal duration of DAPT in patients with HBR or LBR.

The HOST-BR (Harmonizing Optimal Strategy for Treatment of coronary artery diseases – Bleeding Risk) trial was an investigator-initiated, randomized, open-label, multicenter trial conducted in 53 centers in South Korea, in which 4897 patients receiving PCI with drug-eluting stents were stratified according to bleeding risk based on the ARC HBR criteria. Patients in the LBR arm (n=3299) were 1:1 randomized to 3-month or 12-month DAPT, whereas patients in the HBR arm (n=1598) were 1:1 randomized to 1-month or 3-month DAPT.

The co-primary endpoints were assessed in a hierarchical order. The first co-primary endpoint was net adverse clinical events (NACE), defined as a composite of all-cause mortality, MI, stent thrombosis, stroke or major bleeding. The 2nd co-primary endpoint was major adverse cardiac and cerebral events (MACCE), a composite of CVD, MI, stent thrombosis or ischemic stroke. The 3rd co-primary endpoint was BARC bleeding (type 2,3,5) at 12 months.

Main results

High bleeding risk (HBR) arm

• At 12 months, NACE occurred in 18.4% of patients treated with 1-month DAPT and 14.0% of patients treated with 3-month DAPT (HR: 1.34; 95%CI: 1.04–1.71; P=0.022; P for non-inferiority=0.818).
• Compared with 3-month DAPT, 1-month DAPT increased the risk of MACCE at 12 months (9.8% vs. 5.8%; HR: 1.72; 95%CI: 1.19–2.50; P=0.004; P for non-inferiority=0.964).
• There was no difference in BARC bleeding (type 2,3,5) at 12 months between 1-month DAPT and 3-month DAPT (HR: 0.85; 95%CI: 0.66–1.11; P=0.232).

Low bleeding risk (LBR) arm

• Compared with 12-month DAPT, 3-month DAPT reduced the incidence of NACE (14.0% vs. 18.4%; HR: 0.66; 95%CI: 0.46–0.95; P=0.025; P for non-inferiority<0.001).
• There was no difference in MACCE between the two groups (HR: 0.96; 95%CI: 0.62-1.56; P=0.95; P for non-inferiority=0.008).
• 3-month DAPT reduced the risk of bleeding compared with 12-month DAPT (7.4% vs. 11.7%; HR: 0.63; 95%CI: 0.50–0.79; P<0.001).

Conclusion

In patients with HBR, 3-month DAPT was superior to 1-month DAPT with regard to NACE and MACCE, and this was associated with similar bleeding risk. In patients with LBR, 3-month DAPT was non-inferior to 12-month DAPT for NACE or MACCE and reduced the risk of any actionable bleeding. “Overall, 3-month would be the optimal duration of DAPT after PCI in general to meet the balance of thrombosis/bleeding,” said Hyo-Soo Kim.

- Our reporting is based on the information provided at the ACC.25 Scientific Session -