One-month dual antiplatelet therapy (DAPT) in patients undergoing acute coronary syndrome (ACS) did not reach the safety and efficacy results observed in the general population of the original trial STOPDAPT-2.
The STOPDAPT-2 ACS compared one-month DAPT followed by clopidogrel monotherapy for one year vs. one-year DAPT after PCI.
Initially, the study enrolled mostly stable patients (38% acute), all receiving the everolimus eluting Xience.
Upon analysis, stable patients (STOPDAPT-2) showed both non-inferiority and superiority of one-month vs 12-month DAPT for the primary efficacy end point of cardiovascular death, MI, stroke, definite thrombosis, and bleeding. This was not the case for ACS patients.
For the same combined end point, in acute patients the accumulated events rate was 3.2% for those in the one-month DAPT group vs 2.83% for patients in the 12-month DAPT (HR 1.15; CI 95% 0.80 to 1.62): not significant.
However, looking at bleeding separately (both major and minor) these resulted significantly lower in the one-month DAPT group (0.54% vs 1.17%, HR 0.46; CI 95% 0.23 to 0.94). MI rates were also different, nearly twice as high for patients in the one-month group. (1.59% vs 0.85%, HR 1.91; CI 95% 1.06 to 3.44).
Outcomes from the STOPDAPT-2 ACS have raised some questions. Most physicians will most likely rule out clopidogrel in ACS patients at high ischemic risk.
We should also take into account bleeding risk. During the same ESC 2021 the MASTER DAPT was presented; it tested one-month DAPT followed by clopidogrel monotherapy in patients at high risk of bleeding (one third of the population were enrolled while undergoing ACS).
MASTER DAPT outcomes were positive in favor of one-month DAPT, and this advantage came hand in hand with reduced bleeding, which maintained safety in ischemic events.
Reference: Watanabe H. et al. Presentado en el ESC 2021.