Background: Time-to-first-event analysis considers only the first event irrespective of its severity. There are several methods to assess trial outcomes beyond time-to-first-event analysis, such as analyzing total events and ranking outcomes. In the GLOBAL LEADERS study, time-to-first-event analysis did not show superiority of ticagrelor monotherapy following one-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention to conventional 12-month DAPT followed by aspirin monotherapy in the reduction of the primary composite end point of all-cause mortality or new Q-wave myocardial infarction. This study sought to explore various analytical approaches in assessing total ischemic and bleeding events after percutaneous coronary intervention in the GLOBAL LEADERS study.
Methods and results: Total ischemic and bleeding events were defined as all-cause mortality, any stroke, any myocardial infarction, any revascularization, or Bleeding Academic Research Consortium grade 2 or 3 bleeding. We used various analytical approaches to analyze the benefit of ticagrelor monotherapy over conventional DAPT. For ischemic and bleeding events at 2 years after percutaneous coronary intervention, ticagrelor monotherapy demonstrated a 6% risk reduction, compared with conventional 12-month DAPT in time-to-first-event analysis (hazard ratio, 0.94 [95% CI, 0.88-1.01]; log-rank P=0.10). In win ratio analysis, win ratio was 1.05 (95% CI, 0.97-1.13; P=0.20). Negative binomial regression and Andersen-Gill analyses which include repeated events showed statistically significant advantage for ticagrelor monotherapy (rate ratio, 0.92 [95% CI, 0.85-0.99; P=0.020] and hazard ratio, 0.92 [95% CI, 0.85-0.99; P=0.028], respectively), although in weighted composite end point analysis, the hazard ratio was 0.93 (95% CI, 0.84-1.04; log-rank P=0.22).
Conclusions: Statistical analyses considering repeated events or event severity showed that ticagrelor monotherapy consistently reduced ischemic and bleeding events by 5% to 8%, compared with conventional 1-year DAPT. Applying multiple statistical methods could emphasize the multiple facets of a trial and result in accurate and more appropriate analyses. Considering the recurrence of ischemic and bleeding events, ticagrelor monotherapy appeared to be beneficial after percutaneous coronary intervention. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01813435.
Keywords: aspirin; mortality; myocardial infarction; percutaneous coronary intervention; ticagrelor.