Composite endpoints after percutaneous coronary intervention (PCI) often assign similar weight to nonfatal events such as heart failure hospitalization (HFH), acute coronary syndrome (ACS), and major bleeding. A multicenter prospective registry analysis from Japan, published in JACC Cardiovascular Interventions, evaluated whether these events differ in their associations with subsequent mortality.

The analysis included 10,482 patients (mean age 69 years; 77.5% men) enrolled between 2008 and 2021, with follow-up extending to 2 years. Time-varying exposures included HFH, ACS, and major bleeding, and the primary outcome was all-cause mortality. Cumulative incidence was estimated with death treated as a competing risk, and Cox proportional hazards models were adjusted for conventional risk factors.

During a median follow-up of 730 days, 1,021 patients (9.7%; 95% confidence interval [CI]: 9.2%-10.3%) experienced adverse events. The 2-year cumulative incidence was 4.7% (95% CI: 4.2%-5.1%) for HFH, 3.4% (95% CI: 3.0%-3.7%) for ACS, and 2.5% (95% CI: 2.2%-2.8%) for major bleeding. HFH showed the strongest association with mortality (adjusted hazard ratio [aHR]: 6.11; 95% CI: 4.76-7.85), followed by ACS (aHR: 3.22; 95% CI: 2.14–4.84) and major bleeding (aHR: 2.62; 95% CI: 1.71-4.02). Population attributable fraction analysis indicated that HFH accounted for 20.1% (95% CI: 19.0%-21.0%) of mortality burden, compared with 4.3% (95% CI: 3.3%-4.9%) for ACS and 2.9% (95% CI: 1.9%-3.5%) for major bleeding.

HFH showed the strongest association with mortality among post-PCI adverse events. These findings indicate differences in the strength of association with mortality across events. Equal weighting of adverse events may not reflect their differing associations with mortality.