Academic Research Consortium for High Bleeding Risk Definitions for Early, Late, and Very Late Bleeding Events.

Background: The validity of the Academic Research Consortium for High Bleeding Risk (ARC-HBR) definitions of early (<1 year), late (1-4 years), and very late (>4 years) bleeding events is unknown.

Methods and results: This study was performed on patients (n=3,453) implanted with second-generation drug-eluting stents (DES) between 2010 and 2013. Data on all criteria of the ARC-HBR definition were collected retrospectively. The primary endpoint was Bleeding Academic Research Consortium Type 3 or 5 bleeding events; the ischemic endpoint was a composite of cardiac death, myocardial infarction, and ischemic stroke. The mean follow-up period was 7.5 years. Compared with non-high bleeding risk (HBR) patients, HBR patients (n=1,840; 53.3%) had an increased risk of the primary endpoint (early events, 3.6% vs. 0.5% [P<0.0001]; late events, 5.3% vs. 2.5% [P<0.0001]; very late events, 5.5% vs. 2.1% [P<0.0001]) and of ischemic events during follow-up. The discrimination ability of the ARC-HBR definition for late and very late bleeding events was comparable to that of early bleeding events (C statistics 0.679, 0.621, and 0.620, respectively) with high negative predictive value (96.6%, 95.1%, and 93.1%, respectively). Multivariate analysis revealed the different effects of individual criteria on bleeding events in each follow-up period.

Conclusions: The ARC-HBR definition consistently identified patients at risk of long-term bleeding and ischemic events after second-generation DES implantation.