Impact of clinical presentation on bleeding risk a ter percutaneous coronary intervention and implications for the ARC-HBR definition

Background: The identification of bleeding risk factors in patients undergoing percutaneous coronary intervention (PCI) is essential to inform subsequent management. Whether clinical presentation per se affects bleeding risk after PCI remains unclear. Aims: We aimed to assess whether clinical presentation per se predisposes to bleeding in patients undergoing PCI and if the Academic Research Consortium (ARC) High Bleeding Risk (I-IBR) criteria perform consistently in acute (ACS) and chronic (CCS) coronary syndrome patients. Methods: Consecutive patients undergoing PCI from the Bern PCI Registry were stratified by clinical presentation. Bleeding events at one year were compared in ACS versus CCS patients, and the originally defined ARC-HBR criteria were assessed. Results: Among 16,821 patients, 9,503 (56.5%) presented with ACS. At one year, BARC 3 or 5 bleeding occurred in 4.97% and 3.60% of patients with ACS and CCS, respectively. After adjustment, ACS remained associated with higher BARC 3 or 5 bleeding risk (adjusted HR 1.21, 95% CI: 1.01-1.43; p=0.034), owing to non-access site-related occurrences, which accrued mainly within the first 30 days after PCI. The ARC-HBR score had lower discrimination among ACS compared with CCS patients, and its performance slightly improved when ACS was computed as a minor criterion. Conclusions: ACS presentation per se predicts one-year major bleeding risk after PCI. The ARC-HBR score discrimination appeared lower in ACS than CCS, and its overall performance improved numerically when ACS was computed as an additional minor risk criterion.