Impact of PARIS and CREDO-Kyoto Thrombotic and Bleeding Risk Scores on Clinical Outcomes in Patients With Acute Myocardial Infarction

Background: The PARIS and CREDO-Kyoto risk scores were developed to identify patients at risks of thrombotic and bleeding events individually after percutaneous coronary intervention (PCI). However, these scores have not been well validated in different cohorts.

Methods and results: This 2-center registry enrolled 905 patients with acute myocardial infarction (MI) undergoing primary PCI. Patients were divided into 3 groups according to the PARIS and CREDO-Kyoto thrombotic and bleeding risk scores. The study endpoints included ischemic (cardiovascular death, recurrent MI, and ischemic stroke) and major bleeding events. Of 905 patients, 230 (25%) and 219 (24%) had high thrombotic and bleeding risks, respectively, with the PARIS scores, compared with 78 (9%) and 50 (6%) patients, respectively, with the CREDO-Kyoto scores. According to the 2 scores, >50% of patients with high bleeding risk had concomitant high thrombotic risk. During the mean follow-up period of 714 days, 163 (18.0%) and 95 (10.5%) patients experienced ischemic and bleeding events, respectively. Both PARIS and CREDO-Kyoto scores were significantly associated with ischemic and bleeding events after primary PCI. For ischemic events, the CREDO-Kyoto rather than PARIS thrombotic risk score had better diagnostic ability.

Conclusions: In the present Japanese cohort of acute MI patients undergoing contemporary primary PCI, the PARIS and CREDO-Kyoto thrombotic and bleeding risk scores were discriminative for predicting ischemic and bleeding events.