The Combinations of the Patterns of Non-adherence to Anti-platelet Regimen in Stented Patients (PARIS) and Coronary Revascularization Demonstrating Outcome Study in Kyoto (CREDO-Kyoto) Thrombotic and Bleeding Risk Scores on Clinical Outcomes in Patients with Acute Myocardial Infarction.

Objective The Patterns of Non-adherence to Anti-platelet Regimen in Stented Patients (PARIS) and Coronary Revascularization Demonstrating Outcome Study in Kyoto (CREDO-Kyoto) thrombotic and bleeding risk scores were established to predict ischemic and bleeding events in patients undergoing percutaneous coronary intervention (PCI). However, whether or not the combination of these risk scores is predictive of clinical outcomes is unclear. Methods This bicenter registry included a total of 1,098 patients with acute myocardial infarction (MI) undergoing primary PCI. Patients were divided into three groups according to the PARIS and CREDO-Kyoto thrombotic and bleeding risk scores. The study endpoints included the rates of both ischemic (cardiovascular death, recurrent MI, and ischemic stroke) and major bleeding (Bleeding Academic Research Consortium type 3 or 5) events at two years. Results Two years after primary PCI, ischemic and major bleeding events occurred in 17.3% and 10.2% of patients, respectively. The higher-risk categories of PARIS and CREDO-Kyoto scores were associated with increased risks of ischemic and bleeding events. The rates of ischemic and major bleeding events progressively increased with the increase in risk categories in the two risk scoring systems. In the receiver operating characteristic curve analysis, the addition of CREDO-Kyoto thrombotic and bleeding risk scores to PARIS scores significantly improved diagnostic ability in predicting ischemic (area under the curve: 0.59 vs. 0.63, p=0.01) and bleeding (area under the curve: 0.65 vs. 0.68, p=0.01) events. Conclusion The combinations of the PARIS and CREDO-Kyoto risk scores might be useful for evaluating ischemic and bleeding risks in patients with acute MI undergoing primary PCI.