Derivation and Evaluation of the Ischemic Risk Model in High-Risk Chinese Patients Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndrome

Abstract

PurposeCoronary artery disease is the top cause of death among the Chinese population. With the establishment of a Chinese prediction model, it is urgent to assess factors related to the prognosis of patients with acute coronary syndrome at extremely high risk. MethodsIn this retrospective study, we enrolled 601 patients assessed as being of extremely high risk, according to specific criteria from the China-PAR (Prediction for Atherosclerotic Cardiovascular Disease Risk) project, and investigated various clinical parameters using Cox multivariate analysis to establish a risk nomogram. C-index and calibration curves were involved to assess the internal identification. By using the all-cause death risk model, we stratified patients by risk level and compared the effects of clopidogrel and ticagrelor on end points. FindingsWe identified several factors, including body mass index, angiopathy, smoking status, β-blocker usage, history of myocardial infarction, total number of stents, and usage of antiplatelet agents, related to ischemic end points, all-cause death, cardiovascular events, and cardiac death. A C-index of >0.7 and the calibration curve demonstrated good concordance. In a subsequent analysis, we used the all-cause death model to stratify patients by risk level, and compared the effects of clopidogrel and ticagrelor. In the subgroup with a 2-year death rate of >50%, ticagrelor showed a positive effect (P = 0.045), but in the subgroup with a 2-year death rate of <50%, the difference between clopidogrel and ticagrelor was not significant. Considering the duration of effect of antiplatelet agents, we also compared these 2 agents at 1-year follow up, with ticagrelor showing no advantage. ImplicationsWe determined the probability of ischemic risk in patients at extremely high ischemic risk and developed new risk models for this specific group. Ticagrelor, compared with clopidogrel, may improve the prognosis of patients at high risk for death after 2 years.