Recurrent Event Analysis of Coronary Artery Stenosis in Patients Undergoing Angioplasty

Background: Restenosis after coronary angioplasty can have serious complications such as coronary artery bypass graft, myocardial infarction, and death. Objectives: The present study aimed at investigating the factors affecting the recurrence of coronary artery stenosis in patients undergoing angioplasty using the recurrent event data analysis. Methods: A cohort study was performed on patients undergoing coronary angioplasty from March 23, 2009, to January 21, 2011. All patients were followed up from angioplasty to January 21, 2015. First, each of the independent variables was entered into the univariate Cox model with a frailty component. Then, variables with p-values of less than 0.2 were entered into the multivariate analysis. The statistical analysis was done using R software, version 3.6, at the significance level of 0.05. Results: The present study was conducted on 1,000 patients who underwent coronary angioplasty. We found that 441 patients experienced restenosis at least once in the study period. The mean survival time to the first event of restenosis was 44.08 +/- 1.06 months. Patients with a history of diabetes, unstable angina, and myocardial infarction had a significantly higher hazard of restenosis compared to other patients (P < 0.05). Conclusions: The results of the recurrent event survival analysis confirmed the significant role of risk factors such as a history of diabetes, unstable angina, and myocardial infarction. Therefore, training to enhance the patients' awareness and attitude seems necessary to prevent them from exposing whit known risk factors. The periodic follow-up of patients with risk factors and more ongoing care are also necessary.