Predictors of death and occurrence of appropriate implantable defibrillator therapies in patients with ischemic cardiomyopathy

Abstract

Most patients with chronic ischemia and an implantable cardiac defibrillator (ICD) for primary prevention do not experience therapies for ventricular arrhythmias on follow-up. The present study aimed to identify independent clinical, electrocardiographic, and echocardiographic predictors of death and occurrence of ICD therapy in patients with chronic ischemic cardiomyopathy and ICD for primary prevention. A total of 424 patients with chronic ischemic cardiomyopathy, ejection fraction ≤ 35%, and New York Heart Association (NYHA) class ≥ II were recruited. All patients underwent echocardiography before ICD insertion. Primary outcome was all-cause mortality; secondary outcome was occurrence of appropriate ICD therapy on follow-up. Primary and secondary outcomes occurred in 84 and 95 patients, respectively. Patients who died were more likely to have diabetes (hazard ratio [HR] 1.67, 95% confidence interval [CI] 1.00 to 2.79, p = 0.049), higher NYHA class (HR 1.96, 95% CI 1.15 to 3.33, p = 0.013), lower peri-infarct strain on echocardiogram (HR 1.25, 95% CI 1.07 to 1.46, p = 0.005), and lower glomerular filtration rate (HR 1.01, 95% CI 1.00 to 1.03, p = 0.022). Only peri-infarct strain (HR 1.22, 95% CI 1.09 to 1.36, p < 0.001) predicted the occurrence of ICD therapy on follow-up. In conclusion, in chronic ischemic patients with an ICD for primary prevention, the presence of diabetes, renal dysfunction, higher NYHA class, and impaired peri-infarct zone function were predictors of all-cause mortality. In contrast, only impaired peri-infarct zone function determined the occurrence of appropriate ICD therapy on follow-up.