R environment version 3

The median follow-up time was 8.4 years (25th-75th percentiles: 5.9-12.2 years). Information about the occurrence of adverse events at follow-up was retrieved from the hospital medical records, the Dutch Personal Records Database, or telephone contact with the patient or their general practitioners. We collected information regarding 4 different adverse events: death caused by cardiovascular disease; heart transplantation or left ventricular assist device (LVAD) implantation; heart failure that required a nonelective hospitalization, despite optimal heart failure therapy, according to the ESC, American College of Cardiology (ACC), and American Heart Association (AHA) guidelines; and life-threatening arrhythmias (LTAs), defined as nonfatal ventricular fibrillation (with or without ICD-shock) or sustained ventricular tachycardia with appropriate ICD shock. The combined endpoint was defined as the occurrence of at least 1 of these adverse events. Patients who died of noncardiac causes were censored at the moment of death (n = 2); those patients did not reach the combined endpoint.
Kaplan-Meier survival curves were estimated and differences among groups were assessed by the log-rank test, using time of diagnosis as time zero. Calculations were done using R environment version 3.5 (R Foundation).