DREAM-ICD-II Study

Background: Regulatory authorities of most industrialized countries recommend 6 months of private driving restriction after implantation of a secondary prevention implantable cardioverter-defibrillator (ICD). These driving restrictions result in significant inconvenience and social implications. This study aimed to assess the incidence rate of appropriate device therapies in contemporary recipients of a secondary prevention ICD. Methods: This retrospective study at 3 Canadian tertiary care centers enrolled consecutive patients with new secondary prevention ICD implants between 2016 and 2020. Results: For a median of 760 days (324, 1190 days), 721 patients were followed up. The risk of recurrent ventricular arrhythmia was highest during the first 3 months after device insertion (34.4%) and decreased over time (10.6% between 3 and 6 months, 11.7% between 6 and 12 months). The corresponding incidence rate per 100 patient-days was 0.48 (95% CI, 0.35-0.64) at 90 days, 0.28 (95% CI, 0.17-0.45) at 180 days, and 0.21 (95% CI, 0.13-0.33) between 181 and 365 days after ICD insertion (P<0.001). The cumulative incidence of arrhythmic syncope resulting in sudden cardiac incapacitation was 1.8% within the first 90 days and subsequently dropped to 0.4% between 91 and 180 days (P<0.001) after ICD insertion. Conclusions: The incidence rate of appropriate therapies resulting in sudden cardiac incapacitation in contemporary recipients of a secondary prevention ICD is much lower than previously reported and declines significantly after the first 3 months. Lowering driving restrictions to 3 months after the index cardiac event seems safe, and revision of existing guidelines should be considered in countries still adhering to a 6-month period. Existing restrictions for private driving after implantation of a secondary prevention ICD should be reconsidered.

Automated summary

This study assessed the incidence rate of appropriate device therapies in patients with secondary prevention ICD implants. The results showed that the risk of recurrent ventricular arrhythmia was highest in the first 3 months after device insertion and decreased over time. The cumulative incidence of arrhythmic syncope resulting in sudden cardiac incapacitation was highest within the first 90 days and subsequently dropped. Therefore, lowering the driving restrictions period to 3 months seems to be safe.