Long-Term Outcomes Among a Nationwide Cohort of Patients Using an Implantable Cardioverter-Defibrillator: UMBRELLA Study Final Results.

Abstract

BackgroundLarge‐scale studies describing modern populations using an implantable cardioverter‐defibrillator (ICD) are lacking. We aimed to analyze the incidence of arrhythmia, device interventions, and mortality in a broad spectrum of real‐world ICD patients with different heart disorders.Methods and ResultsThe UMBRELLA study is a prospective, multicenter, nationwide study of contemporary patients using an ICD followed up by remote monitoring, with a blinded review of arrhythmic episodes. From November 2005 to November 2017, 4296 patients were followed up. After 46.6±27.3 months, 16 067 episodes of sustained ventricular arrhythmia occurred in 1344 patients (31.3%). Appropriate ICD therapy occurred in 27.3% of study population. Patients with ischemic cardiomyopathy (hazard ratio [HR], 1.51; 95% CI, 1.29–1.78), dilated cardiomyopathy (HR, 1.28; 95% CI, 1.07–1.53), and valvular heart disease (HR, 1.94; 95% CI, 1.43–2.62) exhibited a higher risk of appropriate ICD therapies, whereas patients with hypertrophic cardiomyopathy (HR, 0.72; 95% CI, 0.54–0.96) and Brugada syndrome (HR, 0.25; 95% CI, 0.14–0.45) showed a lower risk. All‐cause death was 13.4% at follow‐up. Ischemic cardiomyopathy (HR, 3.09; 95% CI, 2.58–5.90), dilated cardiomyopathy (HR, 3.33; 95% CI, 2.18–5.10), and valvular heart disease (HR, 3.97; 95% CI, 2.25–6.99) had the worst prognoses. Delayed high‐rate detection was enabled in 39.7% of patients, and single‐zone programming occurred in 52.6% of primary prevention patients. Both parameters correlated with lower risk of first appropriate ICD therapy, with no excess risk of mortality. The rate of inappropriate shocks at follow‐up was low (6%) and did not differ among type of ICD but was lower in SmartShock‐capable devices.ConclusionsIrrespective of the cause, contemporary ICD patients with heart failure–related disorders had a similar risk of ICD life‐saving interventions and death. Current ICD programming recommendations still need to be implemented.RegistrationURL: https://www.clinicaltrials.gov; Unique identifier: NTC01561144.