Usefulness of Sleep-Disordered Breathing to Predict Occurrence of Appropriate and Inappropriate Implantable-Cardioverter Defibrillator Therapy in Patients With Implantable Cardioverter-Defibrillator for Primary Prevention of Sudden Cardiac Death

Advanced heart failure (HF) is associated with severe sleep-disordered breathing (SDB). In addition, most patients with HF are treated with an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death. The incidence of ICD therapy in such a patient cohort with SDB has never been investigated. The present study sought to determine the effect of SDB on the incidence of appropriate and inappropriate ICD therapy in patients with a categorical primary prevention ICD indication. A total of 133 consecutive ICD patients with New York Heart Association class II-III HF and depressed left ventricular function (≤35%) with no history of ventricular arrhythmia underwent a sleep study before ICD implantation and were followed for 24 ± 8 months, prospectively. A relevant SDB was defined as an apnea-hypopnea index of ≥10 events/hour. Of these 133 patients, 82 (62%) had SDB. Overweight (body mass index >29.1 vs 24.7 kg/m2; p <0.001) was identified as the only independent risk factor for SDB. Appropriate ICD therapy intervention was significantly greater among patients with SDB than among patients without SDB (54% vs 34%, p = 0.03). Inappropriate ICD therapy intervention was documented more often in patients with SDB (n = 24 [29%] vs 7 [14%]; p = 0.04). An apnea-hypopnea index >10 events/hour was an independent predictor of appropriate ICD therapy on multivariate analysis (odds ratio 2.5, 95% confidence interval 1.8 to 4.04; p = 0.01). In conclusion, the present study is the first trial exploring the effect of SDB on the incidence of appropriate and inappropriate ICD therapy in patients with HF with a primary prevention indication. These results indicate that a preimplantation sleep study will identify patients with HF prone to receive appropriate and inappropriate ICD therapy.