Central sleep apnea is a predictor of cardiac readmission in hospitalized patients with systolic heart failure

Background: Hospitalized heart failure patients have a high readmission rate. We sought to determine the independent risk due to central sleep apnea (CSA) of readmission in patients with systolic heart failure (SHF). Methods and Results: This was a prospective observational cohort study of hospitalized patients with SHF. Patients underwent sleep studies during their hospitalization and were followed for 6 months to determine their rate of cardiac readmissions; 784 consecutive patients were included; 165 patients had CSA and 139 had no sleep-disordered breathing (SDB); the remainder had obstructive sleep apnea (OSA). The rate ratio for 6 months' cardiac readmissions was 1.53 (95% confidence interval 1.1-2.2; P =.03) in CSA patients compared with no SDB. This rate ratio was adjusted for systolic function, type of cardiomyopathy, age, weight, sex, diabetes, coronary disease, length of stay, admission sodium, creatinine, hemoglobin, blood pressure, and discharge medications. Severe OSA was also an independent predictor of readmissions with an adjusted rate ratio of 1.49 (P =.04). Conclusion: In this first evaluation of the impact of SDB on cardiac readmissions in heart failure, CSA was an independent risk factor for 6 months' cardiac readmissions. The effect size of CSA exceeded that of all known predictors of heart failure readmissions.