Central sleep apnea, right ventricular dysfunction, and low diastolic blood pressure are predictors of mortality in systolic heart failure

Objectives The purpose of this study was to determine whether central sleep apnea (CSA) contributes to mortality in patients with heart failure (HF). Background Cheyne-Stokes breathing with CSA commonly occurs in patients with systolic HF. Consequences of CSA, including altered blood gases and neurohormonal activation, could result in further left ventricular dysfunction. Therefore, we hypothesized that CSA might contribute to mortality of patients with HF. Methods We followed 88 patients with systolic HF (left ventricular ejection fraction <= 45%) with (n = 56) or without (n = 32) CSA. The median follow-up was 51 months. Results The mean (+/- SD) of apnea-hypopnea index was significantly higher in patients with CSA (34 +/- 25/h) than those without CSA (2 +/- 1/h). Most of these events were central apneas. In Cox multiple regression analysis, 3 of 24 confounding variables independently correlated with survival. The median survival of patients with CSA was 45 months compared with 90 months of those without CSA (hazard ratio = 2.14, p = 0.02). The other 2 variables that correlated with poor survival were severity of right ventricular systolic dysfunction and low diastolic blood pressure. Conclusions In patients with systolic HF, CSA, severe right ventricular systolic dysfunction, and low diastolic blood pressure might have an adverse effect on survival.