Effects of continuous positive airway pressure on cardiovascular outcomes in heart failure patients with and without Cheyne-Stokes respiration

Background-Continuous positive airway pressure (CPAP) improves cardiac func tion in patients with congestive heart failure (CHF) who also have Cheyne-S tokes respiration and central sleep apnea (CSR-CSA). However, the effects o f CPAP in CHF patients without CSR-CSA have not been tested, and the long-t erm effects of this treatment on clinical cardiovascular outcomes are unkno wn. Methods and Results-We conducted a randomized, controlled trial in which 66 patients with CHF (29 with and 37 without CSR-CSA) were randomized to eith er a group that received CPAP nightly or to a control group. Change in left ventricular ejection fraction (LVEF) from baseline to 3 months and the com bined mortality-cardiac transplantation rate over the median 2.2-year follo w-up period were compared between the CPAP-treated and control groups. For the entire group of patients, CPAP had no significant effect on LVEF, but i t was associated with a 60% relative risk reduction (95% confidence interva l, 2% to 64%) in mortality-cardiac transplantation rate in patients who com plied with CPAP therapy. Stratified analysis of patients with and without C SR-CSA revealed that those with CSR-CSA experienced both a significant impr ovement in LVEF at 3 months and a relative risk reduction of 81% (95% confi dence interval, 26% to 95%) in the mortality-cardiac transplantation rate o f those who used CPAP. CPAP had no significant effect on either of these ou tcomes in patients without CSR-CSA. Conclusions-CPAP improves cardiac function in CHF patients with CSR-CSA but not in those without it. Although not definitive, our findings also sugges t that CPAP can reduce the combined mortality-cardiac transplantation rate in those CHF patients with CSR-CSA who comply with therapy.