Abstract 3399: Effects of Exercise Training in Chronic Heart Failure Patients with Sleep Apnea
Background: Although exercise training (ET) has been recommended to the treatment of heart failure (HF), its impact in chronic HF patients with sleep apnea is unknown. We tested the hypothesis that ET would reduce muscle sympathetic nerve activity (MSNA) and improve forearm blood flow (FBF), sleep pattern, and quality of life (QoL) in HF patients with sleep apnea.
Methods: Thirty-six HF patients, ejection fraction <45% (42–70 yrs, Functional Class II–III) underwent standard polysomnography. MSNA was recorded by microneurography. FBF was measured by venous occlusion plethysmography. Exercise capacity was measured by cardiopulmonary exercise test, and QoL was assessed by questionnaire. All groups were evaluated at baseline, after 4 month-control period, and 4 month-period ET. Eleven HF patients were excluded during the control period (1 mixed sleep apnea, 2 unsatisfactory MSNA recording, 4 unstable HF, 2 dropped out, 2 death). Eight HF with obstructive sleep apnea (OSA), 9 with central sleep apnea (CSA) and 8 with no sleep apnea (NSA) finished the study. ET consisted of cycling, resistance strengthening exercise, and stretching 3 times/wk.
Results: Although baseline FBF was not different among the 3 HF groups (P>0.05), MSNA was significantly greater in OSA and CSA compared with NSA (60±3 and 51±2 vs. 38±2 bursts/min, P<0.001). There was no change in any of the variables during the control period. ET significantly reduced MSNA (P<0.001) and increased FBF (P<0.01), peak VO2 (P<0.01), and QoL (P<0.001) in all HF groups. Despite no decrease in body weight, ET significantly improved apnea-hypopnea index (33±4 vs. 21±6 no./hr of sleep, P<0.01), arousal index (P<0.01), stage S3–S4 (P< 0.01), and minimum O2 saturation during sleep (79± 1 vs. 84±1%, P<0.05) in OSA patients.
Conclusions: ET improves neurovascular function, functional capacity, and overall QoL in in HF patients with sleep apnea. Moreover, ET substantially improves sleep in OSA patients, possibly by increasing neck muscle tone, thereby avoiding episodes of airway collapse with consequent hypoxemia during sleep. These findings suggest that ET is a non pharmacological strategy that must be included in treatment of HF patients especially with coexistent sleep apnea.