Influence of Obstructive Sleep Apnea on Diastolic Heart Failure

Heart failure is frequently complicated by obstructive sleep apnea, which raises blood pressure and arrhythmiaand worsens prognosis. However, the incidence and influence of obstructive sleep apnea in patientswith diastolic heart failure is unknown. We hypothesized that patients with diastolic heart failurecomplicated by obstructive sleep apnea may have a worse outcome compared to those without obstructivesleep apnea. The study included 49 patients with an ejection fraction ≥ 50 %, of whom 34 had diastolic heartfailure and 15 did not have diastolic heart failure. The patients were examined in a sleep study and byechocardiography. Brain natriuretic peptide (BNP) levels were determined at admission and 1, 6 and 12months thereafter. The prevalence of obstructive sleep apnea in patients with diastolic heart failure( 18/34,53 %) was significantly higher than that in those without diastolic heart failure (3/15, 20 %)(p=0.032).BNP levels were high at admission in patients with diastolic heart failure, but then decreased gradually inthose without obstructive sleep apnea. However, BNP in patients with diastolic heart failure and obstructivesleep apnea remained high and was significantly elevated compared to the level in patients without obstructivesleep apnea at 6 and 12 months after admission. Patients with diastolic heart failure and obstructivesleep apnea showed prolongation of elevated BNP, indicating that complication of diastolic heart failure byobstructive sleep apnea may aggravate cardiac function