Abstract 4350: Beneficial Effects of Continuous Positive Airway Pressure on Left Ventricular Diastolic Function in Patients with Acutely Decompensated Congestive Heart Failure and Obstructive Sleep Apnea
Prior studies showed left ventricular (LV) diastolic dysfunction is an independent predictor of outcome in patients with congestive heart failure (CHF). Recent studies demonstrated that continuous positive airway pressure (CPAP) improved LV systolic function in patients with CHF and obstructive sleep apnea (OSA) after several weeks of treatment. We hypothesized that CPAP could have beneficial effects on LV diastolic function in patients with acutely decompensated CHF and OSA after short term administration. Thirty-three patients with CHF (LV ejection fraction of <45%) and OSA (apnea hypopnea index > 15 events/hour) were prospectively studied. 18 patients were randomized to receive standard therapy plus CPAP (CPAP group), and 15 patients received standard therapy only (control group). Echocardiography was performed prior and in 4 days after the treatment. LV diastolic function was assessed using both conventional and tissue Doppler imaging. LV peak early filling velocity (E), atrial filling velocity (A), E to A ratio (E/A), the deceleration time (DT), peak mitral annulus diastolic velocity (E′), left atrial area and right ventricular diastolic diameter were measured. Sixty-eight percent of patients had severe LV diastolic dysfunction (LV restrictive filling pattern). LV diastolic function improved in the CPAP group with a significant decrease in E/A ratio (3.2±1.3 vs. 2.2±1.3, P<0.01) and an increase in DT (146±52 ms vs. 172±51 ms, P<0.05). E/E’ ratio tended to decrease in the CPAP group (21.9±9.4 vs. 18.6±6.7, P=0.079). Patients with a LV restrictive filling pattern decreased from 85% to 46% after CPAP treatment (p<0.05). The left atrial area (29±5 cm 2 vs. 26±6 cm2, P<0.05) and right ventricular end-diastolic diameter (4.4±1.0 cm vs. 4.2±0.9 cm, P<0.01) decreased after CPAP treatment. There were no significant changes in LV diastolic function parameters in the control group. Severe LV diastolic dysfunction is common in patients with CHF and OSA. CPAP therapy significantly improved LV diastolic function in patients with CHF and OSA. A larger study is warranted to assess the effects of CPAP on mortality in this high risk patient population and to further investigate the mechanisms.