Acute and chronic effects of continuous positive airway pressure therapy on left ventricular systolic and diastolic function in patients with obstructive sleep apnea and congestive heart failure

• Published in: Canadian journal of cardiology Vol. 24; no. 9; pp. 697 - 704
• Main Authors: Johnson, Chris B., MD, Beanlands, Rob S., MD, Yoshinaga, Keiichiro, MD, Haddad, Haissam, MD, Leech, Judith, MD, de Kemp, Rob, PhD, Burwash, Ian G., MD
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01-09-2008; Pulsus Group Inc
• Subjects: Cardiovascular; Clinical Studies; Congestive heart failure; Continuous Positive Airway Pressure; Continuous positive airway pressure therapy; Diastole - physiology; Echocardiography; Echocardiography, Doppler; Female; Heart Failure - physiopathology; Humans; Left ventricular function; Male; Middle Aged; Obstructive sleep apnea; Prospective Studies; Sleep Apnea, Obstructive - physiopathology; Sleep Apnea, Obstructive - therapy; Stroke Volume - physiology; Systole - physiology; Ventricular Dysfunction, Left - diagnostic imaging; Ventricular Dysfunction, Left - physiopathology; Continuous positive airway pressure therapy; Echocardiography; Congestive heart failure; Obstructive sleep apnea; Left ventricular function
• ISSN: 0828-282X; 1916-7075
• DOI: 10.1016/S0828-282X(08)70668-8

Background Obstructive sleep apnea (OSA) may contribute to the pathogenesis of congestive heart failure (CHF). Nocturnal continuous positive airway pressure (CPAP) therapy can alleviate OSA and may have a role in the treatment of CHF patients. Objectives To investigate the acute and chronic effects of CPAP therapy on left ventricular systolic function, diastolic function and filling pressures in CHF patients with OSA. Methods Twelve patients with stable CHF (New York Heart Association II or III, radionuclide ejection fraction lower than 40%) underwent overnight polysomnography to detect OSA. In patients with OSA (n=7), echocardiography was performed at baseline (awake, before and during acute CPAP administration) and after 6.9±3.3 weeks of nocturnal CPAP therapy. Patients without OSA (n=5) did not receive CPAP therapy, but underwent a baseline and follow-up echocardiogram. Results In CHF patients with OSA, acute CPAP administration resulted in a decrease in stroke volume (44 ± 15 mL versus 50 ± 14 mL, P = 0.002) and left ventricular ejection fraction ([LVEF] 34.8 ± 5.0% versus 38.4±3.3%, P=0.006) compared with baseline, but no change in diastolic function or filling pressures (peak early diastolic mitral annular velocity [Ea]: 6.0 ± 1.6 cm/s versus 6.3 ± 1.6 cm/s, P not significant; peak early filling velocity to peak late filling velocity [E/A] ratio: 1.05 ± 0.74 versus 1.00 ± 0.67, P not significant; E/Ea ratio: 10.9 ± 4.1 versus 11.3 ± 4.1, P not significant). In contrast, chronic CPAP therapy resulted in a trend to an increase in stroke volume (59 ± 19 mL versus 50 ± 14 mL, P=0.07) and a significant increase in LVEF (43.4 ± 4.8% versus 38.4 ± 3.3%, P=0.01) compared with baseline, but no change in diastolic function or filling pressures (Ea: 6.2 ± 1.2 cm/s versus 6.3 ± 1.6 cm/s, P not significant; E/A ratio: 1.13 ± 0.61 versus 1.00 ± 0.67, P not significant; E/Ea ratio: 12.1 ± 2.7 versus 11.3 ± 4.1, P not significant). There was no change in left ventricular systolic function, diastolic function or filling pressures at follow-up in CHF patients without OSA. Conclusions Acute CPAP administration decreased stroke volume and LVEF in stable CHF patients with OSA. In contrast, chronic CPAP therapy for seven weeks improved left ventricular systolic function, but did not affect diastolic function or filling pressures. The potential clinical implications of the discrepant effects of CPAP therapy on left ventricular systolic and diastolic function in CHF patients with OSA warrant further study.