Reversal Of Cardiac Dysfunction In Obstructive Sleep Apnea Treated With Continuous Positive Airway Pressure (CPAP)

Abstract

Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular morbidity and mortality. Although Background: previous echocardiographic studies have demonstrated short term improvement in cardiovascular remodeling in OSA patients treated with continuous positive airway pressure (CPAP), a long term study incorporating cardiac biomarkers, echocardiography and cardiac magnetic resonance imaging (CMR) has not been performed. We examined the long term outcome of CPAP on systolic and diastolic cardiac function in patients with OSA using serial cardiac biomarkers, echocardiography and CMR.: We conducted a prospective study of 50 patients diagnosed with OSA on a split-night polysomnography. Cardiac biomarkers Methods including C reactive protein (CRP), brain natriuretic peptide (pro BNP), and troponin T (TnT) were measured at baseline and serially over one year. All patients underwent baseline and serial transthoracic echocardiographic (TTE) studies, tissue Doppler imaging (TDI) and CMR imaging at baseline, 6 and 12 months to assess for cardiac morphology, myocardial edema and degree of fibrosis.: A total of 50 participants (52±11 years, 21 males) with a mean BMI of 35±8 kg/m were recruited. At baseline, mean systolic and Results 2 diastolic blood pressure was 134±15 mmHg and 80±18 mmHg respectively. Other comorbidities included: diabetes (6%), dyslipidemia (27%) and smoking (53%). Cardiac biomarkers including CRP, proBNP and TnT were all within normal limits at baseline and did not change significantly on CPAP. On serial echocardiography, there was a decrease in left ventricular end diastolic diameter (59±4 mm at baseline to 51±6 mm at 6 months, p <0.05) and a decrease in right ventricular end diastolic diameter (40±3 mm at baseline to 33±4 at 6 months, p <0.05) following 6 months of CPAP therapy. Left atrial volume decreased from 52±3 mm at baseline to 44±4 mm at 6 months of follow-up. A decrease was also noted in the degree of pulmonary hypertension (61±4 mm Hg at baseline to 48±6 mmHg at 6 months, p <0.05).Although there were no changes in conventional parameters of diastolic dysfunction, the LA filling pressures as reflected by E/E', decreased from 19±2 at baseline to 9±1 at 6 months, p <0.05. LV mass as determined by CMR, decreased from 180 g/m to 165 g/m at 6 2 2 months of CPAP therapy. : Since both systolic and diastolic abnormalities in OSA patients reversed at 6 months of CPAP therapy, long term use of CPAP Conclusion is likely to prevent morbidity and mortality associated with OSA. This abstract is funded by: Section of Respirology Am J Respir Crit Care Med