Relation of Echocardiographic Characteristics of the Right-Sided Heart With Incident Heart Failure and Mortality in Patients With Sleep-Disordered Breathing and Preserved Left Ventricular Ejection Fraction

Sleep-disordered breathing (SDB) has been associated with right-sided heart dysfunction and adverse cardiovascular outcomes. Longitudinal data are sparse in terms of understanding the prognostic implications of right ventricular remodeling in SDB on cardiovascular risk. We therefore investigated the predictive value of right-sided cardiac functional alterations on incident heart failure (HF) or death in SDB. Patients with SDB who underwent echocardiography within 1 month of index polysomnogram from January 2002 to July 2011 with normal left ventricular ejection fraction were included. Cox proportional prognostic hazard models predicting HF or death were used. Of a potential 375 subjects, 202 fulfilled the inclusion criteria (58 ± 14 years; 50% men). Subjects were followed for 3.1 ± 2.4 years with a total of 34 (16.8%) developing HF or death. Right ventricular end-systolic area (hazard ratio [HR] 1.3, 95% CI 1.01 to 1.6, p = 0.038), pulmonary vascular resistance (PVR; HR 1.4, 95% CI 1.1 to 1.7, p = 0.005) and also left atrial volume index (HR 1.7, 95%, CI 1.3 to 2.3, p <0.001) and E/A ratio (HR 1.4, 95% CI 1.1 to 1.7, p <0.001), were predictive of HF or death. Patients with increased PVR had significantly shorter event-free survival than without increased PVR (p = 0.04). In sequential Cox models, a model based on clinical data and left ventricular ejection fraction (χ2, 5.4) was improved by left atrial volume index (χ2, 12.7; p = 0.011) and further increased by PVR (χ2, 19.7; p = 0.015). In conclusion, right-sided heart dysfunction provides important prognostic information in SDB and may aid in identifying those at highest risk to target for closer follow-up.