Predictive value of respiratory parameters in patients with obstructive sleep apnea and chronic heart failure with preserved ejection fraction

Aim. To study individual functional parameters of respiration in different phases of sleep in patients with obstructive sleep apnea (OSA) and chronic heart failure with preserved ejection fraction (HFpEF) and to assess their effect on the clinical course of the disease. Methods. The study included 86 men with OSA [with an apnea-hypopnea index (AHI) ≥15 per hour]. Upon inclusion in the study, all patients underwent a polysomnographic study and echocardiography, the level of brain natriuretic peptide (NT-proBNP) was determined, a six-minute walk test was performed. After 12 months of prospective observation, the patients were divided into 2 groups according to the clinical course of chronic heart failure: with unfavorable (n=33) and favorable (n=53) clinical course. The prognostic significance of the studied parameters of respiration to the course of the disease was assessed by using logistic and linear regression. Results. A significant role of the following respiratory parameters as predictors of chronic heart failure progression was established: obstructive apnea-hypopnea index for the entire night sleep [odds ratio (OR) 1.04, p=0.002] and in the phase of rapid eye movement sleep (REM) (ОR 1.24, p=0.001); the index of respiratory disorders for the entire sleep period (ОR 1.06, p=0.044) and in REM sleep phase (ОR 1.25, p=0.003). For hospital readmission, the predictive role was determined for obstructive apnea/hypopnea index for REM phase (ОR 1.07, p=0.044) and index of respiratory disorders for REM phase (ОR 1.13, p=0.040). Conclusion. The prognostic value of the obstructive apnea-hypopnea index and the index of respiratory disorders for the entire night sleep and in the phase of REM sleep was revealed for patients with OSA and chronic heart failure with preserved ejection fraction, which allows considering these parameters as independent predictors of an unfavorable clinical course in this group of patients.