P5415Sleep disordered breathing in patients before and after heart transplantation: association with biomarkers and clinical parameters

Abstract

Abstract Background Sleep-disordered breathing (SDB) is highly frequent in patients with severe heart failure (HF). SDB, and predominantly central sleep apnea (CSA), may improve after recovery of cardiac function, but available data are limited and inconclusive, especially in patients who have undergone heart transplantation. The assessment of the severity of sleep apnea is mainly based on the apnea-hypopnea index (AHI), but this event-based parameter alone may not sufficiently reflect the complex pathophysiological mechanisms underlying SDB potentially contributing to adverse outcomes in patients with heart failure. Purpose To assess SDB in patients with severe HF before and after heart transplantation, their relationship with biomarkers and clinical parameters. Methods We included 117 patients (mean age 52.4±4.7 years) with HF NYHA class II-IV in the prospective cohort study, follow-up period was 5 years. The left ventricular ejection fraction (LVEF) was 28.05±9.57%. All patients underwent a comprehensive clinical examination, echocardiography, polysomnography (PSG, Embla N7000, Natus, USA). The plasma level of NT-proBNP, was analyzed by immunoassay (ELISA). The SPSS statistical software (version 23.0) was used. Results PSG showed the following types of SDB in the studied cohort: obstructive sleep apnoea (OSA) was diagnosed in 48 patients (41%), central - in 20 (17%), mixed - in 26 (22%). Among them mild SDB was diagnosed in 29 cases, moderate in 32 and severe in 33 patients. SDB was not found in 23 patients. The following correlations were identified: NT-proBNP and obstructive apnea index (OAI) (r=−0.44, p=0.007), NT-proBNP and sleep efficiency (r=−0.71, p=0.006), AHI and body mass index (BMI) (r=0.32, p=0.01), OAI and BMI index (r=0.34, p<0.001), desaturation index and BMI (r=0.43, p<0.001), average saturation oxygen and BMI (r=−0,6, p<0,001). Twenty-three patients underwent heart transplantation. According PSG-data 1 year after transplantation we observed decrease of central apnea index (CAI) (p=0,04). On the other hand, OAI increased (p=0,01) independently of the significant change in BMI (p=0,08). Conclusion We found very high rate of SDB (80%) in patients with severe HF, the predominant type was OSA. AHI, OAI and indicators of oxygen saturation correlate with BMI and biomarkers before heart transplantation. After 1 year after transplantation CAI decreased, assessment of the dynamics of obstructive sleep apnea requires further study.