A prospective study analysing the prevalence of sleep disordered breathing in stable patients of congestive heart failure with reduced ejection fraction

Heart failure is known to cause sleep disordered breathing (SDB) and SDB in the setting of heart failure is known to worsen it and increase morbidity and mortality. <bold>Methodology:</bold> A prospective observational study of 100 haemodynamically stable patients with chronic heart failure with reduced ejection fraction(HFrEF)<40% was conducted from October 2022-December 2023. A level 1 polysomnography(PSG) was performed. SDB was said to be present if apnea-hypopnea index(AHI) was >5/hr. <bold>Results:</bold> The mean age of the study population was 62 years with male predominance with an average BMI of 28 kg/m2 and the average ejection fraction of 32%. 68% of the study population had SDB of which 62% (42/68) had obstructive sleep apnea(OSA) and 38%(26/68) had central sleep apnea(CSA). The prevalence of OSA was found to be significantly higher than CSA. Only 41.17% patients diagnosed with SDB on PSG turned out to be high risk for sleep apnea on Berlin questionnaire and only 14.70% were classified as high risk for SDB based on Epworth sleepiness score. Both of these were statistically not significant. <bold>Conclusion:</bold> According to many western studies, prevalence of CSA is higher in patients of HFrEF as compared to OSA. We found that prevalence of OSA in HFrEF patients was higher compared to CSA. The higher prevalence in the Indian context could be due to ethnicity, subcontinental craniofacialanatomical features, regular use of heart failure medications like betablockers. As the sensitivity of the questionnaires was low and due to the potential adverse effects of SDB on HF, a PSG must be performed in all patients of SDB with HFrEF irrespective of sleep related symptoms.