Elevated Cardio-Ankle Vascular Index (CAVI) predicts severe sleep disordered breathing in non-overweight patients with chronic heart failure

Abstract

Background: Though sleep disordered breathing (SDB) is a prevalent comorbidity and associated with poor outcomes in patients with chronic heart failure (CHF), SDB tends to be overlooked especially in non-overweight patients. The aim of the present study was to examine whether cardio-ankle vascular index (CAVI), which has been shown to be elevated in patients with SDB, predicts severe SDB in non-overweight CHF patients. Methods and Results: We performed nocturnal sleep polygraphy and CAVI in 87 consecutive non-overweight CHF patients (body mass index (BMI) <25 kg/m2). The exclusion criteria were age of <20 or >90 years old, under oxygen therapy or supplementation, and end-stage renal disease. We defined that apnea-hypopnea index (AHI) of 30 times/h or higher as severe SDB. CHF patients with severe SDB included more males and had higher BMI, higher serum uric acid, and higher CAVI compared with those without severe SDB. The receiver operating characteristic curve showed the area under the curve of CAVI for severe SDB was 0.779 (cut-off value, 8.6; sensitivity and specificity, 84% and 66%, respectively). In multivariate logistic regression analysis, CAVI was an independent predictor of severe SDB (per 1SD increase, odds ratio 4.177, 95% confidence interval, 1.839-11.707). CAVI correlated with AHI (r = 0.468, P<0.001), especially with obstructive and mixed apnea indices but not with central apnea index. (Figure presented) Conclusion(s): Elevated CAVI predicts severe SDB in non-overweight patients with CHF.