Long-term myocardial effects of noninvasive ventilation in patients with obesity hypoventilation syndrome

Introduction: Chronic effects of noninvasive ventilation on myocardial function in patients with obesity hypoventilation syndrome (OHS) are scarcely understood. The aim of the present study was to evaluate the long-term effects of volume-targeted bilevel positive airway pressure ventilation (BiPAP) on cardiac parameters and myocardial biomarkers in patients with OHS.

Methods: Clinically stable patients with OHS referred to the tertiary center for the initiation of long-term BiPAP therapy were consecutively enrolled. At baseline, all participants underwent overnight cardiorespiratory polygraphy. BiPAP therapy using volume-targeted spontaneous/timed mode delivered via an oro-nasal mask was initiated. Beat-to-beat noninvasive monitoring by impedance cardiography was used to assess heart function at baseline and after 3 and 12 months of BiPAP use. Serum troponin 1, N-Terminal Pro-B-Type Natriuretic Peptide (NT-ProBNP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) were monitored.

Results: Thirteen patients (10 men; mean age, 55.8 ± 9.8 years; mean body mass index of 47.8 ± 5.9 kg/m²) were recruited. From baseline to 3, and to 12 months of BiPAP use, left ventricular stroke volume (SV), ejection time (LVET), and ejection time index significantly increased (P = 0.030; P < 0.001; P = 0.003, respectively), while heart rate and systolic time ratio significantly decreased (P = 0.004; P = 0.034, respectively). Reductions in serum NT-proBNP, IL-6 and TNF-α were observed (P = 0.045; P = 0.018; P = 0.003, respectively). No significant changes in serum troponin were detected throughout the study.

Conclusions: The present findings of increased SV, in association with lengthening of LVET, reductions of NT-proBNP and reductions in circulatory inflammatory markers in patients with stable OHS and chronic moderate-to-severe daytime hypercapnia treated with BiPAP over 1 year support the role of this therapeutic mode in such patients.