Functional impact of pulmonary hypertension due to hypoventilation and changes under noninvasive ventilation

We aimed to characterise the association of pulmonary hypertension due to hypoventilation and exercise capacity, and the haemodynamic and functional changes under noninvasive ventilation. A retrospective analysis was carried out to assess haemodynamics and functional capacity in 18 patients with daytime pulmonary hypertension, due to hypoventilation, at baseline and after 3 months of noninvasive ventilation. Patients presented with a mean±SD pulmonary artery pressure of 49±13 mmHg, preserved cardiac index (3.2±0.66 L·min(-1)·m(-2)), 6-min walking distance of 303±134 m and severely elevated N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Mean pulmonary artery pressure correlated negatively with maximum work rate (R= -0.72; p=0.03) and 6-min walking distance (R= -0.62; p=0.01). Following noninvasive ventilation we found a significant reduction of mean pulmonary artery pressure (-18 mmHg; p<0.001) and NT-proBNP levels (-2110 pg·mL(-1); p=0.001), and improvement in the 6-min walking distance (+66 m; p=0.008) and maximum work rate (+18 W; p=0.028). Changes in work rate correlated inversely with pulmonary artery pressure (R= -0.75; p=0.031). In this specific cohort with hypoventilation and severe pulmonary hypertension, pulmonary hypertension was associated with reduced exercise capacity. Following noninvasive ventilation, haemodynamics and exercise capacity improved significantly.