Pulmonary hypertension-specific therapy in patients with chronic respiratory insufficiency.

We read with much interest the article by HELD et al. [1] regarding pulmonary hypertension (PH) due to hypoventilation. In this retrospective study, the authors reported 18 patients with alveolar hypoventilation (due to obesity or chronic obstructive pulmonary disease (COPD)) and daytime PH associated with reduced exercise capacity. They showed that noninvasive positive-pressure ventilation (NIPPV) was followed by significant improvement in haemodynamics and exercise capacity; thus, strongly supporting the use of NIPPV in patients with hypoventilation and PH, and suggesting a major role for hypoxia and hypercapnia in PH [2].