Chest. 2012 Aug 1. doi: 10.1378/chest.11-3124. [Epub ahead of print]

High occurrence of hypoxemic sleep respiratory disorders in precapillary pulmonary hypertension and mechanisms.

Jilwan FN, Escourrou P, Garcia G, Jaïs X, Humbert M, Roisman G.

ClinicalTrials.gov Identifier: NCT013716691
Université Paris-Sud, Faculté de médecine, Le Kremlin-Bicêtre, F-94276, France;
AP-HP, Unité de Médecine du Sommeil, Hôpital Antoine Béclère, Clamart, F-92140, France;
AP-HP, Service de Pneumologie et Réanimation Respiratoire, Hôpital Antoine Béclère, Clamart, F-92140, France;
INSERM U999, Hypertension Artérielle Pulmonaire: Physiopathologie et Innovation Thérapeutique, Le Plessis-Robinson, F-92350, France;
Université Paris-Sud, EA3544, Faculté de Pharmacie, Châtenay-Malabry, F-92290, France

Abstract

BACKGROUND: The occurrence and mechanisms of nocturnal hypoxemia (NH) in precapillary pulmonary hypertension (PH) are not clearly defined.
METHODS: In an observational prospective and transversal design, we studied 46 clinically stable PH patients with BMI < 35 kg/m2, FEV1 > 60% of predicted and diagnosis of idiopathic pulmonary arterial hypertension (IPAH, n=29) or chronic thrombo-embolic PH (CTEPH, n=17). They underwent nocturnal polysomnography with transcutaneous capnography.
RESULTS: Most patients were in NYHA functional class II (69.6%). Mean pulmonary arterial pressure was 44 ± 13 mmHg and cardiac index 3.2 ± 0.6 L/min/m2. The time spent below a saturation of 90% (D90%) was 48.9 ± 35.9% of sleep time and 38 out of 46 (82.6%) patients had NH. Mean apnea hypopnea index (AHI) was 24.9 ± 22.1/ hour and 41 patients (89%) had sleep apnea. The major mechanism of NH was a ventilation/perfusion mismatch alone or associated with obstructive apneic events. Multivariate logistic regression identified both FEV25-75 (odds ratio, 0.9519; 95% CI, 0.9089 to 0.9968; P = 0,036) and mean pulmonary arterial pressure (odds ratio, 1.1068; 95% CI, 1.0062 to 1.2175; P = 0,037) as significant predictors of NH. Clinical symptoms were not predictive of NH.
CONCLUSIONS: The occurrence of NH is high in PH and should be systematically screened for. Further studies are needed to determine the impact of NH on the outcome of patients with PH.

PMID:22878784