Pulmonary artery hemodynamics are associated with duration of nocturnal desaturation but not apnea-hypopnea index

Abstract

Study Objectives: Sleep-disordered breathing and nocturnal hypoxia are prevalent among patients with precapillary pulmonary hypertension (PAH). The rationale for these associations remains unclear and these relationships have not been well studied in other forms of pulmonary hypertension (PH). We hypothesized that severity of sleep-disordered breathing and nocturnal hypoxia are associated with worsening pulmonary hemodynamics, regardless of hemodynamic profile. Methods: Four hundred ninety-three patients were divided into 4 groups: 1) no PH, 2) postcapillary pulmonary hypertension, 3) PAH, and 4) mixed PAH/postcapillary pulmonary hypertension. The relationship between right heart catheterization measurements and apnea-hypopnea index or the percentage of sleep time spent with oxygen saturation < 90% (T90) was calculated using multiple linear regression. Analysis of variance was used for between-group comparisons. Statistical models were adjusted for known confounders. Results: Apnea-hypopnea index did not differ between hemodynamic subgroups (P =.27) and was not associated with right atrial pressure (.11 ±.19, P =.55), cardiac index (.25 ± 1.64, P =.88), mean pulmonary artery pressure (−.004 ±.09, P =.97), or pulmonary artery occlusion pressure (.16 ±.14, P =.26). While patients with PH had a higher T90 than those without (mean 24.2% vs 11.7%, P