Pulmonary hypertension as estimated by Doppler echocardiography in adolescent and adult patients with cystic fibrosis and their relationship with clinical, lung function and sleep findings

Background In cystic fibrosis (CF) patients, end stage of pulmonary disease is characterized by pulmonary hypertension (PH), hypoxemia, decrease in exercise tolerance, and sleep quality. Objective To evaluate the association between clinical, lung function, sleep quality, and polysomnographic variables with PH in CF patients aged 16 years or older. Methods In a cross‐sectional study, 51 clinically stable CF patients underwent a clinical evaluation, an overnight polysomnography and answered sleep questionnaires (Pittsburgh Sleep Quality Index and Epworth sleepiness scale). Also, CF patients had their pulmonary function, 6‐minute walk test (6MWT) and echocardiography assessed. Results Fifty‐one CF patients participated in the study; 47% were female. The mean age was 25.1 ± 8.8 years. Pulmonary artery systolic pressure (PASP) was greater than 35 mm Hg in 11 (27.5%) patients. Variables associated with PASP>35 mm Hg in univariate analysis were Shwachman‐Kulczycki clinical score, forced expiratory volume in 1 second % of predicted, Pseudomonas aeruginosa in sputum culture, at‐rest peripheral capillary oxygen saturation (SpO2), SpO2 at end of 6MWT and time of oxygen desaturation 35 mm Hg was at‐rest SpO2 (OR = 10.8, CI 95% 1.7‐67.3, P = .011). The cuttoff SpO2< 94% had the sensitivity = 7/11 = 64%, specificity = 40/40 = 100%, positive predicted values = 7/7 = 100% and negative predicted values = 40/44 = 91% to the diagnosis of PH. Conclusion the present study showed a high rate of PH in adolescent and adult CF patients. At‐rest SpO2 was associated with PH.