Abstract
Pulmonary arterial hypertension in cystic fibrosis: a study in adult lung transplant candidates Introduction: Pulmonary arterial hypertension (PAH) is a significant comorbidity in patients with advanced lung diseases including cystic fibrosis (CF). PAH affects the morbidity and mortality of these patients and impairs their quality of life and exercise tolerance.
The study evaluated the prevalence of and factors associated with PAH in adult lung transplant candidates with CF. Methods: The study group consisted of adults with CF listed on the lung transplant waiting list in the Transplant Center of the University Hospital in Motol (Prague, Czech Republic) during the 2009-2013 period.
We evaluated the age at waiting list placement, sex, lung function (forced expiratory volume in the first second [FEV1]), respiratory parameters (PaO2 and PaCO2) and exercise tolerance (six-minute walking distance [6-MWD]). Pulmonary artery pressures were examined using right heart catheterization and pulmonary artery mean pressure (PAMP) was evaluated.
Results: Nineteen patients (10 men and 9 women) with a mean (+- SD) age of 28.9 +- 8.4 years were included into study. The values of the examined parameters were as follows: FEV1 23 +- 5 % pred., PaO2 7.30 +- 0.86 kPa, PaCO2 5.04 +- 0.76 kPa, 6-MWD 297 +- 86 m and PAMP 26 +- 8 mmHg.
Pulmonary hypertension (PAMP GREATER-THAN OR EQUAL TO 25 mmHg) was observed in 6 (31.6 %) patients. The values of FEV1 (r = -0.495; p = 0.031) and PaCO2 (r = 0.463; p = 0.041) correlated with the PAMP value.
In regression analysis adjusted for sex and age, the FEV1 value showed a tendency (p = 0.057) to predict the PAMP value. The cut-off value of FEV1 < 20 % pred. predicted the PAMP value GREATER-THAN OR EQUAL TO 25 mmHg with sensitivity, specificity and accuracy of 66.7 %, 100.0 % and 89.5 %, respectively.
The area under the ROC curve for this cut-off value was 0.70 with fair accuracy of prediction (p = 0.11).