Pulmonary hypertension (PH) may affect survival in cystic fibrosis (CF) and can be assessed on echocardiographic measurement of the pulmonary acceleration time (PAT). The study aimed at evaluating PAT as a tool to optimize timing of lung transplant in CF patients. Prospective multicenter longitudinal study of patients with forced expiratory volume in 1 second (FEV1) ≤60% predicted. Echocardiography, spirometry and nocturnal oximetry were obtained as part of the routine evaluation. We included 67 patients (mean FEV1 42±12% predicted), among whom 8 underwent lung transplantation during the mean follow-up of 19±6 months. No patients died. PAT was determined in all patients and correlated negatively with systolic pulmonary artery pressure (sPAP, r=-0.36, P=0.01). Patients in the lowest PAT tertile (<101 ms) had lower FEV1 and worse nocturnal oxygen saturation, and they were more often on the lung transplant waiting list compared to patients in the other tertiles. Kaplan-Meier curves showed a shorter time to lung transplantation in the lowest PAT tertile (P<0.001) but not in patients with sPAP>35 mmHg. By multivariate analysis, FEV(1)and nocturnal desaturation were the main determinants of reduced PAT. A PAT<101 ms reduction is a promising tool for timing of lung transplantation in CF.
Keywords: cystic fibrosis; echocardiography; pulmonary acceleration time; pulmonary hypertension; pulmonary transplantation.