Conference: 2014 International PHA Conference and Scientific Sessions
Release Date: 06.21.2014
Presentation Type: Abstracts
Introduction: Cystic fibrosis (CF) is the most common autosomal recessive disorder in the Caucasian population. Pulmonary hypertension (PH) is a recognized comorbidity in CF and is associated with increased mortality. Other than right heart catheterization for lung transplant evaluation, no screening or treatment protocols exist for this population. We present three CF patients who were diagnosed with PH during transplant evaluation and were treated with selective pulmonary vasodilator therapy prior to lung transplantation.
Case Series: Three patients with advanced bronchiectasis due to CF, significant dyspnea on exertion and a FEV1 less than 25% predicted, were evaluated for lung transplant. All underwent transthoracic echocardiography demonstrating preserved left ventricular function and variable right ventricular (RV) function, ranging from minimal dysfunction to a dilated hypokinetic RV. All patients underwent right heart catheterizations demonstrating PH. Selective pulmonary artery vasodilator therapy was initiated due to advanced functional classification and evidence of RV failure. Two patients were treated with phosphodiesterase inhibitor (PDE-5) mono-therapy. The third required combination therapy with a PDE-5 and an endothelin receptor antagonist (ERA). All three noted an improvement in symptoms without worsening hypoxemia, and subsequently underwent successful lung transplantation.
Discussion and Conclusions: PH occurs frequently in patients with advanced CF lung disease, ranging from subclinical to overt right ventricular failure and is associated with increased mortality. The mechanism of disease is most likely mediated by alveolar hypoxemia and parenchymal lung destruction. While selective pulmonary vasodilator therapy is classically reserved for the treatment of pulmonary arterial hypertension (World Health Organization Group I), there may be a role for its use in this scenario, as unaddressed right heart dysfunction may result in death prior to potential transplantation. In this series, both ERAs (bosentan) and PDE-5s (sildenafil, tadalafil) were used. One potential complication of pulmonary artery vasodilator therapy in advanced parenchymal lung disease is worsening ventilation-perfusion mismatching resulting in further hypoxemia. A recent case series reported no worsening of oxygenation or lung function at 30 days with selective vasodilator therapy in this population. Similarly, our patients demonstrated no worsening hypoxemia. This case series highlights the need for a high index of suspicion, and suggests that a standardized approach to PH screening is important in the care of the adult CF patient. There are currently no guidelines to direct therapy when PH is identified in the setting of CF. Our experience with oral pulmonary artery vasodilators demonstrates they can be used safely and effectively while awaiting transplantation.
Type: Case Study