Pilot Study of the Safety and Efficacy of Carvedilol in Pulmonary Arterial Hypertension

Patients with pulmonary arterial hypertension (PAH) will be treated with carvedilol for 24 weeks. During this time, carvedilol will be titrated from an initial dose of 3.125mg BID to a maximal dose of 25mg BID. At the start and end of the study, we will obtain cardiac MRI, 6 minute walk distance, brain natriuretic peptide (serum), echocardiogram, and functional class assessment. Our primary outcome is a change in right ventricular ejection fraction with cardiac MRI.

Inclusion criteria

• idiopathic, familial or associated PAH, WHO group 1
• NYHA class II or III
• clinically stable with optimized PAH treatment for at least 3 months
• no or minimal evidence of fluid overload or volume depletion, with or without diuretic treatment
• age > 18 years
• mean pulmonary artery pressure (mPAP) > 25 mmHg
• 6 minute walk distance (6MWD) over 100m

Exclusion criteria

• Structural heart disease unrelated to PAH
• Recent (<3 months) treatment with an intravenous positive inotropic agent
• current use of β-blockers
• history of reactive airways disease
• history of adverse reaction to β-blockers
• heart block on ECG or resting heart rate < 60 bpm
• cardiac index < 1.8 l/min/m2
• systemic hypotension (systolic pressure < 90 mmHg)
• pulmonary capillary wedge pressure > 15 mmHg
• inability to give informed consent
• contraindications to CT and/or PET scanning
• coagulopathy (INR>1.5 or platelet count<50000/mm3)
• severe renal insufficiency (creatinine clearance <30 ml/min/m2)
• malignancy or any co-morbidity limiting survival or conditions predicting inability to complete the study.