Preserving right ventricular function in patients with pulmonary arterial hypertension: Single centre experience with a cardiac magnetic resonance imaging-guided treatment strategy

The feasibility and usefulness of routine cardiac magnetic resonance imaging (CMR) in the management of idiopathic pulmonary arterial hypertension (IPAH) is unknown. The aims of the study were: 1) to study whether a decrease in CMR-derived right ventricular ejection fraction (RVEF) coincides with clinical deterioration; 2) to determine whether RVEF is responsive to early escalation of pulmonary arterial hypertension (PAH)-specific therapy. This was a prospective study including 30 incident IPAH patients. Patients underwent right heart catheterization and CMR at regular follow-up visits (baseline, four, eight, 12, 24 months; no right heart catheterization at eight months). New York Heart Association (NYHA) functional class II patients started with monotherapy (endothelin receptor antagonist or phosphodiesterase-5-inhibitor) and NYHA III patients with combination therapy (endothelin receptor antagonist plus phosphodiesterase-5-inhibitor). In the case of a deterioration in RVEF of more than 3% compared with the previous measurement, PAH-specific therapy was added (i.e. treatment escalation). In 11 patients without signs of clinical deterioration, a greater than 3% decrease in RVEF occurred. After treatment escalation, RVEF significantly improved (average improvement of 7%, p = 0.009) whereas right ventricle volumes, N-terminal pro-brain natriuretic peptide and six-minute walking distance remained stable. Clinical worsening did not occur after escalating therapy. Throughout the study, four patients presented with clinical worsening, despite a stable RVEF. Three of these four patients had a baseline RVEF <35%. In IPAH patients presenting with an early decrease in RVEF but otherwise stable disease, progressive right ventricle failure and subsequent clinical worsening did not occur when therapy was escalated. Nevertheless, clinical worsening did occur in patients with a low baseline RVEF.