Role of cardiac magnetic resonance in stratifying the prognosis of patients with pulmonary arterial hypertension

Abstract

Abstract Background Pulmonary arterial hypertension (PAH) is a rare disease characterized by a complex remodeling of heart structures. Cardiac magnetic resonance (CMR) is the gold standard for a non-invasive evaluation of right ventricle (RV) volumes and mass. Purpose To define the relationship between clinical, functional, biochemical, haemodynamic and CMR parameters and survival in patients with PAH. Methods Consecutive patients with PAH referred to our centre underwent clinical, functional, brain natriuretic peptide (BNP) plasma levels, haemodynamic and CMR evaluation. All patients were treated according to current guidelines. Univariate Cox analysis for survival was performed. Parameters with a p-value <0.1 at the univariate analysis were included in the multivariate analysis. Results One hundred forty-seven patients with PAH (mean age 49±17 years, 69% female) were included in the study. Etiology of PAH was: idiopathic/heritable (49%), associated with connective tissue disease (19%), congenital heart disease (12%), portal hypertension/HIV infection (12%) and pulmonary veno-occlusive disease (8%). Thirty-six patients died during follow-up. Parameters significantly associated with mortality at the univariate analysis were age [Hazard Ratio (95% Confidence Interval): 1.043 (1.020–1.067); p<0.001], six-minute walk test (6MWT) [HR: 0.995 (0.993–0.998); p<0.001], WHO-functional class [HR: 2.489 (1.025–6.041); p=0.044], idiopathic-heritable-congenital heart disease aetiology [HR: 0.182 (0.085–0.389); p<0.001], connective tissue disease aetiology [HR: 2.274 (1.099–4.704); p=0.027], pulmonary veno-occlusive disease aetiology [HR: 5.864 (2.328–14.773); p<0.001], right atrial pressure [HR: 1.098 (1.032–1.169); p=0.003], pulmonary artery oxygen saturation [HR: 0.947 (0.921–0.975); p<0.001], BNP levels [HR: 2.214 (1.213–4.039); p=0.010], RV wall thickness [HR: 0.633 (0.399–1.006); p=0.053], RV end diastolic volume [HR: 1.012 (1.003–1.021); p=0.007], RV end systolic volume [HR: 1.014 (1.003–1.024); p=0.011]. Parameters independently associated with mortality at the multivariate analysis were age [HR: 1.035 (1.006–1.064); p=0.018], idiopathic-heritable-congenital heart disease aetiology [HR: 0.355 (0.146–0.860); p=0.022], pulmonary veno-occlusive disease aetiology [HR: 3.129 (1.071–9.143); p=0.037], pulmonary artery oxygen saturation [HR: 0.953 (0.919–0.989); p=0.011], RV wall thickness [HR: 0.527 (0.300–0.927); p=0.026], RV end systolic volume [HR: 1.016 (1.003–1.029); p=0.014]. Conclusion RV wall thickness and RV end-systolic volume are associated with prognosis in patients with PAH independently from clinical and haemodynamic characteristics. These parameters may be used in the overall risk stratification of PAH patients. Funding Acknowledgement Type of funding sources: None.