Cardiac magnetic resonance imaging in mortality risk stratification of patients with pulmonary arterial hypertension in a South American cohort

Objective. To conduct a comparative assessment of cardiac magnetic resonance imaging (MRI) parameters with known determinants of prognosis in patients with pulmonary arterial hypertension (PAH). Material and methods. The prospective single-center study included 60 patients with PAH aged 21-72 years. The study assessed baseline cardiac MRI, right heart catheterization, echocardiography, N-terminal pro-brain natriuretic peptide (NT-proBNP) and 6-minute walk test (T6MW) levels in a South American cohort. Results. Significant correlations between invasive hemodynamic parameters, NT-proBNP and cardiac MRI parameters were confirmed. There were no significant correlations between the contractility of the right ventricle (RV), RV volume and distance in T6MX, and the functional class (FC) of PAH. Cardiac MRI indicators made it possible to reliably separate low-risk patients from intermediate- and high-risk patients in accordance with the ESC/ERS 2015 scale. According to multivariate regression analysis, the RV end-systolic volume index was >54 ml/m2 (risk ratio 0.2; 95% confidence interval : 0.05-0.9; p=0.004) and 3-4 FC PAH (risk ratio 0.2; 95% confidence interval: 0.07-0.8; p=0.026) remained independent predictors of mortality. Conclusion. The use of cardiac MRI in low-risk patients can significantly improve the early detection of RV myocardial dysfunction and contribute to the timely optimization of PAH-specific therapy. During the follow-up of patients with PAH, the use of cardiac MRI has the potential to reduce the need for repeated invasive examinations