Cardiovascular magnetic resonance imaging (CMR) may be useful in detecting clinically relevant changes in right ventricular (RV) volumes and function related to pulmonary arterial hypertension (PAH), according to a study published in Pulmonary Circulation.

Targeted therapy has demonstrated a reduction in morbidity and mortality in patients with PAH. As RV dilatation may predict clinical worsening in PAH, understanding clinically significant changes in RV volumes and function is of particular relevance to clinicians.

CMR has shown high precision for measuring RV volumes, but researchers have yet to determine which changes are clinically significant.

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Researchers in Denmark followed 25 patients with PAH who were examined with CMR every 6 months for 2.5 years. A World Health Organization (WHO) functional class (FC) assessment was performed immediately prior to every CMR session.

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In total, 107 MRI scans were performed. The researchers found that a significant change in clinical status (ie, a step change in WHO FC) was associated with an 11% change in RV volume (P <.0001) and a 9% change in stroke volume (P =.003). 

Limitations to this study include a small sample size and that patient selection was restricted to idiopathic and heritable PAH. It is important to validate the findings of this study in other populations (eg, PAH associated with systemic sclerosis and congenital heart disease) and to possibly include a wider array of tests as anchors.

“In conclusion, this study adds to the current knowledge of RV function in PAH that changes in WHO functional class are associated with an 11% change in RV end-diastolic volume using transversal images in the studied population,” the researchers stated.

“Furthermore, this study shows how filling of the right ventricle changes in accordance with changes in WHO functional class, mimicking the pattern seen in echocardiography in assessment of diastolic function.”


Göransson C, Vejlstrup N, Carlsen J. Clinically important changes of right ventricular volume and function in pulmonary arterial hypertension assessed with cardiac magnetic resonance imaging. Pulm Circ. Published online June 2, 2022. doi:10.1002/pul2.12097