Cardiac MRI Could Be Useful in Pulmonary Arterial Hypertension Risk Stratification

Cardiac magnetic resonance imaging (MRI) is useful for risk stratification in patients with pulmonary arterial hypertension (PAH), according to study results published in the American Journal of Respiratory and Critical Care Medicine.¹

Individual risk stratification is used to determine the therapeutic strategy for patients with PAH. This risk assessment integrates pulmonary hemodynamics, symptoms, functional capacity, laboratory values, and echocardiographic parameters to classify patients as low, intermediate, or high risk. Cardiac MRI is considered to be the gold standard for evaluating right ventricular (RV) volumes and function, and is recommended for the follow-up of patients with PH, but has not been integrated into risk stratification.

Using a referral center registry, Lewis and colleagues carefully analyzed cardiac MRI data in a large PAH patient population at baseline and, for a proportion of the patients, at the first follow-up.² They were able to identify patients at low, intermediate, and high risk for 1-year mortality based on RV ejection fraction, and patients at low and high risk were identified using RV end systolic volume index percent predicted and left ventricular (LV) end diastolic volume index.¹ Cardiac MRI is probably the best possible way to determine RV adaptation and maladaptation in PH through its holistic assessment of RV and LV volumes and function.

This work will hopefully introduce cardiac MRI parameters into the risk stratification of PAH.¹ The authors concluded that, “Additional parameters such as SV/[end systolic volume], RV mass, measures of RV deformation such as feature-tracking strain, 4D-flow in the right ventricle including assessment of vorticity, late enhancement, and T1 and T2 mapping, in combination with right atrial phase assessment with strain imaging, are promising tools to be explored in future in terms of prognosis and perhaps risk stratification.”

References

1. Richter MJ, Tello K. Against the odds: risk stratification with cardiac MRI in pulmonary arterial hypertension [published on November 14, 2019]. Am J Respir Crit Care Med. doi:10.1164/rccm.201910-2069ED

2. Lewis RA, Johns CS, Cogliano M, et al. Identification of cardiac MRI thresholds for risk stratification in pulmonary arterial hypertension [published online October 24, 2019]. Am J Respir Crit Care Med. doi:10.1164/rccm.201909-1771OC