Submaximal exercise significantly reduced pulmonary regurgitation fraction (40.8% to 35.3%, p<0.0001) and RVEDVi (139.8 to 128.4 ml/m2, p=0.0002) in patients with severe pulmonary regurgitation.
Observational (n=17)
Does submaximal exercise alter CMR-derived right ventricular end-diastolic volume index and pulmonary regurgitation fraction in patients with severe pulmonary regurgitation?
Heart rate significantly impacts CMR-derived volumetric measurements like RVEDVi and PR fraction, suggesting it should be accounted for when determining the timing of pulmonary valve replacement.
Effect estimate: Δ -13.2%
Absolute Event Rate: 35.3% vs 40.8%
p-value: p=<0.0001
Abstract Background Severe pulmonary regurgitation is a frequent long-term complication in patients with congenital heart disease, such as tetralogy of Fallot, pulmonary atresia, and pulmonary stenosis. While symptomatic individuals are generally treated with pulmonary valve replacement (PVR), the optimal timing of intervention in asymptomatic patients remains a topic of active investigation. Cardiovascular magnetic resonance (CMR) imaging, with its capacity for volumetric assessment and quantification of ejection fractions, serves as a cornerstone of diagnostic evaluation, guiding the timing of PVR. Purpose This study aimed to investigate whether the right ventricular end-diastolic volume index (RVEDVi) and pulmonary regurgitation (PR) fraction, used as criteria for PVR, are constant parameters or vary depending on heart rate and/or adrenergic stimulation. Methods We prospectively investigated 17 patients with chronic severe pulmonary regurgitation (PR fraction 40.8% +/- 6.2) due to tetralogy of Fallot (70%), pulmonary atresia with intact ventricular septum (12%), and pulmonary valve stenosis (18%). CMR imaging included flow measurements of the main pulmonary artery and ascending aorta acquired during free breathing, as well as steady-state free precession (SSFP) cine images in axial orientation obtained during breath-hold for volumetric assessment. All examinations were performed on a 1.5 Tesla MR scanner at rest and during submaximal exercise, which increased heart rate by an average of 24%—equivalent to a workload of approximately 25% of peak VO2. Exercise was conducted using a custom-built, MRI-conditional leg paddle ergometer, without interruptions during imaging. Results The results showed a reduction in PR fraction (from 40.8% +/- 6.2 to 35.3%+/-7.6, Δ -13.2%, p 0.0001) and RVEDVi (from 139.8ml/m2 +/-19.9 to 128.4ml/m2 +/- 20.7, Δ -8%, p 0.0002) during exercise. Left ventricular ejection fraction (LVEF) remained within the normal range and increased appropriately with exercise. In contrast, right ventricular ejection fraction (RVEF), although normal at rest (57.2% +/- 4.3), demonstrated a blunted response to exercise, with only a modest, non-significant increase (Δ 3.5%, p = 0.14), suggesting impaired contractile reserve of the right ventricle. Conclusions In the presence of severe pulmonary regurgitation, we observed a decrease in RVEDVi during exercise, accompanied by a concurrent reduction in pulmonary regurgitation fraction. Notably, this effect was evident even with modest elevations in heart rate. These findings highlight heart rate as a significant determinant of CMR-derived volumetric measurements and suggest it should be carefully considered in the clinical decision-making process for pulmonary valve replacementResults General Parameters
Skarlatoudi et al. (2026) conducted an observational in Chronic severe pulmonary regurgitation (n=17). Submaximal exercise vs. Rest was evaluated on Pulmonary regurgitation (PR) fraction (Δ -13.2%, p=<0.0001). Submaximal exercise significantly reduced pulmonary regurgitation fraction (40.8% to 35.3%, p<0.0001) and RVEDVi (139.8 to 128.4 ml/m2, p=0.0002) in patients with severe pulmonary regurgitation.