Free-breathing, multi-shot, navigated CMR during continuous exercise was feasible and highly reproducible, detecting an increase in LVEF at 75% HRmax compared to baseline (68% vs 58%, P=0.001).
Observational (n=16)
Is a free-breathing, multi-shot, navigated CMR image acquisition technique feasible and reproducible for ventricular volume quantification during continuous exercise?
A free-breathing, multi-shot, navigated CMR technique allows feasible and highly reproducible simultaneous assessment of left and right ventricular volumes during continuous exercise.
Absolute Event Rate: 68% vs 58%
p-value: p=0.001
Background: Cardiovascular magnetic resonance (CMR) image acquisition techniques during exercise typically requires either transient cessation of exercise or complex post-processing, potentially compromising clinical utility. We evaluated the feasibility and reproducibility of a navigated image acquisition method for ventricular volumes assessment during continuous physical exercise. Methods: Ten healthy volunteers underwent supine cycle ergometer (Lode) exercise CMR on two separate occasions using a free-breathing, multi-shot, navigated, balanced steady-state free precession cine pulse sequence. Images were acquired at 3-stages, baseline and during steady-state exercise at 55% and 75% maximal heart rate (HRmax), based on a prior supine cardiopulmonary exercise test. Intra-and inter-observer variability and inter-scan reproducibility were derived. Clinical feasibility was tested in a separate cohort of patients with severe mitral regurgitation (n=6). Results: End-diastolic volume (EDV) of both LV and RV decreased during exercise at 55% and 75% HRmax, although a reduction in RVEDV index was only observed at 75% HRmax. Ejection fractions (EF) for both ventricles were significantly higher at 75% HRmax compared to their respective baselines (LVEF 68%±3% vs. 58%±5%, P=0.001; RVEF 66%±4% vs. 58%±7%, P=0.02). Intra-observer and inter-observer reproducibility of LV parameters was excellent at all 3-stages. Although measurements of RVESV were more variable during exercise, the reproducibility of both RVEF and RV cardiac index was excellent (CV <10%). Inter-scan LV and RV ejection fraction were highly reproducible at all 3 stages, although inter-scan reproducibility of indexed RVESV was only moderate. The protocol was well tolerated by all patients. Conclusions: Exercise CMR using a free-breathing, multi-shot, navigated cine imaging method allows simultaneous assessment of left and right ventricular volumes during continuous exercise. Intra- and inter-observer reproducibility were excellent. Inter-scan LV and RV ejection fraction were also highly reproducible.
Chew et al. (Thu,) conducted a observational in Healthy volunteers and severe mitral regurgitation (n=16). Free-breathing, multi-shot, navigated CMR during continuous exercise vs. Baseline (rest) was evaluated on LVEF at 75% HRmax compared to baseline (p=0.001). Free-breathing, multi-shot, navigated CMR during continuous exercise was feasible and highly reproducible, detecting an increase in LVEF at 75% HRmax compared to baseline (68% vs 58%, P=0.001).