Abstract Body (Do not enter title and authors here): Background
Right ventricular dysfunction (RVD) is common in patients with heart failure with preserved ejection fraction (HFpEF) and is associated with shortened life expectancy. Early identification of these at-risk patients could facilitate the initiation of future treatments. Evaluating the RV during exercise has proven to enhance the diagnostic accuracy in revealing RVD that is not detectable at rest. The CardioMEMS device has emerged as a non-invasive tool to remotely monitor pulmonary artery pressures (PAP) and enable early identification of clinical worsening.
Research Questions
Using a hybrid approach of combined real-time CMR-derived volume measurements with CardioMEMS-derived PAP measurements, we aimed to identify RVD during exercise which is not detectible at rest in a population of patients with HFpEF and pulmonary hypertension (PH).
Methods
In this prospective cohort study, we used a hybrid approach of two consecutive exercise tests in HFpEF patients (Figure 1). First, PAP were measured using the CardioMEMS signal on a supine bike at rest, and 25%, 50%, and 75% of peak power output determined previously on an upright cycle ergometer. Subsequently, volumes were derived by CMR at rest and during exercise at 25% and 50% of peak power output. The RV end-systolic pressure-volume relationship (RVESPVR), a surrogate of RV contractility, was calculated as mean PAP divided by RV end-systolic volume. RV contractile reserve, as a marker of RVD during exercise, was calculated as the ratio of peak exercise to resting RVESPVR, with values < 2.0 indicating impairment.
Results
Fourteen patients with HFpEF-PH were included (age 76.6±6.9 years, 57% women). Eleven (79%) had impaired RV contractile reserve during exercise (Table 1). Although not significant, RVESPVR at rest tended to be better in the group with RVD during exercise (0.47±0.17 vs 0.27±0.03; P=0.070). Peak VO₂ was significantly reduced in patients with RVD during exercise (13.1±2.0 vs. 18.6±6.4%; P<0.021).
Conclusion
A new hybrid approach combining cardiac MRI and CardioMEMS is feasible during exercise in HFpEF patients and identifies RVD in approximately eighty percent of patients with HFpEF and elevated mPAP at inclusion. Evaluation of RV contractility at rest showed a discordant trend, pointing out the need to test the RV during exercise. Further research is needed to determine if this approach can predict progression of RVD over time and serve as a risk stratification tool for these patients.