Assessing right ventricular functional response during incremental exercise in heart failure: insights on mitral regurgitation and ventilatory efficiency

Abstract

Purpose: Right ventricular (RV) dysfunction and pulmonary hypertension (PH) are predictors of adverse prognosis in patients with heart failure reduced ejection fraction (HFrEF).Mitral regurgitation (MR) plays a central role in determining pulmonary flowoverload and PH. We explored the functional response of the RV during maximal exercise according toMRseverity and ventilatory response by combining stress Echo with cardiopulmonary exercise test (CPET). Methods: 45 HFrEF patients (age 67±11; male 64%; ischemic 79%; NYHA class II/III/ IV 46%/42%/12% and EF 36±8%) were evaluated at rest and during exercise (tilt table cycleergometer) assessing the changes in the RV TAPSE (length) vs pulmonary arterial systolic pressure PASP (developed pressure, force) relationship along with exerciseinduced MR changes and ventilatory efficiency (VE/VCO2) response. Results: Patientswith an impaired RV function (n 14, Group A, TAPSE , 16 mm; average 12.8±2.5 mm and PASP 44±20 mmHg) compared to Group B (n 31, TAPSE > 16, average 21.6±3 and PASP 35.2±11.6) presented with a high prevalence of rest moderate-to-severe MR (43% vs 13%; p<0.05), a remarkable steeper VE/VCO2 slope (41.2±9 vs 30.5±6; p<0.001) and an unfavorable TAPSE vs PAPS relationship (Figure). At peak exercise, the relationship TAPSE vs PAPS of the group A shifted upward to a functional RV response lower than the one observed at rest in group B (Figure), suggesting a limited degree of RV contractile reserve. Conclusions: In HFrEF the functional response of the RV during maximal exercise differs according to thedegree ofMRthat,whenmoderatetosevere, typicallycombineswith ventilatory inefficiency. The functional evaluation of RV function during maximal exercise provides adjunctive insights in the clinical work-up of HFrEF. (Figure presented).