Abstract 16657: Role of Exercise Induced Mitral Regurgitation and Its Prevalence in Functional Limitation of Heart Failure Patients With Preserved Ejection Fraction

Abstract

Background: Functional limitation in heart failure (HF) patients recognize multiple mechanisms. Exercise-induced mitral regurgitation (Ex-MR) has been extensively studied in HF population with reduced ejection fraction (HFrEF, EF < 40%), as responsible of right ventricle (RV) to pulmonary circulation (PC) uncoupling phenomenon. The relative role of this hemodynamic determinant has not been investigated so far in HF patients with preserved (HFpEF, EF > 50%) and mid-range EF (HFmrEF, EF 40 - 49%). Aim: To describe functional phenotypes and cardiac response to exercise in HF patients, with respect to the development of Ex-MR. Methods: 179 HF patients and 23 controls were tested with cardiopulmonary exercise test (CPET) combined with exercise-echocardiography. Based on current guidelines, we identified 114 HFrEF, 34 HFmrEF and 31 HFpEF, further divided according with the presence of at least moderate (>2+/4+) Ex-MR. Results: Ex-MR rate was 58%, 41% and 42% in HFrEF, HFmrEF and HFpEF, respectively. Ex-MR was associated with echocardiographic signs of RV-PC uncoupling (TAPSE/PASP ratio), particularly enhanced by the exercise in HFpEF patients. HFpEF with Ex-MR showed a distinct phenotype with chronotropic competence and increased peripheral oxygen extraction, compared to Ex-MR - cohort, possible expression of a compensatory mechanism to significant reduction in contractile reverse. The Ex-MR was associated with lower peak VO2 and workload in HFrEF and HFmrEF, while there were no differences related to HFpEF. The presence of Ex-MR significantly compromised also ventilatory efficiency (VE/VCO2) in all HF classes. Conclusion: Ex-MR emerged as a new mechanism of functional limitation in HFpEF, sharing a common pathophysiological basis with other HF patients. The RV-PC uncoupling is the best haemodynamic correlate of Ex-MR.