Rest and exercise oxygen uptake and cardiac output changes 6 months after successful transcatheter mitral valve repair

Abstract

Aims Changes in peak exercise oxygen uptake (VO2) and cardiac output (CO) 6 months after successful percutaneous edge‐to‐edge mitral valve repair (pMVR) in severe primary (PMR) and functional mitral regurgitation (FMR) patients are unknown. The aim of the study was to assess the efficacy of pMVR at rest by echocardiography, VO2 and CO (inert gas rebreathing) measurement and during cardiopulmonary exercise test with CO measurement. Methods and results We evaluated 145 and 115 patients at rest and 98 and 66 during exercise before and after pMVR, respectively. After successful pMVR, significant reductions in MR and NYHA class were observed in FMR and PMR patients. Cardiac ultrasound showed reverse remodelling (left ventricular end‐diastolic volume from 158 ± 63 mL to 147 ± 64, P < 0.001; ejection fraction from 51 ± 15 to 48 ± 14, P < 0.001; pulmonary artery systolic pressure (PASP) from 43 ± 13 to 38 ± 8 mmHg, P < 0.001) in the entire population. These changes were significant in PMR (n = 62) and a trend in FMR (n = 53), except for PASP, which decreased in both groups. At rest, CO and stroke volume (SV) increased in FMR with a concomitant reduction in arteriovenous O2 content difference [ΔC(a‐v)O2]. Peak exercise, CO and SV increased significantly in both groups (CO from 5.5 ± 1.4 L/min to 6.3 ± 1.5 and from 6.2 ± 2.4 to 6.7 ± 2.0, SV from 57 ± 19 mL to 66 ± 20 and from 62 ± 20 to 69 ± 20, in FMR and PMR, respectively), whereas peak VO2 was unchanged and ΔC(a‐v)O2 decreased. Conclusions These data confirm pMVR‐induced clinical improvement and reverse ventricular remodelling at a 6‐month analysis and show, in spite of an increase in CO, an unchanged exercise performance, which is achieved through a ‘more physiological’ blood flow distribution and O2 extraction behaviour. Direct rest and exercise CO should be measured to assess pMVR efficacy.

Successful intervention for decompensated heart failure with complicated pathophysiologies with complex interdependence: a case report

“… 7 Moreover, TMVR can increase forward stroke volume in cases of FMR by reducing MR and improving EF through left ventricular reverse remodelling; however, the effect is generally observed in the chronic phase, and its impact in the acute phase remains uncertain. 8 , 9 Similarly, CRT implantation increases cardiac output by establishing contraction resynchronization and left ventricular reverse remodelling. Cardiac resynchronization therapy has also been reported to improve the FMR immediately in 39–43% of cases.…”

An Overview of Sport Participation and Exercise Prescription in Mitral Valve Disease

“…Patients with functional MVR who underwent TEER showed an improvement in CPET parameters, including the peak VO 2 , likely due to the increase in anterograde stroke volume, decrease in pulmonary pressures, and reverse remodelling of the LV [81,82]. On the contrary, it has been reported that individuals affected by degenerative or secondary MVR treated with TEER did not exhibit an increase in peak VO 2 despite the improvement in cardiac output [83]. The authors have interpreted these results as the expression of a reduced arterial-venous O 2 content difference at the peak of exercise with respect to the pre-operative assessment.…”

Non-Invasive Cardiac Output Measurement Using Inert Gas Rebreathing Method during Cardiopulmonary Exercise Testing—A Systematic Review

“…The researchers conducting the studies included in this systematic review conducted CPET-IGR using varied testing protocols. Most of these were tests involving a progressive work rate [31,[59][60][61]63,[65][66][67][68][69][70][72][73][74][75][76][77][78][79][80]82,83,85,[93][94][95][96][97][98]101,102], while a few studies used constant load protocols in addition to progressive work rate tests [71,81,92,99,100].…”

“…Firstly, some of the studies included in this review were based on small patient groups [31,51,59,66,76,79], and most of the studies focused on patients with either healthy conditions or heart failure. There were few studies available that focused on other disease entities [85,89,[95][96][97][98][99]. Additionally, not all the required values could be obtained from the studies because they were not described.…”