Cardiac reverse remodeling in primary mitral regurgitation: mitral valve replacement vs. mitral valve repair

• Published in: Journal of cardiovascular magnetic resonance 2023-07, Vol.25 (1), p.43-43, Article 43
• Main Authors: Craven, Thomas P., Chew, Pei G., Dobson, Laura E., Gorecka, Miroslawa, Parent, Martine, Brown, Louise A.E., Saunderson, Christopher E.D., Das, Arka, Chowdhary, Amrit, Jex, Nicholas, Higgins, David M., Dall'Armellina, Erica, Levelt, Eylem, Schlosshan, Dominik, Swoboda, Peter P., Plein, Sven, Greenwood, John P.
• Format: Article
• Language: English
• Subjects: Aorta; Cardiovascular magnetic resonance; CMR; Comparative analysis; Echocardiography; Fibrosis; Gadolinium; Heart; Humans; Imaging; Ischemia; Magnetic resonance; Medical research; Medicine, Experimental; Mitral regurgitation; Mitral valve; Mitral Valve - diagnostic imaging; Mitral Valve - surgery; Mitral valve insufficiency; Mitral Valve Insufficiency - diagnostic imaging; Mitral Valve Insufficiency - pathology; Mitral Valve Insufficiency - surgery; Mitral valve repair; Mitral valve replacement; Multivariate analysis; Patients; Phase contrast; Predictive Value of Tests; Preservation; Pulmonary arteries; Regurgitation; Stroke Volume; Surgeons; Surgery; Ventricle; Ventricular Function, Right
• ISSN: 1097-6647; 1532-429X
• DOI: 10.1186/s12968-023-00946-9

When feasible, guidelines recommend mitral valve repair (MVr) over mitral valve replacement (MVR) to treat primary mitral regurgitation (MR), based upon historic outcome studies and transthoracic echocardiography (TTE) reverse remodeling studies. Cardiovascular magnetic resonance (CMR) offers reference standard biventricular assessment with superior MR quantification compared to TTE. Using serial CMR in primary MR patients, we aimed to investigate cardiac reverse remodeling and residual MR post-MVr vs MVR with chordal preservation. 83 patients with ≥ moderate-severe MR on TTE were prospectively recruited. 6-min walk tests (6MWT) and CMR imaging including cine imaging, aortic/pulmonary through-plane phase contrast imaging, T1 maps and late-gadolinium-enhanced (LGE) imaging were performed at baseline and 6 months after mitral surgery or watchful waiting (control group). 72 patients completed follow-up (Controls = 20, MVr = 30 and MVR = 22). Surgical groups demonstrated comparable baseline cardiac indices and co-morbidities. At 6-months, MVr and MVR groups demonstrated comparable improvements in 6MWT distances (+ 57 ± 54 m vs + 64 ± 76 m respectively, p = 1), reduced indexed left ventricular end-diastolic volumes (LVEDVi; − 29 ± 21 ml/m2 vs − 37 ± 22 ml/m2 respectively, p = 0.584) and left atrial volumes (− 23 ± 30 ml/m2 and − 39 ± 26 ml/m2 respectively, p = 0.545). At 6-months, compared with controls, right ventricular ejection fraction was poorer post-MVr (47 ± 6.1% vs 53 ± 8.0% respectively, p = 0.01) compared to post-MVR (50 ± 5.7% vs 53 ± 8.0% respectively, p = 0.698). MVR resulted in lower residual MR-regurgitant fraction (RF) than MVr (12 ± 8.0% vs 21 ± 11% respectively, p = 0.022). Baseline and follow-up indices of diffuse and focal myocardial fibrosis (Native T1 relaxation times, extra-cellular volume and quantified LGE respectively) were comparable between groups. Stepwise multiple linear regression of indexed variables in the surgical groups demonstrated baseline indexed mitral regurgitant volume as the sole multivariate predictor of left ventricular (LV) end-diastolic reverse remodelling, baseline LVEDVi as the most significant independent multivariate predictor of follow-up LVEDVi, baseline indexed LV end-systolic volume as the sole multivariate predictor of follow-up LV ejection fraction and undergoing MVR (vs MVr) as the most significant (p < 0.001) baseline multivariate predictor of lower residual MR. In primary MR, MVR with chordal preservati