Project description:This review outlines the first trial experience with transcatheter therapy for mitral regurgitation (MR), developed from the EVEREST II MitraClip trial in a trial population comprised predominantly of patients with degenerative mitral regurgitation (DMR). Subsequent experience with MitraClip and several other devices has been mostly in functional MR patients. At the same time, there has been ongoing experience with MitraClip in DMR, and a variety of other devices have been developed for catheter-based treatment of MR. Annuloplasty devices have been indicated for DMR, and the potential for transcatheter annuloplasty to be used, in conjunction with other catheter techniques, such as chordal replacement, as it is in standard mitral repair, is developing. Transcatheter mitral valve replacement will clearly have some role for MR of both functional and degenerative etiologies, when repair is not feasible or fails. This review will discuss the evidence base and future development of these mitral repair and replacement approaches for DMR.
Project description:BackgroundWhen 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.Methods83 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).Results72 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.ConclusionIn primary MR, MVR with chordal preservation may offer comparable cardiac reverse remodeling and functional benefits at 6-months when compared to MVr. Larger, multicenter CMR studies are required, which if the findings are confirmed could impact future surgical practice.
Project description:Preservation of the subvalvular apparatus has the merits of postoperative outcomes during mitral valve replacement for mitral regurgitation. We performed mitral valve replacement with anterior and posterior leaflet chordal preservation in a 65-year-old woman. On the 2nd postoperative day, routine postoperative trans-thoracic echocardiography showed an unknown aortic subvalvular mobile mass. We report a case of a remnant mitral subvalvular apparatus detected by echocardiography after chordal preserving mitral valve replacement which was confused with postoperative aortic valve vegetation.