ABSTRACT
Background: Functional mitral regurgitation (FMR) is common in
patients with myocardial infarction or dilated cardiomyopathies, and
portends a poor prognosis despite guideline-directed medical therapy.
Surgical or transcatheter mitral repair for FMR from recent randomized
clinical trials showed disappointing or conflicting results.
Aims: To provide an update on the role of surgical repair in
the management of FMR.
Materials & Methods: A literature search was conducted
utilizing PubMed, Ovid, Web of Science, Embase and Cochrane Library. The
search terms included secondary/functional mitral regurgitation,
ischemic mitral regurgitation, mitral repair, mitral replacement, mitral
annuloplasty, transcatheter mitral repair, and percutaneous mitral
repair. Randomized clinical trials over the past decade were the
particular focus of this current review.
Results: Recent data underlined the complexity and poor
prognosis of FMR. Guideline-directed medical therapy and cardiac
resynchronization, when indicated, should always be applied. Accurate
assessment of the interplay between ventricular geometry and mitral
valve function is essential to differentiate proportionate FMR from the
disproportionate subgroup, which could be helpful in selecting
appropriate transcatheter intervention strategies. Surgical repair, most
commonly performed with an undersized ring annuloplasty, remains
controversial. Adjunctive valvular or subvalvular repair techniques are
evolving and may produce improved results in selected FMR patients.
Conclusion: FMR resulted from complex valve-ventricular
interaction and remodeling. Distinguishing proportionate FMR from
disproportionate FMR is important in exploring their underlying
mechanisms and to guide medical treatment with surgical or transcatheter
interventions. Further studies are warranted to confirm the clinical
benefit of appropriate surgical repair in selected FMR patients.