Are recurrence of ischemic mitral regurgitation and left ventricular reverse remodeling after restrictive annuloplasty ring dependent?
Introduction
The treatment of chronic ischemic mitral regurgitation (CIMR) is still controversial [1]. The main challenges rise from its complex pathophysiology and high post-repair recurrence rate secondary to continued left ventricular remodeling [[2], [3], [4], [5]]. Complex changes involve also the mitral annulus which increases in size, flattens its 3D saddle-like shape and loses its dynamic function [[5], [6], [7]]. The deeper understanding of such pathophysiological dynamic annular modifications has led to a new generation of non-planar mitral rings for mitral repair aimed at maintaining normal 3D annular geometry and allowing for an improved surface area of coaptation [4,[8], [9], [10], [11], [12], [13], [14]]. More recently, asymmetric rings have been introduced that reduce the septal-lateral dimension greatly in the P3 region which is the site of the most extensive tethering in CIMR [15]. Nonetheless, no successfully completed randomized trials exist comparing the efficacy of different types of rings and clearly demonstrating superiority of one device over the others. Therefore, the aim of this systematic review and meta-analysis is to investigate mitral regurgitation recurrence and degree of left ventricular reverse remodeling (LVRR) after restrictive mitral annuloplasty (RMA) in CIMR patients employing different ring designs.
Section snippets
Search strategy
Literature search was conducted in accordance with the Preferred Reporting Items for Systematic Review and Metanalyses (PRISMA) and Cochrane Handbook [16,17]. Participants, interventions, comparisons, outcomes and study design were addressed following PICOS (Population or Problem-Intervention or exposure-Comparison- Outcome-Study design) [18]. For the purpose of the review, rings identified through database search are stratified to either planar or non-planar ring groups. The search strategy
Characteristics of the studies
The selection process is illustrated in the PRISMA flowchart in the Supplemental Fig. S1. The total number of studies found was 1029. After a first screening, 208 articles remained to be assessed for eligibility and final inclusion in the qualitative assessment. Among these, 18 articles satisfied the inclusion criteria. Two additional studies were included from further search conducted on the reference lists of the original sources. Therefore, a total of 20 articles were eligible [[2], [3], [4],
Discussion
Recent evidence shows that restoration of the mitral annular area and the physiological 3D saddle shape is essential for a durable mitral valve (MV) repair [[38], [39], [40]]. Furthermore, it has been shown that, in chronic ischemic mitral regurgitation (CIMR) the tethering is prevalent at the medial aspect [15]. Consequently, different ring designs have been proposed, addressing the annulus shape or the tethering asymmetry.
However, despite the great amount of literature on the topic, there is
Limitations
Our study has some limitations that have to be pointed out. Firstly, the majority of the studies included have retrospective nature because no randomized clinical trial has been found regarding this topic. Secondly, relevant variability in follow-up periods was reported among the studies. Thirdly, data on volume reduction was not widely available, therefore we used LVEDD as index of ventricular remodeling, but LV volumes have been demonstrated to be more reliable than LV diameters in assessing
Conclusions
Recurrence of MR was not influenced by the ring employed. Nonetheless, in the single analyses, the IMR-ETlogix showed the lowest rate of recurrence. In contrast, left ventricular reverse remodeling occurred at a greater extent in planar symmetric rings. The paper despite it does not gives clear-cut conclusions is the proof that a randomized trial between rings or better selection patients for single studies are needed to address the issue.
The following are the supplementary data related to this
Funding
The authors received no financial support for the research and/or authorship of this article.
CRediT authorship contribution statement
Linda Renata Micali: Investigation, Writing - original draft. Gianmarco Parise: Data curation. Amalia Ioanna Moula: Data curation, Formal analysis. Yazeed Alayed: Investigation. Orlando Parise: Formal analysis. Francesco Matteucci: Software. Monique de Jong: Data curation. Cecilia Tetta: Methodology, Writing - review & editing. Sandro Gelsomino: Writing - original draft, Writing - review & editing, Supervision.
Declaration of competing interest
The authors declare no conflicts of interest.
Acknowledgements
We kindly acknowledge Dr. Judith Wilson for the English Editing of the Manuscript.
References (53)
- et al.
A comparison of 2 mitral annuloplasty rings for severe ischemic mitral regurgitation: clinical and echocardiographic outcomes
Semin. Thorac. Cardiovasc. Surg.
(2016) - et al.
A prospective study of predicting factors in ischemic mitral regurgitation recurrence after ring annuloplasty
Ann. Thorac. Surg.
(2007) - et al.
Remodeling annuloplasty using a prosthetic ring designed for correcting type-IIIb ischemic mitral regurgitation
Rev. Esp. Cardiol.
(2007) - et al.
Mid-term results of mitral valve repair for ischemic mitral regurgitation with ETlogix ring: a single-center study
Int. J. Cardiol.
(2016) - et al.
Three-dimensional valve repair—the better care? Midterm results of a saddle-shaped, rigid annuloplasty ring in patients with ischemic mitral regurgitation
J. Thorac. Cardiovasc. Surg.
(2014) - et al.
Mitral valve repair for ischemic mitral regurgitation using the Carpentier-McCarthy-Adams IMR ETlogix(R) ring: medium-term echocardiographic findings
Rev. Esp. Cardiol.
(2010) - et al.
Five-year real world outcomes of GeoForm ring implantation in patients with ischemic mitral regurgitation
J. Thorac. Cardiovasc. Surg.
(2014) - et al.
In-vivo analysis of selectively flexible mitral annuloplasty rings using three-dimensional echocardiography
Ann. Thorac. Surg.
(2014) - et al.
Saddle-shaped annuloplasty improves leaflet coaptation in repair for ischemic mitral regurgitation
Ann. Thorac. Surg.
(2015) - et al.
Recurrent mitral regurgitation after annuloplasty for functional ischemic mitral regurgitation
J. Thorac. Cardiovasc. Surg.
(2004)