Clinical value of preoperative cardiac magnetic resonance imaging and echocardiography to identify post-operative left ventricular dysfunction in primary mitral regurgitation
Authors: Altes A , Hanet V , Belhakia I , Selin N , Vancraeynest D , Pasquet A , Delelis F , Toledano M , Silvestri V , Gerber B L , Marechaux S 
Published: January 2025

Abstract

Background
Post-operative left ventricular (LV) dysfunction remains a common adverse consequence in patients with primary mitral regurgitation (MR) undergoing mitral valve (MV) surgery. Currently, cardiac magnetic resonance imaging (CMR) is a very useful imaging modality that complements echocardiography (Echo) in providing accurate grading of MR severity in these patients. Yet it remains unclear whether the consideration of CMR-assessed LV volumes and function would offer advantages over conventional echocardiographic LV measurements in identifying patients at risk of LV systolic dysfunction after MV surgery.

Purpose
We sought to compare the relationship between CMR- or Echo-assessed preoperative LV volumetric and function measurements and the occurrence of post-operative LV systolic dysfunction in patients with chronic significant primary MR undergoing MV surgery.

Methods
The study population consisted of 214 patients (median age: 59 years, 20% women) with chronic significant primary MR due to MV prolapse or flail who underwent echocardiography and CMR in 2 tertiary centers, between 2005 and 2022, before MV repair surgery. The endpoint was the occurrence of post-operative LV systolic dysfunction (defined as LV ejection fraction [EF] &lt; 50%) at echocardiographic follow-up when available. ROC curves were used to evaluate relations between preoperative Echo or CMR characteristics and post-operative LV dysfunction. Side-by-side comparisons of AUCs were done using DeLong’s tests.

Results
At echocardiographic follow-up, 40 patients (19%) had post-operative LV dysfunction, with a median follow-up time of 8.6 months (interquartile range: 6.7 – 12.5 months) after MV surgery. Compared with those with normal LV function, patients with post-operative LV dysfunction exhibited higher absolute and indexed (ind) LV end-systolic diameters (ESD) and volumes (ESV) (all p&lt;0.043, Figure 1). These patients also showed lower preoperative CMR-assessed LVEF (p=0.004), while Echo-LVEF did not show a significant relationship (p=0.071). Additionally, no relationship was found between MR quantitative parameters (regurgitant orifice area, volume, or fraction) and post-operative LV function (all p&gt;0.247). The AUCs of the imaging preoperative characteristics tested (LVESD, indLVESD, Echo-indLVESV, CMR-indLVESV, Echo-LVEF, CMR-LVEF) numerically ranged from 0.59 (0.50-0.69), p=0.034 (Echo-LVEF) to 0.69 (0.60-0.77), p&lt;0.001 (Echo-indLVESD, Figure 2). No significant differences were found in the side-by-side comparisons of the AUCs (all p&gt;0.118).

Conclusion
In this series of patients with chronic significant primary MR who underwent MV surgery, conventional preoperative Echo and CMR LV measurements had similar diagnostic value in detecting post-operative LV systolic dysfunction. Our results indicate that both echocardiography and CMR are valuable imaging tools for identifying primary MR patients at risk of post-operative LV dysfunction.
Figure 1
Figure 2