Multimodality imaging in PMV: comparison between cardiac computed tomography and echocardiography from multicenter mitral stenosis registry (MASTER registry)
Authors: Lee H J , Kim N Y , Suh Y J , Cho I , Hong G R 
Published: November 2023

Abstract

Background
The Wilkins score is a grading system that, from the past to the present, provides vital hints in patients with rheumatic mitral stenosis (MS). However even if the score is modest, complications may occur after percutaneous mitral valvuloplasty (PMV)1. Also Wilkins score alone does not reflect the development of various multi-modality imaging related to mitral stenosis. The purpose of this study was to evaluate the variability between echocardiography and cardiac computed tomography (CT) in measuring the score, and to examine the immediate PMV outcome related to the score measured by each modalities.

Methods
From the Multicenter mitrAl STEnosis with Rheumatic etiology (MASTER) registry of 3,140 patients with at least moderate MS, we included 96 rheumatic MS patients (age 56.4±11.5 years, 78 women) who underwent PMV and had remeasurable images between January 2010 and December 2022. We analyzed the discrepancies between the Wilkins score determined by echocardiography (transthoracic echocardiography or transesophageal echo in certain individuals) and the score determined by cardiac CT as a whole or among each parameter. Furthermore, the frequency of composite outcomes with high scores was compared between modalities. A composite outcome was defined as a case in which the outcome following PMV was not optimal (post PMV mitral valve area (MVA) less than 1.5 cm2 or mitral regurgitation (MR) with grade II-III or higher occurred).

Results
The average Wilkins score obtained by echocardiography was less than that measured by CT. (7.2±1.3 vs. 8.0±2.4) CT displayed higher score values than echocardiography, particularly for thickness (n= 47, 41.7%) and sub-valvular thickness (n= 40, 41.7%). Echo evaluated the presence of calcium, but CT showed no calcium in many cases. (n=19, 19.4% vs. n=38, 39.6%).
Based on the previously commonly used Wilkins score of 9 points, when evaluated by echocardiography, there wasn't a significant difference except for the post MVA (1.6±0.2 vs. 1.5±0.2 cm2, p value = 0.015) between less than and more than 9 points. Yet, in 40 patients with a CT-evaluated Wilkins score of 9 or higher, the post MVA was substantially smaller (1.6±0.1 vs. 1.5±0.3 cm2, p = 0.019) than in those without, and MDPG remained elevated even after the procedure. (4.0±1.4 vs. 4.9 ± 1.9 mmHg, p = 0.017) In addition, there were more cases where the MVA remained less than 1.5 cm2 after the procedure (n=10, 17.9% vs. n=22, 55.0%, p&lt;0.001). For this reason, the composite outcome found to be highly likely to occur. Even when the Wilkins score evaluated by echo was low, the composite outcome ratio was similarly high if the CT score was high.

Conclusions
The average value of the Wilkins score measured by echocardiography was lower than that measured by CT, mainly due to differences in leaflet thickness and sub-valvular thickness evaluation. Cases with a high Wilkins score evaluated by CT were more likely to have suboptimal MVA or significant MR after PMV.Wilkins score measured by each modalitieComposite event rate by Wilkins score