Risk stratification of patients undergoing cardiac surgery for severe mitral regurgitation: the role of speckle tracking echocardiorgraphy
Authors: Pastore M C , Marrese F , Tanzi L , Lisi M , Mandoli G E , Stefanini A , Rizzo M , Lorenz V , Alba G , Cavigli L , Montesi G , Focardi M , D'ascenzi F , Valente S , Cameli M 
Published: January 2025

Abstract

Background
Mitral regurgitation (MR) is the second most common valvular heart disease (VHD) in Europe, for which the most resolutive treatment is surgical intervention. A careful preoperative evaluation of patients with MR is important to optimize the timing of intervention and avoid the possible complication after surgery. For this purpose, finding reliable prognostic markers to predict adverse outcome after mitral valve surgery may be fundamental. The aim of this study was to assess prognostic parameters, among basic and speckle tracking echocardiography (STE), including myocardial work (MW) parameters, in patients undergoing surgical treatment for MR.

Methods
We prospectively enrolled patients with severe MR who underwent preoperative clinical, biohumoral and echocardiographic evaluation, completed by STE, before mitral valve surgical repair or replacement. Patients with atrial fibrillation at the time of enrolment, previous cardiac surgery or other severe VHD were excluded. After surgery, patients were followed by on-site visits or phone calls to investigate clinical outcome. The primary endpoint was the occurrence of a composite endpoint (heart failure hospitalizations and all cause-mortality), the secondary endpoint was the assessment of postoperative functional capacity assessed by NYHA class and Borg CR10 and of postoperative hospitalization lenght.

Results
Among 110 patients (65±13 years), 10 patients reached the primary endpoint (7 deaths and 3 hospitalizations for heart failure). The population presented a preserved left ventricular ejection fraction (58±4%) and dilated left atria (55 ±19 ml/m2). Among strain variables, there was a reduction of mean peak atrial longitudinal strain (PALS)=22%±8, a mild reduction of mean free wall right ventricular longitudinal strain (FW-RVLS)=-22.3% ± 7.6, and normal left ventricular strain=-20.4% [-17.5 to -22.8]. MW parameters was nearly normal (global work index=1927 ± 573 mmHg%, mean global wasted work (GWW)=243 ± 156 mmHg%). Patients who had events presented lower PALS and FWRVLS values compared with patients without events. Receiver operating characteristic (ROC) curves revealed as optimal cutoff values for PALS ≤ 21.5% and FW-RVLS ≥ -22% for the prediction of the primary endpoint, which was used to divide the population into three groups according to both preserved PALS and FWRVLS, preserved either PALS or FWRVLS ad both reduced PALS and FWRVLS. Event-free survival analysis by Kaplan Meier curves showed a good risk stratification for the three groups (Fig.1). Regarding the functional capacity in the postoperative period (secondary endpoint), it was found that GWW was the only parameter associated with NYHA class &gt; II at follow-up (p = 0.04)

Conclusions
The use of speckle tracking through a combined evaluation of global PALS and FWRVLS offers a reliable prediction of unfavorable outcomes in patients undergoing mitral surgery for severe MR.