Left Atrial Strain as a Predictor of Postoperative Atrial Fibrillation After Mitral Valve Replacement for Mitral Stenosis: A Prospective Observational Study.

OBJECTIVES

Postoperative atrial fibrillation (POAF) is a common and serious complication following mitral valve replacement (MVR) in patients with mitral stenosis (MS). The goal of this study was to evaluate the predictive value of intraoperative left atrial (LA) strain for POAF in patients undergoing MVR for severe MS. Secondary objectives were to compare LA strain with conventional echocardiographic predictors, including LA length, LA volume, LA volume indexed (LAVi), and left atrial appendage peak flow (LAAPF) velocity, to find the optimal predictor for atrial fibrillation and LA/left atrial appendage (LAA) clot presence.

DESIGN

Prospective, observational study.

SETTING

Single tertiary care center.

PARTICIPANTS

Forty patients (38 analyzed) aged 18 to 50 years undergoing elective MVR. Patients were categorized into preoperative normal sinus rhythm (NSR) (n = 20) and preoperative atrial fibrillation (AF) groups (n = 18).

INTERVENTIONS: LA strain, LA length, LA volume, LAVi, and LAAPF velocity were measured intraoperatively using transesophageal echocardiography, after sternotomy, prior to heparinization for cardiopulmonary bypass.

MEASUREMENTS AND MAIN

RESULTS

New-onset POAF occurred in 45% of patients who were in NSR preoperatively. In this group, LA reservoir strain was the only significant predictor of POAF (14.8% v 20.7%, p < 0.001), with a strain value <16.5% having high predictive accuracy (area under the curve [AUC], 0.828) for new-onset POAF. In contrast, LA dimensional parameters were the best indicators of preexisting AF (AUC, ∼0.71), while LAAPF velocity was the superior predictor of LA/LAA clots (AUC, 0.953).

CONCLUSIONS

In patients with severe MS, the optimal echocardiographic predictor depends on the clinical question. LA strain is the most reliable parameter for predicting new-onset POAF in patients with sinus rhythm. In contrast, LA dimensional parameters showed the strongest correlation with preexisting AF, and LAAPF velocity is the superior predictor of LA/LAA clot. A multiparametric intraoperative assessment is therefore essential for comprehensive risk stratification.