Speckle tracking echocardiography predicts electroanatomical scar in patients with ischaemic cardiomyopathy undergoing catheter ablation for ventricular tachycardia

INTRODUCTION Characterisation of the myocardial substrate before ventricular arrhythmia (VA) ablation procedures is paramount for procedural planning. Cardiac magnetic resonance (CMR) can identify areas of fibrosis, but it is often not feasible. Speckle tracking echocardiography (STE) may be an alternative for identifying subtle left ventricular alterations. This study evaluated a segment- and layer-specific longitudinal strain (LS) approach for predicting electroanatomical scar. METHODS From April 2022 to May 2024, consecutive patients with ischaemic cardiomyopathy undergoing ablation for recurrent VAs were prospectively enrolled. LS and electroanatomical data were matched using an 18-segment model. Prediction of electroanatomical scar with segmental layer-specific LS was evaluated using mixed-effects logistic regression. Receiver Operating Characteristic (ROC) curve analysis was used to evaluate diagnostic performance and optimal thresholds. RESULTS Thirty-two patients were enrolled: median age was 70.3 years, median left ventricular ejection fraction was 37%, and 1458 pairs of segments were analysed. LS was impaired in segments with electroanatomical scar compared to normal segments in all myocardial layers (p < 0.0001). Endocardial strain predicted bipolar voltage-defined scar (5.0% higher odds per strain unit, p = 0.004, AUC 0.787). Midmyocardial strain predicted unipolar voltage-defined scar (5.6% higher odds per strain unit, p = 0.016, AUC 0.834). Optimal thresholds were - 5.4% for endocardial strain and - 14.6% for midmyocardial strain. CONCLUSION Segmental layer-specific STE effectively predicts electroanatomical scar in patients with ischaemic cardiomyopathy, and may be a valuable pre-procedural planning tool, particularly when CMR is unavailable.