PhD Scientific Days 2023

Clinical Medicine II.

Specle tracking strain analysis predicts mortality and ventricular tachycardia recurrence after catheter ablation in patients with structural heart disease

Text of the abstract

Introduction
Catheter ablation is the gold standard therapy for drug-refractory, recurrent ventricular tachycardia (VT) in patients with structural heart disease. Wide range of clinical and procedural predictors of post-ablation VT recurrence and mortality are described by previous studies. However, echocardiographic predictors, besides left ventricular ejection fraction (LVEF), are still unknown. Speckle tracking echocardiography (STE) is a novel and promising method to evaluate systolic and diastolic function. STE derived parameters, such as global longitudinal strain (GLS), are proven predictors of mortality and arrhythmic events in heart diseases.

Aims
The aim of the present study was to assess whether STE derived parameters could be considered predictors of VT recurrence and mortality after catheter ablation of ventricular tachycardia in patients with structural heart disease in this retrospective study.

Method
We measured the pre-ablation strain and strain rate values with speckle tracking, using TomTec Arena® (TOMTEC Imaging Systems GmbH, Germany). Left ventricular four-chamber longitudinal strain (LV4CLS), early diastolic strain rate (e’-sr), right ventricular free wall longitudinal strain (RVFWLS) and right ventricular four-chamber longitudinal strain (RV4CLS) were assessed in 88 cases. All patients were followed at least one year, median follow-up was 3.4 years. The primary endpoint was VT recurrence, which was defined as either ICD recording of a sustained VT episode requiring therapy or an episode of sustained VT recorded on 12-lead ECG. The secondary endpoint was all-cause mortality.

Results
LV4CLS was the predictor of one year and long-term VT recurrence (HR: 0.57 [0.35-0.92]; p = 0.02 and HR: 0.67 [0.45-0.99]; p = 0.04, respectively) in univariate analysis. RV4CLS was the predictor of one year and long-term mortality (HR: 0.45 [0.24- 0.85]; p = 0.01 and HR: 0.68 [0.47-0.97]; p = 0.04, respectively) in univariate analysis. The optimal cut-off value of RV4CLS for one year mortality was 9.74% by ROC analysis. Kaplan-Meier curves showed an increased risk of death (log-rank p <0.01) in the <9.74% group.

Conclusion
Strain parameters may supplement anamnestic, clinical, procedural and conventional echocardiographic parameters in the prediction of VT recurrence and mortality after catheter ablation in patients with structural heart disease. Further prospective clinical studies are necessary to verify the significance of strain parameters.