Speckle-Tracking Echocardiography Parameters Associated With Ventricular Arrhythmia Recurrence-Free Survival After Ablation in Structural Heart Disease.

BACKGROUND

Catheter ablation (CA) is indicated for drug-refractory ventricular arrhythmias (VAs). Predicting adverse outcomes (recurrent VA or mortality) after CA is important, but current tools are imperfect. Speckle-tracking echocardiography quantifies global longitudinal strain (GLS), a measure of myocardial deformation, and mechanical dispersion (MD) and delta contraction duration (DCD) (measures of myocardial contraction heterogeneity). The aim of this study was to examine the associations between clinical, procedural, and echocardiographic parameters and subsequent VA recurrence or death.

METHODS

One hundred eighty-one patients (ischemic cardiomyopathy, n = 82; nonischemic cardiomyopathy, n = 99) with VAs undergoing CA underwent echocardiography, including measurements of left ventricular GLS, MD, and DCD. Patients were longitudinally followed for first occurrence of VA recurrence or death; in the absence of VA recurrence or death, a patient was deemed to have VA recurrence-free survival.

RESULTS

Median follow-up duration was 21.0 months. After the procedure, 20 patients (11%) died without any prior VA recurrence, and 77 patients (43%) experienced VA recurrence, of whom 11 subsequently died. Cox proportional-hazards regression analysis identified acute procedural failure, at least two inducible VAs, DCD, and the interaction between GLS and DCD as significant predictors of VA recurrence-free survival. When GLS and DCD were dichotomized by their median values (GLS ≤ -11.5% vs >-11.5%; DCD ≤ 190 vs >190 ms), DCD > 190 ms was a predictor of the composite endpoint irrespective of GLS status. MD was not as strong a predictor as DCD.

CONCLUSIONS

In patients undergoing CA for VAs, the only echocardiographic predictor of VA recurrence-free survival was prolonged DCD, irrespective of GLS and clinical and procedural factors. Hence, DCD may facilitate risk stratification before CA.