Outcomes of ventricular tachycardia ablation in patients with structural heart disease: The impact of electrical storm

Abstract

Aims: To investigate predictors of long-term outcomes after catheter ablation (CA) for ventricular tachycardia (VT) and the impact of electrical storm (ES) prior to index ablation procedures.

Methods: We studied consecutive patients with structural heart disease and VT (n = 328; age: 63±12 years; 88% males; 72% ischaemic cardiomyopathy; LVEF: 32±12%) who had undergone CA. According to presenting arrhythmia at baseline, they were divided into ES (n = 93, 28%) and non-ES groups. Clinical predictors of all-cause mortality were investigated and a clinically useful risk score (SCORE) was constructed.

Results: During a median follow-up of 927 days (IQR: 564-1626), 67% vs. 60% of patients (p = 0.05) experienced VT recurrence in the ES vs. the non-ES group, respectively; and 41% vs. 32% patients died (p = 0.02), respectively. Five factors were independently associated with mortality: age >70 years (hazard ratio (HR): 1.6, 95% confidence interval (CI): 1.1-2.4, p = 0.01), NYHA class ≥3 (HR: 1.9, 95% CI: 1.2-2.9, p = 0.005), a serum creatinine level >1.3 mg/dL (HR: 1.6, 95% CI: 1.1-2.3, p = 0.02), LVEF ≤25% (HR: 2.4, 95% CI: 1.6-3.5, p = 0.00004), and amiodarone therapy (HR: 1.5, 95% CI: 1.0-2.2, p = 0.03). A risk SCORE ranging from 0-4 (1 point for either high-risk age, NYHA, creatinine, or LVEF) correlated with mortality. ES during index ablation independently predicted mortality only in patients with a SCORE ≤1.

Conclusions: Advanced LV dysfunction, older age, higher NYHA class, renal dysfunction, and amiodarone therapy, but not ES, were predictors of poor outcomes after CA for VT in the total population. However, ES did predict mortality in a low-risk sub-group of patients.

Conflict of interest statement

JK is a member of advisory boards for Bayer, Biosense Webster, Boehringer Ingelheim, Boston Scientific, Daiichi Sankyo, Medtronic, Liva Nova (Sorin), and St. Jude Medical. He has received speaking honoraria from Bayer, Biosense Webster, Biotronik, Boehringer Ingelheim, Boston Scientific, Liva Nova (Sorin), Medtronic, and St. Jude Medical. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Figures

Fig 1. Event-free survival analysis in ES versus non-ES patients.

Kaplan-Meier curves show event-free survival in the 2 main study groups—in patients who were ablated for ES (red line) versus non-ES ventricular arrhythmia (blue line). Separate graphs and comparisons were assembled for individual endpoints—VT recurrence after index ablation (left panel), and all-cause death after index ablation (right panel). Note that ES patients had worse outcomes for both endpoints.

Fig 2. All-cause mortality—impact of individual clinical factors.

Kaplan-Meier survival curves for the population dichotomised by ES/non-ES index ablation and by individual clinical factors: age ≤70 yrs (left upper panel), NYHA class

Fig 3. All-cause mortality—impact of clinical risk score.

Kaplan-Meier survival curves for the population categorised by clinical risk score (Panel A) and in sub-groups defined by the combination of the main study groups (ES/non-ES) and dichotomised clinical risk scores (≤1 or ≥2) (Panel B).