Primary outcome, by electrical storm at presentation. The primary outcome was a composite of death at any time or VT storm (three or more documented episodes of VT within 24 h) or appropriate ICD shock after a 30-day treatment period. Kaplan–Meier survival curves for the primary outcome between escalated antiarrhythmic drug therapy vs. catheter ablation are shown, by the presence of electrical storm at presentation, for the overall trial population (N = 259) and for those taking amiodarone at baseline (N = 169). Log-rank P-values and unadjusted hazard ratios (escalated therapy vs. ablation) are also presented. AAD, antiarrhythmic drug; CI, confidence interval; VT, ventricular tachycardia.