SMASH-VT Trial Presented at The Heart Rhythm Society Meeting May 2006 Presented by Dr. Vivek Reddy Substrate Mapping and Ablation in Sinus Rhythm to Halt Ventricular Tachycardia Trial

SMASH-VT Trial: Background The goal of the trial was to evaluate treatment with ICD implantation with catheter ablation compared with ICD alone among post myocardial infarction (MI) patients with sustained ventricular tachycardia (VT)/ ventricular fibrillation (VF)The goal of the trial was to evaluate treatment with ICD implantation with catheter ablation compared with ICD alone among post myocardial infarction (MI) patients with sustained ventricular tachycardia (VT)/ ventricular fibrillation (VF) Presented at HRS 2006

SMASH-VT Trial: Study Design Presented at HRS 2006  Primary Endpoint: Appropriate ICD therapies ICD implantation with substrate-based catheter ablation n=62 n=62 ICD alone n=64 n= patients not using class l or lll antiarrhythmic drugs, prior MI, and either VF arrest, unstable VT, or prior ICD and single appropriate shock Randomized. 13% female, mean age 66 years, mean follow-up 2 years 71% NYHA Class ll, 18% NYHA Class lll, Mean EF 31.7% 18% had VF arrest, 52% had unstable VT, 21% had syncope and inducible VT and 9% had prior ICD and single appropriate shock, 96% received beta-blockers and 91% received ACE-inhibitors, index MI was anterior in 41% of patients and 67% had prior revascularization 126 patients not using class l or lll antiarrhythmic drugs, prior MI, and either VF arrest, unstable VT, or prior ICD and single appropriate shock Randomized. 13% female, mean age 66 years, mean follow-up 2 years 71% NYHA Class ll, 18% NYHA Class lll, Mean EF 31.7% 18% had VF arrest, 52% had unstable VT, 21% had syncope and inducible VT and 9% had prior ICD and single appropriate shock, 96% received beta-blockers and 91% received ACE-inhibitors, index MI was anterior in 41% of patients and 67% had prior revascularization  Ablation was performed with electroanatomic mapping to delineate the endocardial infarct margins  The radiofrequency ablation catheter used either a standard 4mm (n=10) or an irrigated 3.5 mm tip (n=52)  Ablation was performed with electroanatomic mapping to delineate the endocardial infarct margins  The radiofrequency ablation catheter used either a standard 4mm (n=10) or an irrigated 3.5 mm tip (n=52)

SMASH-VT Trial: Primary Endpoint Presented at HRS 2006 Primary endpoint of appropriate ICD therapy (%) p<0.05 Incidence of appropriate ICD shock (%) p<0.05 The primary endpoint of appropriate ICD therapy occurred less frequently in the ablation group compared with the control group (15% vs. 33% p=<0.05), as did appropriate ICD shock (10% vs. 33%, p=<0.05). The primary endpoint of appropriate ICD therapy occurred less frequently in the ablation group compared with the control group (15% vs. 33% p=<0.05), as did appropriate ICD shock (10% vs. 33%, p=<0.05).

SMASH-VT Trial: Adverse Events SMASH-VT Trial: Adverse Events Presented at HRS 2006 Mortality occurred in 7% of the ablation group and 17% of the control group (p=0.073).Mortality occurred in 7% of the ablation group and 17% of the control group (p=0.073). Among the adverse events in the ablation group, there was one pericardial effusion without tamponade, one deep vein thrombosis, and one CHF exacerbation.Among the adverse events in the ablation group, there was one pericardial effusion without tamponade, one deep vein thrombosis, and one CHF exacerbation. Mortality among both patient groups (%) p=0.073

SMASH-VT Trial: Summary Among post-MI patients with sustained VT/VF, ICD implantation with substrate-based catheter ablation was associated with a reduction in appropriate ICD therapy through two years compared with ICD therapy alone.Among post-MI patients with sustained VT/VF, ICD implantation with substrate-based catheter ablation was associated with a reduction in appropriate ICD therapy through two years compared with ICD therapy alone. The present trial suggests that the procedure can also be effective in reducing ICD shocks in the post-MI setting, although it should be noted that the procedure is difficult to perform and extremely technical, so use for prophylactic therapy should be undertaken with caution and only in experienced centers.The present trial suggests that the procedure can also be effective in reducing ICD shocks in the post-MI setting, although it should be noted that the procedure is difficult to perform and extremely technical, so use for prophylactic therapy should be undertaken with caution and only in experienced centers. Among post-MI patients with sustained VT/VF, ICD implantation with substrate-based catheter ablation was associated with a reduction in appropriate ICD therapy through two years compared with ICD therapy alone.Among post-MI patients with sustained VT/VF, ICD implantation with substrate-based catheter ablation was associated with a reduction in appropriate ICD therapy through two years compared with ICD therapy alone. The present trial suggests that the procedure can also be effective in reducing ICD shocks in the post-MI setting, although it should be noted that the procedure is difficult to perform and extremely technical, so use for prophylactic therapy should be undertaken with caution and only in experienced centers.The present trial suggests that the procedure can also be effective in reducing ICD shocks in the post-MI setting, although it should be noted that the procedure is difficult to perform and extremely technical, so use for prophylactic therapy should be undertaken with caution and only in experienced centers. Presented at HRS 2006