Hybrid therapy with ablation + subcutaneous ICD for secondary prevention of sudden cardiac death in ischemic heart disease

Abstract

Abstract Background The aim of the prospective Ventricular Tachycardia Ablation- Subcutaneous ICD (VTAbl-SICD) Trial was to provide data on the efficacy and safety of a novel hybrid management strategy that combines VT ablation (VTAbl) with S-ICD implantation in patients who present with scar-related VT. The rate of appropriate therapy in patients with S-ICD may be a quite fairest surrogate of true residual sudden death (SD) risk compared to transvenous ICD (TV-ICD). More specific data on ischemic heart disease – the prominent cause of VT with the better results of VTAbl – may give arguments for questioning current practices in the future. Methods 32 patients with post ischemic scar-related sustained VT/VF were included. Patients underwent VTAbl with subsequent (or previous prophylactic n=8) S-ICD implant and were followed for 2-years. We evaluate the occurrence of appropriate and ICD therapies once ablated, as well as cardiovascular (CV) readmissions or death. We also compared to 64 propensity-score matched patients implanted with a secondary prevention TV-ICD (enrolled in the Ranolazine in High-Risk Patients With Implanted Cardioverter-Defibrillators (RAID) trial). Results Mean age was 57±12 years (28 males, 87%) (53% hypertension, 31% diabetes and 47% congestive heart failure with NYHA 1.6±1). Mean LVEF was 39±9%.There were no major complications associated with the ablation and implant procedures. Propensity-score matched patients implanted with a secondary prevention TV-ICD displayed similar clinical characteristics. At 16.5±8.6 months FU, appropriate ICD therapy occurred in 5 patients (15%) in the VTAbl-SICD group, significantly lower compared to the TV-ICD group (34 pts, 53%) (p<0.001). This corresponded to 2-year cumulative probability of 20% vs. 71% in the VTAbl-SICD vs. TV-ICD groups, respectively (log-rank p<0.001; Figure 1) and a significant 83% reduction in the risk of appropriate ICD therapy associated with VTAbl-SICD (HR= 0.17 [95% CI 0.07 - 0.39; p<0.001). Two of the patients who received appropriate ICD therapy in the VTAbl-SICD group may have had unrecognized transient causes of VT (torsades de pointes or unrecognized ischemia), letting 3 out of 32 (10%) with possible aborted SD caused by VT recurrences. There were no cases of untreated symptomatic VT. The rate of CV readmissions was similar in the VTAbl-SICD (41%) vs. TV-ICD group (44%) (p=0.7), whereas mortality was significantly lower in the VTAbl-SICD- vs.TV-ICD- group (0% vs. 17%, respectively; p<0.001) Conclusions Our findings suggest that VT ablation in ischemic heart disease patients allow reaching a low residual true risk for SD, which should now be evaluated in terms of cost-effectiveness compared to ablation + S-ICD implantation. Concommitant S-ICD implantation seems to be a safe alternative to TV-ICD without ablation.Appropriate ICD therapy-free KM