Prophylactic Substrate Ablation in Post-myocardial Patients Undergoing Defibrillator Implantation.

Prophylactic substrate ablation in post-MI patients undergoing defibrillator implantation reduces appropriate defibrillator therapies.

Background In patients with Ventricular Tachycardia (VT) and structural heart disease, the Implanted Cardioverter Defibrillator (ICD), provides a significant protection against the risk of sudden death, however it does not prevent arrhythmia recurrences [1-7]. ICD therapies, especially shocks, pose several risks, including decreased quality of life, increased mortality among patients who suffer ICD shock compared with patients who do not and clinically significant anxiety and depression as a result of recurrent ICD shocks, which has been found to occur in more than 50% of patients [8-12]. Furthermore, ICD implantation has been found not to protect against sudden cardiac death in 3-7% of patients [13]. The benefit of novel ICD programming in reducing inappropriate ICD therapy and mortality was demonstrated in Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy (MADIT-RIT) [14]. Catheter ablation has been considered a plausible curative therapy for VT prevention, especially in patients with VT episodes [15]. The Substrate Mapping and Ablation in Sinus Rhythm to Halt Ventricular Tachycardia (SMASH-VT) and the Ventricular Tachycardia Ablation in Coronary Heart Disease (VTACH) found that prophylactic catheter ablation reduces the incidence of appropriate ICD therapy in patients who had undergone ICD implantation as a means of secondary prevention and had a history of myocardial infarction (MI) [16,17]. It was also shown in a small retrospective study that prophylactic catheter ablation for induced VT reduced the incidence of appropriate ICD therapy in primary prevention post-MI patients [18]. Aim of the study - Statement of Hypothesis Prophylactic substrate ablation in post-MI patients undergoing defibrillator implantation reduces appropriate defibrillator therapies.

Prophylactic substrate ablation group will undergo substrate mapping and ventricular tachycardia substrate ablation

Study protocol Baseline programmed ventricular stimulation performed from the LV High density endocardial LV mapping using CARTO® 3 System Randomized substrate ablation in half patients. Ablation end-point is considered the elimination of all endocardial late and early potentials (LPs and EPs) Final programmed ventricular stimulation performed from the LV Programmed ventricular stimulation with up to 4 extrastimuli from LV is performed and repeated at the end of the procedure in patients undergoing substrate ablation.

All post-MI patients will undergo ICD implantation and electroanatomical substrate mapping of the left ventricle. Half patients will also undergo prophylactic VT ablation aiming to late and early potentials elimination. Post-MI patients who underwent ICD implantation in the setting of primary prevention and prophylactic substrate ablation will have significant less appropriate ICD therapies.

Inclusion Criteria: Post-MI patients eligible for ICD implantation in the setting of primary prevention Exclusion Criteria: NYHA IV or ambulatory NYHA IV Acute coronary syndrome in the last 40 days Stable angina not eligible to revascularization Revascularization in the last 3 months (except MI) Antiarrhythmic therapy other than b-blockers LVEF<20% GFR<30ml/min/1.73m2 Systematic illnesses

Kheiri B, Barbarawi M, Zayed Y, Hicks M, Osman M, Rashdan L, Kyi HH, Bachuwa G, Hassan M, Stecker EC, Nazer B, Bhatt DL. Antiarrhythmic Drugs or Catheter Ablation in the Management of Ventricular Tachyarrhythmias in Patients With Implantable Cardioverter-Defibrillators: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Circ Arrhythm Electrophysiol. 2019 Nov;12(11):e007600. doi: 10.1161/CIRCEP.119.007600. Epub 2019 Nov 8.