LONG-TERM RESULTS OF SUBSTRATE-BASED VENTRICULAR TACHYCARDIA ABLATION IN PATIENTS WITH PREVIOUS MYOCARDIAL INFARCTION. IDENTIFICATION OF ANATOMICAL AND ELECTROPHYSIOLOGICAL SUCCESS PREDICTORS

Methods: We analyzed 60 patients (age 67±9, LVEF: 30±11%) with chronic myocardial infarction who underwent substrate based VT ablation (SBVTA). Electroanatomic maps were obtained to measure the scar (≤1,5 mV) and dense scar ((≤ ,5 mV ) and to delimit the scar borders. The targets of SBVTA were all E-IDC and CC of the scar tissue. Results: Ablation targeted E-IDC and CC in 95% and 75% of patients, in 5 % the ablation targeted multicomponent electrogram from the scar border where pace-mapping reproduced VT morphology. The ablation area was 14±10 cm 2, no major life-threatening complications/incessant VT were observed after the procedure. During a median follow-up of 35 months 57% of patients remained free of VT recurrences. Patients with an above-median dense scar extension (25 cm 2 ) were at higher risk for VT recurrence compared with those with a below-median (65% versus 24%, p<0.0001, median follow-up 31 vs. 39 months, p: 0.1). Multivariable analysis showed that scar extension was the only predictors of VT recurrence (p<0.004). Conclusion: In patients with a prior MI SBVTA is safe and effective, the extent of dense scar provides incremental prognostic value post MI smvt recurrence