Non-revascularized chronic total occlusion is associated with worse outcomes in post-MI drug-refractory electrical storm patients treated by catheter ablation

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Outcomes in post-myocardial infarction (MI) patients which are referred for catheter ablation (CA) for drug-refractory electrical storm (ES) are influenced both by patient characteristics and procedural results. Previous data has shown higher risk for the first incident ES episode in the presence of non-revascularized chronic total occlusions (nCTOs). However, the prognostic effect of nCTOs in post-ES ablation patients is relatively unknown. Purpose We evaluated the impact of the presence of nCTO on all-cause mortality and sustained VT recurrence rate after CA for ES in post-MI patients. Methods In this single centre retrospective longitudinal study, we included consecutive post-MI patients referred for CA for drug-refractory ES. The median follow-up interval was 34.36 (7.25-63.65) months. CA outcome was defined by the absence or presence of residual sustained monomorphic VT at end-procedural programmed ventricular stimulation (PVS). Coronary angiography was performed prior to ablation in all patients. Results Sixty-four patients were included (85.9% (n = 55) males, age 62.64 ± 11.13 years). The mean left ventricular ejection fraction (LVEF) was 31.41 ± 10.99. There were 18.8% (n = 12) patients with nCTOs. Residual sustained monomorphic VT inducibility was documented in 28.1% (n = 18) cases. There were 29.7% (n = 19) deaths and sustained VT recurrences, respectively, during the monitored interval. Nine out of twelve (75%) nCTO patients died during follow-up. The presence of a nCTO induced a borderline significant higher risk of sustained VT recurrence during follow-up (HR 2.527, CI.95% 0.992 – 6.435, p = 0.052) in univariable Cox regression. In addition to age and residual sustained monomorphic VT at PVS, a multivariable Cox regression model identified the presence of nCTO as an independent predictor for all-cause mortality (HR 3.194, CI 95% 1.212-8.420, p = 0.019) (Figure 1). Conclusion(s) The presence of a nCTO in post-MI patients may be associated with higher all-cause mortality and sustained VT recurrences after ablation for drug-refractory electrical storm.