B-AB15-01 PROGNOSTIC IMPLICATIONS OF PURE MONOMORPHIC VENTRICULAR TACHYCARDIA IN ELECTRICAL STORM

Abstract

Outcomes of electrical storm (ES) based on the underlying arrhythmia - monomorphic ventricular tachycardia (MMVT), polymorphic VT (PMVT), ventricular fibrillation (VF) - has not been evaluated. ES due to PMVT, VF, or a combination of rhythms (non-MMVT; n = 97) was compared to purely MMVT (n = 109) to evaluate differences in 1-year all-cause mortality and ventricular arrhythmia (VA) rehospitalization. Secondary outcomes include rates of ablation, revascularization, and mechanical circulatory support (MCS). Single center, retrospective study that included consecutive patients admitted to the coronary ICU with ES between April 2014 - 2020. ES was defined as ≥ 3 isolated sustained VA or ICD therapies within 24 hours. Of 214 patients admitted with ES, 206 had an identifiable rhythm. Overall mean age 64 +/- 13 years, 84.5% male, mean EF 30 +/- 13%. Pure MMVT ES had a lower risk of 1-year all-cause mortality and VA rehospitalization (45.9% vs. 64.9%; HR 0.76 [95% CI 0.63 - 0.91]; p 0.003; Figures 1 & 2) and 1-year all-cause mortality (33.0% vs. 50.5%; HR 0.729; p 0.004) compared to non-MMVT ES. This was largely due to lower in-hospital all-cause mortality (9.2% vs. 24.7%; RR 0.37; p 0.0043) as 1-year VA rehospitalization was not significantly different (28.4% vs. 40.2%; HR 0.81; p 0.081). MMVT was less likely to require revascularization (4.6% vs. 13.4%; RR 0.34; p 0.028) or MCS (18.3% vs. 33.0%; RR 0.56; p 0.017) and more likely to be ablated (56.0% vs. 17.5%; RR 3.19; p < 0.0001). ES due to purely MMVT is associated with decreased all-cause in-hospital and 1-year mortality compared to non-MMVT rhythms even through rates of VA rehospitalization were similar.