Procedural non-inducibility and post-ablation amiodarone therapy as complementary determinants of 1-year outcome after electrical storm ablation
M I A Bistriceanu, C Cojocaru, V Gondos, A Deaconu, C Iorgulescu, R G VatasescuAbstract
Background
Electrical storm (ES) is associated with substantial mortality despite contemporary catheter ablation strategies. Amiodarone is frequently continued after ablation, yet its relationship with long-term survival in ES remains poorly defined.
Purpose
We aimed to evaluate the relative impact of procedural non-inducibility and post-discharge amiodarone therapy on 1-year mortality and composite clinical outcomes.
Methods
We retrospectively analyzed 101 consecutive patients who underwent radiofrequency catheter ablation for drug-refractory ES (2014-2022). Acute complete success was defined as the non-inducibility of any sustained monomorphic ventricular tachycardia (VT) during aggressive programmed ventricular stimulation with 4 extra stimuli at the end of the procedure. Primary endpoints were 1-year all-cause mortality and a composite endpoint of death or VT recurrence. Multivariable logistic regression was used to adjust for age, procedural success, baseline left ventricular ejection fraction, severe heart failure (NYHA III/IV), and chronic kidney disease.
Results
Acute procedural success was achieved in 79.2% of patients (80/101). The overall 1-year mortality rate was 8.9% (9/101). Mortality was lower in patients with procedural success than in those with residual inducibility (6.3% vs 19.0%; p=0.067). Amiodarone was maintained at discharge in 71.3% of the cohort. In univariate analysis, amiodarone continuation was associated with higher composite event rates (p=0.015) but showed no significant association with 1-year mortality (9.7% vs. 6.9%, p=0.652) (Figure 1). In the multivariable model, acute complete success emerged as the only significant independent predictor of favourable 1-year composite outcomes (OR: 0.177, 95% CI 0.06-0.51; p < 0.001) (Figure 2). Conversely, amiodarone at discharge was not an independent predictor of outcomes (p=0.611) after adjusting for procedural success and baseline clinical frailty.
Conclusion
Long-term survival and clinical stability after electrical storm ablation are primarily driven by non-inducibility rather than post-ablation amiodarone therapy. Although amiodarone use is common and correlates with higher event rates in unadjusted analyses - likely reflecting a higher baseline risk profile - it provides no independent survival benefit. These findings suggest that achieving a successful electrical outcome is the most significant determinant of the 1-year prognosis.