Long-term outcome of catheter ablation and other form of therapy for electrical storm in patients with implantable cardioverter-defibrillators.

PURPOSE

Radiofrequency catheter ablation (RFCA) for electrical storm (ES) has become a widely used therapeutic method. Its effectiveness in comparison to other forms of ES treatment is however uncertain.

METHODS

This single-centre retrospective study investigated the long-term clinical outcome after RFCA for ES and compared long-time effects of ablation to other forms of treatment. The study population consisted of 70 consecutive patients hospitalised between January 2010 and June 2015 due to ES. Patients were recruited for the study if the following criteria were fulfilled: first ES caused by ventricular tachycardia (VT) or ventricular fibrillation (VF), implanted cardioverter defibrillator or cardiac resynchronisation therapy device and left ventricular ejection fraction < 50%. The follow-up data on VT/ES recurrence was obtained from pacemaker/implanted cardioverter defibrillator memory. Data on all-cause mortality was collected during outpatient visits or by telephone contact.

RESULTS

Of the 70 patients enrolled, 28 (40%) were treated with RFCA (group A) and 42 (60%) received other forms of treatment for ES (group B). During a mean (±SD) 864 (629) days of follow-up, death occurred in 4 (14.3%) patients in the ablation group and in 16 (38.1%) patients treated with other methods [p = 0.03]. There was no significant between-group difference in VT/VF and ES recurrence. Statistical analysis revealed that the presence of cardiac resynchronisation therapy device during ES, stroke and/or transient ischaemic attack and lower baseline hematocrit level were the multivariate predictors of all-cause mortality.

CONCLUSIONS

In patients treated with RFCA for ES, all-cause mortality was significantly lower compared to the group treated with other methods.