Incidence and predictors of mortality following ablation of ventricular tachycardia in patients with an implantable cardioverter-defibrillator

Background

Long-term outcomes following ablation of ventricular tachycardia (VT) have not been well described.

Objective

The purpose of this study was to identify the incidence and predictors of mortality following catheter ablation of VT in patients with an implantable cardioverter-defibrillator (ICD).

Methods

The cohort included in the analysis consisted of patients with ischemic or nonischemic cardiomyopathy undergoing electrophysiologic study and ablation of VT. Catheter ablation of VT involved the use of pacemapping, entrainment mapping (when possible), and substrate modification. Clinical recurrences, ICD therapy history, and mortality were recorded for all patients included in the cohort. Comparisons were made between those subjects who died over a 3-year follow-up period and those who survived.

Results

A total of 208 subjects underwent 327 VT ablations over the course of the study period. Sixty-seven deaths (75% of all deaths and 32% of the cohort) occurred within 3 years after VT ablation. After multivariable adjustment, clinical predictors of mortality included age, lower left ventricular ejection fraction, and presence of renal insufficiency. Procedural variables associated with reduced mortality following VT ablation included presence of hemodynamically tolerated VT, lack of inducibilty of any VT following ablation, and procedural date in the latter part of the study.

Conclusion

The survival rate after VT ablation has improved over time and may reflect improved mapping and ablation techniques, in addition to improved therapies for treatment of congestive heart failure. Tolerated VT and lack of inducible ventricular arrhythmias following VT ablation was associated with improved survival in this study, suggesting their value as a risk factor for subsequent mortality.

Keywords: Ablation, Mortality, Ventricular tachycardia

Abbreviations: CI, confidence interval, ICD, implantable cardioverter-defibrillator, VT, ventricular tachycardia