Long-term outcomes of ventricular tachycardia ablation in repaired tetralogy of Fallot: Systematic review and meta-analysis

Background

Ventricular tachycardia (VT) remains a risk in repaired Tetralogy of Fallot (rTOF); however, long-term benefits of VT ablation have not been established. This study compares the outcomes of rTOF patients with and without VT ablation.

Methods

We searched multiple databases examining the outcomes of rTOF patients who had undergone VT ablation compared to those without ablation. Primary outcomes were VT recurrence, sudden cardiac death (SCD), and all-cause mortality. Subgroup analysis was conducted based on the type of ablation (catheter and surgical). Slow-conducting anatomical isthmus (SCAI)-based catheter ablation (CA) was also analyzed separately. The secondary outcome was the risk factors for the pre-ablation history of VT.

Results

Fifteen cohort studies with 1459 patients were included, 21.4% exhibited VTs. SCAI was found in 30.4% of the population, with 3.7% of non-inducible VT. Factors significantly associated with VT before ablation included a history of ventriculostomy, QRS duration ≥180 ms, fragmented QRS, moderate to severe pulmonary regurgitation, high premature ventricular contractions burden, late gadolinium enhancement, and SCAI. Ablation was only beneficial in reducing VTs recurrence in SCAI-based CA (risk ratio (RR) 0.11; 95% CI 0.03 to 0.33. p < 0.001; I² = 0%) with no recurrence in patients with preventive ablation (mean follow-up time 91.14 ± 77.81 months). The outcomes of VT ablation indicated a favorable trend concerning SCD and all-cause mortality (RR 0.49 and 0.44, respectively); however, they were statistically insignificant.

Conclusions

SCAI-based CA has significant advantages in reducing VT recurrence in rTOF patients. Risk stratification plays a key role in determining the decision to perform ablation.