Left Atrial Substrate Modification Targeting Low-Voltage Areas for Catheter Ablation of Atrial Fibrillation: A Systematic Review and Meta-Analysis.

BACKGROUND: This meta-analysis aims to assess the impact of a voltage-guided substrate modification by targeting low-voltage area (LVA) in addition to pulmonary vein isolation (PVI) in patients undergoing catheter ablation for atrial fibrillation (AF).

METHODS: MEDLINE/PubMed, Cochrane Library, and references reporting AF ablation and "voltage* OR substrate* OR fibrosis OR fibrotic area*" were screened and studies included if matching inclusion and exclusion criteria.

RESULTS: Six studies were included. Patients enrolled were 885 (517 in the study group and 368 in the control group). Median age was 60 years; 92% had nonparoxysmal AF. At a mean follow-up of 17 months, 70% of patients in the study group vs. 43% in the control group were free from AF/atrial tachycardia (AT) recurrences (odds ratio [OR] = 3.41, 95% confidence interval [CI] 2.22-5.24). LVA ablation in addition to PVI was more effective than PVI alone and PVI + conventional wide empirical ablation (70% vs. 43%, OR = 3.41, 95% CI 2.22-5.24), without increasing the adverse event rate (2.5% vs. 6%, OR = 0.43, 95% CI 0.15-1.26). Compared to PVI + conventional wide empirical ablation, LVA ablation reduced the occurrence of postablation AT (14% vs. 46%, OR = 0.16, 95% CI 0.07-0.37), procedure time (176 min vs. 220 min, OR = 0.36, 95% CI 0.24-0.56), fluoroscopy time (25 min vs. 31 min, OR = 0.22, 95% CI 0.12-0.39), and radiofrequency time (55 min vs. 90 min, OR = 0.49, 95% CI 0.27-0.90).

CONCLUSIONS: A voltage-guided substrate modification by targeting LVA in addition to PVI is more effective, safer, and holds a lower proarrhythmic potential than conventional ablation approaches. Further randomized studies are necessary to confirm these findings.