Ablation of mitral annular flutter ablation utilizing a left atrial anterior line versus a lateral mitral isthmus line: a systematic review and meta-analysis

PURPOSE: Mitral annular flutter (MAF) is a common arrhythmia after atrial fibrillation ablation. We sought to compare the efficacy and safety of catheter ablation utilizing either a left atrial anterior wall (LAAW) line or a lateral mitral isthmus (LMI) line. METHODS: We performed a systematic review for all studies that compared LAAW versus LMI lines. Risk ratio (RR) and mean difference (MD) 95% confidence intervals were measured for dichotomous and continuous variables, respectively. RESULTS: Four studies with a total of 594 patients were included, one of which was a randomized control trial. In the LMI ablation group, 40% of patients required CS ablation. There were no significant differences in bidirectional block (RR 1.26; 95% CI, 0.94–1.69) or ablation time (MD −1.5; 95% CI, −6.11–3.11), but LAAW ablation was associated with longer ablation line length (MD 11.42; 95% CI, 10.69–12.14) and longer LAA activation delay (MD 67.68; 95% CI, 33.47–101.89.14) when compared to LMI. There was no significant difference in pericardial effusions (RR 0.36; 95% CI, 0.39–20.75) between groups and more patients were maintained sinus rhythm (RR 1.19; 95% CI, 1.03–1.37, p = 0.02) who underwent LAAW compared to LMI. CONCLUSION: Ablation of mitral annular flutter with a LAAW line compared to a LMI line showed no difference in rates of acute bidirectional block, ablation time, or pericardial effusion. However, LAAW ablation required a longer ablation line length, resulted in greater LAA activation delayed and was associated with more sinus rhythm maintenance, with the added advantage of avoiding ablation in the CS.