Comparison of anterior mitral line and mitral isthmus line for ablation of mitral annular flutter

Abstract

AbstractBackgroundMitral annular flutter (MAF) is the most common left atrial macro‐reentrant arrhythmia following catheter ablation of atrial fibrillation (AF). The best ablation approach for this arrhythmia remains unclear.MethodsThis single‐center, retrospective study sought to compare the acute and long‐term outcomes of patients with MAF treated with an anterior mitral line (AML) versus a mitral isthmus line (MIL). Acute ablation success, complication rates, and long‐term arrhythmia recurrence were compared between the two groups.ResultsBetween 2015 and 2021, a total of 81 patients underwent ablation of MAF (58 with an AML and 23 with a MIL). Acute procedural success defined as bidirectional block was achieved in 88% of the AML and 91% of the MIL patients respectively (p = 1.0). One year freedom from atrial arrhythmias was 49.5% versus 77.5% and at 4 years was 24% versus 59.6% for AML versus MIL, respectively (hazard ratio [HR]: 0.38, confidence interval [CI]: 0.17–0.82, p = .009). Fewer patients in the MIL group had recurrent atrial flutter when compared to the AML group (HR: 0.32, CI: 0.12–0.83, p = .009). The incidence of recurrent AF, on the other side, was not different between both groups (21.7% vs. 18.9%; p = .76). There were no serious adverse events in either group.ConclusionIn this retrospective study of patients with MAF, a MIL compared to AML was associated with a long‐term reduction in recurrent atrial arrhythmias driven by a reduction in macroreentrant atrial flutters.