Anterior mitral line in patients with persistent AF and anterior scar: a multicenter matched comparison. The MiLine Study

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background The benefit of an anterior mitral line (AML) in patients with persistent atrial fibrillation (AF) and anterior atrial scar undergoing ablation has never been investigated. Objective to evaluate the outcomes of AML on top of standard treatment, compared to standard treatment alone (no-AML), in this subset of patients. Methods Patients with persistent AF and anterior low voltage zone (LVZ) treated with AML in three Centers were retrospectively enrolled. These patients were matched in a 1:1 fashion with patients with persistent AF and anterior LVZ, who underwent conventional ablation, in the same centers. Matching parameters were: age, LVZ burden, and repeated ablation. Primary endpoint was AF/atrial tachycardia (AT) recurrence. Results 186 patients (66±9 years, 34% women) were selected and included into two matched groups. Bidirectional conduction block was achieved in 95% of AML. After a median follow-up of 2 years, AF/AT recurrence occurred in 29% of the patients in the AML-group, vs. 48% in the No-AML-group (log-Rank p=0.024) (Figure 1). At Cox-regression multivariate­-analysis left atrial volume (HR 1.03, p=0.006) and AML (HR 0.46, p=0.003) were significantly associated with the primary endpoint. At univariate logistic-regression, lower BMI, older age, extensive anterior LVZ and the position of the left atrial activation breakthrough away from the AML (Figure 2), were associated with first-pass AML block. Conclusion In this retrospective matched analysis of patients with persistent AF and anterior scar, AML on top of standard treatment was associated with improved AF/AT-free survival compared with matched patients treated with standard treatment alone.