Sinus-rhythm conduction phenotyping using vector-flow mapping in first-time atrial fibrillation ablation: Associations with structural remodeling and thromboembolic risk.

Background: Pulmonary vein isolation achieves success in 60%-80% of first ablation procedures. Sinus-rhythm vector-flow mapping (COHERENT module) may enable phenotype-guided ablation. Objective: This study aimed to classify sinus-rhythm conduction phenotypes using COHERENT mapping and assess associations with atrial remodeling, recurrence, and thromboembolic risk. Methods: We prospectively enrolled 80 consecutive patients (mean age 65.1 ± 12.5 years; 32.5% persistent atrial fibrillation [AF]) undergoing initial AF ablation with high-density sinus-rhythm mapping. 5 phenotypes were defined: normal flow, conduction delay, congested flow, disrupted flow, and Bachmann's bundle split (BBS). Patients were grouped into 8 mutually exclusive, collectively exhaustive phenotype-burden categories (normal, 4 single-phenotype groups, double, triple, quadruple). Outcomes were assessed by unadjusted logistic regression with normal as the reference; all 80 patients completed 24-month follow-up. Results: Phenotype-burden categories showed gradients in structural and AF-related markers. Each 10 mL/m Conclusion: Sinus-rhythm COHERENT mapping delineated distinct conduction phenotypes associated with progressive atrial structural remodeling. Phenotype burden defined a graded atrial cardiomyopathy continuum, with double showing the highest 24-month recurrence. BBS only and quadruple shared borderline thromboembolic signals via distinct mechanisms. These findings provide mechanistic insight into atrial cardiomyopathy and generate hypotheses for substrate-guided ablation and thromboembolic-risk assessment.