1Universitätsklinikum Jena Klinik für Innere Medizin I - Kardiologie Jena, Deutschland
Background: Recent evidence suggests that a rhythm control strategy in patients with atrial fibrillation (AF) might reduce morbidity and mortality, besides a substantial symptomatic benefit. Pulmonary vein isolation (PVI) by catheter ablation has proven to be more effective than antiarrhythmic drugs in maintaining sinus rhythm. Regarding paroxysmal AF radiofrequency ablation and cryoballon ablation are considered equally safe and effective. With respect to persistent AF this might not be the case, as in patients with persistent AF a greater prevalence of arrhythmic substrate outside the pulmonary vein antra can be observed. Therefore, these patients might benefit from the selection of an ablation technique with the capability of mapping and targeting this substrate. In this study we evaluated potential predictors of left atrial low voltage areas as potential ablation targets beyond PVI.
Methods: We analyzed demographic and clinical data, preinterventional CT studies, and voltage maps of all patients undergoing first catheter ablation for persistent AF at our institution between January 2021 and October 2023, who were concurrently enrolled in a prospective biomarker trial. High density 3D endocardial voltage mapping was carried out using EnSite Precision™ or EnSite X™ and the Advisor™ HD-Grid Mapping Catheter (Abbott Medical, Eschborn).
Results: In total, 90 patients with complete data could be included in this study. Mean age was 66.9 years [95%CI 65,2-68.6], 24/90 (26.7%) were female. In 40 patients (44.4%) AF was first diagnosed within 12 months prior to the procedure. Median CHA2DS2-VASc-Score was 3 [95%CI 2-3]. In 35 patients (38.9%) we found left atrial low voltage areas (LVA, <0.5mv) outside the pulmonary veins. In patients with and without LVA outside the pulmonary veins neither left atrial volume index (84.3 ml/m² [95%CI 77.6-91.0] vs. 77.5 ml/m² [95%CI 72.4-82.6], p=0.104), BMI (29.2 kg/m² [95%CI 27.4-31.0] vs. 29.9 kg/m² [95%CI 28.6-31.1], p=0.514), estimated glomerular filtration rate (64.7 ml/min [95%CI 58.3-71.0] vs. 70.9 ml/min [95%CI 65.2-76.7], p=0.157), nor left ventricular ejection fraction (52.3 [95%CI 48.7-55.9] vs. 53.2 [95%CI 50.8-55.7], p=0.668) differed significantly. Patients with LVA outside the pulmonary veins were older (69.8 [95%CI 67.8-71.8] vs. 65.1 [95%CI 62.7-67.4], p=0.007) and more often female, OR 3.83 [95%CI 1.44-10.20], although these findings did not hold in multivariate analysis. In a logistic regression model neither age, sex, body mass index, left ventricular ejection fraction, estimated glomerular filtration rate, CHA2DS2-VASc-Score, or left atrial volume index predicted the presence of LVAs outside the pulmonary veins.
Conclusion: In our study only age and female sex were in univariate analysis independently associated with the presence of left atrial low voltage areas outside the pulmonary veins. It can be assumed that more sophisticated prediction models integrating clinical, imaging and laboratory data are needed to reliably predict the presence of LVAs and therefore facilitate selection of appropriate ablation techniques.