Characterization of patients with extensive left atrial myopathy referred for atrial fibrillation ablation: incidence, predictors, and outcomes.

BACKGROUND: Although atrial fibrosis has a relevant impact on ablation success rate, experimental studies have reported that extensive fibrosis may be accompanied by a reduced burden secondary to a prominent depression of atrial excitability. OBJECTIVES: We aimed to identify clinical and echocardiographic factors associated with extensive left atrial myopathy (ELAM), to analyze the predictive ability of established scores (AF score, APPLE, and DR-FLASH) and assess outcomes in terms of AF recurrence, left atrial flutter, and post-procedural heart failure admissions. METHODS: A total of 950 consecutive patients undergoing the first AF ablation were included. A 3D electroanatomical mapping system (CARTO3, Biosense Webster) was created using a multipolar mapping catheter (PentaRay, Biosense Webster). ELAM was defined as ≥ 50% low voltage area. A subanalysis with four groups was also created (< 10%; 10-20%; 10-20%; and > 30%). Logistic regressions, Cox proportional hazards models, and log-rank test were used to test the predictors independently associated with the presence of ELAM and AF recurrence. The model was prospectively validated in a cohort of 150 patients obtaining an excellent ability for prediction AUC 0.90 (CI 95% 0.84-0.96). RESULTS: Overall, 78 (8.42%) presented ELAM. Age, female sex, persistent AF, first-degree AV block, and E/e' were significant predictors. The model incorporating these factors outperformed the existing scores (AUC = 0.87). During a mean follow-up of 20 months (IQR 9 to 36), patients with ELAM presented a higher rate of AF recurrence (42.02% vs 26.01%, p = 0.030), left atrial flutter (26.03% vs 8.02%, p < 0.001), and post-procedural heart failure admissions (12.01% vs 0.61%, p < 0.001) than non-ELAM patients. CONCLUSIONS: This study reveals the incidence and clinical factors associated with ELAM in AF, highlighting age, female, persistent AF, first-degree AV block, and E/e'. Importantly, the presence of ELAM is associated with poorer outcomes in terms of recurrence and HF admission.

Impact of initiation of SGLT2 inhibitor treatment on the development of arrhythmias in patients with implantable cardiac devices.

INTRODUCTION AND OBJECTIVES: Sodium-glucose cotransporter type 2 inhibitors (SGLT2i) have been associated with improved prognosis in patients with heart failure, but their impact on atrial arrhythmic (AA) and ventricular arrhythmic (VA) events is not fully understood. METHODS: This multicenter retrospective study included patients with implantable cardioverter-defibrillators who initiated treatment with SGLT2i. AA and VA events were compared in 2 time periods for each patient: 1 year before and 1 year after starting SGLT2i. RESULTS: The study included 195 patients (66.8 [61.3-73.1] years, 18.5% women). In the post-SGLT2i period, there was a reduction in the percentage of patients with any VA (pre: 52.3% vs post: 30.3%; P<.001) and clinically relevant VA (excluding nonsustained ventricular tachycardia) (pre: 21.5% vs post: 8.7%; P<.001). There was also a decrease in the number of episodes per patient/y of nonsustained ventricular tachycardia (pre: 2 (1-5) vs post: 1 (0-2); P<.001) and sustained ventricular tachycardia (pre: 1 (1-3) vs post: 0 (0-2); P=0.046). However, no differences were observed in the prevalence of AA (24.7% vs 18.8%; P=.117) or the burden of atrial fibrillation (pre: 0% (0-0.1) vs post: 0% (0-0); P=.097). CONCLUSIONS: Initiation of SGLT2i treatment was associated with a decrease in the percentage of patients with relevant VA but this effect was not observed for AA.

Atrial fibrillation ablation in patients with arrhythmia-induced cardiomyopathy: a prospective multicentre study.

AIMS: This study aims to investigate the clinical and biochemical characteristics of patients with atrial fibrillation (AF) referred for ablation who develop arrhythmia-induced cardiomyopathy (AiCM) as well as their long-term outcomes after catheter ablation (CA). METHODS AND RESULTS: A prospective multicentre study was conducted on consecutive AF patients who underwent CA. AiCM was defined as the development of heart failure in the presence of AF and an improvement of left ventricular fraction by at least 10% at 6 months after ablation. A subgroup of patients underwent peripheral and left atrial blood samples [galectin-3, fatty acid-binding protein 4 (FABP4), and soluble receptor for advanced glycation end products (sRAGE)] at the time of the procedure. Of the 769 patients who underwent AF ablation, 135 (17.56%) met the criteria for AiCM. Independent predictors of AiCM included persistent AF, male gender, left atrial volume, QRS width, active smoking, and chronic kidney disease (CKD). Biomarker analysis revealed that sRAGE, FABP4, and galectin-3 levels were not predictive of AiCM development nor did they differ between groups or predict recurrence. There were no differences in AF recurrence between patients with and without AiCM (30.83% vs. 27.77%; P = 0.392) during a median follow-up of 23.83 months (inter-quartile range 9-36). CONCLUSIONS: In the subset of patients referred for AF ablation, the development of AiCM was associated with persistent AF and CKD. Biomarker analysis was not different between groups nor predicted recurrence. Patients with AiCM benefited from ablation, with a significant improvement in left ventricular ejection fraction and similar AF recurrence rates to those without AiCM.