ASIRVATHAM, SAMUEL

ABSTRACT Background Superior vena cava isolation (SVCI) is performed as an adjunct to pulmonary vein isolation (PVI) for atrial fibrillation, yet whether an empiric or trigger‐guided strategy is preferable remains uncertain. Prior meta‐analyses have been largely restricted to index procedures in paroxysmal AF and have not explicitly stratified by ablation strategy. We sought to address these gaps through a systematic review of available randomized evidence. Methods Major databases were searched through November 2025 for RCTs comparing PVI+SVCI versus PVI alone. Trials were stratified by strategy: empiric SVCI (performed irrespective of SVC ectopy) or trigger‐guided SVCI (performed only upon demonstrated SVC triggers). The primary outcome was atrial tachyarrhythmia recurrence (≥30 s) beyond the blanking period. Random‐effects models, pre‐specified subgroup analyses, meta‐regression, and GRADE certainty assessment were performed. Results Eight RCTs ( n = 1231) were included; most enrolled paroxysmal AF, while two incorporated non‐paroxysmal AF subtypes and one evaluated repeat ablation procedures. Overall, SVCI+PVI significantly reduced recurrence versus PVI alone (97/604 vs. 135/627; RR 0.77, 95% CI 0.61–0.97; p = 0.03; I 2 = 0%). On stratified analysis, empiric SVCI demonstrated a significant recurrence reduction (RR 0.70, 95% CI 0.53–0.92; p = 0.01; I 2 = 0%), while trigger‐guided SVCI did not reach statistical significance (RR 0.80, 95% CI 0.37–1.74; p = 0.57; I 2 = 52%). In paroxysmal AF ( n = 1038), adjunctive SVCI significantly reduced recurrence compared with PVI alone (RR 0.68, 95% CI 0.52–0.90; p = 0.01; I 2 = 0%). Fluoroscopy time was longer with SVCI; total procedure duration was comparable. Major complications were infrequent but numerically higher with SVCI+PVI (15/604 vs. 7/627; RR 1.96, 95% CI 0.87–4.38; p = 0.10). Meta‐regression identified no significant effect modifiers. GRADE certainty was high for overall and empiric analyses, and moderate for trigger‐guided SVCI. Conclusions Empiric SVCI significantly reduced AT/AF recurrence as an adjunct to PVI, while trigger‐guided SVCI did not demonstrate a significant benefit. These findings suggest SVC isolation confers benefit independent of prior trigger documentation, supporting the role of empiric SVCI as an adjunct to AF ablation.

Abstract Background Elevated left ventricular filling pressure (LVFP) is associated with an increased risk of heart failure and mortality. Pulmonary artery wedge pressure (PAWP) is considered the gold standard for assessing LVFP. Recently, we validated an artificial intelligence-enabled electrocardiogram (AI-ECG) to assess LV diastolic function (LVDF) and LVFP. Herein, we compare AI-ECG with PAWP in predicting long-term mortality. Methods We included adults who had comprehensive echocardiography with available ECG within 14-days and right-heart-catheterization (RHC) within 30-days of echocardiography. Elevated-LVFP was defined as PAWP>15 mmHg by RHC, grades 2-3 LVDF by echocardiography, or as adjudicated by the AI-ECG algorithm. Prognosis by AI-ECG was compared to that by echocardiography and PAWP. Results Among 4,168 patients (median age 64 years, 47.7% female), 1,841 had normal-LVFP, and 2,327 had elevated-LVFP by RHC. Echocardiography classified 1,502 patients as normal-LVFP, 1,643 as elevated-LVFP, and 1,023 as indeterminate-LVFP. AI-ECG demonstrated an area-under-the-curve of 0.879 (95%-confidence-interval 0.867-0.891) for predicting elevated-LVFP as determined by echocardiography and 0.742 (95%-confidence-interval 0.724-0.759) for predicting elevated-LVFP as determined by RHC. Over a median follow-up of 7.7 years, 2,735 (34.4%) patients died. In multivariable models, elevated-LVFP by any modality was associated with an increased risk of death (AI-ECG: adjusted-hazard-ratio 1.80, 95% confidence-interval 1.55-2.09; echocardiography: adjusted-hazard-ratio 1.74, 95% confidence-interval 1.51-2.02; PAWP: adjusted-hazard-ratio 1.26, 95% confidence-interval 1.11-1.43). AI-ECG-derived LVFP provided incremental prognostic discrimination compared to echocardiography- or RHC-derived LVFP. Conclusions AI-ECG-derived LVFP offers an accessible, affordable, and noninvasive alternative for detecting elevated LVFP, with potential independent prognostic value beyond traditional echocardiographic and invasive assessments.Survival across LVFP concordance

Abstract Background Catheter ablation for atrial fibrillation (AF) improves quality of life and lowers cardiovascular adverse events. However, AF recurrence rates remain high - thus the need for better or improved predictors of AF recurrence. The role of left atrial (LA) stiffness remains unclear, as prior findings were controversial. Purpose To explore the relationship between a noninvasive LA stiffness index (LAstiffn) and AF recurrence after catheter ablation. Methods We analyzed a prospectively recruited cohort of patients who underwent catheter ablation for AF, were in sinus rhythm at 3 months post-ablation, had no significant (< moderate) valvular disease, and had LA volumes and LA diastolic function prospectively measured. LAStiffn was calculated as (E/e’)/LA emptying fraction (LAEF) ratio (abnormal defined as >15/45≈0.3). Outcome endpoint was the first documented AF/atrial flutter episode, lasting >30s, beyond 3 months post ablation (end of blanking period). Results A total of 589 patients were studied (mean age 60±10 years; 75% men; 50% with persistent AF; Table 1). At 3 months post-ablation, mean LAVI(Left atrial volume index) was 36±10 mL/m2 and LAstiffn 0.32±0.22. LAstiffn tended to be higher in older patients, in females, and patients with persistent AF and comorbidities (hypertension, congestive heart failure, coronary artery disease, CHA2DS2-VASc score ≥2, etc). At multivariable regression analysis, LAstiffn correlated with LV size and mass, degree of mitral/tricuspid regurgitation, and right ventricular systolic pressure. At 1 year, 3 years, and 8 years follow up, AF recurred in 118, 191, and 347 patients, respectively. At univariate Cox proportional hazards regression analysis, LAstiffn index >0.3 was significantly associated with AF recurrence at 1 year (log-rank P=.0005), 3 years (P=.0002), and 8 years follow up (P<.0001; Figure). In multivariate analysis including all clinical and laboratory factors with P<.10 in univariate analysis, LAstiffn >0.3 remained an independent factor for AF recurrence only at 3-years (adjusted HR 1.40 [1.03-1.91], P=.03) and 8 years follow up (adjusted HR 1.65 [1.29-2.13], P<.0001) after adjustment for age, sex, type of AF (persistent/paroxysmal), LA volume index (LAVi), obstructive sleep apnea, and prior pacemaker/ICD implantation (best independent factors); P=.14 at 1 year follow up. In ROC analysis, LAstiffn (AUC 0.61, P=.001) performed slightly better than LA deformation LAEF (AUC 0.59, P=.002) or E/e’ (AUC 0.58, P=.03), though with modest sensitivity/specificity (58%/62%). Conclusions LAstiffn may reflect LA myopathy that is likely due to the cumulative effects of comorbidities, diastolic dysfunction, and intrinsic LA tissue remodeling. LA stiffening may be a substrate facilitating redevelopment of AF, thus patients with increased LAstiffn may need more frequent monitoring to prevent/treat AF recurrence earlier.

Abstract Background Atrial fibrillation (AF) occurs more frequently in men, but women suffer more AF recurrence; mechanisms are not completely understood. Purpose To explore whether sex related differences in LA stiffness (LAstiffn) in patients with AF ablation could potentially explain differences in AF recurrence. Methods We screened patients with catheter ablation for AF, in sinus rhythm at 3 months post-ablation, with no significant mitral valve disease (< moderate), and with prospectively measured LA volumes [maximum (LAVI) and minimum volume index] by echocardiography. LAStiffn index was estimated as (E/e’)/LA emptying fraction. Outcome endpoint was AF recurrence up to 14 years post ablation. Results A total of 591 patients with AF ablation were studied (mean age 60±10 years; 25% women; Table1). At 3 months post-ablation, LAVI was 36±10 mL/m2 and LAstiffn was 0.31±0.21 1/%. Compared to males, female patients were slightly older, had more frequently hypertension, congestive heart failure, prior stroke/TIA, higher CHA2DS2-VASc score; they less often had persistent AF, coronary artery disease, or dilated cardiomyopathy. Women also had higher LAstiffn (0.37±0.24 vs. 0.29±0.19, P <.0001, Figure 1), despite similar indexed LA volumes (Table1). Rates of AF recurrence at follow-up (median 7.5 years; 347 patients with events) were higher in women vs. men (Figure 2, left; log-rank P<.001) and persisted after adjustment for age, type and duration of AF, body mass index, cardiovascular risk factors and comorbidities, CHA2DS2-VASc score ≥2, LV ejection fraction, and LAVI (adjusted HR 1.58 [1.20-2.08], P=.001). Overall, LA volumes and LAstiffn were higher in patients with older age and more comorbidities (hypertension, congestive heart failure, coronary artery disease, persistent AF, CHA2DS2-VASc score ≥2, etc; P<.01 for all). At multivariable regression analysis, LAVI and LAstiffn correlated with E/e’, LV size and mass, degree of mitral/tricuspid regurgitation, and LV stroke volume index (only LAVI). In addition, LAstiffn was higher in patients with elevated right ventricular systolic pressure (RVSP) >35 mmHg and increase in RVSP more than 10 mmHg from pre-ablation (P<.0001) (correlation R=0.44, P<.0001). At follow-up, after adjusting for age and LAVI, higher LAstiffn remained associated with AF recurrence in women (P=.02, HR 2.82 per unit change, 95% CI, 1.08-6.72; Figure 2, right), but not in men (P=.30). Conclusions LAStiffn is higher in women vs. men and correlates with burden of comorbidities, aging, diastolic dysfunction and pulmonary hypertension, possibly reflecting more extensive LA myopathy, and potentially contributing to sex differences in AF recurrence.Figure 1Table 1

Abstract Background The use of irreversible electroporation (IRE) for cardiac ablation in the management of cardiac arrhythmias, known as Pulsed Field Ablation (PFA), has gained the attention of many researchers, physicians and companies. Despite the demonstrated efficacy and safety profiles of the technique, there are still many open questions. One of them deals with the effective electric field thresholds necessary for cardiac tissue ablation. Contrary to radiofrequency (RF) ablation, where the thermotemporal thresholds for tissue damage are well established, the electric field thresholds for effective IRE are uncertain and depend on the tissue type and the waveform characteristics of the delivered electric field. Purpose The use of numerical models to understand the electric field distribution and the corresponding lesion for a specific electrode geometry are widely used in IRE for cancer treatment. Models can predict ablation volumes when the field thresholds are known or can be used to estimate the field thresholds when the lesion geometry is established post-treatment. The goal of the present study was to build a subject-specific realistic 3D numerical model to assess the ability of modeling to predict PFA lesions. Methods PFA experiments were performed in male mongrel dogs following a protocol approved by the Mayo Clinic Institutional Animal Care and Use Committee. Briefly, animals were sedated and intubated, and two non-irrigated deflectable catheters with an 8-mm tip were positioned on both sides of the interventricular septum under fluoroscopy guidance. Submicrosecond pulses were delivered in a bipolar fashion across both catheters. Sequences of pulses of 300 ns duration (or other durations in that range) were repetitively applied with voltage levels in the kV range. 30 days after the procedure, MRI with late gadolinium enhancement (LGE) were acquired to assess the presence of ablation lesions in the treated tissue. Ventricular areas were segmented from MRI images and 3D volumes were created. The generated 3D geometries were imported into software COMSOL Multiphysics. Realistic 3D geometries of the catheters were placed in the same positions than during the experiments, fluoroscopy videos recorded during the procedures were used as a guidance. The computed electric field intensity distributions were compared to the LGE areas to extract the range of electric field thresholds where the predicted lesion size was compatible with the real size of the LGE areas for each application site and pulsing protocol. Results and conclusions Our results show how the numerical model is able to reproduce the shape of the LGE fibrotic lesion areas observed 30 days after the procedure. Additionally, the model clearly confirms the dose-dependent lesion sizes observed experimentally. This study supports that numerical modeling is a valuable tool for understanding PFA treatments and that it could be used as patient-specific treatment planning tool. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie