Catheter Ablation Research Articles

Association of atrial mechanical dispersion with atrial fibrillation recurrence following catheter ablation: results of the ASTRA-AF pilot study.

For patients with symptomatic drug-refractory atrial fibrillation (AF), catheter ablation to achieve rhythm control is an important therapeutic option. The atrial mechanical dispersion measured as standard deviation of the time to peak strain (SD-TPS) is associated with the risk of AF recurrence following catheter ablation. The study cohort prospectively enrolled n = 132 consecutive patients with paroxysmal (n = 88) or persistent AF (n = 44) presenting for de novo pulmonary vein isolation (PVI) and followed for 1year. We related left atrial (LA) volume, LA ejection fraction, SD-TPS, and global longitudinal strain of the left ventricle and clinical variables (sex, age, and type of AF) to AF recurrence. Kaplan-Meier curves showed higher AF recurrence rate with an increase of SD-TPS with the calculated cut-off of 38.6ms. Uni- and multivariable Cox regression analysis could show that SD-TPS had the highest relevance regarding AF recurrence with a HR of 1.05 (95% CI, 1.01; 1.09, p = 0.01) and HR of 1.05 (95% CI, 1.01; 1.09, p = 0.02) per 10ms increase. In the additional analyses for the model including the clinical variables age, sex, and type of AF with paroxysmal or persisting AF, SD-TPS did only show a trend and after adjusting for covariates, SD-TPS showed a HR of 1.04 (95% CI, 0.99; 1.09, p = 0.09) per 10ms increase. Atrial mechanical dispersion was associated with recurrent AF.

Technical principles of ablation therapy

Catheter ablation is astandard procedure in modern cardiology. It can significantly improve the quality of life and life expectancy of cardiac arrhythmia patients. Besides cardiac mapping, ablation itself is afundamental step tosuccessfully treat cardiac arrhythmias. There are various ablation technologies at hand: In traditional radiofrequency (RF) ablation, electrical current flow generates coagulation necrosis. When understanding the biophysical principles of RF ablation, the investigator is capable to adapt lesion geometry and size to the requirements of the procedure and vary them individually. In addition, lesion metric indices evaluate and integrate important parameters such as power, duration, impedance and contact force to standardize and control RF lesions. Cryoablation induces ice crystals within myocardial tissue, which lead to destruction and electrical scarring of the treated tissue. Histologically, cryolesions are well-delineated with preserved tissue architecture and intact endocardium. Pulsed field ablation (PFA) is anovel rising technology, particularly used for pulmonary vein isolation. In contrast to classic thermal technologies (RF and cryoablation), PFA uses pulsed electrical fields to electroporate cardiac tissue and thereby creates damage on acellular level only.

Vein of Marshall chemical ablation decreases atrial fibrillation drivers detected by CARTOFINDER.

This study sought to elucidate the impact of vein of Marshall (VOM) chemical ablation on atrial fibrillation (AF) drivers by investigating the changes in CARTOFINDER mappings before and after VOM chemical ablation in patients with persistent AF. This study included 23 consecutive patients undergoing catheter ablation for long-persistent AF (>18 months). VOM chemical ablation was performed following pulmonary vein isolation. CARTOFINDER and AF cycle length (AFCL) maps were created in the left atrium (LA) before and after VOM chemical ablation. The LA was divided into 8 segments, and the number of focal activation points with 6 or more repetitions was counted in each segment. The number of focal activation points was largest in the LA appendage (LAA). After VOM chemical ablation, the number of focal activation points in the LA decreased significantly (37 [interquartile range, IQR: 19-55] vs. 15 [IQR: 7-21], p < .001), and median AFCL was significantly prolonged (159 [147-168] vs. 164 [150-173] ms, p < .001). In the assessment of each segment, significant decreases in focal activation points were observed in the inferior, lateral, and anterior segments and LAA. Among the focal activation points disappearing after chemical ablation, the number in the non-ethanol-affected area was significantly larger than that in the affected area (13 [8-25] vs. 4 [1-10], p < .001). VOM chemical ablation decreases AF drivers detected by CARTOFINDER. Mechanisms other than direct myocardial damage are considered to contribute the attenuation of AF drivers.

Omitting transesophageal echocardiography before catheter ablation of atrial fibrillation.

Data about necessity of performing transesophageal echocardiography (TOE) prior to every catheter ablation (CA) of atrial fibrillation (AF) is scarce. We aimed to evaluate the safety of an individualized risk-based approach to TOE with respect to thromboembolic cerebrovascular events (CVE) in patients undergoing CA for AF or left atrial tachycardia (AT). We performed a retrospective clinical study based on our institutional registry database. Patients undergoing CA for AF or left-sided AT following initial AF ablation at two participating centers were enrolled. Prior to the procedure, patients were scheduled for TOE only if they had a history of thromboembolic stroke, left atrial appendage (LAA) thrombus, or inappropriate anticoagulation regimen in the previous 3 to 4 weeks. The incidence of periprocedural cerebrovascular thromboembolic events was assessed. We analyzed 1155 patients (median age 70 years, 54.8% male, 48.1% had persistent AF/AT). In 261 patients, a TOE was performed; in 2 patients (0.7%), an LAA thrombus was detected, which led to cancellation of the catheter ablation; in 894 patients, the TOE was omitted. Of the 1153 (0.35%) patients who underwent ablation, 4 (0.35%) experienced a CVE (one TIA and three strokes). The rate of CVE in our study does not exceed that reported in most multicenter trials. The low event rates limited statistical analysis of possible risk factors for CVE. In all 4 patients with CVE, post-CVE imaging showed the absence of LAA thrombus. An individualized selective approach to TOE before catheter ablation of AF or left AT showed a very low risk of overt intraprocedural thromboembolic events for the population in our study. A further randomized controlled study is needed to determine whether TOE prior to catheter ablation without ICE could be omitted in patients with uninterrupted OAC without previous thromboembolic events or a history of left atrial thrombus.

Catheter ablation for persistent atrial fibrillation: patterns of recurrence and impact on quality of life and health care utilisation.

Patterns of atrial fibrillation (AF) recurrence post catheter ablation for persistent AF are not well described. This study aimed to describe the pattern of AF recurrence seen following catheter ablation for persistent AF (PsAF) and the implications for healthcare utilisation and quality of life. This was a post-hoc analysis of the CAPLA study, an international, multi-centre study that randomised patients with symptomatic PsAF to pulmonary vein isolation plus posterior wall isolation or pulmonary vein isolation alone. Patients underwent twice daily single lead ECG, implantable device monitoring or three monthly Holter monitoring. 154 of 333 (46.2%) patients (median age 67.3 years, 28% female) experienced AF recurrence at 12-month follow-up. Recurrence was paroxysmal in 97 (63%) patients and persistent in 57 (37%). Recurrence type did not differ between randomisation groups (p=0.508). Median AF burden was 27.4% in PsAF recurrence and 0.9% in paroxysmal AF (PAF) recurrence (p<0.001). Patients with PsAF recurrence had lower baseline left ventricular ejection fraction (PsAF 50% vs PAF 60%, p<0.001) and larger left atrial volume (PsAF 54.2±19.3 ml/m² vs PAF 44.8±11.6 ml/m², p=0.008). Healthcare utilisation was significantly higher in PsAF (45 patients [78.9%]) vs PAF recurrence (45 patients [46.4%], p<0.001) and lowest in those without recurrence (17 patients [9.5%], p<0.001). Patients without AF recurrence had greater improvements in quality of life as assessed by the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire (Δ33.3±25.2 points) compared to those with PAF (Δ24.0±25.0 points, p=0.012) or PsAF (Δ13.4±22.9 points, p<0.001) recurrence. AF recurrence is more often paroxysmal after catheter ablation for PsAF irrespective of ablation strategy. Recurrent PsAF was associated with higher AF burden, increased healthcare utilisation and antiarrhythmic drug use. The type of AF recurrence and AF burden may be considered important endpoints in clinical trials investigating ablation of PsAF.

Catheter-based pulmonary vein isolation fails to prevent transient atrial arrhythmogenic changes related to acute obstructive respiratory events in a porcine model.

Pulmonary vein isolation (PVI) is the corner stone of modern rhythm control strategies in patients with atrial fibrillation (AF). Sleep-disordered breathing (SDB) is prevalent in more than 50% of patients undergoing AF ablation and studies have indicated a greater recurrence rate after PVI in patients with SDB. Herein, we study the effect of catheter-based PVI on AF in a pig model for SDB. In 11 sedated spontaneously breathing pigs, obstructive apnoeas were simulated by 75 seconds of intermittent negative upper airway pressure (INAP) applied by a negative pressure device connected to the endotracheal tube. INAPs were performed before and after PVI. AF-inducibility and atrial effective refractory periods (aERP) were determined before and during INAP by programmed atrial stimulation. PVI prolonged the aERP by 48 ± 27 ms in the right atrium (RA) (p < 0.0001) and by 40 ± 34 ms in the left atrium (LA) (p = 0.0004). Following PVI, AF-inducibility dropped from 28 ± 26% to 0% (p = 0.0009). INAP was associated with a transient aERP-shortening (ΔaERP) in both atria, which was not prevented by PVI (INAP indued ΔaERP after PVI in the RA: -57 ± 34 ms, p = 0.0002; in the LA: -42 ± 24 ms, p < 0.0001). INAP was associated with a transient increase in AF-inducibility (from 28 ± 26% to 69 ± 21%; p = 0.0008), which was not attenuated by PVI (INAP-associated AF-inducibility after PVI: 58 ± 33% (p = 0.5)). Transient atrial arrhythmogenic changes related to acute obstructive respiratory events are not prevented by electrical isolation of the pulmonary veins, which partially explains the increased AF recurrence in patients with SDB after PVI procedures.

LOCK PROTOCOL: A NEW ROBUST WORKFLOW FOR A VERY HIGH FIRST PASS PULMONARY VEIN ISOLATION DURING ATRIAL FIBRILLATION ABLATION

Abstract Introduction Pulmonary vein isolation (PVI) is the gold standard for atrial fibrillation (AF) ablation. First pass PVI is often demanding when a raw geometry reconstruction is used in combination with an inaccurate automarks annotation, accounting for discontinuous or non–transmural lesions and related AF recurrences. We hypothesized that a magnetic–post processing of left atrial geometry in combination with an LSI–guided high power short duration (HPSD) automarks annotation could improve procedural efficiency. Purpose Aim of the study was to determine the impact on procedural outcomes of the new “Lock PVI protocol” during AF ablation with the new voxel mode EnSite X mapping system. Methods We included in the study consecutive patients with AF scheduled for pulmonary vein isolation (PVI) at our Departement between January 2021 and December 2022. Patients were divided in two Groups, the Lock–PVI Group and the control No Lock–PVI Group. The “Lock PVI” Group was ablated with the new Ensite X System using the new protocol, which consisted in (1) performing a road map with contact–force annotation at potential PVI sites after High Density reconstruction, (2) shaving the magnetic geometry reconstruction to unearth true 3D location of contact points, (3) Use of 3D–Automarks color–coded with a Lesion Index (LSI) target of 5.5 (anterior) and 4.5 (posterior) (4) Inter–lesion distance £6 mm (5) High Power Short Duration Approach (50 W). The No–Lock PVI was represented by patients ablated with and HPSD ablation with the previous version of the EnSite Precision mapping suit as per local standard practice. Groups were compared in term of procedural duration, radiological exposure and “first pass” isolation. Results Forty–four patients (22 “Lock PVI” and 22 controls mean age 63,3±8 years, 65,9% male, 47,7% persistent AF), for a total of 88 PVI circles were enrolled. Procedural duration was similar between approaches (121,1±43,6 vs 125,3±30,1 min; P=0,72) but RF time was shorter in the “Lock PVI” group (19,6±4 vs 29,55±9,1 min; P&amp;lt;0,001), even if with a longer fluoroscopy (19,5±10,1 vs 13,4±4,9 min; P=0,01). Of note, first pass isolation was significantly higher in the “Lock PVI” group: 40/44 (90,9%) vs 28/44 (63,6%) circles (P=0,002). Conclusion The new “Lock PVI” approach allowed a consistently better first pass isolation (&amp;gt;90%) with less RF time when compared to standard of care PVI.

Catheter ablation versus antiarrhythmic drug therapy for sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy.

Ventricular tachycardia (VT) is the primary cause of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, the strategy for VT treatment in HCM patients remains unclear. This study is aimed to compare the effectiveness of catheter ablation versus antiarrhythmic drug (AAD) therapy for sustained VT in patients with HCM. A total of 28 HCM patients with sustained VT at 4 different centers between December 2012 and December 2021 were enrolled. Twelve underwent catheter ablation (ablation group) and sixteen received AAD therapy (AAD group). The primary outcome was VT recurrence during follow-up. Baseline characteristics were comparable between two groups. After a mean follow-up of 31.4 ± 17.5 months, the primary outcome occurred in 35.7% of the ablation group and 90.6% of the AAD group (hazard ratio [HR], 0.29 [95%CI, 0.10-0.89]; P = 0.021). No differences in hospital admission due to cardiovascular cause (25.0% vs. 71.0%; P = 0.138) and cardiovascular cause-related mortality/heart transplantation (9.1% vs. 50.6%; P = 0.551) were observed. However, there was a significant reduction in the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation in ablation group as compared to that of AAD group (42.9% vs. 93.7%; HR, 0.34 [95% CI, 0.12-0.95]; P = 0.029). In HCM patients with sustained VT, catheter ablation reduced the VT recurrence, and the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation as compared to AAD.

Recurrences after Pulsed Field Ablation of Atrial Fibrillation: Incidence, Mechanisms, Predictors, and Comparison with Thermal Energy

Pulsed Field Ablation (PFA) is the latest and most intriguing technology for catheter ablation of atrial fibrillation, due to its capability to generate irreversible and cardiomyocytes-selective electroporation of cell membranes by delivering microsecond-lasting high-voltage electrical fields, leading to high expectations. The first trials to assess the clinical success of PFA, reported an arrhythmia-free survival at 1-year of 78.5%, while other trials showed less enthusiastic results: 66.2% in paroxysmal and 55.1% in persistent AF. Nevertheless, real world data are encouraging. The isolation of pulmonary veins with PFA is easily achieved with 100% acute success. Systematic invasive remapping showed a high prevalence of durable pulmonary vein isolation at 75 and 90 days (range 84–96%), which were significatively lower in redo procedures (64.3%). The advent of PFA is prompting a reconsideration of the role of the autonomic nervous system in AF ablation, as PFA-related sparing of the ganglionated plexi could lead to the still undetermined effect on late arrhythmias’ recurrences. Moreover, a new concept of a blanking period could be formulated with PFA, according to its different mechanism of myocardial injury, with less inflammation and less chronic fibrosis. Finally, in this review, we also compare PFA with thermal energy.

MID–TERM OUTCOMES OF ENDOSCOPIC MITRAL VALVE REPAIR VIA RIGHT ANTERIOR MINI–THORACOTOMY

Abstract The adoption of less–invasive mitral repair (MVr) surgery is increasing, backed by evidence of satisfactory short–term results and lower major morbidity. We assessed mid–term follow–up results of our experience, and compared two techniques: isolated leaflet resection and neochord implantation for posterior leaflet (PML) prolapse. Between 2012–2021, 700+ operations were performed with a video–assisted right mini–thoracotomy (RMT) approach. We report 309 consecutive patients who had endoscopic MVr, including those receiving concomitant tricuspid repair, ablation for atrial fibrillation, closure of patent foramen ovale and/or left atrial appendage. The early and mid–term follow–up results were ascertained. Primary outcome was the incidence of mortality and significant mitral regurgitation (MR) during follow–up which were summarized by Kaplan–Meier estimator and compared between treatment arms via log–rank test. Secondary outcomes were the early–postoperative results including 30–days mortality and major complications. All patients had endoscopic MVr via RMT at the 3rd/4th intercostal space (IS). A soft–tissue retractor is used, accompanied or not by a rib spreader, and two ports in the fourth and sixth IS are used for 3D thoracoscopy and carbon dioxide insufflation. Femoral vessels exposure through a right groin incision and echo–guided cannulation sec. Seldinger is achieved post–heparinization. Thoracic fascia bisection is performed during single–lung ventilation using a double–lumen endotracheal tube, integral to our anesthetic management, including percutaneous right internal jugular vein cannulation. The pericardium is opened and an aortic root cannula for cardioplegia delivery and venting is placed via working incision. After establishing cardiopulmonary bypass, a Chitwood clamp is passed through the second IS and cardioplegia is delivered. Endoaortic balloon clamping is primarily used in redo cases. With ring annuloplasty, 136 (44%) patients received PML resection (122 isolated) and 97 (31%) PML chords implantation (88 isolated). Forty–nine patients had annuloplasty alone. In–hospital mortality was 1.0%. Mean follow–up was 29±22 months (max 8.3 years). Kaplan–Meier 5–year survival was 97.3±1.0%. MR (3/4+) free–survival at 5 years was 94.5±2.3%. Subgroup time–to–event analysis for the indexed outcomes showed no statistical significance between techniques. In conclusion, endoscopic MVr is safe with excellent mid–term outcomes.

A COMPLEX CASE OF EARLY ONSET ATRIAL FIBRILLATION IN AN ENDURANCE ATHLETE: THE IMPORTANCE OF FAMILY HISTORY

Abstract Introduction Early onset atrial fibrillation (AF) in an endurance athlete represents a challenge for the cardiologist, especially in apparent absence of an overt structural heart disease. Different genetic variants have been associated with early onset AF but indications to genetic testing are still under definition. Case A 54–year–old man (BMI 19 kg/sqm), previous competitive athlete (Nordic running and walking) presented to the Emergency Department with sudden onset palpitations and dyspnea due to high penetrance AF (145 bpm). Family history (FH) was positive for cerebrovascular accidents in both parents and for early onset (&amp;lt;60 years) AF in the father. The man had a recent history of borderline hypertension, of effort related syncope of and of infundibular, isolated, premature ventricular complexes during a maximal exercise stress test (otherwise negative for ischemia) which ultimately led to the denial of competitive sport eligibility. Sinus rhythm (SR) was acutely restored with flecainide and the patient was discharged with low dose nadolol. Cardiac US showed normal left ventricular (LV) dimensions and thicknesses (10 mm), with regular LVEF (60%) and global longitudinal strain (–18%), mildly dilated left atrium (LAVI 36 ml/sqm) and bi–leaflet mitral valve prolapse without significant mitral regurgitation, mitro–anular disjunction nor Pickelhaube sign; 24h Holter ECG showed SR with rare supraventricular (SV) ectopic beats and a 4 beats SV run. Due to the recurrence of short episodes of palpitations, rhythm control with flecainide and antithrombotic prophylaxis were started and AF ablation was planned. Genetic testing for early onset AF identified a nonsense variant (c.84665delG; p.Gly28222fs*2) in TTN gene, classified as likely pathogenic (C4), so far not reported in scientific literature. Also, despite a moderate–low cardiovascular risk as assessed by SCORE2, mostly due to the FH and the desire to engage in high intensity exercise, coronary CT was prescribed, which showed a critical coronary disease leading to stenting on left anterior descending artery and intermediate branch. Cardiac MRI was planned. Conclusions Early onset AF in endurance athletes should not be underrated and a thorough examination including a detailed family history should be performed. TTN is the single gene most frequently associated with early onset AF in absence of an overt structural heart disease, but the subsequent clinical evolution is still largely unknown.

The Impact of Gastroesophageal Reflux Disease and Proton Pump Inhibitor Use on the Risk of Repeat Catheter Ablation for Atrial Fibrillation.

Gastroesophageal reflux disease (GERD) has been associated with increased incidence/recurrence of atrial fibrillation (AF). However, the impact of GERD and proton pump inhibitor (PPI) therapy on outcomes of AF catheter ablation remains unclear. We aimed to assess the association between the presence of GERD and risk of repeat AF ablation, stratified by PPI therapy. A retrospective cohort study was conducted on paroxysmal/persistent AF patients undergoing initial ablation in 1/2011-9/2015. GERD was defined by endoscopic findings, objective reflux testing, or clinical symptoms. The association between GERD/PPI use and time to repeat ablation was evaluated by time-to-event analysis with censoring at last clinic follow-up within one year. 381 subjects were included. GERD patients (n=80) had a higher one-year repeat ablation rate compared to no GERD (25% vs 11.3%, p=0.0034). Stratifying by PPI use, untreated GERD patients (37.5%) more likely needed repeat ablation compared to reflux-free (11.3%, p=0.0003) and treated GERD (16.7%, p=0.035) subjects. On multivariable Cox regression analyses, GERD was an independent risk factor for repeat ablation (HR 3.30, CI:1.79-6.08, p=0.0001). Specifically, untreated GERD was associated with earlier repeat ablation compared to those with no GERD (HR 4.02, CI:1.62-12.05, p=0.0013). However, no significant difference in repeat ablation risk was noted between reflux-free and PPI-treated GERD groups. GERD was an independent predictor for risk of repeat AF ablation within one year, even after controlling for major cardiovascular comorbidities and confounders. PPI therapy modulated this risk, as repeat ablation-free survival for PPI-treated GERD was non-inferior to reflux-free patients.

FEASIBILITY AND MICRO–COSTING ANALYSIS OF A SAME–DAY DISCHARGE PROTOCOL FOR CATHETER ABLATION OF ATRIAL FIBRILLATION: A PILOT STUDY USING CRYOBALLOON ABLATION

Abstract Background Catheter ablation (CA) is a well–established treatment for atrial fibrillation (AF). Due to the ageing population, increasing prevalence of AF risk factors, improving detection methods for AF, and broadening indications for ablation, CA for AF is the most common resource–consuming ablation procedure, strongly impacting waiting list times and healthcare costs. The combination of these factors and limited bed availability led to development of a same–day discharge (SDD) protocol with acceptable efficacy and safety outcomes. Due to the COVID–19 outbreak, we started the SDD pilot project to reduce patient hospital stays and time spent on the waiting list. Objective We aimed to assess our day–case service‘s overall effectiveness and safety. Furthermore, we aimed to evaluate the health–economic impact of a routine adoption of day–case AF ablation. Methods Patients with symptomatic and drug–refractory PAF or early Pe–AF scheduled for de–novo ablation were included in the study protocol if they had the following clinical and non–clinical criteria for an SDD protocol: 1–Clinical factors: a) stable anticoagulation, b) No history of bleeding, c) No systolic heart failure, d) No history of pulmonary disease, e) No interventional procedure within 60 days, f) BMI &amp;lt;35, g) CHA DS –VASc ≤3, h) non–severely dilated left atrium, i) age &amp;lt;65 years old; 2–Non–clinical factors: a) home residence within 50 km, or if more, with an emergency department (ER) reachable within 30 minutes, b) home assistance to the patients the same day of the procedure. Results Fifty–two patients were included in the SDD protocol and underwent PVI with the Arctic Front Advance cryoballoon ablation catheter. Patients were admitted to a cardiac short–stay unit on the day of ablation at 7 am. SDD procedures were carried out in conscious sedation without the presence of an anesthesiologist. After ablation, the patient was admitted to the recovery area for at least 6 hours. Postprocedural echocardiography was performed to rule out pericardial effusion. The bed occupancy cost reduction was 493€/procedure with the SDD protocol (2415€ vs. 1921€). No minor or major complications were observed in the SDD protocol. Conclusion The adoption of an optimized path would lead to a reduction in the length of hospital stays, optimization of beds, a reduction in waiting lists, an accelerating patient access to care and a reduction in patient management costs by optimizing the consumption of resources.

URIC ACID SIGNIFICANTLY CORRELATES WITH THE PRESENCE OF LOW–VOLTAGE AREAS AT THE ENDOCARDIAL MAPPING IN PATIENTS WITH NON–VALVULAR ATRIAL FIBRILLATION

Abstract Background Interest in the role of atrial substrate in maintaining Atrial Fibrillation (AF) is growing. Fibrosis is the culprit in the electrical derangement of the myocites. Many cardiovascular risk factors are known to be linked to atrial scarring; among them Uric Acid (UA) is emerging. The purpose of our study is to evaluate whether UA is associated with atrial fibrosis in AF patients. Methods 81 patients who underwent radiofrequency transcatheter ablation for nonvalvular AF at the cardiological department of the Niguarda Hospital were enrolled. UA levels were analysed before the procedure as well as known predictors of atrial fibrosis. High density electroanatomic mapping of the left atrium was performed and patients were divided according to the presence or not of areas of pathological substrate (bipolar voltage &amp;lt; 0.5mV in sinus rhythm). Results 19 patients showed a pathological atrial substrate. The population of patients with pathological atrial substrate was older (64.7±1.6 vs 58.2±10.9 years, p=0.032) and had more often a persistent phenotype of AF (84.3 vs 35.8%, p&amp;lt;0.001). UA levels were significantly higher in the pathological group (6.8±1.9 vs 5.3±1.4, p&amp;lt;0.001) as well as the prevalence of hyperuricemia (26.5 vs 6.5%, p=0.021). The association between uric acid and pathological atrial substrate remains significant even after correction for confounding factors (age, left ventricular dysfunction, valvular disease, AF phenotype and furosemide use). Conclusions In a population of patients who underwent atrial fibrillation’s ablation, higher uric acid’s levels were significantly associated with pathological left atrium’s substrate at electro–anatomical mapping.

ATRIAL VOLTAGE ANALYSIS FOLLOWING VEIN OF MARSHALL ETHANOL INFUSION PREDICTS MITRAL LINE BLOCK

Abstract Background The vein of Marshall (VoM) is a promising target for atrial fibrillation (AF) treatment, matching with the ‘Coumel triangle‘ by housing triggers, autonomic connections, and serving as a substrate for perimitral flutters. Lateral mitral line (ML) represents a fundamental part for AF treatment, but achieving bidirectional block through endocardial ablations is challenging. VoM ethanol infusion (VOM–EI) facilitates ML block, with the newly–formed bipolar lesion serving as an effectiveness index. Voltage analysis assessment after VOM–EI in predicting ML block is poorly investigated. Purpose To compare unipolar and bipolar low–voltage areas (LVAs) along VOM trajectory after VOM–EI, and their role in predicting ML block. Methods We enrolled 59 patients undergoing catheter ablation of persistent AF or ML–dependent atrial flutter. High–density voltage mapping of left atrium was followed by VOM–EI and LA remapping. The area width difference was obtained and defined as ΔLVA. Normal bipolar voltage cutoffs were 0.50 mV in sinus rhythm or 0.29 mV in AF. Unipolar cutoffs were 2.7 mV and 1.1 mV, respectively. After VOM–EI, anatomical lesions included PVI, linear lesion for dome and ML isthmus. Systematic lines block validation was performed, defining ML block after coronary sinus (CS) electrograms sequence inversion (septal–to–lateral) during left atrial appendage pacing. Radiofrequency (RF) applications into the CS–great cardiac vein targeted epicardial gaps if present. Ablation time for ML block (AblTime) was obtained. Results In our cohort, 94.5% achieved ML block. Bipolar and unipolar low voltage areas after VOM–EI were 9,9 ± 6,9 cm2 and 12,2 ± 5,9 cm2 respectively. Bipolar ΔLVAs were significantly lower than unipolar ΔLVA (8.2 ± 6.5 cm2 vs. 9.4 ± 6.0 cm2; p=0.03) (Fig 1). A strong linear correlation between AblTime and bipolar ΔLVA (R: 0.76), and a significant correlation between AblTime and unipolar ΔLVA (R: 0.6) were found (Fig 2). Patients requiring RF applications into the CS for ML block (13/59, 22%) showed lower ΔLVAs in logistic regression for both bipolar (p&amp;lt;0.01) and unipolar (p=0.03) analyses. Conclusions VOM–EI induces unipolar LVAs wider than bipolar along the mitral isthmus trajectory. Unipolar and bipolar voltage analysis predicts a short time ML block achievement. Moreover, wider unipolar and bipolar LVAs following VOM–EI correlates with higher likelihood to avoid the targeting of epicardial gaps via the CS musculature.

Model for predicting the recurrence of atrial fibrillation after monopolar or bipolar radiofrequency ablation in patients with AF and mitral valve disease

ObjectivesThis study aimed to identify the risk factors for postoperative atrial fibrillation in patients with valvular atrial fibrillation, and establish predictive models of atrial fibrillation recurrence.MethodsOverall, 224 patients who underwent radiofrequency ablation of atrial fibrillation from November 2014 to November 2020 were included. The statistical package for social sciences, X-tile, and R-studio were used for statistical analysis.ResultsPatients were divided into training and validation sets according to a ratio of 3:1. The training set was analysed using univariate and multivariate Cox regression analysis and showed that preoperative uric acid > 401 μmol/L (P = 0.006), B-type natriuretic peptide > 202 ng/L (P = 0.042), hypersensitivity C-reactive protein > 6.1 mg/L (P = 0.026), erythrocyte sedimentation rate > 7.0 mm/h (P = 0.016), preoperative left atrial diameter > 48 mm (P = 0.031) were significantly correlated with the recurrence of atrial fibrillation after radiofrequency ablation in patients with valvular atrial fibrillation. In the training set, a Cox regression model of the five related factors was established using the R language. The C-index of the model was 0.82, and the area under the receiver operating characteristic curve was 0.831 (P < 0.001). Internal and external verification was performed in the training and validation sets, respectively, and both showed that the fit of the verification curve was relatively good at 3 months, 6 months, 1 year, and 3 years postoperatively. After calculating the weight of each related factor using the nomogram, a new risk predictive model (BLUCE) for postoperative atrial fibrillation was established.ConclusionsIn patients with atrial fibrillation, preoperative uric acid, B-type natriuretic peptide, hypersensitivity C-reactive protein, erythrocyte sedimentation rate, and left atrial diameter are risk factors for atrial fibrillation or atrial flutter recurrence after radiofrequency ablation. The BLUCE predictive model can distinguish high-risk groups of postoperative atrial fibrillation. High-risk patients in the BLUCE model were more likely to experience recurrence of atrial fibrillation after radiofrequency ablation and a low possibility of maintaining sinus rhythm.

REAL WORLD USAGE OF RANOLAZINE FOR ANTIARRHYTHMIC PURPOSES: SINGLE CENTER EXPERIENCE

Abstract Introduction Ranolazine is a late sodium current blocking drug developed as an antianginal agent, with good preliminary efficacy data even for antiarrhythmic purposes (both at atrial and at ventricular level). Objectives To evaluate patients’ clinical characteristics and antiarrhythmic efficacy of ranolazine in subjects with a history of atrial and/or ventricular arrhythmias, isolated or repetitive. Patients and methods we included patients who received a first prescription of ranolazine for antiarrhythmic purposes in our center from 1/2022 to 11/2023 and evaluated the survival free from major arrhythmic relapses/ablation. Results 93 patients were enrolled (66±13 years, 15% women): 59% with arterial hypertension, 26% diabetics, 46% with post–ischemic dilated heart disease, 32% with primary cardiomyopathy (including 11% with hypertrophic cardiomyopathy, 10% with LMNA, 14% with TTN), 46% with implantable cardioverter defibrillator, 9% with pacemaker. The mean LV ejection fraction was 42 ± 15%, the mean serum creatinine 1 ± 0.3 mg/dL. Half (50%) had a history of atrial arrhythmias in the 6 months before starting the drug, mainly paroxysmal atrial fibrillation (AF), 67% of ventricular arrhythmias (VAs), mainly isolated and repetitive premature ventricular beats (PVB, 47% of the total), but also sustained or treated VAs (n=18, 19%). Overall, 18% of patients had already undergone AF ablation, 13% ventricular tachycardia ablation, 3% cardiac sympathetic denervation. Finally, 95% of patients were on beta–blocker therapy and 28% were on amiodarone. Ranolazine was prescribed at an average initial dose of 535± 150 mg. The majority (54%) of patients (n=50) had a follow–up longer than 3 months (median 9 months, IQR 6–14); in 6% the drug was stopped due to intolerance and the average dose at the last FU was 641 ± 150 mg. Twenty–eight percent of patients with paroxysmal/persistent atrial arrhythmias had relapses, requiring ablation in 6%. Among patients with major VAs, 57% suffered recurrences, but only 19% required ablation (invasive in 2 cases, non–invasive in 1 case). Finally, among the patients with PVBs, none suffered major VAs or required PVB/VA ablation. Conclusions This is the largest available case–series reporting about the real–world usage of ranolazine for antiarrhythmic purposes. Our single center experience supports ranolazine’s good safety and tolerability and shows encouraging efficacy results in terms of clinical stabilization of complex patients.

WHEN AND WHERE DOES A CARRIER OF HEREDITARY TRANSTHYRETIN AMYLOIDOSIS (ILE88LEU) SHOW THE FIRST SIGNS OF THE DISEASE? DIAGNOSTIC CHALLENGES OF A NOT ONLY CARDIOGENIC MUTATION

Abstract We present the case of a 58–year–old man with a familiar history (mother affected) positive for ATTR–v (Ile88Leu) amyloidosis. The mother initially had a pure cardiac phenotype and was firstly treated with tafamidis, but progression of the disease to the nervous system warranted a switch to patisiran. Our patient carried the Ile88Leu mutation and had a medical history notable for surgically treated left carpal tunnel syndrome (CTS) and untreated right CTS. Furthermore, he was affected by systemic arterial hypertension and was a habitual smoker. He has been followed at our Institution since 2018. His first echocardiogram showed normal left ventricular ejection fraction (LVEF 65%), mild hypertrophy (anterior septum: 12 mm), and borderline values of GLS (– 16%) without any specific pattern. Further exams were executed: Bone scintigraphy (BS): negative (Perugini score 0); Coronary artery ct scan: moderate stenosis of proximal LAD; Neurologic evaluation: no signs of peripheral neuropathy. The clinical picture remained unaltered in 2020 and 2021. However, during November 2022 the patient developed atrial fibrillation (AF) and presented to the ED for dyspnea and palpitations. Electrical cardioversion was performed with success but subsequent recurrences warranted AF ablation in April 2023. At that moment, the patient was re–evaluated. Basal ECG did not show any significant alteration (FIg.1)This time, echocardiogram showed mild worsening of hypertrophy (13 mm septum), GLS – 16% with apical sparing pattern, no other major variations (Fig.2). BS was repeated and revealed grade 1 Perugini score (Fig.3). Hence, a series of clinical question arose: Should we begin a specific treatment or is the disease in an excessively early stage that does not warrant treatment? Is AF linked to concomitant arterial hypertension or might it be an early marker of disease? We questioned the usefulness of endomyocardial biopsy in this specific setting. In this case, we repeated electromyography that showed mild axonal sensitive–motor polyneuropathy. Finally, we concluded for initial signs of systemic amyloidosis ATTR–v (Ile88Leu) type with mixed phenotype (neurological+cardiac). The neurological involvement allowed us to start a gene–silencer (Patisiran). In conclusion, a periodic neurological evaluation is necessary and has crucial therapeutic implications in all genotypes. Indeed, there is increasing evidence that Ile88Leu is a not only cardiogenic mutation.

FOLATES–RELATED AND BONE MARROW DISORDERS PROMOTE ATRIAL CARDIOMYOPATHY INPATIENTS AFFECTED BY PAROXYSMAL ATRIAL FIBRILLATION VIA BOTH EPCS AND ENDOTHELIAL DYSFUNCTION

Abstract Background Atrial Cardiomyopathy (AC) has been recently postulated to explain those embolic strokes not due to atrial fibrillation (AF) and paradoxical embolism. Pathogenic mechanisms underlying AC are still largely unknown. Folate cycle disorders (FD) are a yet underrated pro–thrombotic dysmetabolism. FD could hinder both endothelial and circulating endothelial progenitor cell (EPCs) functioning, therefore providing one–shot explanation to both atrial fibrosis and endothelial dysfunction (ED). Purpose This study aims to enquire for the hypothesis that: 1) atrial fibrosis (AFib) would relate to FD (intended as both: a)MTHFR C677T inherited mutations and b)bone–marrow function disorders, here referring to erythropoiesis diversions) and 2) AF patients would show dysfunctional EPCs. Methods We studied 59 consecutive patients admitted to the cardiology Unit of the General Hospital“F.Miulli”, with preserved EF, subjected to AF ablation. AFib was quantified in term of percentage of bipolar peak–to–peak voltage points below 0,5mV with respect to the wholeness of picked points. Blood count cell was evaluated at the admission. MTHFR C677T genotypes and serum folate were assessed. EPCs isolation and characterization were performed by cytometry analysis (CD45, CD34, CD133, VEGFR2 and KDR). EPCs functional wound healing assay was performed to determine the percentage of EPCs able to "fix the wound” and compared with matched–controls. Results Baseline characteristics did not differ between Sample and Control groups (Fig. 1 – Left Table). % of Afib significantly differs between C677T MTHFR homozigosis patients (n=15) with respect to non–C677TMTHFR homozygosis patients (n=44) (Fig.1 – Right graph. – p &amp;lt; 0,02). Once univariate analysis was performed, subsequent multivariate analysis highlight highest fit, once merged RBC, RDW–SD and folates values were inputed (Fig.2 – superior graph. – R2=0,39;p=0,0001). Either RBC, RDW–SD and folates coefficient reached significance (p &amp;lt; 0,0001; p &amp;lt; 0,01; p &amp;lt; 0,05 respectively). Number of EPCs signifi cantly differs between AF patients and matched controls (Fig 2 – inferior graph. –p &amp;lt; 0,001). Conclusions Our findings support the hypothesis that genetically determined folates dysmetabolism (MTHFR dysfunction) promotes AFib via a complex cardiac–bone marrow networking involving circulatingEPCs and unraveled by erythropoiesis diversions. Such results suggest a pathogenic role of folate cycle disorders in the AC development.

Atrio-oesofageale fistels na ablatie bij voorkamerfibrillatie: diagnose en aanpak voor de eerste lijn

How to diagnose and manage atrio-esophageal fistulas occurring after atrial fibrillation ablation procedures? An atrio-esophageal fistula (AEF) is a rare complication occurring after an ablation procedure for atrial fibrillation, associated with a high mortality. The aim of this study is to provide a practical flowchart for first-line healthcare professionals on the diagnostics and management of these patients. A literature search was performed, resulting in the inclusion of 100 AEF cases after atrial fibrillation ablation procedures (85 reports). The documentation on these 100 patients was analyzed to compose the flowchart. All patients presented within 2 months after the ablation procedure (23 ± 11 days). Neurologic symptoms (75%), fever (73%) and both symptoms (57%) occurred in the majority. A CT scan of the chest was performed in 78% of the cases. In 30% of the patients, an AEF was observed. In other patients, the diagnosis was suspected based on air in the left cardiac circulation or the mediastinum. An esophagogastroscopy resulted in an infaust deterioration in 14/26 of the cases. In total, 41 patients received esophageal surgery (76% survival) versus 9 with only stenting (22% survival). In 27 patients, the diagnosis or treatment was not obtained in time. An AEF should be suspected in patients presenting with fever or neurological symptoms after a recent ablation procedure. CT scans of the chest and head can support the diagnosis. Once diagnosed, one should proceed to emergency surgery to prevent further complications. An esophagogastroscopy should be avoided. The authors hope to provide a practical management guide, allowing an earlier diagnosis, a faster treatment and thus an improved survival in these patients.