Loop Recorder Research Articles

An international multicentre experience with the third-generation laser balloon system: safety, efficiency, and efficacy

Abstract Background Pulmonary vein isolation (PVI) with the use of an endoscopic laser balloon (ELB) is an alternative option for catheter ablation of atrial fibrillation (AF). The third-generation system has several improvements, including the novel RAPID mode (RM), potentially allowing a one-shot, continuous, circumferential laser lesion for PVI. Objective In an international, multicentric cohort, we assessed the third-generation ELB’s safety, efficacy, and long-term effectiveness. We also focused on the learning curve (LC) and the use of RM. Methods Between June 2019 and December 2022, we prospectively obtained data on all the patients who consecutively underwent ablation of AF using the third-generation ELB in eight Italian and one German hospital. Each operator attempted to use the RM to the maximum extent in every procedure. Follow-up (FU) visits were scheduled at 3, 6, 12 and 24 months and included a Holter-ECG of 24 hours or, if the patient was a carrier, a device interrogation (implantable loop recorder or two-chamber/three-chamber pacemaker/defibrillator). For FU analysis, we included patients with data available after the blanking period (the first 90 days after the procedure). We analysed the LC, comparing the outcomes of the first fifteen patients of each centre with the remaining patients. In addition, we investigated the impact of an extensive use of the RM (at least 90% of all PV circumferences) on the procedural and FU outcomes. Results we enrolled 427 patients. Of these, 328 had a FU >90 days. The mean total procedural and fluoroscopic times were 105 (66-150) and 17 (10-28) minutes, respectively. Serious adverse procedural events occurred in 11 patients (2.6 %) as follows: 3 periprocedural transient ischaemic attacks, 4 pericardial tamponades, 1 persistent phrenic nerve palsy and 3 severe vascular complications. The mean FU period was of 365 days (194-533). AF recurrence-free rate was 76.7% (95% CI, 70.8%-81.5%) at 12 months. Median RM use was 94% (81-100) of the PVs circumference. RM could be used for at least 90% of all PV circumferences in 188 (55.8%) patients, and the operators could perform an RM-only procedure in 82 (24.3%) patients. Patients treated after the LC or with extensive use of RM showed significantly reduced procedural times and rates of AF recurrence. In a multivariate analysis, the use of the RM was not an independent predictor of a lower recurrence rate at FU, demonstrating only a tendency toward significance (86.0% [77.3-91.6] vs 71.3% [61.3-79.2], HR 0.52, CI 0.26-1.07, p 0.075). Conclusion In this prospective, multicentre, international registry of patients treated with the third-generation ELB, the system proved efficient, safe, and effective. Completing the LC and using the RM reduced procedural time and arrhythmia recurrence. However, using RM was not an independent predictor of a lower recurrence rate.

Weight change does not impact the long-term outcomes following pulmonary vein isolation in obese patients with atrial fibrillation

Abstract Background Weight loss has been shown to reduce the burden of atrial fibrillation (AF) in obese patients. However, there are limited data on the impact of weight loss on long-term outcomes in patients with atrial fibrillation (AF) who undergo pulmonary vein isolation (PVI). Objective To understand the impact of weight change, as assessed by freedom from recurrent AF, in obese patients undergoing cryoballoon (CB) PVI. Methods We enrolled consecutive obese (BMI ≥ 30 kg/m2) patients with AF who underwent CB PVI; all patients had an implantable loop recorder (ILR) for long-term ECG monitoring. The cohort was divided into 3 groups based on their weight change 1-year after ablation: (1) weight loss (WL) > 3% weight decrease; (2) no weight change (NWC) - weight change < 3%, (3) weight gain (WG) > 3% weight increase. We assessed long-term AF recurrences, after excluding an initial 3-month post-ablation blanking period. Results Out of total of 137 pts with obesity, 61 pts had weight available at the ablation and at 1-year follow-up (65 ± 9 years; 41 [67%] male; 23 [38%] PAF; CHA2DS2-VASc 2.9 ± 1.7). There were no differences in baseline characteristics. At follow-up, 24 (39%), 26 (43%), and 11 (18%) pts lost, had no change, or gained weight, respectively. Of the 24 pts who lost weight, 3 pts lost > 10% body weight. During a follow-up of 964 ± 512 days, 41 (67%) pts had recurrent AF; the change in weight did not impact outcomes (Figure), including those who lost > 10% body weight. Conclusions During 3-years of follow-up, 2/3 of obese patients had objective evidence of AF recurrence following CB PVI. Weight change in the first-year post ablation did not alter long-term outcomes. Other strategies may be needed in these patients to improve outcomes.

Long-term results of cardioneuroablation evaluated by implantable loop recorder

Abstract Background Cardioneuroablation (CNA) is a catheter ablation technique based on radiofrequency application in the atrial endocardium to decrease vagal response. Since the first series publication, its use has greatly increased, with CNA being now used in vasovagal syncope (VVS), functional atrioventricular block (AVB), symptomatic sinus bradycardia (SB) and Atrial Fibrillation (AFib). There is still limited data regarding long-term follow-up (FUP) of patients who have undergone this procedure. Purpose The aim of this study was to evaluate long-term results of CNA in a single center with the use of an implantable loop recorder (ILR). Methods We performed a prospective single-center cohort study. Patients with significant documented functional bradyarrhythmias between September 2019 and October 2023 were enrolled. All patients underwent ILR implantation before ablation. CNA was performed using catheter ablation aiming at right epicardial GPs with 3-dimensional electroanatomical mapping support. A 2 mg atropine test (bolus) was carried out before and after CNA and the subsequent heart rate (HR) increase registered. Successful CNA was defined as absence of HR increase with atropine after the ablation. HR pre and post ablation was compared. Immediate and late procedure complications were assessed. Recurrence of symptoms, the presence significant vagal-induced bradyarrhythmias on ILR and the need for pacemaker (PM) implantation were also assed. Results Fifteen patients (pts) were included, with a mean age of 64 (± 12 years) and a 53.3% male prevalence. None of the pts had structural heart disease. The main indication for CNA was AFib with brady-tachy syndrome (8 pts, 53.3%), followed by VVS (4 pts, 26.7%), SB (2 pts, 13.3%) and AVB (2:1 AVB; 1 pt). The most common symptom was syncope (46.7%), followed by pre-syncope (40%) and fatigue (20%). There was a significant improvement in HR after CNA (55 ± 13 vs. 67 ± 14 bpm pos-CNA, p=0.002). The achievement of success was verified in all patients (mean HR variation with atropine before CNA 35 ± 10% vs. 2 ± 2% after CNA; p=0.001). Procedure mean time was 28 ± 12 min. During a maximum FUP of 48 months (minimum 1 month, median 5), 1 patient had recurrence of VVS with a 10s pause documentation on ILR requiring PM implantation and 1 patient had a 4s pause without translation into symptoms and a duration decreasing tendency during FUP. Freedom from recurrence of symptoms was 93.3%, freedom from pacemaker implantation was 93.3% and freedom from significant bradyarrhythmias was 86.7% – Figure 1. No immediate or long-term complications were seen. Conclusions CNA aiming at the right GPs is a safe and quick procedure for patients with functional bradyarrhythmias. This ablation technique in most patients not only reduces symptoms, but also avoids early PM implantation, therefore improving quality of life. Further randomized clinical trials are needed to support these data and refine patient selection criteria.

Predicting atrial fibrillation risk following embolic stroke of unknown source using cardiac magnetic resonance imaging

Abstract Background Approximately 25% of embolic strokes of unknown source (ESUS) are attributed to undiagnosed atrial fibrillation (AF).1 The European Stroke Organisation (ESO) recommends implantable loop recorder (ILR) monitoring to identify ESUS patients with AF, permit the initiation of anticoagulation and reduce risk of recurrent stroke.2 However, this approach delays treatment and carries significant cost and resource implications. An alternative approach, where early anticoagulation is initiated in the absence of AF has failed to reduce recurrent stroke in four randomised controlled trials (NAVIGATE ESUS, RE-SPECT ESUS, ATTICUS and ARCADIA).3-6 An urgent need exists for new strategies to identify ESUS patients with undiagnosed AF that are at high risk of future thromboembolism. Purpose The primary objective of this study was to produce a substrate-based predictive model for AF in ESUS patients using atrial cardiac magnetic resonance imaging (CMRi). Method The Atrial CARdiac Magnetic resonance imaging in patients with embolic stroke of unknown source without documented AF (CARM-AF) Study is a prospective, multi-centre, observational study. All patients underwent CMRi and ILR insertion for AF detection within 3 months of ESUS. The main inclusion criteria were expected survival >12 months, CHA2DS2VASc≥3 and eGFR >30ml/min. Patients were allocated to the study group if AF >30 seconds was detected by ILR during the first year of follow-up and control group if no AF detected (Figure 1). Univariable analysis was used to identify clinical, echocardiographic and CMR parameters associated with AF diagnosis. Parameters with p<0.2 and no co-linearity were used to develop multivariable logistic regression models for AF prediction. Results From September 2020 to September 2022, 102 patients were enrolled and 91 were included in the final analysis. AF was detected in 17 patients during the first year of follow-up (18.6%). In univariable analysis, patients with AF were more likely to be female (p=0.02), but there were no significant differences in age, race, body mass index (BMI) or CHA2DS2VASc score (p=0.06, 0.272, 0.195, 0.211) between groups. Increased left atrial (LA) volume, surface area and reduced LA ejection fraction were associated with increased risk of AF detection at 1 year (p=0.006, 0.044, 0.008). LA fibrosis and sphericity were not associated with AF (p=0.84, 0.98). Logistic regression models for AF risk prediction were developed using patient, echocardiographic and CMR parameters. A combined model of patient and CMR parameters outperformed assessment of patient characteristics alone, achieving an AUC of 0.85 for predicting AF occurrence (p<0.005). Pseudo R2 of 0.30 (McFadden) indicated excellent model fit (Figure 2). Conclusion CARM-AF is the first study to demonstrate feasibility and utility of CMR imaging to predict AF risk following ESUS. A randomised controlled trial initiating anticoagulation using the developed model is recommended.Study DesignModel Comparison (ROC Curves)

First experience of focal pulsed field ablation for premature ventricular contractions

Abstract Introduction Pulsed field ablation (PFA) has emerged as a novel strategy to achieve ablation of cardiac tissue. Clinical evidence suggests a remarkable lesion durability and safety profile for AF ablation. Nonetheless, a growing interest exists in broadening its field of application for catheter ablation of ventricular arrhythmias (VA). The CENTAURI system arises as a promising PFA system for targeting VA as it allows pulsed electric field (PEF) delivery via standard, commercially available focal ablation catheters and concomitant coupling with their mapping systems. Purpose To assess, for the first time, the feasibility of focal PFA via the CENTAURI system for premature ventricular complex (PVC) ablation. Methods We conducted a prospective analysis of patients with either high burden (>10%) or symptomatic idiopathic PVC undergoing focal PFA using CENTAURI system at our institution. Procedures were performed between December 2022 and August 2023. Acute and long-term success were defined as no PVC recurrence during a 24h in-hospital monitoring period, and ≥80% burden reduction with absence of symptoms after at least 30 days post-ablation, respectively. PVC monitoring was performed by implantable loop recorder (ILR) or surface ECG Holter monitoring. Results Fourteen patients (age range: 16-87 years; 10 females) were included. Procedures were performed via the CENTAURI system in combination with CARTO 3 system and EnSite X EP system in 4 (28.6%) and 10 cases (71.4%) respectively. Targeted ablation sites were the right ventricular outflow tract (6 cases), right moderator band (2 cases), left postero-medial papillary muscle -PM- (2 cases), and right posterior PM, tricuspid annulus, left posterior fascicle and aortomitral continuity (AMC) in one case. On average, 6.5 applications were delivered to the site of origin with a mean contact force of 11g. Procedural duration and fluoroscopy time were 102 and 8.9 minutes. Two minor complications were observed: one transitory ST depression (solved after i.v. nitrate administration) after repeated applications to AMC, and a femoral pseudoaneurysm. The remaining 12 procedures were uneventful. Although most of the procedures were performed under general anesthesia due to concerns about potential significant muscular contraction, 3 cases (21.4%) were successfully managed with light sedation, without significant muscular contraction nor map shift. Incomplete abolishment of PVC during first 24 h was observed in 2 patients (14.3%). After a median follow-up of 113 days (IQR: 83-188), recurrences were detected in one patient (7.14%). Conclusion Herein we report the feasibility and efficacy of PVC ablation using a focal PEF delivery system (CENTAURI). Furthermore, we describe the possibility of performing PVC ablation with this technology under light sedation, which might be important for minimizing anesthesia impact on PVC burden.Table of characteristicsPVC morphologies

Morphological identification of brugada type 1 pattern using loop recorder: a feasibility study

Abstract Introduction The presence of spontaneous type 1 Brugada pattern (BP1) is associated with an elevated risk of arrhythmic events. Diagnosis of this condition is often underestimated due to its intermittent nature. While periodic ambulatory ECG monitoring can distinguish patients with pharmacologically induced patterns from those with spontaneous patterns, the diagnostic capabilities of this method are limited. Implantable cardiac monitors (ICM), designed to continuously record heart rhythm, may offer higher sensitivity in detecting patients with intermittent patterns. However, the ICM's ability to morphologically identify the ST segment elevation associated with BP1 remains uncharted. Purpose This study aimed to assess the ICM's capacity to morphologically identify the ST segment elevation associated with BP1. Methods We enrolled all patients who underwent ajmaline testing (AT) between November 2022 and September 2023 in our centre. For positive patients, the external simulator of a loop recorder was utilized to evaluate four positions (I-II left intercostal space at a 45° tilt, II-III left intercostal space at a 45° tilt, II-III right parasternal intercostal space, and II-III left parasternal intercostal space). These positions were selected to capture the trace with the most significant ST segment elevation at the J point during the peak positivity of the ECG during the ajmaline test. Measurements from the recorded traces were acquired using dedicated software. Results Out of 50 patients, 21 (male-to-female ratio 1.62:1, mean age 43.4±13.1 years) had a positive AT result. Seventeen patients exhibited ST segment elevation in the simulator trace during the highest ajmaline dose. Among these patients, the optimal recording position was in the I-II left intercostal space at a 45° tilt in 66.7% of cases. The median ST segment elevation recorded by the simulator was 0.9 mm (interquartile range 0.6-1.1 mm). Notably, there was no observed correlation between the extent of ST segment elevation in the ECG and that recorded by the simulator trace (Pearson linear coefficient = 0.09). Conclusions ICM may offer the potential to record BP1, a finding that holds significant diagnostic and prognostic implications for asymptomatic patients with pharmacologically induced BP1. Further research is needed to develop useful programming algorithms for the automatic recording of this pattern.

Premature ventricular contractions increase with heart rate in patients with mitral valve prolapse

Abstract Background A subset of patients with mitral valve prolapse (MVP) are at risk of life-threatening ventricular arrhythmias (VAs), and a high burden of premature ventricular contractions (PVCs) is associated with increased mortality in patients with MVP. Previous studies indicate that PVC burden could either increase with increasing heart rate (HR), decrease with increasing HR, or with no relationship to HR. The association between PVC burden and HR in MVP is not known, nor if there is an association with VAs. Purpose We aimed to explore the relationship between PVC burden and HR in patients with MVP. Furthermore, we aimed to explore whether the different PVC profiles were associated with severe VA. Methods In this cross-sectional ambispective outcome study, we included patients with MVP and available Holter monitorings with >100 PVCs per 24-hours seen at our tertiary centre. The Holter monitoring with the highest PVC burden was used in case of multiple recordings. We investigated the relationship between hourly PVC burden and hourly mean HR by univariable mixed linear regression. We defined PVC profiles as (1) fast-HR-dependent-PVC (F-HR-PVC) when there was a significant positive correlation, (2) slow-HR-dependent-PVC (S-HR-PVC) when there was a significant negative correlation, and (3) independent-HR-PVC (I-HR-PVC) when no correlation between PVC and HR was found. The significance was set to 0.05. Severe VA was defined as sustained ventricular tachycardia, non-sustained ventricular tachycardia with haemodynamic instability, ventricular fibrillation, aborted cardiac arrest, or appropriate shock by a primary preventive implantable cardioverterefibrillator. Severe VA was recorded from retrospective medical history, prospective ICD interrogation or monitoring with implantable loop recorder. Results We included 75 patients with >100 PVCs at Holter monitoring (median age 48 years [IQR 35-58], 58% female). The median PVC burden was 1.9% per 24-hours (IQR 0.4-7.2). We found F-HR-PVC in 49 patients (65%), S-HR-PVC in 1 (1%), and I-HR-PVC in 25 (33%). Twelve (16%) patients had severe VA and these had higher PVC burden compared to those without severe VA (7.3% per 24-hours [IQR 4.2-10.4] vs 1.1% per 24-hours [IQR 0.3-5.3], p=0.004). The median PVC burden was 1.5% (IQR 0.3-8.0) for F-HR-PVC, 5.7% for S-HR-PVC and 1.5% (IQR 0.3-8.0) for I-HR-PVC. We found no association between different PVC profiles and the presence of severe VA (F-HR-PVC 65% vs 67%, S-HR-PVC 2% vs 0%, I-HR-PVC 33% vs 33%, p>0.05 for all groups). Conclusion Fast-HR-dependent-PVC was most common in MVP patients, and slow-HR-dependent-PVC were rare. A higher PVC burden was associated with severe VA. However, different PVC profiles did not infer higher risk of severe VA in our study. Further studies are needed to explore whether distinct PVC profiles can predict severe VA in larger patient populations.

Risk factors for asymptomatic bacterial colonization of cardiac implantable electronic devices

Abstract Introduction With broadening indications and a progressively ageing demographic, incidence of cardiac electronic implantable device (CIED) implantation increased. Despite device infection being rare, it persists as a serious complication concomitant with a high mortality rate. While extensive research on cardiac device infection (CDI) has been conducted, the incidence and clinical significance of asymptomatic bacterial CIED colonisation has not been investigated so far. Purpose Our study aims to elucidate potential risk factors for and investigate the clinical significance of asymptomatic bacterial CIED colonisation. Methods and Results In this prospective single centre study, 345 patients with no clinical signs of CIED infection underwent a generator exchange. In total, 78 pacemakers (PM), 97 implantable cardiac defibrillators (ICD), 67 cardiac resynchronisation therapy devices (CRT), 1 baroreceptor stimulator, as well as 102 implantable loop recorders were sonicated to determine the presence of adherent microorganisms (biofilms). Intraoperative swabs were collected in 329 patients. For statistical analysis, detection of ≥1 colony forming units (CFU) during sonication was considered a significant level of bacterial colonisation. The ≥50 CFU threshold was established in order to examine risk factors relevant for higher levels of bacterial colonization. 88 CIED (25.5%) showed bacterial colonisation ≥1 CFU while 44 CIED (12.8%) were colonised with ≥50 CFU. Multivariate analysis revealed male gender as independent risk factor for both ≥1 CFU (p<0.001; OR 7.73, CI 2.84-21.04) and ≥50 CFU (p<0.001; OR 12.14, CI 2.79-52.78). and immunosuppressive medication (p=0.018; OR 3.31; CI 1.23-8.92) as independent risk factor identified for ≥50 CFU colonisation. For both cutoffs, Cutibacterium acnes emerged as the most frequently detected bacterium during sonication, followed by coagulase negative Staphylococci (CoNS) with Staphylococcus epidermidis being the most common within this CoNS group. During the follow-up (384.5 +/- 480.6 days), 287 patients showed absence of CDI (53 patients lost to follow-up). Of the five patients with CDI, one exhibited concordant results between sonication, swab, and blood culture for Cutibacterium acnes, one presented with partially concordant results, whereas the other three showed varying degrees of disconcordance between index event microbiological results and subsequent CDI pathogens. Conclusion Remarkably, 27.2% of CIEDs with leads (PM, ICD, CRT) exhibited bacterial colonisation. Out of the 5 CDIs identified, 4 were associated with positive sonication results. In addition, our study identifies male gender and immunosuppressive medication as significant risk factors for asymptomatic bacterial CIED colonisation. Thus, in patients with these given risk factors, CIED sonication should be considered for risk stratification with regard to a subsequent CIED infection and possible targeted antimicrobial therapy.Flow Chart

Effects of long-term continuous screening for atrial fibrillation on heart failure events - results from the randomized LOOP Study

Abstract Background Previous research established a solid link between atrial fibrillation (AF) and heart failure (HF). However, while two landmark trials have assessed AF screening for stroke prevention, the potential impact of AF screening on HF remains unclear. Purpose This secondary analysis of the LOOP Study aimed to investigate the effects of AF screening on HF events. Methods The LOOP Study was a randomized clinical trial evaluating long-term continuous AF screening with implantable loop recorder (ILR) in individuals aged 70-90 years and with ≥1 of arterial hypertension, diabetes mellitus, HF, and/or prior stroke. At inclusion, study participants were randomized 1:3 to either ILR screening or usual care. Anticoagulation was recommended upon AF detection, whereas other treatment was left to the discretion of the treating physician. In this secondary analysis, a cause-specific Cox regression model was applied to explore the effects of AF screening vs usual care on 1) time-to-first HF event and 2) total HF events, with the latter performed using the Andersen-and-Gill extension. HF event was defined as newly diagnosed HF with left ventricular ejection fraction ≤40% or any HF hospitalization in participants with prior diagnosis of HF with reduced ejection fraction. Results In total, 6004 participants were enrolled in the LOOP Study: 1501 in the ILR group vs 4503 in the Control group. The study population had a mean age of 75 years and slightly more males than females (53% vs 47%), whereas 266 (4.4%) were previously diagnosed with HF at baseline. During a median follow-up of 5.4 years, a total of 208 HF events were reported in 175 (2.9%) participants: 37 events among 34 (2.3%) participants in the ILR group vs 171 events among 141 (3.1%) participants in the Control group. For time-to-first HF event, the annualized event rate was 0.44%/year [95% confidence interval (CI): 0.30-0.62] vs 0.61%/year [95% CI: 0.51-0.72] for ILR vs Control, corresponding to a hazard ratio (HR) of 0.72 [95% CI: 0.50-1.05]. When assessing total HF events, a significantly lower event rate was observed in the ILR group (0.47%/year [95% CI: 0.33-0.65]) compared with the Control group (0.73%/year [95% CI: 0.62-0.84]), resulting in a HR of 0.65 [95% CI: 0.44-0.97]. Conclusions Among elderly individuals with additional stroke risk factors, long-term continuous AF screening led to a significantly reduced risk of total HF events, compared with usual care. This should be considered as hypothesis-generating and warrants further investigation.Cumulative incidence of HF event

Impact of obesity and pattern of atrial fibrillation on long-term outcome following cryoballoon pulmonary vein isolation

Abstract Background Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for treatment of paroxysmal and persistent atrial fibrillation (PAF, PeAF). Obese and PeAF patients do worse following ablation. However, there are limited data on the impact of both variables on outcomes. Objective To understand the impact of obesity and AF pattern on long-term outcomes following CB PVI. Methods We enrolled consecutive AF patients undergoing CB PVI; all patients had an implantable loop recorder (ILR) for long term continuous monitoring. Obesity (O) was defined as a BMI ≥ 30 kg/m2. The cohort was divided into 4 groups based on presence of obesity and type of AF at the initial ablation: (1) N-O (non-obese) and PAF, (2) O and PAF, (3) N-O and PeAF, and (4) O and PeAF. We assessed long-term AF recurrences, after excluding an initial 3-month post-ablation blanking period. Results The cohort included 322 patients (67 ± 9 years; 209 [65%] male; 177 [55%] PAF; CHA2DS2-VASc 2.7 ± 1.6, 137 [43%] O). Obese patients were younger and more likely to have hypertension and diabetes. During a follow-up of 931 ± 599 days, 211 (66%) patients had recurrent AF. The best outcome was seen in N-O obese patients with PAF; all other groups fared similarly (Figure). Group 1 had significantly lower AF recurrence compared to all 3 other groups (Figure). In multivariate analysis, obesity/AF type was the only significant predictor of AF recurrence (Table). As compared to N-O PAF pts, O PeAF patients had a 2-fold greater likelihood of AF recurrence. Conclusions During almost 3-years of objective follow-up, we found that CB PVI performs best in non-obese pts with PAF. Once obesity occurs, PAF pts respond as poorly to PVI as pts with PeAF, irrespective of obesity status. Additional strategies are needed in these patients.

Posterior wall isolation in patients with persistent atrial fibrillation: a single center comparative study between ablation index and very high power short duration radiofrequency ablation protocol

Abstract Background Circumferential pulmonary veins ablation (CPVA) with posterior wall isolation (PWI) using radiofrequency catheter ablation (RFCA) is gaining increasing interest in terms of safety and efficacy. Purpose To compare procedural data and efficacy between two radiofrequency ablation protocols for the treatment of persistent atrial fibrillation (PersAF): very high power-short duration (vHPSD) ablation using a novel temperature-controlled ablation catheter and Ablation Index (AI) guided RFCA using traditional contact-force catheter. Methods This single center prospective study enrolled 75 consecutive patients (Group 1) with symptomatic PersAF undergoing RFCA using a novel contact-force catheter optimized for temperature-controlled ablation with microelectrodes and 6 thermocouples for real-time temperature monitoring during ablation. The vHPSD algorithm modulates power to maintain target temperature during these lesions (90 Watts, 4 s) in the posterior wall. RF delivery in anterior regions was performed in a temperature guided setting (1-45W, 45°C) to achieve a 500-550 AI. These patients were compared to 75 propensity matched patients (Group 2) undergoing PersAF ablation with traditional AI-guided ablation. Procedural data were compared between the two groups (Table 1). Procedural outcome was considered as loop recorder documented atrial arrhythmias recurrences and compared between the two groups. Results Seventy-five patients (69% male, 63.1±11.2 years old) underwent ablation with vHPSD protocol (Group 1). CPVA and PWI was achieved in all patients with total procedure and fluoroscopy times of 67.5±28.8 min and 4.5±2.8 min, respectively. After 12-month median follow-up, 57/75 patients (76%) were free from AF. Seventy-five propensity matched patients (69% male, 60.7±9.9 years old) have undergone ablation with standard contact-force catheter. CPVA and PWI was achieved in all patients with total procedure and fluoroscopy times of 81.99±20.5 min and 5.7±2.1 min, respectively. After 12-month median follow-up, 55/75 patients (73%) were free from AF. Procedural and fluoroscopy times were significantly lower in in Group 1 than in Group 2 (Table 1). AF recurrencies were comparable between the two groups as assessed with survival analysis (Figure 1, log-rank 0.509). There were no deaths or other severe periprocedural complications. Conclusions PWI on top of CPVA is effective in limiting arrhythmic recurrences following RFCA of PersAF. Compared to standard AI guided ablation, vHPSD protocol significantly reduces procedural time and fluoroscopy exposure. Clinical outcomes between the two protocols are similar.Figure 1

Initial experience with a virtual atrial fibrillation clinic after pulmonary vein isolation

Abstract Introduction To detect recurrent atrial fibrillation (AF), a variety of methods are used, ranging from incidental electrocardiogram to rhythm monitoring with implantable loop recorders (ILRs). In clinical practice, routine use of ILRs is not feasible due to cost. Repeated (week)-Holters cause a considerable burden, both on patients and hospitals, and moreover are inadequate for detecting recurrent AF. Purpose To investigate whether remote monitoring (RM) is feasible in patients with AF after pulmonary vein isolation. Methods We set up a virtual AF clinic. Patients were equipped with a photopletysmography (PPG) application and asked to perform a recording when symptomatic. Recordings uploaded to the Hospital Electronic Patient Dossier and monitored by dedicated eNurses. The number of hospital contacts, hospital visits, electrocardiograms and Holter recordings were noted. Patient satisfaction and quality of life was measured by (validated) questionnaires. Comparisons were made with a historic control group from Jan-March 2019 with a traditional follow up of outpatient visits, electrocardiograms and Holters. Results 157 patients were studied, 78 in the RM group and 79 in the control group. Mean age was 63 ± 10 years, 64% male. AF was paroxysmal in 68% of patients. Follow-up was 1 year and completed in all patients. In the RM group, patients performed 16±29 recordings/year. AF was detected in 37 (47%) patients on RM. While more planned remote contacts were performed in the RM group, significantly less planned and unplanned outpatient clinic visits, AF-related hospital admissions, and Holters took place. Patients report a high satisfaction with this form of remote monitoring. Conclusions A virtual AF clinic is feasible. When asked to record when symptomatic, patients perform few measurements. Compared to patients with a traditional follow-up, patients on PPG-based RM need fewer hospital visits and admissions, and undergo fewer Holters. Patient satisfaction with RM is high.

Right atrial endomysial fibrosis is associated with higher POAF-burden

Abstract Background Atrial endomysial fibrosis, rather than overall connective tissue content, determines the complexity of conduction in human atrial fibrillation (AF). Moreover, the AF-specific blood biomarker BMP10 is associated with atrial endomysial fibrosis, but not overall connective tissue content. It is unclear whether pre-operative atrial endomysial fibrosis predicts post-operative AF (POAF) incidence and burden. Objective To determine the predictive value of atrial fibrosis for early and late POAF burden. Methods Patients with and without AF history were included in the RACE V tissue bank study (n=134). Post-operative rhythm was monitored continuously for 2.5 years with implantable loop recorders. Late POAF-burden was investigated following a 90-day blanking period. Left (n=89) and/or right (n=92) atrial appendage biopsies (LAA/RAA) were snap-frozen and histologically investigated following WGA-staining. Results Logistic regression, corrected for age, sex and AF history, showed that left (st.β = 0.54 [0.23-0.85], p=0.001) and right (st.β=0.35 [0.07-0.64], p=0.017) atrial endomysial fibrosis were associated with early POAF burden in the blanking period. Only right atrial endomysial fibrosis, however, predicted late POAF-burden (st.β=0.44 [-], p=0.009). Adjusted Cox proportional hazards analyses indicated that patients in the highest tertile of right atrial endomysial fibrosis, in particular, are at risk for late POAF (HR T3 vs T1: 2.47 [1.18-5.17], p=0.016, Fig 1). Overall connective tissue content in both atria was not associated with POAF-burden. Conclusion Patients with higher levels of right atrial endomysial fibrosis are at risk for developing late POAF with a higher POAF-burden.Figure 1

Cardiac tumors with life threatening arrhythmia, an eight year single centre experience

Abstract Background Cardiac tumors are rare cardiac disorders which occur either as primary or secondary tumors. They have a wide variety of clinical presentations from accidental discovery till sudden cardiac death. Manifestations are mainly due to mass effect, local invasion, embolization, or constitutional symptoms. (1) Cardiac tumor related arrhythmias are more often incessant, especially in younger children, and the mechanism can be reentry or triggered automaticity. (2) Arrhythmia management depends on its clinical impact as well as tumor size, site, and nature. Surgical resection is preferred in life threating arrhythmias however, the decision should be tailored. Purpose To describe our institution’s tailored approach in treatment of cardiac tumors presenting with life threatening ventricular arrhythmias (VAs), including surgical resection, coiling of feeding vessels or even ICD implantation with long term rhythm monitoring. Methods We reviewed patients with primary cardiac tumors presenting to our center from 2015 to 2023 with emphasis on those with life threatening VAs. Patient records were examined for clinical presentation, ECGs, imaging modalities, histopathological analysis of the resected tumors and interrogation data for those with cardiac implantable electronic devices (CIEDS). Results Over 8 years, 64 patients were diagnosed to have primary cardiac tumors. Of those, 3.8% (6 patients) presented with life threatening monomorphic VT, half of them were pediatrics. Tissue characterization by CMR and histopathological analysis for the resected tumors revealed: 4 fibromas, one lipoma and one hemangioma. Surface ECGs during VT showed exit at, or close to, the site of the tumor (Table). Total surgical resection was performed in four cases (3 fibromas and one lipoma), one of them (the youngest, 6 months old) died during the postoperative period due to refractory heart failure. Partial resection was done in one patient with fibroma as the tumor involved the majority of RV free wall while the patient with hemangioma underwent coiling of the feeding vessels twice with marked decrease in the tumor size however he had one further episode of VT, so ICD was implanted. Over a mean follow up period of 3 years, four patients had no recurrence of tachycardia as confirmed with implantable loop recorders (ILRs) while the patient with ICD had infrequent episodes. Conclusion Total surgical resection, albeit risky, is highly effective in eliminating life threatening VAs caused by cardiac tumors. Other modalities like partial resection or coiling of the feeding vessels could be effective in high-risk patients. Devascularization, in our hemangioma case was not totally protective. Finally, ILRs were highly beneficial in confirming long-term freedom of arrhythmia after resection.Table: VT exit, tumor site and typeECG, CMR, angiogram& surgical view

Long-term Monitoring to Detect Risk of Sudden Cardiac Death in Inherited Arrhythmia Patients

BackgroundRisk stratification in inherited arrhythmia syndromes is challenging. Implantable cardioverter defibrillators (ICDs) are effective in the prevention of sudden cardiac death but are associated with significant complications. We aimed to determine the value of long-term implantable loop recorder (ILR) monitoring to determine risk factors for arrhythmias in inherited arrhythmia patients. MethodsWe conducted a prospective multicentre study between 2015 and 2020 recruiting inherited arrhythmia probands and family members at intermediate arrhythmic risk, with no class 1 indication for ICD implantation. The primary endpoint was the detection by ILR of nonsustained ventricular tachycardia over ≥ 10 consecutive beats. Secondary endpoints included ICD insertion during follow-up, all-cause mortality, and ILR complication rates. ResultsA total of 45 individuals (30 female participants) were enrolled in the study. The most common diagnoses were long-QT syndrome (28%), Brugada syndrome (26%), and arrhythmogenic cardiomyopathy (11%). Following ILR insertion (mean follow-up 633 days; range, 387-969), cardiac symptoms occurred in 19 of 45 patients (42%), 5 of whom had nonsustained ventricular tachycardias (11%), which were symptomatic in 3 individuals. This situation led to ICD implantation based on ILR in 5 of 45 patients (11%). Fifty percent of symptomatic events occurred in ARVC patients. The median time from ILR insertion to ICD implantation was 152 days (interquartile range (25th, 75th percentiles) 55 of 209). No patient experienced sudden cardiac death. ConclusionsILRs enable the detection of high-risk arrhythmic features and facilitate selection of ICD candidates in inherited arrhythmia patients with borderline indications.

Long-term clinical outcomes and cost-effectiveness of catheter vs thoracoscopic surgical ablation in long-standing persistent atrial fibrillation using continuous cardiac monitoring: CASA-AF randomized controlled trial

BackgroundLong-term clinical outcomes of catheter ablation (CA) compared to thoracoscopic surgical ablation (SA) to treat patients with long-standing persistent atrial fibrillation (LSPAF) are not known. ObjectiveThe purpose of this study was to compare the long-term (36-month) clinical efficacy, quality of life, and cost-effectiveness of SA and CA in LSPAF. MethodsParticipants were followed up for 3 years using implantable loop recorders and questionnaires to assess the change in quality of life. Intention-to-treat analyses were used to report the findings. ResultsOf the 115 patients with LSPAF treated, 104 (90.4%) completed 36-month follow-up [CA: n = 57 (95%); SA: n = 47 (85%)]. After a single procedure without antiarrhythmic drugs, 7 patients (12%) in the CA arm and 5 (11%) in the SA arm [hazard ratio 1.22; 95% confidence interval (CI) 0.81–1.83; P = .41] were free from atrial fibrillation/tachycardia (AF/AT) ≥30 seconds at 36 months. Thirty-three patients (58%) in the CA arm and 26 (55%) in the SA arm (hazard ratio 1.04; 95% CI 0.57–1.88; P = .91) had their AF/AT burden reduced by ≥75%. The overall impact on health-related quality of life was similar, with mean quality-adjusted life year estimates of 2.45 (95% CI 2.31–2.59) for CA and 2.32 (95% CI 2.13–2.52) for SA. Estimated costs were higher for SA (mean £24,682; 95% CI £21,746–£27,618) than for CA (mean £18,002; 95% CI £15,422–£20,581). ConclusionIn symptomatic LSPAF, CA and SA were equally effective at achieving arrhythmia outcomes (freedom from AF/AT ≥30 seconds and ≥75% burden reduction) after a single procedure without antiarrhythmic drugs. However, SA is significantly more costly than CA.

REMOTE MONITORING IN CRYPTOGENIC STROKE

Abstract Introduction In the neurological field, one of the pathologies that receives the most attention due to its etiopathogenetic complexity is cryptogenic stroke. In the literature, a significant percentage of cryptogenic stroke is associated with Paroxysmal Atrial Fibrillation (FAP). With this study we wanted to compare our data with those of the literature and evaluate the incidence of remote control in promoting patient adherence to anticoagulant therapy, also analyzing the incidence of possible stroke recurrences in the monitored patients. Methodology All patients admitted to the Stroke Unit with cryptogenic stroke were evaluated with the ESUS SCORE. Patients who tested positive following the administration of the score underwent Loop Recorder (ILR) implantation for prolonged cardiac monitoring. Patients who showed episodes of FAP during monitoring were subsequently referred to the Stroke Unit to start anticoagulant therapy. A close telephone follow-up was subsequently carried out (every 15 days) to evaluate adherence to therapy and any stroke recurrences. Results 43 patients with cryptogenic stroke coming from the Stroke Unit and implanted by our center with Loop Recorder were evaluated. Among these 43 patients, 16 (37%) presented at least one episode of FAP, while 27 (63%) have not yet had any FAP event since the date of device implantation. In 60% of patients with FAP the duration of the event is greater than 5 hours. The time period between the stroke and the first FAP event in 6 out of 16 patients is approximately 1 month. Two patients presented the first episode within 7 days, while 8 patients within 10 months. In the telephone follow-up performed, 100% adherence to anticoagulant therapy was recorded, resulting in a recurrence of stroke in 0% of patients. Conclusions From the results obtained it was possible to conclude that the use of remote monitoring associated with close telephone follow-up allows the diagnosis of FAP and guarantees better patient adherence to anticoagulant therapy, significantly reducing stroke recurrences.

ATRIAL FIBRILLATION IN A CIED POPULATION: RESULTS FROM A TELEMONITORING FOLLOW–UP

Abstract Background Telemedicine has emerged as a crucial tool in managing patients with Cardiac Implantable Electronic Devices (CIED), addressing the common challenge of the Atrial Fibrillation (AF) in cardiology. The incidence of AF in CIED recipients varies widely (30–70%), influenced by implant indication, device type, and population characteristics. This study aims to evaluate AF in an unselected, real–world CIED population, considering patients’ characteristics and the remote follow–up. Methods and Results 808 consecutive CIED recipients were evaluated between 2021 and 2023 in two Italian Division of Cardiology by collecting patients’ baseline characteristics and the scheduled remote follow–up data. Mean age was 75.6±12.6 years, 42% were females. 16.7% of the population was working actively and 73% of individuals were assisted by at least one caregiver, reflecting a diminished quality of life (EQ–5D score 8.9±4.3). Over a median follow–up of 20.6 months, 8.9% of patients died. 68.8% of the patients received a pacemaker, 19.3% an ICD and 11.9% a loop recorder. History of AF was present in 40.1% of the population, with a prevalence of permanent AF (46.6%). Ongoing anticoagulant therapy was documented in 303 patients (37.5%), 71% of whom were taking direct oral anticoagulants. Baseline CHA2DS2–VASC score was ≥3 in 79.7%, and the median HAS–BLED score was 1. During the observation period, scheduled remote transmissions revealed 719 AF episodes (15.7 episodes/patient/year), causing 21% of the overall remote alarms. Among patients without AF history, 69 (14.3%) experienced AF episodes (4.8 episodes/patient/year). Notably, 21.8% of the AF episodes lasted less than 10 minutes. Conclusions The wide spreading of heart rhythm monitoring technologies reveals the challenge of the subclinical AF in healthcare systems. This study, encompassing an unselected CIED population of elderly and frail patients with high AF prevalence, highlights AF as a primary cause of remote alerts and a substantial burden in telemonitoring controls. Telemedicine facilitated new AF diagnoses in 14.3% of individuals without a prior AF history and resulted a valuable tool considering the significant cardioembolic risk in these patients. However, the initiation of anticoagulation therapy remains debatable, especially for episodes of brief duration which in our experience exceeded 20% of the cases.

CARDIOVASCULAR CONSIDERATIONS IN ANTIDEPRESSANT THERAPY: SINUS ARREST DUE TO SERTRALINE

Abstract A 39–year–old Caucasian woman with a silent cardiac anamnesis and no family history of cardiovascular diseases, and a history of mood disorder treated with Sertraline for about 1 month, went to the Emergency Department reporting several syncopal episode, all with rapid and complete recovery of consciousness. In the Emergency Department, another syncopal episode occurred in the supine position, characterized by sinus bradycardia evolving into a brief asystole, with spontaneous restoration of normal sinus rhythm. Admitted to the Cardiovascular Intensive Care Unit, the patient showed no abnormalities in laboratory testsas well as in echocardiography results. The patient received appropriate hydration, and home medication was discontinued. A non–contrast head CT scan showed no acute lesions. Cardiac MR revealed normal morpho–functional findings, with no evidence of myocardial edema or pericardial effusion and no pathological late gadolinium enhancement areas. Brain MRI demonstrated normal anatomical and functional findings, with no signal abnormalities. Considering the patient‘s young age and the suspicion of an iatrogenic origin of the rhythm disorder, the decision to postpone pacemaker implantation was made, and cardiac electrical activity was monitored using a loop recorder. At the one–month follow–up, the patient, who had been off Sertraline since admission, was in good health, reporting no further syncopal or pre–syncopal episodes. Loop recorder monitoring revealed no significant arrhythmias. The only relevant anamnestic data was the use of Sertraline, and the application of the Adverse Drug Reaction Probability Scale suggests that the iatrogenic origin of this event as a pharmacological adverse effect is at least probable (score: 7). Limited literature connects Sertraline directly to documented cases of asystole, but reports indicate that drugs in the same pharmacological class may induce cardiac rhythm disturbances, including tachyarrhythmias and bradyarrhythmias. This case draws attention to sinus arrest during sertraline therapy and how an appropriate pharmacological washout led to the resolution of the pathology.

MAGNETIC RESONANCE AND CARDIAC IMPLANTABLE DEVICES: A SAFE COMBINATION

Abstract Despite guidelines the presence of a cardiac implantable device (CIED) in a magnetic resonance (MR) ambient raises fears and perplexities and generates the often inappropriate request for support from the electrophysiologist. From January 2019 to November 2023 all patients with a cardiac implantable device (CIED) undergoing magnetic resonance (MR) were evaluated. All CIEDS were classified into three subgroups: MR–conditional, MR–unsafe and "non MR–conditional" (catheters and generators MR–conditional but of different manufacturers). No implantable loop recorders were enrolled. We performed a device control immediately before and after the RM procedure. We analyzed the percentage variations of each parameter (sensing, impedance and pacing threshold) pre– and post–MR and the variation versus the latest or the subsequent ambulatory control. 151 patients were proposed to undergo MR. 16 patients underwent multiple exams. The districts explored from RM were head (47%), column (21%), breast (1%), heart (3%), abdomen (20%), prostate (2%) and arms (16%). The median age was 70 years old, and 102 patients were males. CIEDS were pacemaker in 67% (3 leadless and 1 CRT–P), 33% defibrillators (5 S–ICD and 10 CRT–D). 85% of the systems were classified as MR–conditional, 3% as MR–unsafe and 12% as "non MR–conditional". The percentage median variation of atrial and ventricular sensing, impedance and threshold during the exam was 0%. MR did not significantly modify the parameters considered. No adverse events arise at the end of MR or in the days after. In our experience, there is no need for the presence of the electrophysiologist during the procedure due to safety even in "non MRI–conditional" or MR–unsafe patients.