Incidence, Implications, and Management of Sense-B-Noise Failure in Subcutaneous Cardioverter-Defibrillator Patients: insights from a large Multicenter Registry.

AIMS AND BACKGROUND: Subcutaneous implantable cardioverter-defibrillators (S-ICDs) offer potentially distinct advantages over transvenous defibrillator systems. Recent randomized trials showed significantly lower lead failure rates than transvenous ICD. Still, S-ICDs remain associated with the risk of inappropriate shocks (IAS). While previous studies have reported varying causes of IAS, this study explores a rare cause of IAS, referred to as "sense-B-noise." It was recently described in cases series, but its incidence has not been studied in a large cohort of S-ICD patients. METHODS: We retrospectively reviewed data from patients implanted with S-ICD models 1010, A209 and A219 between October 2009 and July 2023 across 9 centers in Europe and the USA. The analysis concentrated on determining the incidence and understanding the implications of sense-B-noise events. Sense-B-noise represents a rare manifestation of distinct electrogram abnormalities within the primary and alternate sensing vectors. Data were collected from medical records, device telemetry, and manufacturer reports for investigation. This registry is registered on https://clinicaltrials.gov (NCT05713708). RESULTS: S-ICD devices of the 1,158 patients were analyzed. The median follow-up time for all patients was 46 (IQR 23-64) months. In 107 patients (9.2%) ≥ 1 IAS was observed during follow-up. Sense-B-noise failure was diagnosed in 6 (0.5% and 5.6% of all IAS) patients, in all patients the diagnosis was made after an IAS episode. Median lead dwell time in the affected patients was 23 (2-70) months. To resolve the sense-B-noise defect, in three patients reprogramming to the secondary vector was undertaken, and two patients underwent system removal with subsequent S-ICD reimplantation due to low amplitude in secondary vector. In one patient the secondary vector was initially programmed, and subsequently, a S-ICD system exchange was performed due to T-wave oversensing IAS episodes. CONCLUSION: This multicenter analysis' findings shed light on a rare but clinically highly significant adverse event in S-ICD therapy. To our knowledge we provide the first systematic multicenter analysis investigating the incidence of sense-B-noise. Due to being difficult to diagnose and limited options for resolution, management of sense-B-noise is challenging. Complete system exchange may be the only option in some patients. Educating healthcare providers involved in S-ICD patient care is crucial for ensuring accurate diagnosis and effective management of sense-B-noise issues.

Atrial fibrillation cryoablation is an effective day case treatment: the UK PolarX vs. Arctic Front Advance experience.

AIMS: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation for atrial fibrillation (AF). There are limited data on the PolarX Cryoballoon. The study aimed to establish the safety, efficacy, and feasibility of same day discharge for Cryoballoon PVI. METHODS AND RESULTS: Multi-centre study across 12 centres. Procedural metrics, safety profile, and procedural efficacy of the PolarX Cryoballoon with the Arctic Front Advance (AFA) Cryoballoon were compared in a cohort large enough to provide definitive comparative data. A total of 1688 patients underwent PVI with cryoablation (50% PolarX and 50% AFA). Successful PVI was achieved with 1677 (99.3%) patients with 97.2% (n = 1641) performed as day case procedures with a complication rate of <1%. Safety, procedural metrics, and efficacy of the PolarX Cryoballoon were comparable with the AFA cohort. The PolarX Cryoballoon demonstrated a nadir temperature of -54.6 ± 7.6°C, temperature at 30 s of -38.6 ± 7.2°C, time to -40°C of 34.1 ± 13.7 s, and time to isolation of 49.8 ± 33.2 s. Independent predictors for achieving PVI included time to reach -40°C [odds ratio (OR) 1.34; P < 0.001] and nadir temperature (OR 1.24; P < 0.001) with an optimal cut-off of ≤34 s [area under the curve (AUC) 0.73; P < 0.001] and nadir temperature of ≤-54.0°C (AUC 0.71; P < 0.001), respectively. CONCLUSIONS: This large-scale UK multi-centre study has shown that Cryoballoon PVI is a safe, effective day case procedure. PVI using the PolarX Cryoballoon was similarly safe and effective as the AFA Cryoballoon. The cryoablation metrics achieved with the PolarX Cryoballoon were different to that reported with the AFA Cryoballoon. Modified cryoablation targets are required when utilizing the PolarX Cryoballoon.

A retrospective analysis of frailty status on atrial fibrillation catheter ablation outcomes.

INTRODUCTION: Catheter ablation for atrial fibrillation (AF) reduces symptoms and improves the quality of life compared with medical treatment. It is unclear if frailty impacts on the outcome of catheter ablation in patients with symptomatic AF. We sought to evaluate the association between frailty as measured by the validated NHS electronic Frailty Index (eFI) and outcomes post-AF ablation. METHODS: Two hundred forty eight patients who had undergone AF ablation with a mean age of 72.9 ± 5.16 were included in the study retrospectively. The primary endpoint for success was defined as freedom from atrial arrhythmia lasting >30 s beyond the 3-month blanking periods. Frailty was based on the eFI, and the cohort split into four groups: fit (no frailty), mild, moderate and severe frailty. RESULTS: Frailty was categorized as fit (118/248; 47.6%), mild (66/248; 26.6%), moderate (54/248; 21.8%), and severe (10/248; 4.0%). Freedom from arrhythmia occurred in 167 of 248 (67.3%) patients after a mean follow-up of 25.8 +/- 17.3 months. Fit patients had significantly greater freedom from arrhythmia (92/118; 78%) compared to mild frailty (40/66; 60.6%, p-value = .020), moderate frailty (31/54; 57.4%, p-value = .006), or severe frailty (4/10; 40.0%, p-value < .001). There was also a significant difference in arrhythmia occurrence between patients with mild frailty and severe frailty (p-value = .044). CONCLUSION: Frailty is associated with poorer outcomes in patients undergoing AF ablation. The eFI may be used in the prognostic evaluation of AF ablation outcomes. Further studies are essential to confirm the findings of this study.

A randomized sham-controlled study of pulmonary vein isolation in symptomatic atrial fibrillation (The SHAM-PVI study): Study design and rationale.

INTRODUCTION: Pulmonary vein (PV) isolation has been shown to reduce atrial fibrillation (AF) burden and symptoms in patients. However, to date previous studies have been unblinded raising the possibility of a placebo effect to account for differences in outcomes. HYPOTHESIS & METHODS: The objective of this study is to compare PV isolation to a sham procedure in patients with symptomatic AF. The SHAM-PVI study is a double blind randomized controlled clinical trial. 140 patients with symptomatic paroxysmal or persistent AF will be randomized to either PV isolation (with cryoballoon ablation) or a sham procedure (with phrenic nerve pacing). All patients will receive an implantable loop recorder. The primary outcome is total AF burden at 6 months postrandomisation (excluding the 3 month blanking period). Key secondary outcomes include (1) time to symptomatic and asymptomatic atrial tachyarrhythmia (2) total atrial tachyarrhythmia episodes and (3) patient reported outcome measures. RESULTS: Enrollment was initiated in January 2020. Through April 2023 119 patients have been recruited. Results are expected to be disseminated in 2024. CONCLUSION: This study compares PV isolation using cryoablation to a sham procedure. The study will estimate the effect of PV isolation on AF burden.

A randomized comparison of retrograde left-sided versus anterograde right-sided ablation of the atrioventricular junction.

BACKGROUND: Catheter ablation of the atrioventricular node (AVN) is an effective treatment for patients with symptomatic atrial fibrillation. This study compares the success rate, procedure time, radiation time, and complication rates of retrograde left-sided (LSA) and anterograde right-sided (RSA) AVN ablation in a randomised controlled trial. METHODS: Thirty-one patients undergoing AVN ablation were randomized to either LSA (15 patients) or RSA (16 patients). Crossover occurred after six unsuccessful radiofrequency (RF) applications. RESULTS: The LSA cohort had a mean age of 77.00 ± 5.17 and the RSA cohort was 79.44 ± 6.08 (p = .0240). There were five crossovers from LSA to RSA and there was one crossover from RSA to LSA. There was no significant difference in ablation time between LSA and RSA (210.40 ± 179.77 vs. 192.19 ± 130.29 seconds, p = .748). There was no significant difference in procedure time, fluoroscopy time, radiation dose, or number of RF applications between the two groups. There was 1 (6.67%) serious adverse event in the LSA group and 1 (6.25%) in the RSA group due to femoral hematomas requiring blood transfusion or intervention. There was no significant difference in patient-reported discomfort between LSA and RSA (16.43 ± 20.67 vs. 17.87 ± 28.08, p = .877). The study was stopped before full recruitment due to futility. CONCLUSIONS: Retrograde LSA of the AVN does not reduce RF applications, procedure time, or radiation exposure compared with conventional RSA and cannot be recommended as a first-line clinical approach.

Immediate implantable loop recorder implantation for detecting atrial fibrillation in cryptogenic stroke.

INTRODUCTION: Atrial fibrillation (AF) is suspected as the main cause of stroke in the majority of patients presenting with cryptogenic stroke (CS). Implantable loop recorders (ILR's) are indicated for detecting AF in these patients. The short term (<1 month) and long-term AF detection rates in patients inserted with an ILR immediately after CS is reported. Secondly, we compare the safety of nurse led vs physician led ILR implantation in these patients. METHODS: This is a retrospective review of all patients who underwent inpatient ILR implantation (Medtronic Linq) between May 2020 and May 2022 at East Sussex Healthcare NHS trust. All patients were remotely monitored via the FOCUSONTM monitoring and triage service. RESULTS: A total of 186 subjects were included in the study and were followed up for a mean period of 363.0 +/- 222.6 days. The mean time between stroke and ILR was 7.0 +/- 5.5 days. The mean time between referral and ILR was 1.0 +/- 2.0 days. AF was detected in 25 (13.4%) patients. During the first 30 days of monitoring, AF was detected in 9 (4.8%) patients. The number of ILR implants performed by the specialist nurse was 107 (57.5%). There was no significant difference in the major complication rate (requiring device removal) between nurse and physician led implant (1 (0.95%) vs 0 (0%), p value = 0.389). CONCLUSION: Inpatient ILR for cryptogenic stroke is feasible. The rate of AF detection in the first month post CS is 4.8% however, more AF was detected up to one year post implant, suggesting rationale for proceeding directly to ILR implant in these patients before discharge to not delay treatment. A nurse led service is also viable with no significant difference in the major complication rate compared to physician led implants.

Open Window Mapping of Accessory Pathways: A Literature Review and Practical Guide.

Catheter ablation is the treatment of choice for patients with symptomatic accessory pathways (APs) causing recurrent atrioventricular reciprocating tachycardia or in situations where APs conduct rapidly, posing a risk of sudden cardiac death. Conventional AP mapping relies on point-by-point assessment of local electrograms looking closely for pathway electrograms or early atrial or ventricular electrograms, which may be challenging and time consuming. Recently, open window mapping (OWM) using 3D navigational systems has emerged as a novel technique to help localise and ablate APs. OWM has significant advantages over conventional point-by-point mapping techniques. The purpose of this review is to summarise the currently available literature on the OWM technique and to highlight the technical aspects and mapping considerations for OWM, including specific cases demonstrating its utility.

The long-term effect of thermal-guided second-generation cryoablation in paroxysmal and persistent atrial fibrillation.

BACKGROUND: Second-generation cryoballoon ablation is safe and effective in patients with paroxysmal (PAF) and persistent atrial fibrillation (AF). OBJECTIVE: This study aimed to assess the long-term clinical outcomes and freedom from AF in patients undergoing thermal-guided cryoablation without the use of an electrical mapping catheter. METHODS: All patients who had undergone thermal-guided second-generation cryoablation without electrical mapping between January 2015 and April 2018 at Eastbourne District General Hospital were retrospectively analysed. Success was defined as freedom from atrial arrhythmia lasting >30 s during the follow up period. RESULTS: The study included 234 patients with a mean age of 65.3 ± 10.6 years. There were 134 (57.0%) and 100 (42.7%) patients who had PAF and persistent AF respectively. Arrhythmia recurrence occurred in 38 of 134 (28.4%) PAF and 42 of 100 (42.0%) persistent AF patients after mean follow up of 40 ± 9.2 months. The patients with PAF had a significantly greater freedom from arrhythmia than patients with persistent AF (p = .040). The mean procedure time was 55.5 ± 12.2 min and the mean fluoroscopy time was 10.9 ± 4.8 min 73.5% of patients were discharged on the same day. CONCLUSION: Thermal-guided cryoablation is feasible, safe and results in freedom from arrhythmia in the majority of paroxysmal and persistent AF patients in the long term. Randomised controlled trials are required to confirm the findings of this study.

Long Term outcomes of percutaneous atrial fibrillation ablation in patients with continuous monitoring.

INTRODUCTION: There is limited data using continuous monitoring to assess outcomes of atrial fibrillation (AF) ablation. This study assessed long-term outcomes of AF ablation in patients with implantable cardiac devices. METHODS: 207 patients (mean age 68.1 ± 9.5, 50.3% men) undergoing ablation for symptomatic AF were followed up for a mean period of 924.5 ± 636.7 days. Techniques included The Pulmonary Vein Ablation Catheter (PVAC) (59.4%), cryoablation (17.4%), point by point (14.0%) and The Novel Irrigated Multipolar Radiofrequency Ablation Catheter (nMARQ) (9.2%). RESULTS: 130 (62.8%) patients had paroxysmal AF (PAF) and 77 (37.2%) persistent AF. First ablation and repeat ablation reduced AF burden significantly (relative risk 0.91, [95% CI 0.89 to 0.94]; P <0.0001 and 0.90, [95% CI, 0.86-0.94]; P <0.0001). Median AF burden in PAF patients reduced from 1.05% (interquartile range [IQR], 0.1%-8.70%) to 0.10% ([IQR], 0%-2.28%) at one year and this was maintained out to four-years. Persistent AF burden reduced from 99.9% ([IQR], 51.53%-100%) to 0.30% ([IQR], 0%-77.25%) at one year increasing to 87.3% ([IQR], 4.25%-100%) after four years. If a second ablation was required, point-by-point ablation achieved greater reduction in AF burden (relative risk, 0.77 [95% CI, 0.65-0.91]; P <0.01). CONCLUSION: Ablation reduces AF burden both acutely and in the long-term. If a second ablation was required the point-by-point technique achieved greater reductions in AF burden than "single-shot" technologies. Persistent AF burden increased to near pre ablation levels by year 4 suggesting a different mechanism from PAF patients where this increase did not occur.

The effect of second-generation cryoablation without electrical mapping in persistent AF using continuous monitoring.

BACKGROUND: Second-generation cryoballoon ablation is safe and effective in patients with persistent atrial fibrillation (AF). The aim of this study is to report the real long-term AF burden and freedom from AF post-cryoablation using continuous monitoring, and to assess whether intraoperative confirmation of pulmonary vein isolation using electrical mapping is necessary. METHODS: A total of 33 patients (mean age 75.7 ± 5.6 years, 16 men) with persistent AF who underwent second-generation cryoablation without electrical mapping were reviewed. All patients had a cardiac implantable device and were followed up for a mean of 755 ± 170 days. RESULTS: AF burden significantly decreased from 67.51% ± 34.90% to 18.28% ± 26.65% at 1-year follow-up, and this reduction was maintained at final follow-up (18.26% ± 23.70%, p < 0.001). Continuous monitoring revealed a freedom from AF rate of 33% and 24% at 1-year and full follow-up, respectively. Patients who remained in persistent AF at final follow-up had a trend towards higher pre-ablation AF burden (81.6% ± 29.7% vs 57.3% ± 36.4%, p = 0.08). CONCLUSION: Second-generation cryoablation without confirming pulmonary vein isolation using electrical mapping is effective leading to significant reductions in AF burden based on continuous beat-to-beat monitoring at 1-year and long-term follow-up.

How many patients with heart failure are eligible for cardiac contractility modulation therapy?

BACKGROUND: Increasing evidence exists suggesting that cardiac contractility modulation therapy (CCM) improves symptoms in heart failure patients if various selection criteria are fulfilled. The aim of this study is to analyse an unselected sample of heart failure patients to establish what percentage of patients would meet the current criteria for CCM therapy. METHODS: All patients admitted to two district general hospitals in the UK in 2018 with a diagnosis of heart failure were audited for eligibility for CCM therapy. The selection criteria were (a) ejection fraction (EF) 25%-45%, (b) QRS duration less than 130 ms, (c) New York Heart Association (NYHA) class 3-4 and (d) treated for heart failure for at least 90 days and on stable medications. Exclusion criteria included: (a) significant valvular disease, (b) permanent or persistent atrial fibrillation, (c) biventricular pacing system implanted or QRS duration more than 130 ms and (4) patients not suitable for device therapy as a result of palliative treatment intent. RESULTS: A total of 475 patients were admitted with heart failure during the study period. From this group, 24 (5.1%) patients fulfilled the criteria for CCM therapy. The mean age and ejection fraction were 70.8 ± 10.2 and 32.5% ± 7.4%. The majority of patients were men (71%) and had an ischaemic cardiomyopathy (75%). If patients with atrial fibrillation were included, an additional 18 (3.8%) patients potentially may be eligible for CCM. CONCLUSION: Only 5.1% of all patients presenting with heart failure might benefit from cardiac CCM. This is a small proportion of the overall heart failure population. However, this population has no other current option for device therapy of their condition.

Utilising video technology in the cardiac catheter lab and operating theatre during the COVID-19 pandemic.

The COVID-19 pandemic has significantly altered working practices within hospitals. This includes surgical theatres and cardiac catheter laboratories. Here we describe how we have harnessed the use of video technology to improve the running of the cardiac catheter lab in our institution, reducing the exposure of staff members to COVID-19, reducing the need for personal protective equipment (PPE) and maintaining and enhancing educational and teaching opportunities for trainees.

An economic evaluation of an advanced video conferencing system for cardiac multidisciplinary team meetings.

INTRODUCTION: Current UK and international guidelines advocate the need for multidisciplinary team (MDT) discussion of selected patients undergoing either percutaneous or surgical cardiac procedures to decide the optimal treatment strategy. To date, it is unknown if using videoconference facilities is cost-effective. Therefore, we performed a cost analysis of using a high-speed internet video conferencing system compared with conventional face-to-face MDT meetings. METHODS: Costs of running a conventional MDT meeting vs a video conferencing MDT were modelled and compared over a 2-year period. Participants were also surveyed on the overall effectiveness of conducting remote MDTs. RESULTS: The set-up and maintenance cost of the video conferencing system over 2 years was £30 400. The staff costs of running the face-to-face MDT were £95 970 and the video conferencing MDT was £23 992.50. The total travel costs of the conventional face-to-face MDTs were £10 555.34. In total, the cost of the conventional face-to-face MDT was £106 525.34 and the video conferencing MDT was £54 392.50 representing a cost saving of 48.9%. Participants rated the effectiveness of conducing a remote MDT and the ease of technology use as very good. CONCLUSIONS: Video conferencing systems provide a highly cost-effective method of facilitating MDT meetings between cardiologists and cardiac surgeons at remote centres.

Care After REsuscitation: Implementation of the United Kingdom's First Dedicated Multidisciplinary Follow-Up Program for Survivors of Out-of-Hospital Cardiac Arrest.

Survival rates after cardiac arrest (CA) are increasing, with more patients and their families living with the psychological consequences of surviving a sudden CA. The currently available neuropsychological assessment tools and therapies were not designed for CA, and may be inadequate. The Essex Cardiothoracic Centre set up the United Kingdom's first dedicated multidisciplinary "Care After REsuscitation" (CARE) service, offering CA survivors and their caregivers systematic psychological, cognitive, and specialized medical support for the first 6 months after CA. Twenty-one patients were recruited into the CARE pilot service evaluation. Patients' health at hospital discharge was poor; however, by 6 months all components (except general health) had improved significantly, and were close to that experienced by "healthy" individuals. Five (26%) required referral to a psychiatrist, with all 5 (26%) subsequently being diagnosed with moderate-to-severe depression, and 3 (16%) with comorbid post-traumatic stress disorder. Our study demonstrates a large unmet clinical need in general and neuropsychological assessment, and our results suggest that offering appropriate and prompt specialist diagnosis and therapies leads to an improvement in health at 6 months.

Delayed ventricular septal rupture complicating anterior wall myocardial infarction.

A 59-year-old woman was admitted to our hospital with acute pulmonary oedema and cardiogenic shock 35 days after anterior ST elevation myocardial infarction. She developed a new loud pan systolic murmur. Echocardiography revealed a ventricular septal rupture with a significant left to right shunt. She was immediately transferred to the local cardiothoracic unit where she underwent a successful ventricular septal defect (VSD) repair. Ventricular septal rupture often presents within the first 24 hours of acute myocardial infarction and is rare thereafter. It carries a poor mortality (41-80%) even when recognised. Timely recognition of this life-threatening complication can help reduce the resultant morbidity and mortality. Doctors should be aware that this well-recognised complication may present unusually late as in this case.

A rare cause of secondary hypertension.

Severe hypertension is a well-recognised cause for acute medical admission, and can have serious consequences if untreated. We present a 48 year old patient in whom coarctation of the aorta was identified following the finding of severe hypertension at the time of routine preoperative assessment, and subsequent finding of absent lower limb pulses. The patient had a past history of Apert syndrome, a rare autosomal dominant inherited condition characterised by craniosynostosis, facial dysmorphia, syndactyly of the hands and feet and cardiac abnormalities. This case report highlights the importance of a careful clinical examination in adults with severe hypertension, without which coarctation of the aorta may go undiagnosed.

The effect of tumor necrosis factor-α antagonists on arterial stiffness in rheumatoid arthritis: a literature review.

BACKGROUND: There is evidence that patients with rheumatoid arthritis (RA) have a higher arterial stiffness than their age-matched healthy counterparts and thus have a higher cardiovascular risk. Under National Institute for Clinical Excellence guidelines, tumor necrosis factor-α (TNF-α) antagonists are indicated clinically in patients with severe active rheumatoid disease. TNF-α antagonists have been found to reduce inflammatory markers in RA; however, it is debatable if they have favorable effects on the cardiovascular system. This review evaluates the effect of TNF-α antagonists on arterial stiffness, a predictor of cardiovascular disease, in RA patients. SEARCH STRATEGY: A search of Ovid MEDLINE and ISI Web of Knowledge databases was conducted to identify studies into the effect of TNF-α antagonists on arterial stiffness in RA patients. Eight studies matching the search criteria were included for analysis. FINDINGS: Two methods were used to assess arterial stiffness: pulse wave velocity and augmentation index. Despite inconsistencies in augmentation index values, aortic pulse wave velocity in all but one study was significantly reduced following TNF-α antagonist treatment. Most studies had methodological limitations, including inadequate sample size, nonblinding of those involved in the measurements, and inadequate inclusion/exclusion criteria. Variation in results could be due to the use of different TNF-α antagonists, different outcome measures being used, and differences in follow-up. CONCLUSIONS: The balance of evidence suggests that TNF-α antagonists may have a beneficial effect on arterial stiffness and therefore cardiovascular risk. However, larger more robust longer term studies are warranted to confirm recent findings.