Cost, Efficiency and Outcomes of Pulsed Field Ablation versus Thermal Ablation for Atrial Fibrillation: A Real World Study.

BACKGROUND: With the exponential growth of catheter ablation (CA) for atrial fibrillation (AF), there is increasing interest in associated healthcare costs. Pulsed field ablation (PFA) using a single-shot pentaspline multi-electrode catheter has been shown to be safe and effective for AF CA, but its cost efficiency compared to conventional thermal ablation modalities (cryoballoon [CB] or radiofrequency [RF]) has not been evaluated. OBJECTIVE: To compare cost, efficiency, effectiveness and safety between PFA, CB and RF for AF ablation. METHODS: We studied 707 consecutive patients (208 PFA, 325 CB, 174 RF) undergoing first-time AF ablation. Individual procedural costs were calculated, including equipment, lab utilisation and hospital stay, and compared between ablation modalities, as effectiveness and safety. RESULTS: Skin-to-skin times and catheter lab times were significantly shorter with PFA (68min/102min) vs CB (91min/122min) and RF (89min/123 min); p<0.001. General anaesthesia utilisation differed across modalities (PFA 100%, CB 10.2%, RF 61.5%); p<0.001. Major complications occurred in 1% of cases, with no significant differences between modalities. Shorter procedural times resulted in lower staffing and lab costs with PFA, but these savings were offset by substantially higher equipment costs, resulting in higher overall median costs with PFA (£10,010) vs CB (£8,106) and RF (£8,949); p<0.001. CONCLUSION: In this contemporary real-world study of the three major AF CA modalities used concurrently, PFA had shorter skin-to-skin and catheter lab times than CB and RF, with similarly low rates of complications. However, PFA procedures were considerably more expensive, largely due to higher equipment cost.

Delineating postinfarct ventricular tachycardia substrate with dynamic voltage mapping in areas of omnipolar vector disarray.

Background: Defining postinfarct ventricular arrhythmic substrate is challenging with voltage mapping alone, though it may be improved in combination with an activation map. Omnipolar technology on the EnSite X system displays activation as vectors that can be superimposed onto a voltage map. Objective: The study sought to optimize voltage map settings during ventricular tachycardia (VT) ablation, adjusting them dynamically using omnipolar vectors. Methods: Consecutive patients undergoing substrate mapping were retrospectively studied. We categorized omnipolar vectors as uniform when pointing in one direction, or in disarray when pointing in multiple directions. We superimposed vectors onto voltage maps colored purple in tissue >1.5 mV, and the voltage settings were adjusted so that uniform vectors appeared within purple voltages, a process termed dynamic voltage mapping (DVM). Vectors in disarray appeared within red-blue lower voltages. Results: A total of 17 substrate maps were studied in 14 patients (mean age 63 ± 13 years; mean left ventricular ejection fraction 35 ± 6%, median 4 [interquartile range 2-8.5] recent VT episodes). The DVM mean voltage threshold that differentiated tissue supporting uniform vectors from disarray was 0.27 mV, ranging between patients from 0.18 to 0.50 mV, with good interobserver agreement (median difference: 0.00 mV). We found that VT isthmus components, as well as sites of latest activation, isochronal crowding, and excellent pace maps colocated with tissue along the DVM border zone surrounding areas of disarray. Conclusion: DVM, guided by areas of omnipolar vector disarray, allows for individualized postinfarct ventricular substrate characterization. Tissue bordering areas of disarray may harbor greater arrhythmogenic potential.

Durability of thermal pulmonary vein isolation in persistent atrial fibrillation assessed by a mandated repeat invasive study.

BACKGROUND: No study has assessed the durability of pulmonary vein isolation (PVI) with radiofrequency (RF) and cryoballoon (CB) in patients with persistent atrial fibrillation. These data are especially lacking for those with a significantly diseased left atrium (LA). OBJECTIVES: The goals of this study were to assess PVI durability in patients with significant LA disease and to compare reconnection rates between RF and CB. METHODS: Forty-four patients (mean age 63 years; 77% male; median time since atrial fibrillation diagnosis 22.5 months; median indexed LA volume 36 mL/m2) were randomized 1:1 to RF (StablePoint catheter, Boston Scientific) or CB (Arctic Front Advance, Medtronic) PVI. A redo procedure using ultra-high-density electroanatomic mapping (Rhythmia, Boston Scientific) was mandated at 2 months, where PV reconnections were identified and reisolated. RESULTS: Thirty-eight patients underwent both procedures (CB n = 17; RF n = 21). Index RF procedures were longer (median 158 minutes vs 97 minutes; P < .001) but required less fluoroscopy (9.5 minutes vs 23 minutes; P < .001). At the index RF procedure, a median of 47% of the LA myocardium had voltage < 0.5 mV, suggesting that half of the mapped LA comprised scar. PV reconnection was observed in 73 of 152 PVs (48.0%) and was more frequent with CB (58.8%) than with RF (39.3%) (P = .022). Reconnection of at least 1 PV was detected in >75% of patients. Significantly more ablation was required at the redo procedure to reisolate PVs in the CB arm (median 10.8 minutes vs 1.2 minutes; P < .001). CONCLUSION: PVI durability may be poor in those with significant LA scarring and dilatation, even with modern thermal ablation technologies. RF resulted in significantly better PVI durability than did CB in this complex population. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT04111731.

Randomised controlled trial of population screening for atrial fibrillation in people aged 70 years and over to reduce stroke: protocol for the SAFER trial.

INTRODUCTION: There is a lack of evidence that the benefits of screening for atrial fibrillation (AF) outweigh the harms. Following the completion of the Screening for Atrial Fibrillation with ECG to Reduce stroke (SAFER) pilot trial, the aim of the main SAFER trial is to establish whether population screening for AF reduces incidence of stroke risk. METHODS AND ANALYSIS: Approximately 82 000 people aged 70 years and over and not on oral anticoagulation are being recruited from general practices in England. Patients on the palliative care register or residents in a nursing home are excluded. Eligible people are identified using electronic patient records from general practices and sent an invitation and consent form to participate by post. Consenting participants are randomised at a ratio of 2:1 (control:intervention) with clustering by household. Those randomised to the intervention arm are sent an information leaflet inviting them to participate in screening, which involves use of a handheld single-lead ECG four times a day for 3 weeks. ECG traces identified by an algorithm as possible AF are reviewed by cardiologists. Participants with AF are seen by a general practitioner for consideration of anticoagulation. The primary outcome is stroke. Major secondary outcomes are: death, major bleeding and cardiovascular events. Follow-up will be via electronic health records for an average of 4 years. The primary analysis will be by intention-to-treat using time-to-event modelling. Results from this trial will be combined with follow-up data from the cluster-randomised pilot trial by fixed-effects meta-analysis. ETHICS AND DISSEMINATION: The London-Central National Health Service Research Ethics Committee (19/LO/1597) provided ethical approval. Dissemination will include public-friendly summaries, reports and engagement with the UK National Screening Committee. TRIAL REGISTRATION NUMBER: ISRCTN72104369.

Lesion metrics and 12-month outcomes of very-high power short duration radiofrequency ablation (90W/4 s) under mild conscious sedation.

INTRODUCTION: Pulmonary vein isolation (PVI) is often performed under general anaesthesia (GA) or deep sedation. Anaesthetic availability is limited in many centers, and deep sedation is prohibited in some countries without anaesthetic support. Very high-power short duration (vHPSD-90W/4 s) PVI using the Q-Dot catheter is generally well tolerated under mild conscious sedation (MCS) though an understanding of catheter stability and long-term effectiveness is lacking. We analyzed lesion metrics and 12-month freedom from atrial arrythmia with this approach. METHODS: Our approach to radiofrequency (RF) PVI under MCS is standardized and includes a single catheter approach with a steerable sheath. We identified patients undergoing Q-Dot RF PVI between March 2021 and December 2022 in our center, comparing those undergoing vHPSD ablation under MCS (90W/MCS) against those undergoing 50 W ablation under GA (50 W/GA) up to 12 months of follow-up. Data were extracted from clinical records and the CARTO system. RESULTS: Eighty-three patients met our inclusion criteria (51 90W/MCS; 32 50 W/GA). Despite shorter ablation times (353 vs. 886 s; p < .001), the 90 W/MCS group received more lesions (median 87 vs. 58, p < .001), resulting in similar procedure times (149.3 vs. 149.1 min; p = .981). PVI was achieved in all cases, and first pass isolation rates were similar (left wide antral circumferential ablation [WACA] 82.4% vs. 87.5%, p = .758; right WACA 74.5% vs. 78.1%, p = .796; 90 W/MCS vs. 50 W/GA respectively). Analysis of 6647 ablation lesions found similar mean impedance drops (10.0 ± 1.9 Ω vs. 10.0 ± 2.2 Ω; p = .989) and mean contact force (14.6 ± 2.0 g vs. 15.1 ± 1.6 g; p = .248). Only median 2.5% of lesions in the 90 W/MCS cohort failed to achieve ≥ 5 Ω drop. In the 90 W/MCS group, there were no procedural related complications, and 12-month freedom from atrial arrhythmia was observed in 78.4%. CONCLUSION: vHPSD PVI is feasible under MCS, with encouraging acute and long-term procedural outcomes. This provides a compelling option for centers with limited anaesthetic support.

Concurrent percutaneous left atrial appendage occlusion and catheter ablation for atrial fibrillation: State-of-the-art review.

Stroke prevention and symptom control are two integral pillars in atrial fibrillation (AF) management. Percutaneous left atrial appendage occlusion (LAAO) is effective at reducing stroke risk in high-risk patients with AF who cannot tolerate oral anticoagulant therapy, whilst catheter ablation is effective at reducing AF burden and improving quality-of-life in patients who remain symptomatic despite medical therapy. If both procedures are indicated in an individual patient, they have traditionally been performed on separate occasions, due to long cumulative procedural times, itself associated with thromboembolic risk. Recently, with the advancement of procedural techniques, the concept of concurrent LAAO and AF catheter ablation has gained traction. This review summarises the evidence for and against concurrent LAAO and AF catheter ablation, discussing procedural considerations, including procedural sequencing and post-procedural antithrombotic therapy, safety and efficacy outcomes, and future directions in the field.

Drive-by collection and self-fitting of ambulatory electrocardiogram monitoring.

Ambulatory electrocardiogram (AECG) monitoring is a common cardiovascular investigation. Traditionally, this requires a face-to-face appointment. In order to reduce contact during the COVID-19 pandemic, we investigated whether drive-by collection and self-fitting of the device by the patient represents an acceptable alternative. A prospective, observational study of consecutive patients requiring AECG monitoring over a period of one month at three hospitals was performed. Half underwent standard (face-to-face) fitting, and half attended a drive-by service to collect their monitor, fitting their device at home. Outcome measures were quality of the recordings (determined as good, acceptable or poor), and patient satisfaction. A total of 375 patients were included (192 face-to-face, 183 drive-by). Mean patient age was similar between the two groups. The quality of the AECG recordings was similar in both groups (52.6% good in face-to-face vs. 53.0% in drive-by; 34.9% acceptable in face-to-face vs. 32.2% in drive-by; 12.5% poor in face-to-face vs. 14.8% in drive-by; Chi-square statistic 0.55, p=0.76). Patient satisfaction rates were high, with all patients in both groups satisfied with the care they received. In conclusion, drive-by collection and self-fitting of AECG monitoring yields similar AECG quality to conventional face-to-face fitting, with high levels of patient satisfaction.

Changes and advances in the field of infective endocarditis.

Infective endocarditis is a rare but deadly disease, with a highly variable presentation. The clinical manifestations of the condition are often multisystemic, ranging from dermatological to ophthalmic, and cardiovascular to renal. Thus, patients with infective endocarditis may first present to the acute or general physician, who may have a variable knowledge of the condition. The diagnosis of infective endocarditis can be challenging, relying on clinical, imaging and microbiological features. Recent decades have seen a transformation in the epidemiology and microbiology of infective endocarditis and yet, despite advances in diagnostics and therapeutics, mortality rates remain high. This review outlines the emerging studies and guidelines on the assessment and management of infective endocarditis, focusing on the evolving epidemiology of the condition, the role of new imaging modalities, updated diagnostic criteria, the latest on antimicrobial and surgical management, and the role of a multidisciplinary approach in the management of patients with infective endocarditis.

Pituitary apoplexy secondary to metastatic breast carcinoma into a gonadotroph cell adenoma of the pituitary.

A 65 year-old lady with metastatic breast cancer presented with pituitary apoplexy. Following surgery, histopathology confirmed metastatic breast carcinoma into a gonadotroph cell adenoma of the pituitary. Tumours that metastasise to a normal pituitary gland are unusual. More so, such neoplasm-to-neoplasm metastasis is extremely rare. This is, as far as we are aware, the first description of a metastasis into a gonadotroph cell pituitary adenoma presenting as apoplexy.

A guide to the management of atrial fibrillation in Santa Claus.

•In view of his advanced age and risk factors, Santa Claus is at high risk of developing atrial fibrillation. Despite this, no guidelines exist on the subject. •Following a review of the literature, we present our position on the management of atrial fibrillation in Santa Claus, and propose the use of the SANTA CLAUS mnemonic to aid clinicians: Screen for atrial fibrillation; Anticoagulate; Normalise heart rate; Treat comorbidities; Anti-arrhythmic drugs; Cardioversion; Lifestyle measures; Ablation treatment; Understand emotional and psychological impact; Save Santa Claus.

Virtual (Computed) Fractional Flow Reserve: Future Role in Acute Coronary Syndromes.

The current management of acute coronary syndromes (ACS) is with an invasive strategy to guide treatment. However, identifying the lesions which are physiologically significant can be challenging. Non-invasive imaging is generally not appropriate or timely in the acute setting, so the decision is generally based upon visual assessment of the angiogram, supplemented in a small minority by invasive pressure wire studies using fractional flow reserve (FFR) or related indices. Whilst pressure wire usage is slowly increasing, it is not feasible in many vessels, patients and situations. Limited evidence for the use of FFR in non-ST elevation (NSTE) ACS suggests a 25% change in management, compared with traditional assessment, with a shift from more to less extensive revascularisation. Virtual (computed) FFR (vFFR), which uses a 3D model of the coronary arteries constructed from the invasive angiogram, and application of the physical laws of fluid flow, has the potential to be used more widely in this situation. It is less invasive, fast and can be integrated into catheter laboratory software. For severe lesions, or mild disease, it is probably not required, but it could improve the management of moderate disease in 'real time' for patients with non-ST elevation acute coronary syndromes (NSTE-ACS), and in bystander disease in ST elevation myocardial infarction. Its practicability and impact in the acute setting need to be tested, but the underpinning science and potential benefits for rapid and streamlined decision-making are enticing.

Implications of the 2021 National Institute for Health and Care Excellence atrial fibrillation guidelines.

In 2021 the National Institute for Health and Care Excellence updated its guidance for diagnosing and managing atrial fibrillation. This editorial summarises the key changes made in these guidelines and discusses their implementation in UK clinical practice.

Feasibility and validation of trans-valvular flow derived by four-dimensional flow cardiovascular magnetic resonance imaging in patients with atrial fibrillation.

Background: Four-dimensional (4D) flow cardiovascular magnetic resonance imaging (MRI) is an emerging technique used for intra-cardiac blood flow assessment. The role of 4D flow cardiovascular MRI in the assessment of trans-valvular flow in patients with atrial fibrillation (AF) has not previously been assessed. The purpose of this study was to assess the feasibility, image quality, and internal validity of 4D flow cardiovascular MRI in the quantification of trans-valvular flow in patients with AF. Methods: Patients with AF and healthy controls in sinus rhythm underwent cardiovascular MRI, including 4D flow studies. Quality assurance checks were done on the raw data and streamlines. Consistency was investigated by trans-valvular flow assessment between the mitral valve (MV) and the aortic valve (AV). Results: Eight patients with AF (88% male, mean age 62±13 years, mean heart rate (HR) 83±16 beats per minute (bpm)) were included and compared with ten healthy controls (70% male, mean age 41±20 years, mean HR 68.5±9 bpm). All scans were of either good quality with minimal blurring artefacts, or excellent quality with no artefacts. No significant bias was observed between the AV and MV stroke volumes in either healthy controls (-4.8, 95% CI -15.64 to 6.04; P=0.34) or in patients with AF (1.64, 95% CI -4.7 to 7.94; P=0.56). A significant correlation was demonstrated between MV and AV stroke volumes in both healthy controls (r=0.87, 95% CI 0.52 to 0.97; P=0.001) and in AF patients (r=0.82, 95% CI 0.26 to 0.97; P=0.01). Conclusions: In patients with AF, 4D flow cardiovascular MRI is feasible with good image quality, allowing for quantification of trans-valvular flow.