Hejie He

Background/Objectives: Primary-prevention implantable cardioverter-defibrillator (ICD) selection remains dominated by left ventricular ejection fraction and clinical heart failure markers, which incompletely distinguish between patients who will experience ventricular arrhythmia and those whose prognosis is limited by competing non-arrhythmic mortality. The Magneto-SCD trial recently reported novel rotation-based magnetocardiography (MCG) indices associated with future appropriate ICD therapies. This substudy explores whether MCG Rotation Score provides incremental information in primary-prevention ICD recipients, particularly beyond NYHA status and MADIT-arrhythmic and non-arrhythmic risk scores. Methods: We included all Magneto-SCD trial participants with a primary-prevention indication with non-missing follow-up/MCG Rotation Score data. The full primary-prevention cohort comprised 54 participants; the post-MI subgroup comprised 28. The primary endpoint was time to first appropriate ICD therapy. Death without prior therapy was used as a pragmatic competing endpoint and not assumed to represent adjudicated non-arrhythmic death. Appropriate shock was a secondary endpoint. Two-year cumulative incidence functions were estimated using Aalen–Johansen methods. Cause-specific Cox models assessed Rotation Score alone and after addition to MADIT-derived scores; nested likelihood-ratio tests evaluated model fit. Results: Of 104 participants, 90 had analysable MCG data and 65 had a primary-prevention ICD indication; after exclusions for missing patients, 54 patients remained (mean age 63.8 ± 13.2 yrs, 45(83.3%) male). Appropriate ICD therapies occurred in 10 (18.5%), including appropriate ICD shock in eight (14.8%); 10 patients (18.5%) died without prior therapy. The median follow-up was 1211.5 days (IQR 793.5–1396.0). Each SD increase in Rotation Score was associated with appropriate ICD therapy with HR 1.64 (95% CI 0.93–2.87; p = 0.086), appropriate ICD shock with HR 2.07 (95% CI 1.15–3.72; p = 0.015), death without prior therapy with HR 1.08 (95% CI 0.54–2.17; p = 0.824), and death without prior ICD shock with HR 0.95 (95% CI 0.48–1.90; p = 0.890). Adding Rotation Score did not significantly improve the primary therapy model beyond MADIT components (LRT p = 0.065) or MADIT benefit score (LRT p = 0.109). Model fit improved for the secondary appropriate ICD shock endpoint when Rotation Score was added to MADIT components (LRT p = 0.016), based on eight shock events. Conclusions: Rotation Score showed an association pattern more closely aligned with arrhythmic endpoints, particularly appropriate ICD shock, than with death without prior therapy. Incremental prognostic value for the primary endpoint was not established. These findings are hypothesis-generating and require confirmation in adequately powered, prospectively designed and externally validated cohorts before any role in clinical risk stratification or ICD decision-making can be determined.

Background: Obstructive sleep apnoea (OSA) is highly prevalent in Western populations, causing breathing cessation during sleep due to airway collapse. OSA is strongly associated with cardiovascular disease and arrhythmia, with several mechanisms likely to increase arrhythmia incidence. Continuous positive airway pressure (CPAP) is the mainstay of treatment, and whilst CPAP effectively treats OSA, specific arrhythmias and major adverse cardiovascular events may remain unchanged. Furthermore, arrhythmias are likely significantly underdiagnosed in this population. Meanwhile, implantable loop recorders (ILRs) are the gold-standard detection method for arrhythmias. Methods: This review aimed to systematically evaluate observational studies using ILRs to identify the incidence of arrhythmia in treated OSA patients. We searched the Medline/Excerpta Medica Database (EMBASE) databases, identifying observational studies involving any OSA patients with no history of arrhythmia and who had ILRs inserted. Two reviewers assessed the quality of the studies and potential bias using the Observational Study Quality Evaluation (OSQE) tool. Results: Three studies met the criteria with 77 participants; however, the study outcomes were incomparable and could not be pooled. CPAP significantly reduced bradyarrhythmia/pauses. There was a high incidence of atrial fibrillation (AF), up to 31%, although the sample size and overall characteristics were insufficient and could not be generalized. AF and other tachyarrhythmias were likely underdiagnosed in OSA patients. CPAP did reduce bradyarrhythmia/pauses but is potentially insufficient to reduce AF or other tachyarrhythmias. Only one ongoing study was found to evaluate the incidence of arrhythmias in OSA. Conclusions: We highlight the need for arrhythmia screening in OSA patients and for further studies to clarify the true incidence of arrhythmias in OSA patients. These additional studies may influence the guidelines for arrhythmia screening and identify mechanisms and therapeutic targets in OSA.

Sudden cardiac death (SCD) is responsible for 15%–20% of deaths globally/year, predominantly due to ventricular arrhythmias (VA) caused by vulnerable cardiac substrate. Identifying those at risk has proved difficult with several limitations of current methods. We evaluated the evidence for magnetocardiography (MCG) in predicting SCD events. We searched Embase/Medline databases for English language papers evaluating MCG in patients at risk of VA. A total of 119 papers were screened with 27 papers included for analysis (23 case–controlled, four cohort studies); study sizes varied (n = 12 to 158). Etiology was ischemic cardiomyopathy (ICM) in 22, dilated cardiomyopathy in 2, arrhythmogenic cardiomyopathy in 1 and mixed in 2. In patients with ICM there were consistent discriminatory features seen using time‐based and signal‐complexity measures that persisted when evaluating the independence of these parameters. Current flow analysis demonstrated promising discriminatory results in other etiologies. The features studied support the role of MCG in identifying substrate for VA, particularly in ICM.

Background: Atrial fibrillation (AF) is associated with significant morbidity/mortality. AF-ablation is an increasingly used treatment. Currently, first-time AF-ablation success is 40–80% at 1-year, depending on individual factors. There is growing evidence for improved outcomes through management of AF risk-factors/comorbidities via patient education/exercise-rehabilitation. There are no studies assessing combined prehabilitation/rehabilitation in this cohort. The aim of this randomised controlled trial is to assess efficacy of comprehensive prehabilitation/rehabilitation and combining supervised exercise-training with AF risk-factor modification/education compared with standard care in people undergoing first-time AF ablation. Methods: This single-centre pragmatic randomised controlled trial will recruit 106 adults with paroxysmal/persistent AF listed for first-time AF-ablation. Participants will be randomised 1:1 to cardiac prehabilitation/rehabilitation/education (CREED AF) intervention or standard care. Both groups will undergo AF-ablation at 8-weeks post-randomisation as per usual care. The CREED AF intervention will involve 6-weeks of prehabilitation (before AF-ablation) followed by 6-weeks rehabilitation (after AF-ablation) consisting of risk factor education/modification and supervised exercise training. Standard care will include a single 30-minute session of risk-factor education. Outcomes will be measured at baseline, 10-weeks and 12-months post AF-ablation, by researchers blinded to treatment allocation. The primary outcome is cardiorespiratory-fitness (peak oxygen uptake, VO_2peak) assessed using cardiopulmonary exercise testing (CPET) at 10-weeks post-ablation. Secondary outcomes include health-related quality of life, AF recurrence/burden assessed by 7-day Holter-monitor, requirement for repeat AF-ablation, study defined major adverse cardiovascular events, and cost-effectiveness (incremental cost per quality-adjusted life year (QALY)). Conclusions: This study will assess clinical-efficacy/cost-effectiveness of comprehensive prehabilitation/rehabilitation/patient-education for people undergoing first time AF-ablation. Results will inform clinical care and design of future multi-centre clinical trials. Trial registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT06042231.Date registered: September 18, 2023.

Background: Pulmonary vein isolation(PVI) is effective treatment for atrial fibrillation(AF) but efficacy of endocardial ablation-alone for long-standing persistent AF is limited(1). Hybrid AF ablation may offer better outcomes but studies were on patients with paroxysmal/persistent-AF(2) and relied on Holter-alone to assess recurrences(3). Our hybrid-AF ablation patients were all long-standing persistent cases and monitored with implantable loop recorders(ILR). Aim: Evaluate long-term outcomes of hybrid-AF ablation using ILR data. Methods: The hybrid approach at our institution consisted of a first-stage minimally invasive surgical epicardial ablation of the left atrial posterior wall via radiofrequency (RF) ablation. An ILR was implanted at the same setting. A few months later, the second-stage endocardial catheter ablation was performed to ensure PVI and ‘touch-up’ of any residual conduction gaps in the left atrium. All epicardial ablation cases were performed at the cardiothoracic operating-room in our tertiary hospital (‘hub’) whilst the endocardial RF-cases were performed at either the hub or satellite centre(‘spoke’) as part of our institution’s ‘hub-and-spoke’ model. Inclusion criteria for hybrid AF-ablation were long-standing persistent AF, body mass index (BMI) 30s. All data were obtained retrospectively via hospital electronic patient records. Results: 38 consecutive patients completed both aspects of hybrid ablation between December 2017-August 2023 with mean follow up of 19±13months(mean±SD). Baseline data, procedure characteristics and details of complications are shown in Table 1. ILR data was obtained in 36/38 patients(ILR implantation precluded in one due to previous breast cancer surgery. One had ILR battery depletion contributed by significant delay between the 2 stages of the hybrid ablation). AF/AT recurred in one third of patients during the blanking period(3 months) whilst 45% remained in sinus rhythm at 1-year; at 2yrs, 39% maintained SR and 25% at 3yrs (Figure 1). Post-hybrid ablation, two patients underwent re-do AF/AT ablation. The relatively high recurrence rate compared to other studies may be due to: very long duration of AF prior to hybrid-ablation(7.0±3.6years), significant delay between both stages of the procedure(9±11months) due to the pandemic and competing waiting list pressures, multiple comorbidities (82% had >2 comorbidities, 42% were obese) and the higher arrhythmia pickup rate with ILRs compared with intermittent rhythm monitoring. Conclusion: Our study provides real world insight into the challenges of delivering a hybrid AF ablation service but highlights its utility in long-standing persistent AF patients.Table 1Figure 1

Introduction Obstructive sleep apnoea (OSA) is associated with increased cardiovascular mortality despite continuous positive airways pressure (CPAP) therapy. This excess risk may be related to increased arrhythmia risk, especially atrial fibrillation (AF). The true incidence of arrhythmia in patients with OSA is unknown. Implantable loop recorders (ILR) are powerful tools for detecting arrhythmias long-term. Cardiac autonomic function may be important in arrhythmogenesis in these patients but needs further study. We aim to identify the true incidence of arrhythmias (especially AF) using ILRs, assess cardiac autonomic function using Holter monitors in patients with OSA and explore cardiovascular outcomes. Methods and analysis A two-centre (University Hospital Coventry and St. Cross Hospital, Rugby) nested cohort study using Reveal LINQ (Medtronic, UK) ILR to identify precise arrhythmia (atrial/ventricular) incidence in patients with moderate–severe OSA. 200 patients will be randomised 1:1 to standard care alone or standard care+ILR (+Holter monitor at baseline and 12 months). The primary objective is to compare arrhythmia detection over 3 years between the two groups. Cardiac autonomic function will be assessed in the ILR-arm at baseline and 12 months post CPAP. Secondary objectives will explore the mechanisms linking OSA and arrhythmia using cardiac autonomic function parameters based on Holter recordings and circulating biomarkers (high sensitivity Troponin-T, N-terminal pro B-type natriuretic peptide, matrix metalloproteinase-9, fibroblast growth factor 23, high sensitivity C-reactive protein, interleukin-6 and tumour necrosis factor-α) before and after CPAP initiation in the ILR-arm. Ethics and dissemination This study has been approved by the Health Research Authority after examination by the Solihull Research and Ethics Committee. The main ethical considerations was the minimally invasive nature of ILR insertion outside of usual care. Patient advisory groups were consulted with a positive outcome for this type of research. We plan on publishing papers in peer-reviewed journals based on the primary objective and any interesting findings from secondary objectives. We will endeavour to publish all relevant data. Trial registration number NCT03866148.