Search

Background: 123 I-meta-iodobenzylguanidine (mIBG) has been applied to patients with chronic heart failure (CHF). However, the relationship between 123 I-mIBG activity and lethal arrhythmic events (ArE) is not well defined. This study aimed to determine this relationship in Japanese and European cohorts., Results: We calculated heart-to-mediastinum (H/M) count ratios and washout rates (WRs) of 827 patients using planar 123 I-mIBG imaging. We defined ArEs as sudden cardiac death, arrhythmic death, and potentially lethal events such as sustained ventricular tachycardia, cardiac arrest with resuscitation, and appropriate implantable cardioverter defibrillator (ICD) discharge, either from a single ICD or as part of a cardiac resynchronization therapy device (CRTD). We analyzed the incidence of ArE with respect to H/M ratios, WRs and New York Heart Association (NYHA) functional classes among Japanese (J; n = 581) and European (E; n = 246) cohorts. We also simulated ArE rates versus H/M ratios under specific conditions using a machine-learning model incorporating 13 clinical variables. Consecutive patients with CHF were selected in group J, whereas group E comprised candidates for cardiac electronic devices. Groups J and E mostly comprised patients with NYHA functional classes I/II (95%) and II/III (91%), respectively, and 21% and 72% were respectively implanted with ICD/CRTD devices. The ArE rate increased with lower H/M ratios in group J, but the relationship was bell-shaped, with a high ArE rate within the intermediate H/M range, in group E. This bell-shaped curve was also evident in patients with NYHA classes II/III in the combined J and E groups, particularly in those with a high (> 15%) mIBG WR and with ischemic, but not in those with non-ischemic etiologies. Machine learning-based prediction of ArE risk aligned with these findings, indicating a bell-shaped curve in NYHA class II/III but not in class I., Conclusions: The relationship between cardiac 123 I-mIBG activity and lethal arrhythmic events is influenced by the background of patients. The bell-shaped relationship in NYHA classes II/III, high WR, and ischemic etiology likely aids in identifying patients at high risk for ArEs., (© 2024. The Author(s).)

Guidelines help clinicians to deliver high-quality care with therapies based on up-to-date evidence. There has been significant progress in the management of heart failure with regards to both medication and cardiac device therapy. These advances have been incorporated into national and international guidelines with varying degrees of success. This article reviews current guidance from the National Institute of Health and Care Excellence in the UK and compares this with European Society of Cardiology guidelines, and evaluates how differences between them may impact on clinical practice., Competing Interests: Disclosure: AR has received honoraria from Medtronic, Boston Scientific, Phillips and Novartis, and has served on the expert consensus committee for leadless pacemakers on behalf of the British Heart Rhythm Society. All other authors have no conflicts of interest to declare., (Copyright © 2023, Radcliffe Cardiology.)

Background: There are few large studies on which factors are associated with the occurrence of arrhythmias. Implantable loop recorders (ILR) are useful in detecting arrhythmia due to prolonged and continuous ECG monitoring. Therefore, the aim of this study is to identify and evaluate clinical characteristics and ECG parameters for predicting arrhythmias requiring pacemaker/ICD implantation by analyzing a study cohort with ILR., Methods: This bicentric study comprised a study cohort of 451 patients (mean age 64 ± 16 years, 209 women) receiving ILR implantation between 2011 and 2021. Patients were followed up on a 3 monthly outpatient interval. All arrhythmias with a pacemaker or ICD indication were considered clinically relevant. The primary study endpoint was the detection of clinically relevant arrhythmia., Results: During a follow up of 678 ± 392 days, a clinically relevant arrhythmia was detected in 81 of 451 patients (18%). Multivariate analysis revealed five independent risk factors: coronary artery disease (HR 1.954, CI 1.077-3.546, p = .028), atrial fibrillation (HR 2.253, CI 1.201-4.228, p = .011), previous syncope (HR 6.404, CI 3.202-12.808, p < .001), right bundle branch block (HR 4.370, CI 2.215-8.621, p < .001) and left bundle branch block (HR 2.685, CI 1.116-6.461, p = .028). Our risk model, based on these independent predictors, divided the study cohort into patients with low (2%), intermediate (18%), medium (34%), and high (45%) risk for clinically relevant arrhythmia., Conclusion: By the use of ILR, a clinically relevant arrhythmia has been detected in almost one fifth of the study cohort. In addition, clinical and electrocardiographic parameters were shown to be suitable predictors of clinically relevant arrhythmia., (© 2022 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Background: The levels of circulating troponin are principally required in addition to electrocardiograms for the effective diagnosis of acute coronary syndrome. Current standard-of-care troponin assays provide a snapshot or momentary view of the levels due to the requirement of a blood draw. This modality further restricts the number of measurements given the clinical context of the patient. In this communication, we present the development and early validation of non-invasive transdermal monitoring of cardiac troponin-I to detect its elevated state., Methods: Our device relies on infrared spectroscopic detection of troponin-I through the dermis and is tested in stepwise laboratory, benchtop, and clinical studies. Patients were recruited with suspected acute coronary syndrome., Results: We demonstrate a significant correlation ( r  = 0.7774, P  < 0.001, n  = 52 biologically independent samples) between optically-derived data and blood-based immunoassay measurements with and an area under receiver operator characteristics of 0.895, sensitivity of 96.3%, and specificity of 60% for predicting a clinically meaningful threshold for defining elevated Troponin I., Conclusion: This preliminary work introduces the potential of a bloodless transdermal measurement of troponin-I based on molecular spectroscopy. Further, potential pitfalls associated with infrared spectroscopic mode of inquiry are outlined including requisite steps needed for improving the precision and overall diagnostic value of the device in future studies., Competing Interests: Competing interestsP.S. is an advisor to Kencor Health, Ultromics and RCE Technologies and holds option equity with these companies. A.W. is an advisor and holds option equity with RCE Technologies. S.B. holds option equity with RCE Technologies. J.T. and A.B. are employees of RCE Technologies., (© The Author(s) 2022.)