Risk Of Arrhythmias In Patients Research Articles

Non-invasive electrocardiographic assessment of arrhythmic risk in ischaemic cardiomyopathy patients undergoing revasularisation

Abstract Background Ventricular arrhythmias are a leading cause of death in patients with ischaemic cardiomyopathy (ICM). Ischaemia is thought to increase arrhythmic risk and coronary revascularisation is frequently undertaken to reduce this risk, although the recent REVIVED-BCIS2 trial did not show a difference in the incidence of death, device therapies or sustained arrhythmias in patients assigned to have percutaneous coronary intervention (PCI) compared to optimal medical therapy alone(1). Purpose We assessed the mechanistic effects of revascularisation on arrhythmic risk in patients with ICM using non-invasive electrocardiographic imaging (ECGi). Methods Patients were eligible if they had a left ventricular ejection fraction (LVEF) <40%, extensive coronary disease (BCIS Jeopardy Score≥6) and were scheduled to undergo revascularisation with coronary artery bypass grafting or PCI. ECGi assessment was performed using a 252-electrode vest with anatomical co-registration using a CT thorax. Patients underwent stress perfusion cardiac magnetic resonance (CMR) imaging; both ECGi and CMR were conducted at baseline and 3 months post revascularisation(Figure 1). The primary outcome measure was dispersion of repolarisation measured using global activation recovery interval (ARI) dispersion. Secondary outcome measures included repolarisation time (RT) dispersion, mean ARI and LV ARI dispersion. We also assessed the relationship between ARI dispersion, revascularisation and left ventricular scar burden. Data are presented as mean ± SD or median [IQR]. Results Thirty patients were recruited between 2020-2023; age 67±11 years, 90% male, BMI 28±5 and baseline LVEF was 29±8%. Twelve patients underwent CABG, 18 (60%) had PCI. The BCIS jeopardy score was 10 [9-11] at enrolment and decreased to 2 [0-4] after revascularisation. The LV scar burden at baseline was 15.1±6.5% and the change at 3 months was -0.5±5% (p=0.70). ARI dispersion and LV ARI dispersion were correlated with LV scar burden (r=0.62,p=0.01 and 0.71,p=0.002 respectively). No differences were seen in ARI dispersion (44.5 vs 44.1, p=0.86) or secondary outcome measures before and after revascularisation (RT dispersion: 45.5 vs 44.7, p=0.49; Mean ARI: 281.3 vs 282.6, p=0.74; ARI dispersion: 44.5 vs 44.1, p=0.86; LV ARI dispersion: 38.4 vs 36.7, p=0.39)(Figure 2). The LVEF change on CMR at 3 months was +6.9±10%; no relationship was seen between change in LVEF and ARI dispersion. Conclusion Arrhythmic risk assessed by non-invasive ECGi was not altered by coronary revascularisation. LV ARI dispersion was highly correlated with scar burden, which is not altered by revascularisation. Future work includes analysis of perfusion data. Our results support the findings of the REVIVED arrhythmia study that revascularisation does not reduce arrhythmic risk in patients with ICM(1). ECGi derived LV ARI dispersion correlates with scar and may represent a non-invasive arrhythmic risk assessment tool.Figure 1Figure 2

Stratification of arrhythmic risk in patients admitted for acute coronary syndrome: the role of the machine learning-derived PRAISE score

Abstract Funding Acknowledgements None. Background Patients with acute coronary syndrome (ACS) have a high arrhythmic burden, and either ventricular and supraventricular arrhythmias are very common during hospitalization[1]. Patients who develop arrhythmias show higher mortality and worse prognosis. The PRAISE (Prediction of Adverse Events Following an Acute Coronary Syndrome) score is a machine-learning based model for predicting 1-year all cause death, recurrent acute myocardial infarction and major bleedings in patients after ACS[2]. To date, its role to predict arrhythmic complications in ACS remains unknown. Purpose We hypothesized that patients with higher PRAISE score have a higher arrhythmic burden. Aim was to evaluate in a prospective protocol the PRAISE score capability for identifying patients with ACS at higher risk of arrhythmic complications during in-hospital stay. Methods A total of 365 consecutive patients admitted to our cardiac intensive care unit for ACS and undergoing percutaneous coronary intervention were enrolled. All patient was monitored by continuous electrocardiogram during hospitalization. The PRAISE score was obtained for each patient <24 hours from admission. Patients were divided into 2 groups based on the results of the PRAISE score for all-cause of death as patients without high PRAISE score (e.g. with low to intermediate risk, n=350) and patients with high PRAISE score (e.g. with high risk, n=15). The occurrence of atrial fibrillation (AF) and ventricular arrhythmias (VAs) up to discharge was recorded. AF was defined by detection of at least one episode of uncoordinated atrial electrical activation and irregular R-R intervals, in absence of distinct repeating P waves and with irregular atrial activations lasting at least 5 minutes. We considered as VAs all episodes of ventricular non-sustained tachycardia, sustained ventricular tachycardia and ventricular fibrillation. Results ROC curve analysis indicated a significant relationship between high PRAISE score and risk of both in-hospital AF (AUC 0.89, 95%CI 0.82-0.94, p=0.0001) and VAs (AUC 0.69, 95%CI 0.64-0.75, p=0.0001). A high PRAISE score had a specificity of 99% for AF and 92% for VAs. By Kaplan-Meier analysis, patients with high PRAISE score more frequently developed AF (30% vs 4% in those without high score; log rank p=0.00001) and VAs (77% vs 35%; log rank p=0.00001). Multivariate analysis showed that a high PRAISE score was an independent predictor of both AF (HR 4.08, 95%CI 1.14-14.58, p=0.030) and VAs (HR 2.36, 95%CI 1.08-5.14, p=0.030). Conclusions In patients hospitalized for ACS, the PRAISE score has a comprehensive capability to identify with high specificity those patients prone to develop arrhythmic events during hospitalization. This may be important in order to stratify patients with higher arrhythmic risk in whom individualized strategies may improve the clinical outcome.Baseline features of the populationKaplan-Meier anaysis

Anthracyclines and the risk of arrhythmias: A systematic review and meta-analysis.

There have been controversial findings from recent studies regarding anthracyclines use and the subsequent risk of arrhythmias. This study aimed to evaluate the existing evidence of the risk of arrhythmias in patients treated with anthracyclines. PubMed, Scopus, and Web of Science databases were searched up to April 2022 using keywords such as "anthracycline" and "arrhythmia." Dichotomous data were presented as relative risk (RR) and confidence interval (CI), while continuous data were presented as mean difference (MD) and CI. Revman software version 5.4 was used for the analysis. Thirteen studies were included with a total of 26891 subjects. Pooled analysis showed that anthracyclines therapy was significantly associated with a higher risk of arrhythmia (RR: 1.58; 95% CI: 1.41-1.76; P < .00001), ST segment and T wave abnormalities (RR: 1.73, 95% CI: 1.18-2.55, P = .005), conduction abnormalities and AV block (RR = 1.86, 95% CI = 1.06-3.25, P = .03), and tachycardia (RR: 1.736, 95% CI: 1.11-2.69, P = .02). Further analyses of the associations between anthracyclines and atrial flutter (RR = 1.30, 95% CI = 0.29-5.89, P = .74), atrial ectopic beats (RR: 1.27, 95% CI: 0.78-2.05, P = .34), and ventricular ectopic beats (RR: 0.93, 95% CI: 0.53-1.65, P = .81) showed no statistically significant results. Higher doses of anthracycline were associated with a higher risk of arrhythmias (RR: 1.49; 95% CI: 1.08-2.05; P = .02) compared to the lower doses (RR: 1.36; 95% CI: 1.00-1.85; P = .05). Newer generations of Anthracycline maintained the arrhythmogenic properties of previous generations, such as Doxorubicin. Anthracyclines therapy was significantly associated with an increased risk of arrhythmias. Accordingly, Patients treated with anthracyclines should be screened for ECG abnormalities and these drugs should be avoided in patients susceptible to arrhythmia. The potential benefit of the administration of prophylactic anti-fibrotic and anti-arrhythmic drugs should also be explored.

Atrial and ventricular arrhythmias with immune checkpoint inhibitor therapy in patients without evidence of myocarditis

Abstract Background Immune checkpoint inhibitor (ICI) therapy has improved the prognosis of many cancer types. Immune-related adverse events (irAEs) are common and recent studies suggest ICI therapy may be associated with an increased risk of arrhythmias. However, data on arrhythmias after ICI therapy has been limited by small sample sizes, the inclusion of patients with ICI myocarditis, or an incomplete characterization of the factors that drive arrhythmias with an ICI. Purpose This study aimed to characterize the association between ICIs and arrhythmias in patients without evidence of myocarditis. Methods We conducted a hospital network-wide retrospective cohort study on all patients treated with ICI who were free from arrhythmias at the start of ICI therapy, and had no evidence of immune-related myocarditis. We used a historical pre-ICI therapy era cohort of cancer patients of similar age and tumor types, diagnosed between 2008-2012. The main study outcome was the incidence of atrial fibrillation, atrial flutter, supraventricular tachycardia, and ventricular tachycardia after ICI therapy. International Classification of Diseases 9th and 10th edition codes were used to ascertain baseline characteristics and to detect the study outcomes. Myocarditis cases were identified through the application of natural language processing techniques to electronic health records. Patients on ICI therapy and controls were followed from the start of ICI therapy, and from the first visit after 2008, respectively, up to three years after the index date. Results The study population consisted of 7441 patients on ICI therapy and 2311 controls. Patients on ICI therapy were older (65±13 vs. 63±13 years, p&amp;lt;0.001) and more frequently had arterial hypertension (52% vs. 47%, p&amp;lt;0.001), but had lower rates of prior congestive heart failure (6% vs. 11%, p&amp;lt;0.001). Over a median follow-up period of 36 months, 9.8% on ICI therapy were diagnosed with any incident atrial or ventricular arrhythmia, compared to 7.1% in the control group (p&amp;lt;0.001) with corresponding incidence rates of 4.4 and 2.3 cases per 100 person-years, respectively (Fig. 1). When correcting for age, sex, cancer type, prior congestive heart failure, and cardiovascular risk factors, patients on ICI therapy had a higher risk of a composite outcome of any arrhythmia (hazard ratio [HR] 1.68, 95% confidence interval [CI]: 1.39-2.04, p&amp;lt;0.001), atrial fibrillation (HR 1.29, 95%CI: 1.02-1.63, p=0.034) and ventricular tachycardia (HR 2.01, 95%CI: 1.34-3.04, p&amp;lt;0.001). In a multivariable logistic regression model, the occurrence of a non-cardiovascular irAE was a predictor of an incident arrhythmia (odds ratio 1.81, 95%CI: 1.56-2.23, p&amp;lt;0.001). Conclusion This study, to the best of our knowledge, is the largest to report on ICI therapy-related arrhythmias and the first to show the occurrence of non-cardiovascular irAEs as a predictor of arrhythmia risk in patients on ICI therapy without evidence of myocarditis.Fig. 1

Prognostic value of modified ADMIIRE-HF risk score in patients with implantable cardioverter defibrillator: a prospective comparative study with 6-minute walk distance

Abstract Background ADIMIRE-HF risk score is a novel risk score that combines clinical characteristics and MIBG imaging variables to predict serious arrhythmic risk in patients with chronic heart failure (CHF) and recent studies showed that highest occurrence of severe arrhythmic events (SAE) was seen in patients with an intermediate decrease in MIBG uptake rather than the lowest values. Six-minute walk distance (6MWD) has also been shown to detect high risk patients with CHF. However, there is no information available on the long-term prognostic value of these indices for the prediction of ventricular tachyarrhythmias in patients with implantable cardioverter defibrillator (ICD). Methods and Results We prospectively enrolled 231 consecutive outpatients with ICD (age: 65±14 years, male: 81%, NYHA class: 1.7±0.7, LVEF: 47±17%). At entry, cardiac MIBG imaging, echocardiography and 6-minute walk test were performed. Modified ADMIRE-HF risk score was derived from the sum of the point values of the following parameters: LVEF (&amp;lt;25%:5 points), MIBG heart-to-mediastinum ratio on delayed planar image (HMR 1.4-1.9: 12 points) and systolic blood pressure (&amp;lt;120: 3 points, 120-139: 0 point, &amp;gt;140: -3 points). During a follow-up period of 4.4±2.8 years, 72 patients had appropriate ICD therapy (ATx). At multivariate Cox analysis, modified ADMIRE-HF risk score and 6MWD were significantly and independently associated with ATx after adjustment of age, sex, non-sustained ventricular tachycardia and NYHA functional class. ATx was significantly more frequently observed in patients with both higher modified ADMIRE HF risk score (&amp;gt;9: median value) and shorter 6MWD (&amp;lt;300m) and with either, than with none of them (54% vs 34% vs 18%, respectively p&amp;lt;0.0001). Conclusion Combination of modified ADMIRE-HF risk score and 6MWD would be strongly associated with an increased risk for ventricular tachyarrhythmias in ICD patients.

Artificial Intelligence ECG Analysis in Patients with Short QT Syndrome to Predict Life-Threatening Arrhythmic Events

Short QT syndrome (SQTS) is an inherited cardiac ion-channel disease related to an increased risk of sudden cardiac death (SCD) in young and otherwise healthy individuals. SCD is often the first clinical presentation in patients with SQTS. However, arrhythmia risk stratification is presently unsatisfactory in asymptomatic patients. In this context, artificial intelligence-based electrocardiogram (ECG) analysis has never been applied to refine risk stratification in patients with SQTS. The purpose of this study was to analyze ECGs from SQTS patients with the aid of different AI algorithms to evaluate their ability to discriminate between subjects with and without documented life-threatening arrhythmic events. The study group included 104 SQTS patients, 37 of whom had a documented major arrhythmic event at presentation and/or during follow-up. Thirteen ECG features were measured independently by three expert cardiologists; then, the dataset was randomly divided into three subsets (training, validation, and testing). Five shallow neural networks were trained, validated, and tested to predict subject-specific class (non-event/event) using different subsets of ECG features. Additionally, several deep learning and machine learning algorithms, such as Vision Transformer, Swin Transformer, MobileNetV3, EfficientNetV2, ConvNextTiny, Capsule Networks, and logistic regression were trained, validated, and tested directly on the scanned ECG images, without any manual feature extraction. Furthermore, a shallow neural network, a 1-D transformer classifier, and a 1-D CNN were trained, validated, and tested on ECG signals extracted from the aforementioned scanned images. Classification metrics were evaluated by means of sensitivity, specificity, positive and negative predictive values, accuracy, and area under the curve. Results prove that artificial intelligence can help clinicians in better stratifying risk of arrhythmia in patients with SQTS. In particular, shallow neural networks’ processing features showed the best performance in identifying patients that will not suffer from a potentially lethal event. This could pave the way for refined ECG-based risk stratification in this group of patients, potentially helping in saving the lives of young and otherwise healthy individuals.

Long-term risk of arrhythmias in patients with inflammatory bowel disease: A population-based, sibling-controlled cohort study.

Although previous evidence has suggested an increased risk of cardiovascular disease (CVD) in patients with inflammatory bowel disease (IBD), its association with arrhythmias is inconclusive. In this study, we aimed to explore the long-term risk of arrhythmias in patients with IBD. Through a nationwide histopathology cohort, we identified patients with biopsy-confirmed IBD in Sweden during 1969 to 2017, including Crohn's disease (CD: n = 24,954; median age at diagnosis: 38.4 years; female: 52.2%), ulcerative colitis (UC: n = 46,856; 42.1 years; 46.3%), and IBD-unclassified (IBD-U: n = 12,067; 43.8 years; 49.6%), as well as their matched reference individuals and IBD-free full siblings. Outcomes included overall and specific arrhythmias (e.g., atrial fibrillation/flutter, bradyarrhythmias, other supraventricular arrhythmias, and ventricular arrhythmias/cardiac arrest). Flexible parametric survival models estimated hazard ratios (aHR) with 95% confidence intervals (95% CIs), after adjustment for birth year, sex, county of residence, calendar year, country of birth, educational attainment, number of healthcare visits, and cardiovascular-related comorbidities. Over a median of approximately 10 years of follow-up, 1,904 (7.6%) patients with CD, 4,154 (8.9%) patients with UC, and 990 (8.2%) patients with IBD-U developed arrhythmias, compared with 6.7%, 7.5%, and 6.0% in reference individuals, respectively. Compared with reference individuals, overall arrhythmias were increased in patients with CD [54.6 versus 46.1 per 10,000 person-years; aHR = 1.15 (95% CI [1.09, 1.21], P < 0.001)], patients with UC [64.7 versus 53.3 per 10,000 person-years; aHR = 1.14 (95% CI [1.10, 1.18], P < 0.001)], and patients with IBD-U [78.1 versus 53.5 per 10,000 person-years; aHR = 1.30 (95% CI [1.20, 1.41], P < 0.001)]. The increased risk persisted 25 years after diagnosis, corresponding to 1 extra arrhythmia case per 80 CD, 58 UC, and 29 IBD-U cases over the same period. Patients with IBD also had a significantly increased risk of specific arrhythmias, except for bradyarrhythmias. Sibling comparison analyses confirmed the main findings. Study limitations include lack of clinical data to define IBD activity, not considering the potential role of IBD medications and disease activity, and the potential residual confounding from unmeasured factors for arrhythmias. In this study, we observed that patients with IBD were at an increased risk of developing arrhythmias. The excess risk persisted even 25 years after IBD diagnosis. Our findings indicate a need for awareness of this excess risk among healthcare professionals.

Importance of blood biomarker determination in the selection of patients with heart failure for cardioverterdefibrillator implantation

Aim. To conduct a comparative analysis of blood biomarker concentrations, to study their prognostic role in the occurrence of sustained ventricular tachyarrhythmia (VT) or VT episodes requiring electrotherapy in patients with heart failure (HF) and left ventricular ejection fraction (LVEF) ≤35% without prior syncope or sustained ventricular arrhythmias.Material and methods. This single-center prospective clinical study included 319 patients (men, 83%) aged 57 (51-63) years with LVEF of 29 (24-33)% receiving optimal therapy for HF, hospitalized for cardioverterdefibrillator implantation for the purpose of primary prevention of sudden cardiac death. Before the procedure, the concentration of blood biomarkers (blood electrolytes, C-reactive protein, creatinine, Soluble suppression of tumorigenicity 2 (sST2), N-terminal pro-brain natriuretic peptide (NT-proBNP), galectin-3) was determined. Based on blood creatinine concentration, glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Patients underwent a two-year prospective follow-up to record the end point of newly occurring clinically significant VT episodes detected by an implantable cardioverter-defibrillator.Results. The studied arrhythmic endpoint occurred in 84 (26,3%) patients. The multivariate analysis revealed three blood biomarkers, the concentration of which was associated with the first manifestation of VT. With sST-2 &gt;35 ng/ml, this risk increased by ~3 times (odds ratio (OR)=2,86; 95% confidence interval (CI): 1,23-6,64 (p=0,013)). Galectin-3 level &gt;12 ng/ml had a comparable prognostic value (OR=2,64; 95% CI: 1,06-6,53 (p=0,032)). In case of an increase in NT-proBNP &gt;2000 pg/ml, the risk of the same outcome was 2,2 times lower (OR=0,46; 95% CI: 0,22-0,95 (p=0,034)).Conclusion. Pre-implantation laboratory screening of NT-proBNP, sST-2 and galectin-3 concentrations can help in personalized assessment of arrhythmic risk in patients with HF and LVEF ≤35% referred for interventional primary prevention of sudden cardiac death.

Index of cardio-electrophysiological balance and Parkinson disease.

Neurodegeneration of the autonomic nervous systems due to Parkinson disease (PD) may lead to increase in the QT duration. In recent years, a new parameter index of cardio-electrophysiological balance (ICEB) was found. ICEB is a significant parameter of medicine related dysrhythmia. The purpose of this research is to assess ICEB in PD. Twenty-eight PD cases and 26 controls participated in our investigation. First diagnosed PD patients were registered in the research. The symptom progression of PD was assessed Modified Hoehn and Yahr Scale. Analyzed ECG variables are QRS, PR, QT, corrected QT (QTc) interval, ICEB and corrected index of cardio-electrophysiological balance (ICEBc). All cases had sinus rhythm. ICEB was analyzed by the ratio of QT/QRS. ICEBc was analyzed by the ratio of QTc/QRS. Twenty-eight PD cases participated in this research. Among PD cases, 15 patients were female (53.5%). The mean age of PD patients are 59.03 ± 9.94 years. There was no important difference between groups with respect to the clinical variables. The Modified Hoehn and Yahr Scale was appreciably higher in the PD group than the Control group. The heart rate of the PD group was significantly lower than that of the control group. PR intervals and QRS duration were similar in both groups. QT and QTc duration were significantly longer in PD patients. Also, the ICEB and ICEBc variables were appreciably higher in PD cases. The findings of our investigation suggest that ICEB is related to PD. ICEB can help to evaluate arrhythmia risk in patients with PD.

Cardiac resynchronization therapy: potential for arrhythmic risk modification

Aim. To evaluate the impact of cardiac resynchronization therapy (CRT) on the risk of sustained ventricular tachyarrhythmias (VT) in patients with heart failure (HF) with a implantable cardioverter-defibrillator (ICD) for the primary prevention of sudden cardiac death.Material and methods. This single-center prospective clinical study included 470 patients (men, 84%) with HF at the age of 57 (51-62) years with a left ventricular ejection fraction (LVEF) of 29 (25-33)%. There were following exclusion criteria: indications for cardiac surgery, known channelopathies, previously registered VT. Depending on intraventricular conduction disorders, dual-chamber ICDs (42%) or CRT-D (58%) were implanted. After ICD implantation, patients were followed up for 24 months to register the end point — a first-time sustained paroxysm of VT detected by the ICD. A positive response to CRT was established in the case of an increase in LVEF by ≥5% of the initial level.Results. A total of 388 patients underwent full postoperative follow-up. The studied arrhythmic endpoint occurred on average 21 (0,6) months after implantation in 104 patients (27%) with higher frequency in the ICD group. However, the differences in the VT rate in the study groups were statistically unreliable (30% in the ICD group versus 24% in the CRT-D group, p=0,142). It was found that the VT rate was reliably lower in CRT-responders (118 patients, 53%): 15% compared to 32% in the group of inefficient CRT. A 5% increase in the LFEF reduced the probability of VT occurrence by 3 times (odds ratio [OR]=0,34; 95% of CI: 0,13-0,86; p=002). Significant modification of arrhythmic risk was verified by increasing LFEF to 36-40% (OR=0,72; 95% CI: 0,63-0,82; p=0,04).Conclusion. The results obtained indicate that effective CRT has the potential to modify arrhythmic risk in patients with HF, especially with an increase in LVEF to the level of 36-40%.

Overview of Cardiac Arrhythmias and Treatment Strategies.

Maintenance of normal cardiac rhythm requires coordinated activity of ion channels and transporters that allow well-ordered propagation of electrical impulses across the myocardium. Disruptions in this orderly process provoke cardiac arrhythmias that may be lethal in some patients. Risk of common acquired arrhythmias is increased markedly when structural heart disease caused by myocardial infarction (due to fibrotic scar formation) or left ventricular dysfunction is present. Genetic polymorphisms influence structure or excitability of the myocardial substrate, which increases vulnerability or risk of arrhythmias in patients. Similarly, genetic polymorphisms of drug-metabolizing enzymes give rise to distinct subgroups within the population that affect specific drug biotransformation reactions. Nonetheless, identification of triggers involved in initiation or maintenance of cardiac arrhythmias remains a major challenge. Herein, we provide an overview of knowledge regarding physiopathology of inherited and acquired cardiac arrhythmias along with a summary of treatments (pharmacologic or non-pharmacologic) used to limit their effect on morbidity and potential mortality. Improved understanding of molecular and cellular aspects of arrhythmogenesis and more epidemiologic studies (for a more accurate portrait of incidence and prevalence) are crucial for development of novel treatments and for management of cardiac arrhythmias and their consequences in patients, as their incidence is increasing worldwide.

Appropriate and inappropriate therapies in remotely monitored patients with cardiac implantable devices long-term experiences of a tertiary centre

Abstract Funding Acknowledgements Type of funding sources: None. Background The evidence supporting the implantation of implantable cardioverter-defibrillator (ICD) in the primary prevention of sudden cardiac death (SCD) comes mostly from the times when optimal management of heart failure was not as effective as at present. Moreover, the detailed data on the long-term risk of arrhythmias in patients with ICD are scarce. Purpose To present the long-term results of the remote monitoring (RM) of patients with ICD from a large, tertiary cardiovascular centre registry. Methods The clinical data from the time of device implantation were derived from the COMMIT-HF registry, while the follow-up data were obtained from the investigator-initiated RM registry. In brief, the registry encompasses data regarding the types of the transmissions and their contents, with particular emphasis on the occurrence of arrhythmic episodes, device interventions, as well as the data on the causes of other alert transmissions. Results In total, 1,299 patients were included in the analysis. The median follow-up duration of RM was 4.4 years, and the primary indication for implantation was ischemic cardiomyopathy (60.3%). Appropriate antitachycardia pacing (ATP) and high-voltage therapy for ventricular arrhythmias occurred in respectively 25.3% and 26.1% of patients, while inappropriate ATP and HV in respectively 11.5% and 8.7%. The prevalence of AF was 40.8%. Conclusions In a large real-life cohort of continuously remotely monitored patients with ICDs, the percentage of patients with appropriate therapies for ventricular arrhythmias exceeded 25%. Further analyses are necessary to stratify the risk of ventricular arrhythmias in the contemporary practice.

Utility of cardiac magnetic resonance in assessing arrhythmic risk in patients with non ischemic cardiomyopathy undergoing biventricular pacing

Abstract Funding Acknowledgements Type of funding sources: None. Background Non-ischemic cardiomyopathy (NICM) is a common heart muscle disorder, which is responsible for approximately one-third of heart failure and is associated with significant morbidity and mortality. Recent data suggested the lack of mortality reduction from adding a defibrillator to cardiac resynchronization therapy (CRT) in all patients with NICM. Myocardial fibrosis detected by cardiac magnetic resonance late gadolinium enhancement (CMR-LGE) can help risk stratify patients who would benefit from adding a defibrillator to CRT in this patient population. Purpose We aim at assessing the relationship between the presence of myocardial fibrosis detected by CMR-LGE and the rate of major arrhythmic events (MAE) that included sustained VT, appropriate CRT-D intervention, VF, and SCD in patients with NICM undergoing (CRT) and to compare all-cause mortality and heart failure improvement between patients who receiving CRT-P vs those who receiving CRT-D based on the presence of myocardial fibrosis. Methods All consecutive patients with NICM satisfying a guideline directed indication for CRT implantation were included in the study after excluding patients who refused to consent, patients with acute decompensated heart failure and those contraindicated for a CMR. Patients were divided into two groups according to presence of fibrosis in cardiac MRI into (CRT-D/LGE) group and CRT-P/No LGE group and followed along for one year. Results Sixty patients were enrolled. Sixteen patients (26.6%) developed MAE during the study duration. Seven patients had myocardial fibrosis (receiving CRT-D as per protocol), while only nine patients had no myocardial fibrosis (receiving CRT-P as per protocol), (41.2% vs 20.9%, P=0.045). Presence of CMR-LGE, regardless the extent and distribution, predicted MAE with odd ratio 2.6 (CI=1.78-8.9, P=0.04). The presence of ≥7.5 % of myocardial fibrosis by CMR was associated with 54 % sensitivity and 100% specificity for MAE in the study population (Figure 1). However, All-cause mortality was significantly higher in the (CRT-P/No LGE) group vs (CRT-D/LGE) group [15 (34.9%) vs 2 (11.8%), P=0.076]. Comparison between both groups regarding symptoms of heart failure, QoL and ejection fraction is shown in Table 1. Conclusion In patients with NICM candidates for biventricular pacing, the presence of LGE on CMR, irrespective of the extent or segmental pattern, is independently associated with a major arrhythmic event and is associated with worse heart failure outcome. However, the absence of LGE did not rule out MAE and implanting CRT-P based on lack of fibrosis may result in higher all-cause mortality.

Evaluation of the Tpeak-Tend Interval as an Arrhythmogenicity Index in Graves' Disease

Introduction.Graves’ disease is the most common cause of hyperthyroidism. The mortality rate increases by 20% in hyperthyroid patients; cardiac problems are the leading cause of death and arrhythmia is the most common cardiac complication.&#x0D; Our study aimed to evaluate the corrected QT interval (QTc), the Tpeak-Tend interval (Tp-e), and the Tp-e/QTc ratio to predict arrhythmia risk in patients with Graves’ disease.&#x0D; Methods. The study included 64 patients with Graves’ disease and 57 euthyroid controls. The 12-lead electrocardiograms of the individuals under study were evaluated. The QTc interval, the Tp-e interval, and the Tp-e/QTc ratio of all participants were determined and statistically evaluated with thyroid stimulating hormone (TSH), free triiodothyronine (fT3) and free thyroxine (fT4) values.&#x0D; Results. Tp-e (p &lt; 0.001) and QTc (p &lt; 0.05) were significantly prolonged in the group of patients with Graves’ disease as compared to the control group. Heart rate was higher in patients with Graves’ disease as well (p &lt; 0.05). Correlation analysis in patients with hyperthyroidism demonstrated that Tp-e (r=0.372, p=0.002), QTc (r=0.291, p=0.020), and fT3 levels were significantly and positively correlated. Similarly, Tp-e (r=0.271, p=0.030), QTc (r=0.259, p=0.039), and fT4 levels were significantly and positively correlated.&#x0D; Conclusions. We observed a significant prolongation of the Tp-e and QTc intervals with the increase in fT3 and fT4 levels. On the other hand, our study demonstrated that the sensitivity and specificity of Tp-e in the prediction of hyperthyroidism were 70.3% and 70.1%, respectively (AUC=0.724 (CI: 0.629-0.818)), the optimal cut-off value=83.5 ms). The Tp-e interval, which has recently been used as one of the arrhythmogenicity indices, may be an indicator of arrhythmia risk in patients with Graves’ disease.

Additional value of cardiac magnetic resonance feature tracking parameters for the evaluation of the arrhythmic risk in patients with mitral valve prolapse

ObjectivesThe identification of patients with mitral valve prolapse (MVP) presenting high arrhythmic risk remains challenging. Cardiovascular Magnetic Resonance (CMR) feature tracking (FT) may improve risk stratification. We analyzed the role of CMR-FT parameters in relation to the incidence of complex ventricular arrhythmias (cVA) in patients with MVP and mitral annular disjunction (MAD). Methods42 patients with MVP and MAD who underwent 1.5 T CMR were classified as MAD-cVA (n = 23, 55%) in case of cVA diagnosed on a 24-h Holter monitoring and as MAD-noVA in the absence of cVA (n = 19, 45%). MAD length, late gadolinium enhancement (LGE), basal segments myocardial extracellular volume (ECV) and CMR-FT were assessed. ResultsLGE was more frequent in the MAD-cVA group in comparison with the MAD-noVA group (78% vs 42%, p = 0.002) while no difference was observed in terms of basal ECV. Global longitudinal strain (GLS) was reduced in MAD-cVA compared to MAD-noVA (− 18.2% ± 4.6% vs − 25.1% ± 3.1%, p = 0.004) as well as global circumferential strain (GCS) at the mid-ventricular level (− 17.5% ± 4.7% vs − 21.6% ± 3.1%, p = 0.041). Univariate analysis identified as predictors of the incidence of cVA: GCS, circumferential strain (CS) in the basal and mid infero-lateral wall, GLS, regional longitudinal strain (LS) in the basal and mid-ventricular inferolateral wall. Reduced GLS [Odd ratio (OR):1.56 (confidence interval (CI) 95%: 1.45–2.47; p < 0.001)] and regional LS in the basal inferolateral wall [OR: 1.62 (CI 95%: 1.22–2.13; p < 0.001)] remained independent prognostic factors in multivariate analysis. ConclusionIn patients with MVP and MAD, CMR-FT parameters are correlated with the incidence of cVA and may be of interest in arrhythmic risk stratification.

A New Scoring System for Predicting Ventricular Arrhythmia Risk in Patients with Acute Myocardial Infarction.

In this study, a risk score for ventricular arrhythmias (VA) were evaluated for predicting the risk of ventricular arrhythmia (VA) of acute myocardial infarction (AMI) patients. Patients with AMI were divided into two sets according to whether VA occurred during hospitalization. Another cohort was enrolled for external validation. The area under the curve (AUC) of receiver operating characteristic (ROC) was calculated to evaluate the accuracy of the model. A total of 1493 eligible patients with AMI were enrolled as the training set, of whom 70 (4.7%) developed VA during hospitalization. In-hospital mortality was significantly higher in the VA set than in the non-VA set (31.4% vs 2.7%, P=0.001). The independent predictors of VA in patients with AMI including Killip grade ≥3, STEMI patients, LVEF <50%, frequent premature ventricular beats, serum potassium <3.5 mmol/L, type 2 diabetes, and creatinine level. The AUC of the model for predicting VT/VF in the training set was 0.815 (95% CI: 0.763-0.866). A total of 1149 cases were enrolled from Xuzhou Center Hospital as the external validation set. The AUC of the model in the external validation set for predicting VT/VF was 0.755 (95% CI: 0.687-0.823). Calibration curves indicated a good consistency between the predicted and the observed probabilities of VA in both sets. We have established a clinical prediction risk score for predicting the occurrence of VA in AMI patients. The prediction score is easy to use, performs well and can be used to guide clinical practice.

Estimation of arrhythmia risk in patients with Fabry disease using a machine learning model

Estimation of arrhythmia risk in patients with Fabry disease using a machine learning model

PS-C02-9: ASSOCIATIONS OF SHORT-TERM BLOOD PRESSURE VARIABILITY WITH ELECTROCARDIOGRAM PARAMETERS IN OBESITY-RELATED HYPERTENSION

Background: Both blood pressure variability (BPV) and mean blood pressure levels can induce target organ damage and affect the prognosis in patients with hypertension. The fluctuation of BPV is more obvious among patients with obesity-related hypertension, yet few researches have shown the correlation between BPV and electrocardiographic parameters. Objective: This study aimed to analyze the association of short-term BPV with electrocardiographic parameters, so as to identify the risk of arrhythmia in patients with obesity-related hypertension. Methods: All enrolled 330 subjects from the Department of Cardiovascular Medicine of the First Affiliated Hospital of Xi’an Jiaotong University were diagnosed with obesity-related hypertension. The short-term BPV, including standard deviation(SD), coefficient of variation(CoV), and weighted standard deviation(wSD), were analyzed by ambulatory blood pressure monitoring(ABPM). The atrial parameters(PR interval, maximum duration of P wave(Pmax), and P wave dispersion(Pwd)) and ventricular parameters(QT interval, Tpe interval, and Tpe/QT ratio) were measured on standard 12-lead electrocardiogram. Multivariate ordinary and binary logistic regression were conducted to evaluate the independent association between short-term BPV and electrocardiographic parameters. The study also analyzed the association of renin-angiotensin-aldosterone system (RAAS) with short-term BPV in 129 patients with obesity-related hypertension. Results: Although short-term BPV of 24 hours showed little association with electrocardiographic parameters, the association of daytime and nighttime BPV with electrocardiographic parameters was remarkably significant. And reverse dippers also showed longer Pmax than nondippers (P = 0.041). In this study, we found that the incidence of prolonged PR interval increased to 6% in patients with obesity-related hypertension, yet the prevalence was only 1% in healthy population younger than 60 years old. And those with a larger SD of nighttime systolic blood pressure had a longer PR interval(P = 0.025). Furthermore, ordinary logistic regression analysis showed that the nighttime CoV of diastolic blood pressure was independently correlated with PR interval. Meanwhile, logistic regression analysis also showed that the nocturnal blood pressure decline rate was independently associated with Tpe/QT ratio. However, the association of RAAS and short-term BPV was not significant. Conclusions:

Timing of cardioverter-defibrillator implantation in patients with cardiac laminopathies—External validation of the LMNA-risk ventricular tachyarrhythmia calculator

LMNA genotype-positive patients have high risk of experiencing life-threatening ventricular tachyarrhythmias (VTAs). The LMNA-risk VTA calculator published in 2019 has not been externally validated. The purpose of this study was to validate the LMNA-risk VTA calculator. We included LMNA genotype-positive patients without previous VTAs from 2 large Scandinavian centers. Patients underwent electrocardiography, 24-hour Holter monitoring, and echocardiographic examinations at baseline and repeatedly during follow-up. Validation of the LMNA-risk VTA calculator was performed using Harrell's C-statistic derived from multivariable Cox regression analysis. We included 118 patients (age 37 years [IQR 27-49 years]; 39 [33%] probands; 65 [55%] women; 100 [85%] with non-missense LMNA variants). Twenty-three patients (19%) experienced VTA during 6.1 years (interquartile range 3.0-9.1 years) follow-up, resulting in 3.0% (95% confidence interval 2.0%-4.5%) yearly incidence rate. Atrioventricular block and reduced left ventricular ejection fraction were independent predictors of VTAs, while nonsustained ventricular tachycardia, male sex, and non-missense LMNA variants were not. The LMNA-risk VTA calculator showed 83% sensitivity and 26% specificity for identifying patients with VTAs during the coming 5 years, and a Harrell's C-statistic of 0.85, when applying ≥7% predicted 5-year VTA risk as threshold. The sensitivity increased to 100% when reevaluating risk at the time of last consultation before VTA. The calculator overestimated arrhythmic risk in patients with mild and moderate phenotype, particularly in men. Validation of the LMNA-risk VTA calculator showed high sensitivity for subsequent VTAs, but overestimated arrhythmic risk when using ≥7% predicted 5-year risk as threshold. Frequent reevaluation of risk was necessary to maintain the sensitivity of the model.

Late gadolinium enhancement is a strong predictor of life threatening arrhythmias in patients with non-ischemic dilated cardiomyopathy undergoing ICD implantation for primary prevention of sudden card

Abstract Funding Acknowledgements Type of funding sources: None. Background The usefulness of implantable cardioverter defibrillators (ICD) for primary prevention of arrhythmic sudden cardiac death (SCD) in patients with non-ischemic dilated cardiomyopathy (DCM) has been questioned. Efforts to improve risk stratification have included scores such as the ‘MADIT-ICD benefit score’, and the use of late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR). The purpose of this study was to evaluate the potential usefulness of these two tools to assess the risk of life-threatening arrhythmias in patients with non-ischemic DCM undergoing ICD implantation for primary prevention of SCD. Methods We conducted a single-center retrospective study of consecutive patients who underwent contrast-enhanced CMR before ICD implantation for primary prevention of SCD. Patients with ischemic cardiomyopathy were used as reference. Patients with non-dilated cardiomyopathies were excluded. The arrhythmic component of the MADIT-ICD benefit score (VT/VF score) was calculated for each patient, and considered high if ≥ 7, as recommended. The primary endpoint was the occurrence of SCD or life-threatening arrhythmias (VF or VT &amp;gt;200 bpm). Follow-up was performed by device interrogation in all patients except those who suffered SCD. Results A total of 151 patients (93 ischemic, mean age 62±13 years, 75% male) with mean left ventricular ejection fraction (LVEF) of 27±8% were included. Overall, 72% (n=67) ischemic and 45% (n=26) non-ischemic patients had scores ≥ 7 and were considered high-risk. LGE was present in all patients with ischemic cardiomyopathy, and in 76% (n=44) of patients with non-ischemic DCM. During a median follow-up of 21 (8-38) months, 21 patients (13.9%, 11 ischemic and 10 non-ischemic) met the primary endpoint. Overall, the event-free survival of non-ischemic patients was similar to that of ischemic patients (log rank p=0.269) – Fig 1A. In patients with non-ischemic DCM, there were 7 arrhythmic events (26.9%) in those with MADIT-ICD VT/VF scores ≥7, and 3 events (9.4%) in those with scores &amp;lt;7 (log rank p= 0.104) – Fig 1B. In the same population, there were 10 arrhythmic events (23%) in patients with LGE, but no events in patients without LGE (log rank p=0.036) – Fig 1C. LVEF was similar in patients with and without arrhythmic events (26±8% vs. 27±7%, p=0.717), and in those with and without LGE (26±7% vs. 28±9%, p=0.342). Conclusion The presence of LGE is a strong predictor of life threatening arrhythmias in patients in non-ischemic DCM undergoing ICD implantation for primary prevention, seemingly outperforming the clinical MADIT-ICD benefit score.