The Lancet Commission to reduce the global burden of sudden cardiac death: a call for multidisciplinary action

Left ventricular rigor mortis interferes with postmortem aortic root geometry

Aortic regurgitation is a common valve disease and can be caused by delineated findings such as fenestrations or hardly discernible alterations of the aortic root geometry. Therefore, aortic regurgitation can be a challenging diagnosis during an autopsy. Cardiac surgeons, however, are confronted with comparable problems during surgery and have developed a refined knowledge of the anatomy of the aortic root including its geometry. Transferring this knowledge from the operating room to the dissection would further complement the panel of postmortem diagnostic tools. To foster translation of the clinical anatomy, the present study assessed the impact of postmortem peculiarities (i.e. myocardial rigor mortis, putrefaction) that might influence aortic root geometry. The aortic root geometry was described by aortic perimeters (basal, sinus, sino-tubular junction, and ascending aorta), effective height (distance from the cusp's free margin to its nadir), geometric height (cusp height), commissural height (distance from the base of an interleaflet triangle to the end of a commissure), and length of the ascending aorta. Data from 140 cases were analyzed (linear regression, comparative testing). Myocardial rigor mortis was associated with smaller basal rings. Weak positive correlations between the duration of the postmortem interval and aortic root dimensions were observed. In summary, postmortem peculiarities, especially the myocardial cadaveric rigidity, influence postmortem aortic root geometry. Despite these circumstances, the current study demonstrates that aortic root geometric assessment, including effective height, is feasible in a postmortem setting. Further studies are needed to elaborate on aortic root geometry as a diagnostic tool in a necropsy setting.

Association of the triglyceride glucose index with sudden cardiac death in the patients with diabetic foot ulcer

BACKGROUND

This study examines the relationship between the TyG index and the risk of sudden cardiac death (SCD) in the patients with diabetic foot ulcer (DFU).

METHODS

688 type 2 diabetes mellitus (T2DM) inpatients with DFU between January 2010 and December 2023 was included in this retrospective study. The 1:1 propensity score matching (PSM) method was applied. The relationship between TyG index and SCD risk was analyzed using the Kaplan-Meier (K-M) survival curve analysis, multivariate Cox proportional hazard regression model, Restricted cubic spline (RCS) model analysis and subgroup analyses.

RESULTS

Over a median follow-up period of 61 months, 38 cases of SCD were recorded. After PSM, 71 pairs of score-matched patients according to TyG index were generated. K-M survival curves revealed higher SCD rates in patients with TyG index ≥9.65. The Cox proportional hazard model, independently associated with the risk of SCD (HR: 75.98; 95 % CI: 9.16 ∼ 630.40; P < 0.001). RCS model showed that SCD risk was non-linearly correlated with gradual increases in TyG index levels. Stratified analyses indicated a consistent relationship between increasing TyG index and SCD risk across all subgroups.

CONCLUSIONS

Elevated TyG index independently confers an increased risk for SCD in individuals with DFU.

Underlying Cause of Out-of-Hospital Cardiac Arrests in Japan in Survivors Versus Nonsurvivors

BACKGROUND

The causes underlying out-of-hospital cardiac arrest (OHCA) are rarely investigated. This study aimed to investigate causes of OHCA in CRITICAL (Comprehensive Registry of In-Hospital Intensive Care for OHCA Survival), a multicenter OHCA registry in Osaka, Japan.

METHODS

Nontraumatic patients with OHCA (by CARES [Cardiac Arrest Registry to Enhance Survival] criteria) aged 18 to 90 years between July 1, 2012 and December 31, 2020 were included. By Japanese law, all patients with OHCA (resuscitated or not) must be transported to the emergency department where death is declared if resuscitation is unsuccessful; this latter group was considered presumed sudden cardiac deaths whereas those surviving to hospitalization were considered resuscitated OHCA. We compared underlying causes of OHCA in presumed sudden cardiac deaths, survivors of OHCA (alive 30 days after the event), and nonsurvivors of OHCA (died during hospitalization). Causes were confirmed when autopsy or postresuscitation hospital workup was performed and probable when determined by attending physician impression (partial workup).

RESULTS

Of 12 252 total OHCAs, 8005 (65.3%) were. presumed sudden cardiac deaths, 4247 (34.7%) were resuscitated, and 1293 (10.6%) were survivors. Resuscitated OHCA cardiac causes comprised 73.2% (n=3110) and noncardiac causes 26.8% (n=1137). Cardiac cause, most commonly acute coronary syndrome, was more prevalent in survivors of OHCA than nonsurvivors (85.7% [n=1137] versus 67.8% [n=2002]; P<0.001). Although 40.4% of the survived at 30 days cases were acute coronary syndrome, cerebrovascular disease accounted for 9.8% of nonsurvivors of OHCA and nearly one fifth (n=144, 17.8%) of middle-aged cases.

CONCLUSIONS

Cardiac cause was more common in survivors than cases dying in the emergency room (sudden deaths) or in hospital after initial resuscitation (nonsurvivors of OHCA). Causes in nonsurvivors of OHCA who died in hospital were more heterogeneous than those of survivors of OHCA, especially cerebrovascular emergencies.

Seizure-related cardiovascular symptoms: Comorbidities or SUDEP risk factors?

Sudden unexpected death in epilepsy (SUDEP) is one of the leading drivers of premature mortality in people with epilepsy (PWE), especially in those with difficult-to-treat epilepsy and frequent tonic-clonic seizures (TCS). Cardiovascular symptoms commonly occur in association with seizures, prompting the hypothesis that SUDEP is primarily linked to seizure-related cardiovascular dysfunction. This short narrative review summarizes the spectrum of cardiovascular alterations in the context of seizures and discusses putative links to SUDEP. Focal seizures go frequently along with increased heart rates (HR) that resolve shortly after seizure cessation. HR decrease and ictal asystole (IA) are rarely observed in focal unaware seizures in a small proportion of people with temporal lobe epilepsy. IA is reported to be a self-limiting benign condition without a link to SUDEP. Focal to bilateral or generalized TCS are typically accompanied by excessively released catecholamines, which underlie, in turn, various postictal symptoms. Prominent, sustained sinus tachycardia is a common and benign finding, whereas ventricular fibrillation/tachycardia were only anecdotally reported in a few near-SUDEP or SUDEP patients. Cases of transient, non-fatal atrial fibrillation were also scarcely described in the aftermaths of TCS. Takotsubo cardiomyopathy was rarely reported following TCS, usually with a favorable outcome. In most recorded SUDEP cases, however, a rather stereotypical fatal cascade was consistently documented, characterized by primary central apnea that occurs in the early postictal phase after a TCS, secondarily followed by bradyarrhythmia and terminal asystole. Blood pressure commonly increases in association with focal seizures and TCS, but the pattern may be complex with transient decreases or no significant change during or after seizures. Apart from the immediate effects on cardiovascular function, increasing evidence suggests that recurrent seizures also have a remote impact on cardiac properties, coined by the term include: "epileptic heart syndrome". In conclusion, cardiovascular symptoms related to focal seizures are typically transitory and benign. In contrast, TCS can rarely cause postical onset of ventricular tachycardia and acute cardiomyopathy, potentially leading to sudden cardiac death. SUDEP, in turn, was consistently reported to occur in the aftermaths of TCS primarily due to central apnea. To prevent potentially serious cardiovascular complications, full control of TCS whether by antiseizure medication, neuromodulatory devices or epilepsy surgery should be aimed at.

Robust EEG Characteristics for Predicting Neurological Recovery from Coma After Cardiac Arrest

OBJECTIVE

Clinically, patients in a coma after cardiac arrest are given the prognosis of "neurological recovery" to minimize discrepancies in opinions and reduce judgment errors. This study aimed to analyze the background patterns of electroencephalogram (EEG) signals from such patients to identify the key indicators for assessing the prognosis after coma.

APPROACH

Standard machine learning models were applied sequentially as feature selectors and filters. CatBoost demonstrated superior performance as a classification method compared to other approaches. In addition, Shapley additive explanation (SHAP) values were utilized to rank and analyze the importance of the features.

RESULTS

Our results indicated that the three different EEG features helped achieve a fivefold cross-validation receiver-operating characteristic (ROC) of 0.87. Our evaluation revealed that functional connectivity features contribute the most to classification at 70%. Among these, low-frequency long-distance functional connectivity (45%) was associated with a poor prognosis, whereas high-frequency short-distance functional connectivity (25%) was linked with a good prognosis. Burst suppression ratio is 20%, concentrated in the left frontal-temporal and right occipital-temporal regions at high thresholds (10/15 mV), demonstrating its strong discriminative power.

SIGNIFICANCE

Our research identifies key electroencephalographic (EEG) biomarkers, including low-frequency connectivity and burst suppression thresholds, to improve early and objective prognosis assessments. By integrating machine learning (ML) algorithms, such as Gradient Boosting Models and Support Vector Machines, with SHAP-based feature visualization, robust screening methods were applied to ensure the reliability of predictions. These findings provide a clinically actionable framework for advancing neurological prognosis and optimizing patient care.

Visual coronary artery calcification score to predict significant coronary artery stenosis in patients presenting with cardiac arrest without ST-segment elevation myocardial infarction

BACKGROUND

Emergency coronary angiogram after a cardiac arrest without ST-segment elevation myocardial infarction (STEMI) is still a matter of debate. To better select patients who may benefit from this procedure, we tested a visual coronary artery calcification (VCAC) score available in chest CT to predict significant coronary artery stenosis and/or culprit lesion or ad hoc or delayed percutaneous coronary intervention (PCI).

RESULTS

A total of 113 patients with cardiac arrest and without STEMI who had a coronary angiogram and chest CT (January 2013 to March 2023, Croix-Rousse Hospital, Lyon, France) were retrospectively included. VCAC was scored from 0 (no calcification) to 3 (diffuse calcification) for each 4 four main arteries (left main, left anterior descending, circumflex, and right coronary artery). At baseline the median [interquartile range] age was 65.8 years [53.4-75.7], 61.9% were male, and 59.3% presented with ventricular fibrillation. Coronary angiogram identified at least one significant coronary artery stenosis in 32.7%, and ad hoc and delayed PCI were performed in 12.4% and 6.2% of the patients, respectively. VCAC score was an excellent predictor of significant coronary artery stenosis with an area under the ROC curve (AUC) of 0.95 (95%CI [0.90-1.00]) and the optimal threshold was ≥ 4 (specificity 94.7%, sensitivity 91.9%). For the detection of culprit coronary artery stenosis, the AUC was at 0.90 (95%CI [0.85-0.96]) and the optimal threshold was ≥ 5 (specificity 83.5%, sensitivity 87.5%). The AUC was 0.886 [0.823-0.948] (specificity 81.8%, sensitivity 85.7%) for ad hoc PCI and 0.921 [0.872-0.972] (specificity 85.3%, sensitivity 88.9%) for both delayed and ad hoc PCI with a same optimal threshold of VCAC ≥ 5. A VCAC score ≥ 4 had a sensitivity at 100% to predict a significant or culprit coronary artery stenosis and ad hoc or delayed PCI.

CONCLUSIONS

The present study found that a non-dedicated CT thorax may be useful to measure VCAC and if this is scored ≥ 4 it allows physicians to better select patients resuscitated from cardiac arrest with non-STEMI and without history of coronary artery disease who may benefit from an emergency coronary angiogram to detect a significant or culprit coronary artery stenosis and had PCI if appropriate.

Motion-unrestricted dynamic electrocardiogram system utilizing imperceptible electronics

Electrocardiogram (ECG) plays a vital role in the prevention, diagnosis, and prognosis of cardiovascular diseases (CVDs). However, the lack of a user-friendly and accurate long-term dynamic electrocardiogram (DCG) device in motion has made it challenging to perform many daily cardiovascular risk screenings and assessments, such as sudden cardiac arrest, resulting in additional economic burdens on society. Here, we present a motion-unrestricted dynamic electrocardiogram (MU-DCG) system, which employs skin-conformal, imperceptible electronics for long-term, comfortable, and accurate 12-lead DCG monitoring. To facilitate assembly for use on the skin, the MU-DCG system features a pressure-activated flexible skin socket for stably soft-connecting the on-skin soft module and the off-skin stiff module during dynamic movements. Crucially, blinded cardiologist evaluations confirm minimal motion artifacts in MU-DCG-acquired ECG signals. Our results demonstrate that the MU-DCG system, with large-area, ultra-thin on-skin electrodes/leads, and an off-skin module, accomplishes anti-motion interference acquisition and in-situ analysis while retaining wearing imperceptibility.

Adrenal aldosterone synthase (CYP11B2) histopathology and its association with disease-induced sudden death: a cross-sectional study

Background

Unidentified cardiovascular risk factors may account for approximately half of sudden deaths, a devastating event with limited preventive tools. We investigated whether adrenal histopathology suggestive of primary aldosteronism, pheochromocytoma, or adrenal masses could explain part of the risk for disease-induced sudden death (DSD).

Methods

In this study, autopsies and histopathological analyses, including aldosterone synthase staining of adrenal glands, were performed on 403 consecutive individuals who experienced sudden death. These individuals were classified into 258 cases of DSD and 144 deaths caused by trauma, suicide, or intoxication, i.e., non-disease-induced sudden death (nDSD). This trial was registered at ClinicalTrials.gov (NCT05446779).

Findings

Adrenal histopathology revealed changes in 31 (7.7%) subjects of the cohort. Of these, the most prevalent findings [25 (6.2%)] were aldosterone-producing adenomas (APA) or nodules (APN), which were associated with myocardial infarction and atherosclerosis at autopsy. Individuals in the DSD group and the subgroup with sudden cardiac death (SCD) were more likely to have APA or APN than individuals in the nDSD group [23 (8.9%) vs. 2 (1.4%), p = 0.002; 16 (8.8%) vs. 2 (1.4%), p = 0.003, respectively]. APA or APN were explanatory factors for DSD (odds ratio [OR] 6.47, 95% confidence interval [CI] 1.40-29.88, p = 0.017) and SCD (OR 10.68, 95% CI 2.02-56.43, p = 0.005). Other findings included two pheochromocytomas, one bilateral adrenal metastasis, and two unilateral adrenal metastases.

Interpretation

In this exploratory study, APA or APN were more frequently seen in DSD and SCD than nDSD cases. Whether primary aldosteronism constitutes a novel risk factor for sudden death warrants further study.

Funding

Finnish State Research funds and independent research foundations: Aarne Koskelo Foundation, the Finnish Kidney Foundation, and the Finnish Foundation for Cardiovascular Research.

Novel Protein-Based Biomarkers of Out-of-hospital Sudden Cardiac Death After Myocardial Infarction

BACKGROUND

Early identification of out-of-hospital high-risk sudden cardiac death (SCD) after acute myocardial infarction is crucial for timely therapeutic interventions. However, left ventricular ejection fraction as a standalone clinical stratification tool has major limitations, necessitating improved risk stratification strategies.

METHODS

Mass spectrometry measured 6592 peptides and 522 proteins, from which targeted proteomics identified the optimal protein combination to assess out-of-hospital SCD risk. ELISA validated its predictive value by comparing it with a clinical stratification tool (left ventricular ejection fraction ≤35%) and 2 reported models (risk score and out-of-hospital cardiac arrest score) in 3 case-control cohorts nested within diverse contemporary postinfarction populations.

RESULTS

In the discovery cohort (105 SCD cases and 105 survivors), mass spectrometry discovered 44 differential proteins associated with SCD, unveiling early circulating features characterized by inflammatory response and complement activation in out-of-hospital SCD cases. Targeted proteomics identified the optimal SCD-warning 3-protein combination, including coronin-1A, haptoglobin, and CFD (complement factor D), to assess out-of-hospital SCD risk. An ELISA-based SCD-warning 3-protein combination model significantly outperformed left ventricular ejection fraction alone (C statistic: 0.752 versus 0.548; P<0.001) and improved their performance (ΔC statistic, 0.281; categorical net reclassification improvement, 0.095; continuous net reclassification improvement, 0.952; integrated discrimination improvement, 0.291). Similar incremental discrimination metrics were observed in 2 reported stratification models (risk score and out-of-hospital cardiac arrest score), particularly within the left ventricular ejection fraction-preserved population. These findings were repeatably validated in 2 independent cohorts (n=234 and 48, respectively). CFD inhibition protection for mortality and pro-malignant arrhythmias in acute myocardial infarction mice supported the biological plausibility of the critical protein in SCD-warning 3-protein combination.

CONCLUSIONS

In high-risk individuals for out-of-hospital SCD, the SCD-warning 3-protein combination may contribute to enhanced early identification for timely intensive management. These findings suggest pivotal proteins for improving understanding SCD pathophysiology.

Near-term prediction of sustained ventricular arrhythmias applying artificial intelligence to single-lead ambulatory electrocardiogram

BACKGROUND AND AIMS

Accurate near-term prediction of life-threatening ventricular arrhythmias would enable pre-emptive actions to prevent sudden cardiac arrest/death. A deep learning-enabled single-lead ambulatory electrocardiogram (ECG) may identify an ECG profile of individuals at imminent risk of sustained ventricular tachycardia (VT).

METHODS

This retrospective study included 247 254, 14 day ambulatory ECG recordings from six countries. The first 24 h were used to identify patients likely to experience sustained VT occurrence (primary outcome) in the subsequent 13 days using a deep learning-based model. The development set consisted of 183 177 recordings. Performance was evaluated using internal (n = 43 580) and external (n = 20 497) validation data sets. Saliency mapping visualized features influencing the model's risk predictions.

RESULTS

Among all recordings, 1104 (.5%) had sustained ventricular arrhythmias. In both the internal and external validation sets, the model achieved an area under the receiver operating characteristic curve of .957 [95% confidence interval (CI) .943-.971] and .948 (95% CI .926-.967). For a specificity fixed at 97.0%, the sensitivity reached 70.6% and 66.1% in the internal and external validation sets, respectively. The model accurately predicted future VT occurrence of recordings with rapid sustained VT (≥180 b.p.m.) in 80.7% and 81.1%, respectively, and 90.0% of VT that degenerated into ventricular fibrillation. Saliency maps suggested the role of premature ventricular complex burden and early depolarization time as predictors for VT.

CONCLUSIONS

A novel deep learning model utilizing dynamic single-lead ambulatory ECGs accurately identifies patients at near-term risk of ventricular arrhythmias. It also uncovers an early depolarization pattern as a potential determinant of ventricular arrhythmias events.

Socio-economic position and sudden cardiac death: a Danish nationwide study

AIMS

The aim of this study was to examine differences in incidence rates of all-cause mortality (ACM) and sudden cardiac death (SCD) in persons of differing socio-economic position (SEP).

METHODS AND RESULTS

All deaths in Denmark from 1 January to 31 December 2010 (1 year) were included. Autopsy reports, death certificates, discharge summaries, and nationwide health registries were reviewed to identify cases of SCD. Socio-economic position was measured as either household income or highest achieved educational level and analysed separately. Hazard rates were calculated using univariate and multivariable Cox regression models adjusting for age, sex, and selected comorbidities. A total of 53 452 deaths were included, of which 6820 were classified as SCDs. Incidence rates of ACM and SCD increased with age and were higher in the lower SEP groups. The greatest difference in SCD incidence was found between the low and high education level groups, with an incidence rate ratio of 5.1 (95% confidence interval 3.8-6.8). The hazard ratios for ACM and SCD were significantly higher for low SEP groups, independent of comorbidities. Compared with the highest income group, the low-income group had adjusted hazard ratios of ACM and SCD that were 2.17 (2.01-2.34) and 1.72 (1.67-1.76), respectively.

CONCLUSION

We observed an inverse association between both income and education level and the risk of ACM and SCD in the general population, which persisted independently of baseline comorbidities. Our results indicate a need for further research into the mechanisms behind socio-economic disparities in healthcare and targeted preventative strategies.

Out-of-Hospital Cardiac Arrest in Apparently Healthy, Young Adults

Importance

Out-of-hospital cardiac arrest incidence in apparently healthy adults younger than 40 years ranges from 4 to 14 per 100 000 person-years worldwide. Of an estimated 350 000 to 450 000 total annual out-of-hospital cardiac arrests in the US, approximately 10% survive.

Observations

Among young adults who have had cardiac arrest outside of a hospital, approximately 60% die before reaching a hospital (presumed sudden cardiac death), approximately 40% survive to hospitalization (resuscitated sudden cardiac arrest), and 9% to 16% survive to hospital discharge (sudden cardiac arrest survivor), of whom approximately 90% have a good neurological status (Cerebral Performance Category 1 or 2). Autopsy-based studies demonstrate that 55% to 69% of young adults with presumed sudden cardiac death have underlying cardiac causes, including sudden arrhythmic death syndrome (normal heart by autopsy, most common in athletes) and structural heart disease such as coronary artery disease. Among young adults, noncardiac causes of cardiac arrest outside of a hospital may include drug overdose, pulmonary embolism, subarachnoid hemorrhage, seizure, anaphylaxis, and infection. More than half of young adults with presumed sudden cardiac death had identifiable cardiovascular risk factors such as hypertension and diabetes. Genetic cardiac disease such as long QT syndrome or dilated cardiomyopathy may be found in 2% to 22% of young adult survivors of cardiac arrest outside of the hospital, which is a lower yield than for nonsurvivors (13%-34%) with autopsy-confirmed sudden cardiac death. Persons resuscitated from sudden cardiac arrest should undergo evaluation with a basic metabolic profile and serum troponin; urine toxicology test; electrocardiogram; chest x-ray; head-to-pelvis computed tomography; and bedside ultrasound to assess for pericardial tamponade, aortic dissection, or hemorrhage. Underlying reversible causes, such as ST elevation myocardial infarction, coronary anomaly, and illicit drug or medication overdose (including QT-prolonging medicines) should be treated. If an initial evaluation does not reveal the cause of an out-of-hospital cardiac arrest, transthoracic echocardiography should be performed to screen for structural heart disease (eg, unsuspected cardiomyopathy) or valvular disease (eg, mitral valve prolapse) that can precipitate sudden cardiac death. Defibrillator implant is indicated for young adult sudden cardiac arrest survivors with nonreversible cardiac causes including structural heart disease and arrhythmia syndromes.

Conclusions and Relevance

Cardiac arrest in apparently healthy adults younger than 40 years may be due to inherited or acquired cardiac disease or noncardiac causes. Among young adults who have had cardiac arrest outside of a hospital, only 9% to 16% survive to hospital discharge. Sudden cardiac arrest survivors require comprehensive evaluation for underlying causes of cardiac arrest and cardiac defibrillator should be implanted in those with nonreversible cardiac causes of out-of-hospital cardiac arrest.

Coronary atherosclerosis in athletes: emerging concepts and preventive strategies

There should be no assumption that an athlete is immune to coronary artery disease (CAD), even when traditional cardiovascular (CV) risk factors appear well-managed. Excelling in certain aspects of health does not equate to total CV protection. Recent data from cardiac imaging studies have raised the possibility that long-term, high-volume, high-intensity endurance exercise is associated with coronary atherosclerosis. Whilst the risk of CV events has not been shown to rise with athletic activity, the potential for CAD should not be overlooked as it is the leading cause of sudden cardiac death in athletes >35 years of age (i.e. 'Masters athletes'). Evaluating both traditional and non-traditional risk factors for CAD is the most important part of pre-participation evaluation in Masters athletes. When managing athletes at risk of CAD it is important to adopt a shared decision-making approach regarding lifestyle adaptation and lipid-lowering treatments. In the great majority of athletes, after excluding the presence of symptoms and inducible ischaemia, this advice should include encouragement to continue exercising as available data indicate that higher levels of fitness are associated with a markedly attenuated incidence of coronary events regardless of the severity of coronary disease. Future research is needed to establish the relationship between clinically relevant CAD outcomes and coronary artery calcification in Masters Athletes, the role of sex, as well as exploration of the mechanisms underpinning these unexpected CV adaptations.

Diagnosis and management of dilated cardiomyopathy: a systematic review of clinical practice guidelines and recommendations

Dilated cardiomyopathy (DCM) is extensively discussed in numerous expert consensus documents and international guidelines, with differing recommendations. To support clinicians in daily practice and decision-making, we conducted a systematic review of key guidelines and recommendations concerning the diagnosis and clinical management of DCM. Our research encompassed MEDLINE and EMBASE databases for relevant articles published, as well as the websites of relevant scientific societies. We identified two guidelines and one scientific statement that met stringent criteria, thereby qualifying them for detailed systematic analysis. Our review revealed consensus on several key aspects: the definition of DCM, the use of B-type natriuretic peptides and high-sensitivity troponin in laboratory testing, the essential role of multimodality cardiovascular imaging for initial diagnosis, genetic counselling, and the management of advanced disease. Nonetheless, notable areas of variation included the formation of multidisciplinary management teams, the role of cascade genetic testing, pathways for arrhythmic risk stratification, and the criteria for prophylactic defibrillator implantation. Significant evidence gaps persist, particularly regarding the clinical trajectory of genetic, non-genetic and gene-elusive forms of DCM, the use of cardiovascular magnetic resonance in phenotype-negative family members with genotype-positive probands, and the development of potential aetiology-oriented therapies. Addressing these gaps could enhance clinical outcomes and inform future research directions and guideline development.

Heritable Burden of Community Sudden Death by Autopsy and Molecular Phenotyping for Precision Genotype Correlation

BACKGROUND

Sudden cardiac death (SCD) genetic studies neglect the majority occurring in older decedents with cardiovascular pathology.

OBJECTIVES

This study sought to determine the burden of genetic disease in unselected adult sudden deaths by precision genotype-postmortem phenotype correlation.

METHODS

The authors used autopsy, histology, and toxicology to adjudicate cause and identify high-suspicion phenotypes (eg, hypertrophic cardiomyopathy) among presumed SCDs aged 18 to 90 years referred to the county medical examiner from February 2011 to January 2018. They tested 231 genes associated with sudden death and correlated genotype with postmortem phenotypes, including myocardial analysis. Family history in high-suspicion phenotype cases was obtained.

RESULTS

Of 856 autopsied presumed SCDs, families of 359 consented and 306 cases (66% cardiac cause) ultimately underwent genetic testing (mean age 62 years, 74% male). Seventy-five cases met high-suspicion phenotype criteria (8.8%), of which 36 underwent testing; 18 families met with a genetic counselor. We found 14 cases with autosomal dominant or X-linked pathogenic/likely pathogenic (P/LP) variants (apparent yield 4.6%); 6 had concordant cause (corrected yield 2%). Yields restricted to autopsy-confirmed cardiac causes (2.5%) and high-suspicion phenotypes (2.7%) were similar. Myocardial genotyping in 14 high-suspicion decedents matched negative blood genotyping, thus did not support somatic mosaicism. Myocardial RNA in a P/LP PKP2 carrier without phenotype demonstrated nonsense-mediated escape as potential mechanism for incomplete penetrance. One-half of high-suspicion cases had a family history of a related condition or sudden death.

CONCLUSIONS

In this 7-year countywide study, 2% of total sudden deaths and 2.5% of confirmed SCDs had identifiable genetic cause, corrected for genotype-phenotype concordance. These results do not support routine genetic testing for community sudden deaths, particularly without autopsy.

Sex Differences in the Incidence of Sudden Cardiac Arrest/Death in Competitive Athletes: A Systematic Review and Meta-analysis

BACKGROUND

Although many studies have demonstrated a lower incidence of sudden cardiac arrest or death (SCA/D) in female athletes than in male, there is limited understanding of the specific underlying causes.

OBJECTIVE

This systematic review aimed to assess the disparities in SCA/D incidence between male and female competitive athletes and explore the associated etiologies.

METHODS

A comprehensive search was conducted for retrospective and prospective studies examining SCA/D incidence in male and female athletes. Incidence and incidence rate ratios (IRRs) according to sex were evaluated.

RESULTS

Among the 16 studies analyzed, 1797 cases of SCA/D were observed; 1578 occurred in males (87.81%). Ages ranged from adolescent to adult. The incidence was 1.42/100,000 athlete-years (AY) in males (95% CI 0.97-2.09), and 0.32/100,000 AY in females (95% CI 0.17-0.59), resulting in an IRR of 5.55. When considering athletes aged ≤ 35 years, the incidence was 1.46/100,000 AY in males (95% CI 0.91-2.34) and 0.30/100,000 AY in females (95% CI 0.14-0.66), with an IRR of 5.47. The IRR was 5.13 (95% CI 3.94-6.67) for the most recent studies with athletes enrolled only after the year 2000, versus 6.02 (95% CI 4.59-7.90) for the remaining studies covering all observed years. Hypertrophic cardiomyopathy (HCM) was the predominant cause among males (45.12%), while congenital coronary anomalies were more prevalent in females (33.04%).

CONCLUSION

The incidence of SCA/D in females was approximately 6 times lower than in males, with sex differences also in the leading causes of SCA/D. Understanding these discrepancies could lead to targeted strategies for the prevention of SCD in athletes.

REGISTRATION NUMBER

(PROSPERO 2023 CRD42023432022)/05.07.2023.

Prediction of sudden cardiac death using artificial intelligence: Current status and future directions

Sudden cardiac death (SCD) remains a pressing health issue, affecting hundreds of thousands each year globally. The heterogeneity among people who suffer a SCD, ranging from individuals with severe heart failure to seemingly healthy individuals, poses a significant challenge for effective risk assessment. Conventional risk stratification, which primarily relies on left ventricular ejection fraction, has resulted in only modest efficacy of implantable cardioverter-defibrillators for SCD prevention. In response, artificial intelligence (AI) holds promise for personalized SCD risk prediction and tailoring preventive strategies to the unique profiles of individual patients. Machine and deep learning algorithms have the capability to learn intricate nonlinear patterns between complex data and defined end points, and leverage these to identify subtle indicators and predictors of SCD that may not be apparent through traditional statistical analysis. However, despite the potential of AI to improve SCD risk stratification, there are important limitations that need to be addressed. We aim to provide an overview of the current state-of-the-art of AI prediction models for SCD, highlight the opportunities for these models in clinical practice, and identify the key challenges hindering widespread adoption.

Declining Trend of Sudden Cardiac Death in Younger Individuals: A 20-Year Nationwide Study

BACKGROUND

Declining cardiovascular mortality rates have been well-documented, yet temporal trends of sudden cardiac death (SCD) in young individuals remain unclear. We provide contemporary nationwide estimates of the temporal trends of SCD in young individuals (1-35 years of age) from 2000 through 2019 and correlate these trends to changes in out-of-hospital cardiac arrest (OHCA) patterns, rates of inherited cardiac diseases, and implantations of implantable cardioverter defibrillators (ICD).

METHODS

All individuals between 1 and 35 years of age living in Denmark from 2000 through 2019 were included, with annual re-evaluation of the at-risk population in regard to age. Adjudication of SCD cases relied on multiple sources, including death certificates, medical files, and autopsy reports. Information on OHCA, diagnostic rates, and ICD implantations were captured from nationwide administrative registries. Annual incidence rates of SCD were calculated, and temporal trends in SCD incidence were computed as percentage change annualized. Trends in OHCA survival and characteristics, diagnostic rates of inherited cardiac diseases, and ICD implantations were assessed.

RESULTS

During the 20-year study period (47.5 million person-years), 1057 SCDs were identified (median age, 29 years; 69% male). The overall incidence of SCD was 2.2 per 100 000 person-years and declined by 3.31% (95% CI, 2.42-4.20) annually, corresponding to a 49% (95% CI, 38.7-57.6) reduction during the study. Rates of witnessed SCD declined markedly (percentage change annualized -7.03% [95% CI, -8.57 to -5.48]), but we observed no changes in the rate of unwitnessed SCD (percentage change annualized -0.09% [95% CI, -1.48 to 1.31]). Therefore, the proportion of unwitnessed SCD increased by 79% (P<0.001). Survival after OHCA in young individuals (1 to 35 years of age) increased from 3.9% to 28%, mainly because of increased bystander cardiopulmonary resuscitation and defibrillation rates. Diagnostic rates of inherited cardiac diseases increased 10-fold (incidence rate ratio, 10.4 [95% CI, 8.46-12.90]) and the ICD implantation rate increased 2-fold (incidence rate ratio, 1.97 [95% CI, 1.51-2.60]).

CONCLUSIONS

SCD incidence rates in young individuals declined by 49% over the past 2 decades. The decline was paralleled by improved survival of OHCA, higher diagnostic rates of inherited cardiac diseases, and higher ICD implantation rates. However, rates of unwitnessed SCD were unchanged, which calls for new perspectives in preventive strategies.

Global burden of ischemic heart disease in older adult populations linked to non-optimal temperatures: past (1990-2021) and future (2022-2050) analysis

Background

Ischemic heart disease (IHD) is a leading cause of death and disability, particularly affecting the older adult population. Extreme temperatures, especially very low and very high temperatures, are known to exacerbate cardiovascular disease burden. With the ongoing global climate change, understanding the impact of non-optimal temperatures on IHD burden becomes increasingly important, especially in vulnerable populations such as the older adult.

Methods

This study used data from the Global Burden of Disease Study 2021 (GBD 2021) to analyze the spatiotemporal trends of low and high temperatures on IHD burden in the older adult population (aged 60 and above) from 1990 to 2021. We used age-standardized rates (ASR), annual percentage change (EAPC), and the Bayesian age-period-cohort (BAPC) model to forecast 2050. Additionally, the geographic differences in IHD burden were analyzed using World Bank regions.

Results

From 1990 to 2021, the IHD burden in the older adult population was mainly attributed to low temperatures. However, it has increased the burden of IHD due to high temperatures, especially in tropical and low-income regions. The analysis of gender difference revealed that men are usually more affected by high temperatures, though generally, women are more sensitive to low temperatures. Forecasts are that in the future, the burden of IHD due to high temperatures will continue to rise, especially in areas with limited adaptive capacity.

Conclusion

Although low temperature remains the most important contributor to IHD burden among the older adult, the burden attributable to high temperature is on the rise, which increases the need to address the extreme temperature fluctuation. That is more so in poor-income and tropical regions where the most vulnerable populations bear a higher risk for health. Thus, there is an urgent need to develop adaptive public health measures against the dual health risks from extreme temperatures. The findings emphasize that targeted interventions are necessary, with adjustments in regional differences and gender-specific risks to effectively address the growing health threats from climate change.

Cardiac Arrest: Can Technology Be the Solution?

Out-of-hospital cardiac arrest (OHCA) mortality remains alarmingly high in most countries. The majority of pharmacological attempts to improve outcomes have failed. Randomized trials have shown limited survival benefits with vasopressin, fibrinolysis, amiodarone, or lidocaine. Even the benefits of adrenaline remain a matter of debate. In this context, relying on technology may seem appealing. However, technological strategies have also yielded disappointing results. This is exemplified by automated external chest compression devices. When first introduced, theoretical models, animal studies, and early clinical trials suggested they could improve survival. Yet, randomized trials failed to confirm this benefit. Similarly, to date, extracorporeal membrane oxygenation (ECMO), therapeutic hypothermia, and primary angioplasty have demonstrated inconsistent survival advantage. Other technological innovations continue to be explored, such as artificial intelligence to improve the diagnosis of cardiac arrest during emergency calls, mobile applications to dispatch citizen responders to patients in cardiac arrest, geolocation of defibrillators, and even the delivery of defibrillators via drones. Nevertheless, it is clear that the focus and investment should prioritize the initial links in the chain of survival: early alerting, chest compressions, and defibrillation. Significant improvements in these critical steps can be achieved through the education of children. Modern technological tools must be leveraged to enhance this training by incorporating gamification and democratizing access to education. These strategies hold the potential to fundamentally improve the management of cardiac arrest.

Effects of Eleclazine (GS6615) on the proarrhythmic electrophysiological changes induced by myocardial stretch

Purpose

Myocardial stretch is a proarrhythmic factor. Eleclazine (GS6615) is a late sodium current (INaL) inhibitor that has shown protective effects against arrhythmias in various experimental models. Data on its effects during myocardial stretch are lacking. The aim of this study was to investigate the electrophysiological modifications induced by eleclazine basally and during acute ventricular stretch.

Methods

Left ventricular stretch was induced at baseline and during perfusion with eleclazine in 26 Langendorff rabbit heart preparations. Programmed stimulation and high-resolution mapping techniques were applied using multiple epicardial electrodes.

Results

At baseline, both the ventricular refractory period measured at a fixed cycle length (250 m) and its surrogate obtained during ventricular fibrillation (VF) decreased significantly during stretch (baseline 128 ± 15 vs. stretch 110 ± 14 m; n = 15; p < 0.001, and baseline 52 ± 13 vs. stretch 44 ± 9 m; n = 11; p < 0.05), while the VF dominant frequency (DF) increased significantly (DF baseline 13 ± 3 vs. stretch 17 ± 5Hz; n = 11; p < 0.01). Eleclazine 1.4 μM prolonged refractoriness, diminished both DF and conduction velocity during the arrhythmia, and avoided the stretch induced variations in refractoriness (baseline 148 ± 19 vs. stretch 150 ± 23 m; n = 15; ns, and baseline 73 ± 15 vs. stretch 77 ± 15 m; n = 11; ns) and in DF (baseline 12 ± 5 vs. stretch 12 ± 3 Hz; ns). The VF complexity index was inversely related to refractoriness (r = -0.64; p < 0.001). Under eleclazine perfusion, the VF activation patterns were less complex, and the arrhythmia stopped in 6 out of 11 experiments (55%; p < 0.05 vs. baseline).

Conclusion

Eleclazine (GS6615) reduced the proarrhythmic electrophysiological changes induced by myocardial stretch and slowed and simplified activation patterns during VF in the experimental model used.

Patient cohorts of interest in resuscitation science - Aligning cardiac arrest registry outputs with stakeholder needs

INTRODUCTION

Cardiac arrest registries can benchmark, enhance quality of care and provide data for research. Key stakeholders from Emergency Medical Communication Centre (EMCC), Emergency Medical Services (EMS), In-Hospital Care Providers (IHCP) and Recovery and Rehabilitation Providers (RRP) have different perspectives, and registry results and patient cohorts should be tailored to facilitate benchmarking, quality improvement projects and research in all sections of the chain of survival. In this paper, we describe different cohorts of interest, exemplified by data from the Norwegian Cardiac Arrest Registry (NorCAR).

METHOD

Data from NorCAR for patients registered in 2022 is presented as descriptive statistics.

RESULTS

The patient cohort with treatment initiated by EMCC comprised 3591 patients (67/100,000 inhabitants). EMS attended 4150 patients with confirmed cardiac arrest (77/100,000 inhabitants) and started cardiopulmonary resuscitation (CPR) in 3083 patients (57/100,000 inhabitants). The patient cohort eligible for treatment by IHCP consists of 1114 patients admitted to hospital alive or with ongoing CPR, along with 1230 in-hospital cardiac arrest cases. The cohort eligible for rehabilitation and follow-up consists of 1227 patients who were alive 24 h after cardiac arrest, 705 out-of-hospital cardiac arrests and 522 in-hospital cardiac arrests.

CONCLUSION

It is essential to clearly define the cohort of interest when engaging with different stakeholders and to provide data that facilitates quality improvement projects in all areas of the chain of survival. We recommend defining several subgroups of cardiac arrest patients to accommodate benchmarking, quality improvement projects and research relevant for all stakeholders involved in resuscitation and care of cardiac arrest patients.

The landscape of rare mitochondrial DNA variants in sudden cardiac death: A potential role for ATP synthase

Sudden cardiac death (SCD) is a major health concern, which can be the sign of a latent mitochondrial disease. However, mitochondrial DNA (mtDNA) contribution is largely unexplored in SCD at population level. Recently, mtDNA variants have been associated with congenital cardiopathy and higher risk of ischemic heart disease, suggesting them as potential risk factors also in SCD. Therefore, we aimed to define the mtDNA mutational landscape in such phenotype, by sequencing the whole blood mtDNA genome in a pilot cohort of 28 unrelated subjects. Coding variants were prioritized according to their population and haplogroup frequency. Out of 28 patients, 36% were diagnosed with coronary artery disease, 39% with structural defects and 25% with unspecified cardiac disease. The overall frequency of macro-haplogroups followed the distribution in the European population. No known or novel mtDNA pathogenic variants were found. Two rRNA and 8 missense variants were rarer than polymorphisms as they had a frequency lower than 1% in population databases. 5/8 missense variants clustered in ATP synthase genes and 4/8 missense variants were previously detected in patients with suspected mitochondriopathy. We concluded that primary mitochondrial disease is not a major cause of SCD, but rare mtDNA variants may occur (35.7% in our cohort vs 0.65% in the population; p < 0.01), potentially modifying the risk.

Mapping Trends Regarding the Cardiopulmonary Resuscitation: A Bibliometric Analysis of the Top 100 Cited Articles

Introduction: Despite significant medical and technological advancements, cardiac arrest remains a critical public health concern due to its persistently high mortality and morbidity rates. Consequently, research on cardiopulmonary resuscitation (CPR) is of significant importance. Materials and Methods: This study presents a bibliometric analysis of the 100 most-cited articles in the field of CPR identified using the Scopus database without time restrictions. Analyses were conducted using VOSviewer and Bibliometrix software. Original research articles published in English were included. Results: The study revealed contributions from 798 distinct authors across 18 journals, with citation counts ranging from 218 least-cited articles to 1194 most-cited articles. The most recent article was published in 2020, and the most frequently used keywords were "CPR" and "heart arrest." In addition, 20% of the analyzed articles were funded by military organizations. Conclusion: This analysis highlights the significant contributions of emergency medicine researchers and the notable development of CPR literature, particularly between the late 1990s and the early 2000s. While the most-cited studies originated from journals with high H-indices, the citation frequency of these articles showed a consistent decline over time. Furthermore, impactful articles in this field were predominantly published in general medical journals rather than in specialized emergency medicine journals. This study provides a foundational resource for researchers, especially early career academicians, seeking to engage in CPR-related research.

Unveiling unexpected adverse events: post-marketing safety surveillance of gilteritinib and midostaurin from the FDA Adverse Event Reporting database

Background

Gilteritinib and midostaurin are FLT3 inhibitors that have made significant progress in the treatment of acute myeloid leukemia. However, their real-world safety profile in a large sample population is incomplete.

Objectives

We aimed to provide a pharmacovigilance study of the adverse events (AEs) associated with gilteritinib and midostaurin through the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database.

Design

A retrospective analysis of the FAERS database was conducted by disproportionality analyses.

Methods

We conducted disproportionality analyses to identify drug-AE associations, including the reporting odds ratio and the Bayesian confidence propagation neural network. A signal was detected if both methods achieved statistical significance.

Results

There were 1887 and 2091 case reports for gilteritinib and midostaurin, respectively. We have separately retained significant disproportionality AEs across two algorithms, with a total of 53 AEs for gilteritinib and 46 for midostaurin. The common AEs observed with gilteritinib included febrile neutropenia, pyrexia, anemia, and thrombocytopenia. Similarly, the prevalent AEs associated with midostaurin were nausea, vomiting, diarrhea, pyrexia, and febrile neutropenia. The common AEs of both drugs are consistent with previous clinical trials. Notably, we also revealed unexpected significant AEs for both drugs. For gilteritinib, 29 positive signals for AEs not mentioned in its instructions were identified, such as cerebral hemorrhage, tumor lysis syndrome, and interstitial lung disease. Midostaurin exhibited 24 positive signals for AEs not listed in its instructions, including neutropenic colitis, neutropenic sepsis, and septic shock.

Conclusion

This study highlights the need for continued monitoring and evaluation of these drugs in clinical practice, as it first reveals their AEs in a large real-world sample population. Some AEs are generally consistent with the instructions and previous studies, but some unexpected AEs are detected for each drug. Due to the limitations of the spontaneous report database, such as including potential underreporting, overreporting, lack of causal relationship, unable to calculate incidence, and other confounding factors, more pharmacoepidemiology studies are needed to validate our findings.

Cardiopulmonary resuscitation coaching for resuscitation teams: A systematic review

Aim

Cardiopulmonary resuscitation (CPR) quality is often substandard to guidelines for resuscitation teams. We aimed to investigate if the use of a CPR coach as part of the resuscitation team can improve teamwork, quality of care, and patient outcomes during simulated and clinical cardiac arrest resuscitation.

Methods

We searched PubMed, Embase, and Cochrane from inception until October 9, 2024 for randomized trials and observational studies. We assessed risk of bias using Cochrane tools and assessed the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. PROSPERO CRD42024603212.

Results

We screened 505 records and included 7 studies. Overall, 6 were randomized studies involving pediatric resuscitation of which 4 studies were secondary analyses of one simulation-based trial, and one was an observational study on adult out-of-hospital cardiac arrest. Reported outcomes were: CPR performance in a simulated setting (n = 3), workload in a simulated setting (n = 2), adherence to guidelines in a simulated setting (n = 1), team communication in a simulated setting (n = 1), and clinical CPR performance (n = 1). All studies suggested improved CPR quality and guideline adherence when using a CPR coach compared to not using a coach. Risk of bias varied from low to critical and the certainty of evidence across outcomes was low or very low.

Conclusions

We identified low- to very-low certainty of evidence supporting the use of a CPR coach as part of the resuscitation team in order to improve CPR quality and guideline adherence. However, further research is needed, in particular for clinical performance and patient outcomes.

Risk scoring systems for early prediction of short-term mortality in resuscitated out-of-hospital cardiac arrest patients

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) is a critical condition associated with high mortality rates and neurological impairment among survivors. In comatose OHCA patients who achieve return of spontaneous circulation, early risk stratification is important to inform treatment pathways and potentially improve outcomes. A range of prognostic tools have been developed to predict survival and neurological recovery. Each tool incorporates a unique combination of clinical, biochemical and physiological markers.

AREAS COVERED

This review article evaluates the required clinical data, predictive performances and practical applicability of major risk scores. A literature review was conducted in PubMed and Embase for studies published between January 2000 and October 2024. The review emphasizes the variability in discriminative power among the selected scores, with some models offering high sensitivity and specificity in outcome prediction, while others prioritize simplicity and accessibility.

EXPERT OPINION

Despite the advancements of these tools, limitations persist in data dependency and the clinical adaptability, highlighting areas for future improvement. Integrating artificial intelligence and real-time analytics could enhance predictive accuracy, offering dynamic prognostic capabilities that adapt to individual patient trajectories. This evolution must be grounded in ethical considerations to ensure predictive technologies complement rather than replace clinical judgment, balancing technology's potential with the complexities of individualized patient care.

Incidence of ventricular arrhythmias after implantable cardioverter-defibrillator implantation or replacement, and driving restriction consequences

BACKGROUND

Following implantation/replacement of an implantable cardioverter-defibrillator, patients are legally subjected to variable lengths of driving restrictions based on the indication (1 and 3 months after primary and secondary prevention, respectively; 1 week after device replacement).

AIM

To assess the incidence of ventricular arrhythmia during the theoretical driving restriction period in a large cohort of patients.

METHODS

Patients who underwent implantable cardioverter-defibrillator implantation for primary or secondary prevention or device replacement between 2015 and 2021 were included retrospectively. The primary endpoint was the occurrence of ventricular arrhythmia during the theoretical driving restriction period, as defined by guidelines.

RESULTS

A total of 914 patients were analysed, including 654 first implantations (438 and 216 for primary and secondary prevention, respectively) and 260 device replacements. The primary outcome occurred in 2/438 patients (0.004%) during the 1-month period following device implantation for primary prevention and in 25/216 patients (11.5%) during the 3-month period following device implantation for secondary prevention; it did not occur in the 1-week period following device replacement. The monthly calculated risk of harm remained below the accepted threshold of 0.005% for each group.

CONCLUSIONS

Primary prevention patients, such as those who have undergone device replacement, have a low risk of ventricular arrhythmia, which could lead to a reduction in their driving restriction period. Secondary prevention patients experienced a higher risk of recurrent ventricular arrhythmia, supporting the 3-month driving restriction period.

Transcriptomic Profiling of Human Myocardium at Sudden Death to Define Vulnerable Substrate for Lethal Arrhythmias

BACKGROUND

While some chronic pathological substrates for sudden cardiac death (SCD) are well known (eg, coronary artery disease and left ventricular [LV] dysfunction), the acute vulnerable myocardial state predisposing to fatal arrhythmia remains a critical barrier to near-term SCD prevention.

OBJECTIVES

This study sought to define the distinct myocardial transcriptomic profile of autopsy-defined arrhythmic sudden deaths, compared to nonarrhythmic sudden deaths and trauma deaths, to determine the acute vulnerable state in the hours to days before SCD.

METHODS

We used autopsy to adjudicate arrhythmic from nonarrhythmic causes in 1,265 sudden deaths in San Francisco County from 2011 to 2018. We performed a degradation-tolerant transcriptomic evaluation of LVs sampled at the time of SCD from 245 consented cases using a curated panel of 448 gene probes with known or hypothesized association with SCD.

RESULTS

The targeted transcriptome of arrhythmic (n = 129) vs nonarrhythmic (n = 90 nonarrhythmic sudden deaths + 26 trauma deaths) LV samples revealed 31 differentially up-regulated and 36 down-regulated genes (adjusted P < 0.05) related to the collagen-containing extracellular matrix (up-regulation of FAP, FMOD, and LTBP2), regulation of ion transport (up-regulation of KCNA5 and KCNN3 and down-regulation of KCNJ8, KCNK1, and KCNJ5), and contraction (down-regulation of MYH6). Fibrosis-related genes showed the highest magnitude increased expression in arrhythmic vs nonarrhythmic deaths and vs published transcriptomes from end-stage heart failure. After molecular stratification by known markers for mature (COL1A1, COL1A2, COL3A1) and active (POSTN, MEOX1) fibrosis, cases with the highest expression of both had the largest proportion of arrhythmic cause of death (n = 27 of 36 [75%]) vs cases with low expression of both markers (n = 87 of 181 [38%]) (P = 0.006) or vs mature only (n = 10 of 14 [71%]) or active only (n = 5 of 14 [36%]). Activated fibroblast gene expression signature was enriched in arrhythmic female vs arrhythmic male cases, among other sex-specific differences in ion-channel and myosin (up-regulation of SCN4B, SCN8A, and KCNAB1 in females and KCNJ4 and MYH7B in males) expression.

CONCLUSIONS

RNA profiling of the myocardium at SCD identifies active fibrosis, undetectable by conventional clinical methods, in the presence of fixed scar and selected ion-channel dysregulation (more pronounced among female cases) as an acute vulnerable substrate for fatal arrhythmias. These findings may represent novel directions to identify patients at elevated near-term risk for SCD and critical pathways for intervention to reduce acute lethal arrhythmias.

Ciprofol Ameliorates Myocardial Ischemia/Reperfusion Injury by Inhibiting Ferroptosis Through Upregulating HIF-1α

Purpose

Ciprofol is a novel intravenous anesthetic that has been increasingly used in clinical anesthesia and sedation. Studies suggested that ciprofol reduced oxidative stress and inflammatory responses to alleviate cerebral ischemia/reperfusion (I/R) injury, but whether ciprofol protects the heart against I/R injury and the mechanisms are unknown. Herein, we assessed the effects of ciprofol on ferroptosis during myocardial I/R injury.

Methods

Experimental models of myocardial I/R injury in mice (ischemia for 30 min and reperfusion for 24 h) and hypoxia/reoxygenation (H/R) injury in H9c2 cardiomyocytes (hypoxia for 6 h followed by 6 h of reoxygenation) were established. Ciprofol was used prior to ischemia or hypoxia. Echocardiography, myocardial TTC staining, HE staining, DAB-enhanced Perl's staining, transmission electron microscopy, FerroOrange staining, Liperfluo staining, JC-1 staining, Rhodamine-123 staining, DCFH-DA staining, and Western blot were performed. Cell viability, serum cardiac enzymes, and oxidative- and ferroptosis-related biomarkers were measured. HIF-1α siRNA transfection and the specific inhibitor BAY87-2243 were utilized for mechanistic investigation.

Results

Ciprofol treatment reduced myocardial infarct area and myocardium damage, alleviated oxidative stress and mitochondrial injury, suppressed Fe2+ accumulation and ferroptosis, and improved cardiac function in mice with myocardial I/R injury. Ciprofol also increased cell viability, attenuated mitochondrial damage, and reduced intracellular Fe2+ and lipid peroxidation in cardiomyocytes with H/R injury. Ciprofol enhanced the protein expression of HIF-1α and GPX4 and reduced the expression of ACSL4. Specifically, the protective effects of ciprofol against I/R or H/R injury were abolished by downregulating the expression of HIF-1α using siRNA transfection or the inhibitor BAY87-2243.

Conclusion

Ciprofol ameliorated myocardial I/R injury in mice and H/R injury in cardiomyocytes by inhibiting ferroptosis via the upregulation of HIF-1α expression.

Wearable Cardioverter Defibrillator as a Treatment in Patients with Heart Failure of Various Aetiologies-A Series of Ten Cases Within the BIA-VEST Registry

Background/Objectives: Sudden cardiac death (SCD) remains a major global health concern and represents one of the most common causes of mortality due to cardiovascular diseases. The wearable cardioverter-defibrillator (WCD) is an innovative, non-invasive medical device designed to provide continuous heart monitoring and immediate defibrillation in patients at risk for SCD. The study aimed to assess the efficacy of WCD usage in patients awaiting decision on therapy with implantable cardioverter-defibrillators (ICDs). Methods: We explored the clinical applications, benefits, and limitations of WCD usage within the BIA-VEST registry in Poland over the years 2021-2023. The study included 10 patients with a mean age of 49.1 ± 12.02 years. Results: All patients demonstrated good tolerance and compliance with the LifeVest WCD, wearing it for an average of 93.1 days, about 22.8 h per day (95.7% of the time). No interventions from LifeVests were recorded, and there were no effective, ineffective, or inadequate discharges. After the first follow-up echocardiography, five patients still required ICDs. Due to improved LVEF and overall condition in six out of ten patients undergoing WCD bridge therapy, ICD implantation was finally waived. Conclusions: The WCD acts as a bridge to therapy, such as ICD implantation or cardiac surgery, and may be particularly beneficial for patients with transient or evolving conditions, such as structural heart diseases and life-threatening ventricular arrhythmias.

Optimizing acute chest pain diagnosis: Efficacy of 64-channel multi-slice CT with Snap-Shot Freeze technique in Triple-Rule-out CT angiography

Objective

This study evaluates the efficacy of Snap-Shot Freeze (SSF) technology combined with optimized contrast medium (CM) injection protocols in Triple-Rule-Out (TRO) computed tomography angiography (CTA) using 64-channel multi-slice CT (MSCT) for diagnosing acute chest pain (ACP).

Materials and methods

A total of 111 patients presenting with ACP were enrolled and divided into two groups: Group 1 (23 patients) underwent TRO CTA using 64-channel MSCT with SSF technology, while the control group (88 patients) which was further divided into three cohorts underwent specific site CTA scans. Quantitative metrics such as CT values, standard deviation (SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for pulmonary artery, coronary arteries, and aortic imaging. Demographic characteristics, image qualification rate and disease diagnosis rate of groups 1-4 were also evaluated. Qualitative evaluations were based on a 5-point scoring system assessing overall image quality, vessel clarity, and artifact presence. Radiation doses were measured in terms of CT dose index volume (CTDIvol), dose length product (DLP), and effective dose (ED).

Results

The demographic characteristics of the patients showed no significant differences in age, BMI, or resting heart rate between Group 1 and the control group. The image qualification rate was 100 % for both groups, with excellent rates of 89.13 % in Group 1 and 85.67 % in the control group. No significant differences were found in average CT values, standard deviation (SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) between Group 1 and the control group for pulmonary artery (e.g., PT: 394.25 ± 124.19 vs 383.64 ± 115.72 HU, p = 0.74), coronary artery (e.g., AA: 483.71 ± 115.62 vs 493.95 ± 138.54 HU, p = 0.79), and aorta (e.g., AAo: 325.1 ± 99.39 vs 348.98 ± 74.23 HU, p = 0.34). Qualitative image quality scores and radiation doses were also comparable (e.g., ED: 28.36 ± 12.6 vs 29.97 ± 10.36 mSv, p = 0.77). Qualitative assessments also revealed comparable image quality scores between the two groups (4.5 ± 0.5 vs 4.3 ± 0.6). The total volume of iodinated CM was significantly reduced in Group 1 (66 mL vs 227 mL).

Conclusion

The use of 64-channel MSCT combined with SSF technology in TRO CTA provides noninferior high-quality imaging comparable to traditional specific site CTA, with the added benefits of reduced CM volume and shorter examination times. This approach is effective for the comprehensive evaluation of ACP in clinical practice.

Out-of-hospital cardiac arrests in Victoria, 2003-2022: retrospective analysis of Victorian Ambulance Cardiac Arrest Registry data

OBJECTIVES

To examine changes in out-of-hospital cardiac arrest (OHCA) characteristics and outcomes during 2003-2022, and 12-month outcomes for people who experienced OHCA during 1 January 2010 - 30 June 2022.

STUDY DESIGN

Retrospective observational study; analysis of Victorian Ambulance Cardiac Arrest Registry (VACAR) data.

SETTING, PARTICIPANTS

OHCA events in Victoria not witnessed by emergency medical services personnel, 1 January 2003 - 31 December 2022.

MAIN OUTCOME MEASURES

Crude and age-standardised annual OHCA incidence rates; survival to hospital discharge.

RESULTS

Of 102 592 OHCA events included in our analysis, 67 756 were in men (66.3%). The age-standardised incidence did not change significantly across the study period (2003: 89.1 cases, 2022: 91.2 cases per 100 000 population; for trend: P = 0.50). The proportion of OHCA cases with attempted resuscitation by emergency medical services in which bystanders attempted cardio-pulmonary resuscitation increased from 40.3% in 2003/2004 to 72.2% in 2021/2022, and that of public access defibrillation from 0.9% to 16.1%. In the Utstein comparator group (witnessed OHCA events in which the initial cardiac rhythm was ventricular fibrillation or ventricular tachycardia, with attempted resuscitation by emergency medical services), the odds of survival to hospital discharge increased during 2003-2022 (adjusted odds ratio (aOR), 3.08; 95% confidence interval [CI], 2.22-4.27); however, the odds of survival was greater than in 2012 only in 2018 (aOR, 1.37; 95% CI, 1.04-1.80) and 2019 (aOR, 1.68; 95% CI, 1.28-2.21). The COVID-19 pandemic was associated with reduced odds of survival (aOR, 0.63; 95% CI, 0.54-0.74). Of 3161 people who survived OHCA and participated in 12-month follow-up, 1218 (38.5%) reported full health according to the EQ-5D.

CONCLUSION

Utstein survival to hospital discharge increased threefold during 2003-2022, and the proportions of cases in which bystanders provided cardio-pulmonary resuscitation or public access defibrillation increased. The COVID-19 pandemic was associated with a substantial reduction in survival, and new strategies are needed to improve outcomes.

Time-Dependent ECG-AI Prediction of Fatal Coronary Heart Disease: A Retrospective Study

Background: Fatal coronary heart disease (FCHD) affects ~650,000 people yearly in the US. Electrocardiographic artificial intelligence (ECG-AI) models can predict adverse coronary events, yet their application to FCHD is understudied. Objectives: The study aimed to develop ECG-AI models predicting FCHD risk from ECGs. Methods (Retrospective): Data from 10 s 12-lead ECGs and demographic/clinical data from University of Tennessee Health Science Center (UTHSC) were used for model development. Of this dataset, 80% was used for training and 20% as holdout. Data from Atrium Health Wake Forest Baptist (AHWFB) were used for external validation. We developed two separate convolutional neural network models using 12-lead and Lead I ECGs as inputs, and time-dependent Cox proportional hazard models using demographic/clinical data with ECG-AI outputs. Correlation of the predictions from the 12- and 1-lead ECG-AI models was assessed. Results: The UTHSC cohort included data from 50,132 patients with a mean age (SD) of 62.50 (14.80) years, of whom 53.4% were males and 48.5% African American. The AHWFB cohort included data from 2305 patients with a mean age (SD) of 63.04 (16.89) years, of whom 51.0% were males and 18.8% African American. The 12-lead and Lead I ECG-AI models resulted in validation AUCs of 0.84 and 0.85, respectively. The best overall model was the Cox model using simple demographics with Lead I ECG-AI output (D1-ECG-AI-Cox), with the following results: AUC = 0.87 (0.85-0.89), accuracy = 83%, sensitivity = 69%, specificity = 89%, negative predicted value (NPV) = 92% and positive predicted value (PPV) = 55% on the AHWFB validation cohort. For this, the 2-year FCHD risk prediction accuracy was AUC = 0.91 (0.90-0.92). The 12-lead versus Lead I ECG FCHD risk prediction showed strong correlation (R = 0.74). Conclusions: The 2-year FCHD risk can be predicted with high accuracy from single-lead ECGs, further improving when combined with demographic information.

HIV-Associated Heart Failure: Phenotypes and Clinical Outcomes in a Safety-Net Setting

BACKGROUND

HIV is associated with increased risk of heart failure (HF) but data regarding phenotypes of HF and outcomes after HF diagnosis, especially within the safety net where half of people with HIV in the United States receive care, are less clear.

METHODS AND RESULTS

Using an electronic health record cohort of all individuals with HF within a municipal safety-net system from 2001 to 2019 linked to the National Death Index Plus, we compared HF phenotypes, all-cause mortality, HF hospitalization, and cause of death for individuals with and without HIV. Among people with HF (n=14 829), 697 individuals had HIV (4.7%). People with HIV were diagnosed with HF 10 years younger on average. A higher proportion of people with HIV had a reduced ejection fraction at diagnosis (37.9% versus 32.7%). Adjusted for age, sex, and risk factors, coronary artery disease on angiography was similar by HIV status. HIV was associated with 55% higher risk of all-cause mortality (hazard ratio [HR], 1.55 [95% CI, 1.37-1.76]; P<0.001) and lower odds of HF hospitalization (odds ratio [OR], 0.51 [95% CI, 0.39-0.66]; P<0.001). Among people with HIV with HF, cause of death was less often attributed to cardiovascular disease (22.5% versus 54.6% uninfected; P<0.001) and more to substance use (17.9% versus 9.3%; P<0.001), consistent with autopsy findings in a subset (n=81).

CONCLUSIONS

Among people with HF who receive care within a municipal safety-net system, HIV infection is associated with higher mortality, despite lower odds of HF hospitalization, attributable to noncardiovascular causes including substance-related and HIV-related mortality.

[Layperson basic life support education in Austria: An overview]

Early interventions of laypersons can improve the survival and neurological outcome in patients with out-of-hospital cardiac arrest. There are several organizations in Austria which train lay people in basic life support and raise awareness for sudden cardiac death. To obtain an overview of the various initiatives, a questionnaire was sent to 26 organizations, and 15 of the organizations (58%) replied. The geographical distribution of the organizations between rural and urban areas was illustrated in a map. Most of them are situated in a university city, resulting in accessibility disparities for individuals in urban and rural settings. Layperson resuscitation education in Austria is largely dependent on the individual commitments of volunteers. The time spent practicing chest compressions in resuscitation courses ranges from 25% to 90% of the total course time. Furthermore, reasons for a lack of scientific endeavours could be identified, and solutions are suggested. Through better networking between organizations and initiatives, more laypersons could be trained in the future, which would lead to improved survival chances for persons suffering from out-of-hospital cardiac arrest in Austria. Appropriate support by political bodies and public authorities is and will remain a key element.

Computational Medicine: What Electrophysiologists Should Know to Stay Ahead of the Curve

PURPOSE OF REVIEW

Technology drives the field of cardiac electrophysiology. Recent computational advances will bring exciting changes. To stay ahead of the curve, we recommend electrophysiologists develop a robust appreciation for novel computational techniques, including deterministic, statistical, and hybrid models.

RECENT FINDINGS

In clinical applications, deterministic models use biophysically detailed simulations to offer patient-specific insights. Statistical techniques like machine learning and artificial intelligence recognize patterns in data. Emerging clinical tools are exploring avenues to combine all the above methodologies. We review three ways that computational medicine will aid electrophysiologists by: (1) improving personalized risk assessments, (2) weighing treatment options, and (3) guiding ablation procedures. Leveraging clinical data that are often readily available, computational models will offer valuable insights to improve arrhythmia patient care. As emerging tools promote personalized medicine, physicians must continue to critically evaluate technology-driven tools they consider using to ensure their appropriate implementation.

An innovative Hearing AED alarm system shortens delivery time of automated external defibrillator - A randomized controlled simulation study

Background

Early defibrillation with an automated external defibrillator (AED) is a key element in the out-of-hospital cardiac arrest (OHCA) chain. However, a public automatic defibrillator (PAD) is often not easily accessible during emergency situations. Here, we have developed an AED-based alarm system together with a smartphone Hearing AED application (APP) that would activate registered public access AED within 300 m radius from the location of an OHCA event. It also alerts nearby related personnel to bring in the AED to the OHCA location for emergency assistance. The aim of this study is to determine if this novel Hearing AED alarm system shortens the AED delivery time.

Methods

This was a randomized controlled simulation study. Participants were randomly assigned to one of the 3 groups: (a) bystander group, (b) APP responder group, and (c) AED alarm responder in equal ratios. The bystanders were stationed at the OHCA scene, and must access a nearby AED by the instruction of the dispatcher of emergency medical services. APP responders were stationed within 300 m of the cardiac arrest scene, and were activated by the Hearing AED APP. The AED alarm responders were brought to AED location, and were activated by the AED-based alarm device mounted on an AED case. We measured the time taken to find and bring the nearby AED to the OHCA scene. The primary outcome was the total delivery time in each group. The secondary outcomes were times needed: (a) from the starting point to AED place, (b) from AED place to the OHCA scene, and (c) the operation time.

Results

We enrolled 90 participants in this study. The total AED delivery times were significantly different across the 3 groups. The shortest time was in the AED alarm responder group, compared with the other two groups. The median time from the starting point to AED was statistically shorter in the bystander group than in the APP responder group (116.0 sec, IQR 80.0-135.0 vs 159.0 sec, IQR 98.5-200.5, p = 0.029). In the analysis with the general linear model, we found statistically shorter total AED delivery time in the AED alarm responder group (β = -122.4, p = 0.004). In contrast, the APP responder group was associated with a markedly longer total AED delivery time (β = 104.6, P=0.016).

Conclusion

In this simulation study, the Hearing AED system contributed to shortening the AED delivery time. Further studies are needed to determine its validation in the real world situation in the future.

Causal association between remnant cholesterol level and risk of cardiovascular diseases: a bidirectional two sample mendelian randomization study

Serum lipids have been associated with an increased risk of various cardiovascular diseases (CVDs) in several observational studies, but the causal inference between the remnant cholesterol (RC) levels and several CVDs risk has not been established. The purpose of this study was to investigate whether there is a causal relationship between RC levels and risk of developing CVDs by a bidirectional two-sample Mendelian randomization (TSMR) analysis. One TSMR analysis was performed using the publicly released large-scale genome-wide association study (GWAS) data. Inverse variance weighted (IVW) method was chosen as the main analysis method, and MR-Egger, weighted median, simple mode, and weighted mode were used as supplementary methods. We conducted a series of sensitivity analyses to assess the robustness of the main results, including the Cochran's Q test, MR-Egger intercept test, leave-one-out sensitivity analysis, and funnel plot. The main IVW method revealed that genetically predicted serum level of RC is significantly associated with an increased risk of developing ischemic heart disease (OR = 1.409, 95%CI = 1.284-1.546, P value = 4.753E-13), unstable angina pectoris (OR = 1.621, 95%CI = 1.398-1.880, P value = 1.672E-10), myocardial infarction (OR = 1.526, 95%CI = 1.337-1.741, P value = 3.771E-10), cardiac arrest (OR = 1.595, 95%CI = 1.322-1.924, P value = 1.076E-06), heart failure (OR = 1.086, 95%CI = 1.009-1.169, P value = 0.028), hypertension (OR = 1.089, 95%CI = 1.043-1.136, P value = 9.458E-05), major coronary heart disease (CHD) events (OR = 1.515, 95%CI = 1.376-1.669, P value = 3.217E-17), coronary atherosclerosis (OR = 1.388, 95%CI = 1.231-1.564, P value = 7.739E-08), cardiac arrhythmias (OR = 1.067, 95%CI = 1.008-1.130, P value = 0.025), and atrial fibrillation and flutter (OR = 1.122, 95%CI = 1.039-1.211, P value = 0.003). Additionally, the causal associations between the RC levels and these CVDs remained significant after correcting for the false discovery rate (all P value < 0.05). However, this study did not find any significant association of RC with cardiomyopathy and pericarditis (both P value > 0.05). Heterogeneity existed in the IVs of RC and ischemic heart disease, unstable angina pectoris, myocardial infarction, heart failure, hypertension, major CHD events, cardiomyopathy, coronary atherosclerosis, cardiac arrhythmias and atrial fibrillation and flutter using the Cochran's Q test (all P value < 0.05). Moreover, there was no horizontal pleiotropy in this study (all P value > 0.05). The leave-one-out sensitivity analyses showed that the causal effects between RC level and CVDs (except for heart failure, cardiomyopathy, pericarditis and cardiac arrhythmias) are not driven by a single SNP. The funnel plots showed that there is no obvious potential bias in our study. In the replication analysis, the genetically predicted RC levels were positively associated with a 43.12% higher risk of coronary artery disease. This present study supported the causal link between RC and heightened the risk of CVDs, indicating that RC-lowering treatment might be effective in preventing CVDs.

Prognostic value of ventricular arrhythmia in early post-infarction left ventricular dysfunction: the French nationwide WICD-MI study

BACKGROUND AND AIMS

Prophylactic implantable cardioverter-defibrillators (ICDs) are not recommended until left ventricular ejection fraction (LVEF) has been reassessed 40 to 90 days after an acute myocardial infarction. In the current therapeutic era, the prognosis of sustained ventricular arrhythmias (VAs) occurring during this early post-infarction phase (i.e. within 3 months of hospital discharge) has not yet been specifically evaluated in post-myocardial infarction patients with impaired LVEF. Such was the aim of this retrospective study.

METHODS

Data analysis was based on a nationwide registry of 1032 consecutive patients with LVEF ≤ 35% after acute myocardial infarction who were implanted with an ICD after being prescribed a wearable cardioverter-defibrillator (WCD) for a period of 3 months upon discharge from hospital after the index infarction.

RESULTS

ICDs were implanted either because a sustained VA occurred while on WCD (VA+/WCD, n = 72) or because LVEF remained ≤35% at the end of the early post-infarction phase (VA-/WCD, n = 960). The median follow-up was 30.9 months. Sustained VAs occurred within 1 year after ICD implantation in 22.2% and 3.5% of VA+/WCD and VA-/WCD patients, respectively (P < .0001). The adjusted multivariable analysis showed that sustained VAs while on WCD independently predicted recurrence of sustained VAs at 1 year (adjusted hazard ratio [HR] 6.91; 95% confidence interval [CI] 3.73-12.81; P < .0001) and at the end of follow-up (adjusted HR 3.86; 95% CI 2.37-6.30; P < .0001) as well as 1-year mortality (adjusted HR 2.86; 95% CI 1.28-6.39; P = .012).

CONCLUSIONS

In patients with LVEF ≤ 35%, sustained VA during the early post-infarction phase is predictive of recurrent sustained VAs and 1-year mortality.

Comparison of end tidal CO2 levels between automated head up and conventional cardiopulmonary resuscitation: A pre-post intervention trial

BACKGROUND

The combination of controlled automated head/thorax elevation, active compression-decompression (ACD) cardiopulmonary resuscitation (CPR), and an impedance threshold device (ITD-16), termed AHUP-CPR, lowers intracranial pressure and increases circulation and neurologically-sound survival in pigs versus conventional (C) CPR. This study examined whether AHUP-CPR increased end tidal (ET) CO2, a non-invasive marker of cardiac output and organ perfusion, compared with C-CPR in witnessed out-of-hospital cardiac arrest patients.

METHOD

We conducted a prospective, single-arm, pre-post intervention trial in France between October 2019 and October 2022.Firefighters treated patients enrolled during the pre-intervention period with manual C-CPR and with AHUP-CPR during the post-intervention period. Advanced life support was provided by a physician-staffed 2nd-tier response vehicle for the two study periods. The primary outcome was the peak ETCO2 value measured during CPR.

RESULTS

122 patients with a mean age of 67 years (standard deviation [SD], 17) were enrolled (59 in the pre-intervention period and 63 in the post-intervention period). Based on an intention-to-treat analysis, mean baseline ETCO2 values were comparable between pre- (20.1 mmHg, SD,16.3) and post-(19.2 mmHg, SD, 16.3) intervention periods. Mean peak ETCO2 values during CPR were 30.3 mmHg (SD, 13.1) versus 40.7 mmHg (SD, 17.8) for the pre- and post-intervention study periods (mean difference, 10.6, 95% confidence interval, 4.6 to 16.1, P < 0.001). Mean differences in peak ETCO2 between study periods did not vary according to the first recorded cardiac rhythm (P for interaction = 0.99). The proportion of return of spontaneous circulation [19 (32.2%) vs. 21 (33.3%)], survival on hospital admission [17 (28.8%) vs. 19 (30.2%)], and 30-day survival with favorable neurological outcome [8 (13.6%) vs. 7 (11.1%)] did not differ between study periods.

CONCLUSION

ETCO2 values during AHUP-CPR reached the range of non-arrest normal physiological levels and were significantly higher than with C-CPR, regardless of the presenting cardiac rhythm.

A Call to Action to Improve Cardiac Arrest Outcomes: A Report From the National Summit for Cardiac Arrest

Sudden cardiac arrest (SCA) represents a major cause of premature mortality globally, with enormous impact and financial cost to victims, families, and communities. SCA prevention should be considered a health priority in Australia. National Cardiac Arrest Summits were held in June 2022 and March 2023, with inclusion from multi-faceted endeavours related to SCA prevention. It was agreed to establish a multidisciplinary Australian Sudden Cardiac Arrest Alliance (AuSCAA) working group charged with developing a national unified strategy, with clear and measurable quality indicators and standardised outcome measures, to amplify the goal of SCA prevention throughout Australia. A multi-faceted prevention strategy will include i) endeavours to progress community awareness, ii) improved fundamental mechanistic understanding, iii) implementation of best-practice resuscitation strategies for all demographics and locations, iv) secondary risk assessment directed to family members, and v) development of (near) real-time registry of cardiac arrest cases to inform areas of need and effectiveness of interventions. Together, we can and should reduce the impact of SCA in Australia.

The triglyceride-glucose index, ventricular arrhythmias and major cardiovascular events in patients at high risk of sudden cardiac death

BACKGROUND

The association between the triglyceride-glucose (TyG) index and ventricular arrhythmias (VAs) is unclear. This study aimed to investigate the relationship between the TyG index, VAs, and major cardiovascular events in patients at high risk of sudden cardiac death (SCD).

METHODS

We enrolled 1046 patients at high risk of SCD with an indication for implantable cardioverter-defibrillator (ICD) implantation at the Chinese National Center for Cardiovascular Diseases. The primary outcome was VAs, defined as sustained ventricular tachycardia and ventricular fibrillation documented by the ICD. The secondary outcomes were cardiac mortality, heart transplantation, and rehospitalization for heart failure.

RESULTS

The mean (± SD) age was 59.6 ± 14.0 years old, and 25.7% were female. During the mean follow-up of 36.1 months, 342 (32.7%) patients had VAs, and 185 (17.7%) patients had major cardiovascular events. The mean fasting glucose and triglyceride levels were 111.9 ± 42.7 mg/dL and 140.0 ± 95.4 mg/L, respectively, with a TyG index range of 6.96-11.8. In the Fine-Gray subdistribution hazard model analysis, an increase in the TyG index was associated with a significant increase in the VAs (per 1 TyG index, hazard ratio [HR] 2.95; 95% confidence interval [CI], 2.29-3.80) and secondary outcome (HR 2.84; 95% CI 1.86-4.34). When stratified into tertiles, the risk of VAs was significantly higher in the highest tertile (HR 4.08; 95% CI, 2.81-5.92) than in the lowest tertile. Analysis of the secondary outcome revealed similar findings (HR 3.18; 95% CI, 1.73-5.85).

CONCLUSIONS

In our cohort, the pre-operational TyG index is significantly associated with VAs and major cardiovascular events for patients with high risk of SCD.

Nonalcoholic fatty liver disease is associated with ventricular arrhythmias and major cardiovascular events in patients with implantable cardioverter-defibrillators

BACKGROUND

Patients with nonalcoholic fatty liver disease (NAFLD) are at risk for cardiovascular diseases. Less is known about the relationship between NAFLD, ventricular arrhythmias (VAs), and cardiovascular events.

OBJECTIVE

We sought to evaluate the association between NAFLD and VAs and major cardiovascular events in patients with implantable cardioverter-defibrillators (ICDs).

METHODS

A total of 921 patients at high risk of sudden cardiac death who received ICDs were retrospectively analyzed. NAFLD is diagnosed by the presence of hepatic steatosis and lack of secondary causes of hepatic fat accumulation. The primary end points were VAs, defined as sustained ventricular tachycardia and ventricular fibrillation documented by the device. The secondary end points were cardiac mortality, heart transplantation, and rehospitalization for heart failure.

RESULTS

The prevalence of NAFLD in patients with ICDs was 24.2% (223/921). The mean age was 58.5 ± 12.7 years, and 25.7% were female. During the mean follow-up of 34.8 months, 272 (29.5%) patients achieved primary end points and 171 (18.6%) achieved secondary end points. Kaplan-Meier analysis revealed that NAFLD was associated with an increased risk of VAs (hazard ratio [HR], 3.90; 95% confidence interval [CI], 2.87-5.29; log-rank P < .0001) and secondary end points (HR, 2.04; 95% CI, 1.72-2.94; log-rank P < .0001). In adjusted Cox regression models, NAFLD was an independent risk factor for VAs (HR, 3.84; CI, 2.87-5.12; P < .001) and secondary end points (HR, 2.26; CI, 1.55-3.28; P < .001).

CONCLUSION

In our retrospective cohort, NAFLD is significantly associated with VAs and major cardiovascular events in patients with ICDs.

Proarrhythmic drugs, drug levels, and polypharmacy in victims of sudden arrhythmic death syndrome: An autopsy-based study from Denmark

BACKGROUND

Sudden arrhythmic death syndrome (SADS), characterized by an unknown or inconclusive cause of death at autopsy together with a negative or nonlethal toxicology screening result, is the most common cause of sudden cardiac death in victims younger than 35 years. The complete causality of SADS remains unclear, with drugs being a potential risk factor.

OBJECTIVE

This study aimed to describe the toxicologic profiles of SADS victims, focusing on proarrhythmic drugs, drug levels, and polypharmacy.

METHODS

All deaths in Denmark of those aged 1-35 years in 2000-2019 and 36-49 years in 2007-2019 were examined through death certificates, national registries, and autopsy reports with toxicology screenings. We investigated all sudden unexpected death victims with an autopsy performed, including negative or nonlethal drug findings, where cause of death was unknown or inconclusive (SADS).

RESULTS

We identified 477 SADS victims; 313 (66%) had a positive toxicology screening result (adjudicated nonlethal), with an average of 2.8 drugs per case. More than half of the SADS victims with a positive toxicology screening result had QT-prolonging or brugadogenic drugs present. Polypharmacy was present in 66%, psychotropic polypharmacy in 37%, and QT-prolonging polypharmacy in 22%, with the most frequent overall and QT-prolonging drug combination being an antipsychotic and a psychoanaleptic drug. QT-prolonging drugs were more often present at suprapharmacologic levels than non-QT-prolonging drugs.

CONCLUSION

The majority of the SADS population had a positive toxicology screening result, with a notably large proportion having proarrhythmic drugs and polypharmacy. This highlights the need for future focus on drugs as a risk factor for SADS.

Short Survey on Cardiopulmonary Resuscitation and Automated External Defibrillator Training in Rural British Columbia Schools: Preliminary Findings and Hypothesis-Generating Insights

Background

British Columbia (BC) faces more than 7000 out-of-hospital cardiac arrests annually, which disproportionately affect rural areas, owing to their slower emergency medical service response and limited specialized care. Despite the known benefits of automated external defibrillator (AED) access and cardiopulmonary resuscitation (CPR) training, their status in rural BC schools is poorly documented.

Methods

We used an online survey of principals and vice-principals of rural schools in BC. The survey assessed AED accessibility, prevalence of CPR and AED training, and obstacles to implementing such training. Questions covered school demographics, AED installation, and CPR and/or AED training for staff and students.

Results

We recruited 23 elementary schools (kindergarten-grade 7; 46%), 6 middle schools (grades 6-8; 12%), and 21 high schools (grades 8- 12; 42%). A total of 72% (36 of 50) had at least one AED installed; 46% required staff CPR training; and 24% provided student CPR training. Significant gaps in training were noted for elementary and middle school students, compared to the training for high schools (P < 0.05).

Conclusions

Disparities in AED and CPR training across rural schools in BC exist, highlighting a need for policy improvements and innovative solutions to enhance first-aid education. Barriers to implementing CPR and AED training included lack of funding, curricular priority, time constraints, and limited resources. Despite a 10.3% response rate, this study reveals significant disparities in AED and CPR training across school levels in rural BC, underscoring the need for targeted policies and educational strategies to enhance emergency preparedness and improve cardiac arrest outcomes in underserved areas.