Prospective Countywide Surveillance and Autopsy Characterization of Sudden Cardiac Death: POST SCD Study

Countywide burden, pathology, and genetics of lethal hypertrophic cardiomyopathy: from the POST SCD study

AIMS

Incidence of sudden cardiac death (SCD) is 1%/year in cohorts with hypertrophic cardiomyopathy (HCM), but this estimate presumes arrhythmic cause and misses occult cases dying before diagnosis.

METHODS AND RESULTS

POST SCD (POstmortem Systematic InvesTigation of Sudden Cardiac Death) is a prospective cohort study using autopsy, clinical records, and toxicology to adjudicate arrhythmic or non-arrhythmic causes among presumed SCDs (pSCDs) meeting WHO criteria aged 0-90 years in San Francisco County. We included all incident cases 2/1/2011-3/1/2014 (n = 525) and approximately every third day 3/1/2014-9/1/2022 (n = 497) based on medical examiner call schedule. We identified HCM victims via three approaches: (i) pathology; (ii) echocardiogram [transthoracic echocardiogram (TTE)]; (iii) genetic criteria. Incidence calculations used county data and estimated HCM prevalence of 1:500 from studies of persons aged 23-35 years old. Of 1022 pSCDs [558 (54.6%) arrhythmic deaths] during the study period, 13 had HCM: 10 met pathology criteria; 2 via review of 203 TTEs (missed on initial report); 1 via genetic testing. Of these, 11 were arrhythmic deaths, yielding 1.3% burden of sudden death (pSCD) and 2% of arrhythmic death. Only 2 of 13 (15%) pSCDs with HCM had pre-mortem diagnosis. Incidence for persons with HCM 18-35 years old was 0.2% pSCDs/year and 0.1% SADs/year. pSCDs with HCM had a higher proportion of arrhythmic cause [11/13 (85%) vs. 547/1009 (54%), P = 0.03] than those without. pSCD burden due to HCM decreased with age (P = 0.003), highest among victims <35 years old, for whom HCM accounted for 7.1% of pSCD and 9.4% of arrhythmic death. Genetic testing of 317 consented pSCDs yielded pathogenic or likely pathogenic variants in 40% (2/5) and identified one additional case without clinical phenotype.

CONCLUSION

In this 11-year countywide post-mortem study, HCM meeting pathologic, clinical, or genetic criteria was associated with autopsy-confirmed arrhythmic cause of sudden death, accounting for 2% of SADs up to age 90, highest in cases <35 years old. Since 85% of cases were undiagnosed before pSCD, the true burden of HCM-related sudden death may be substantially underestimated.

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.

Investigation of Myocardial Substrate for Sudden Arrhythmic Death in Coronary Artery Disease Without Acute Coronary Thrombosis or Myocardial Infarction

BACKGROUND

This cohort study aimed to evaluate the potential myocardial arrhythmic substrate in people with coronary artery disease who died from sudden arrhythmic death (SAD) without acute coronary thrombosis or myocardial infarction.

METHODS AND RESULTS

We performed histological analysis of the left ventricular free wall obtained at autopsy from decedents with ≥1 coronary artery and ≥75% area stenosis who died suddenly from either noncardiac causes (25 men, 23 women) or SAD (25 men, 25 women), matched for age and sex. Decedents with acute coronary thrombosis, myocardial infarction, or other myocardial abnormality were excluded. Decedents with either noncardiac death or SAD had similar height, weight, and heart weight. Decedents with SAD had higher cumulative area stenosis of coronary arteries (mean, 162% versus 134%; mean difference, 29% [95% CI, 1%-56%], P=0.042) and a higher proportion of decedents with SAD had diabetes (mean, 10% versus 0%; mean difference, 10% [95% CI, 2%-18%], P=0.025) and chronic, nonocclusive, organized coronary artery thrombus (mean, 16% versus 0%; mean difference, 16% [95% CI, 6%-26%], P=0.0040). Moreover, decedents with SAD had lower cardiomyocyte width (mean, 18.6 μm versus 19.6 μm; mean difference, 1.0 μm [95% CI, 0.2-1.8], P=0.014) and higher capillary length density (mean, 3618 mm/mm3 versus 3164 mm/mm3; mean difference, 453 mm/mm3 [95% CI, 210-697], P=0.0003) than decedents with noncardiac death.

CONCLUSIONS

SAD in people with coronary artery disease without acute coronary thrombosis or myocardial infarction was associated with greater coronary artery plaque burden and cardiomyocyte atrophy that may have contributed to myocardial substrate for arrhythmia.

Sudden Unexpected Death in Patients With Implanted Cardiac Defibrillators: Results of Postmortem Interrogation in MADIT-CRT

BACKGROUND

Ventricular tachyarrhythmia presumably causes sudden unexpected death (SUD) in patients lacking an implantable cardioverter-defibrillator (ICD). The mechanism of SUD is less clear in patients with an ICD to remedy ventricular tachycardia (VT) or ventricular fibrillation (VF).

OBJECTIVES

This study sought to assess mechanisms of SUD in patients with an ICD.

METHODS

MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy) compared ICD alone with ICD with added cardiac resynchronization therapy in 1,820 patients with ischemic or nonischemic cardiomyopathy. In the current analysis, all 35 postmortem device interrogations were reviewed among the trial's 191 decedents. SUD (<3 hours after symptom onset or found dead <3 days after last seen) occurred in 39 (20%) of 191 decedents, including 24 with and 15 without ICD interrogation.

RESULTS

Interrogation showed 11 of 24 with SUD had fatal VT/VF: 6 had inadequate ICD performance (inappropriate shock initiating VT/VF in 2 and failure to detect low-amplitude and/or slow VF in 4), 4 had refractory or recurrent VT/VF, and 1 had refractory bradycardia following defibrillating shock. The remaining 13 interrogated SUDs had no tachyarrhythmia initiating device activation. Autopsy in 3 disclosed only scattered myocardial fibrosis. No clinical features discriminated 11 interrogated SUD patients with VT/VF from 13 without VT/VF.

CONCLUSIONS

First, spontaneous VT/VF, undetected by ICD or refractory to ICD shock, caused a minority (33%) of SUD in 24 MADIT-CRT patients. Second, no tachyarrhythmia was identified in many (54%), suggesting SUD unrelated to tachyarrhythmia - or due to VT/VF undersensing. Last, ICD-related proarrhythmia instigated SUD in 2 (17%). Postmortem device interrogation revealed important outcomes and should be encouraged for decedents with ICD, particularly when investigating cardiovascular therapies.

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.

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.

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.

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.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

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.

Inheritance of Imaging Parameters of Arrhythmic Risk in Mitral Valve Prolapse: A Pedigree Study

BACKGROUND

A subset of patients with mitral valve prolapse (MVP), a highly heritable condition, experience sudden cardiac arrest (SCA) or sudden cardiac death (SCD). However, the inheritance of phenotypic imaging features of arrhythmic MVP remains unknown.

METHODS

We recruited 23 MVP probands, including 9 with SCA/SCD and 14 with frequent/complex ventricular ectopy. Participants underwent interviews, 2-dimensional and speckle-tracking echocardiography, and 48-hour Holter/event monitoring. Each individual was categorized as having a normal mitral valve, MVP, or borderline MVP. We assessed mitral annular disjunction, curling, global longitudinal strain, segmental peak longitudinal strain, electrical/mechanical dispersion, and the postsystolic shortening index in family members and unrelated healthy controls.

RESULTS

We enrolled 23 pedigrees (14 extended pedigrees, 4 trios, and 5 duos) with a total of 121 participants (mean age 45 years, 50% women). Multigenerational SCA/SCD occurred in 2 of 14 extended pedigrees (14%) with an SCA/SCD proband. Mitral annular disjunction was present in 2 generations among 3 families (13%) and absent in 3 of 9 (33%) SCA/SCD cases. Compared with nonarrhythmic cases, arrhythmic MVP cases had more bileaflet involvement, mitral annular disjunction, curling, and abnormal valvular-myocardial mechanics, as expressed by a higher mid-inferior/inferolateral postsystolic shortening index (P<0.05). Among arrhythmic MVP cases, those with SCA had the highest mechanical dispersion (P=0.04). Family members with normal valves had lower global longitudinal strain and greater mechanical dispersion compared with nonpedigree controls (both P<0.05).

CONCLUSIONS

In the context of familial MVP, SCA/SCD is rarely observed in multiple generations and is not consistently linked to mitral annular disjunction. Instead, SCA may result from combination of abnormal valvular-myocardial mechanics and a substrate of increased mechanical/electrical dispersion. Family members with normal mitral valves also exhibit mildly abnormal global strain parameters, suggesting an underlying myopathy independent of MVP expression. Future studies are needed to determine whether SCA/SCD in MVP requires the concomitant presence of abnormal mechanics and a primary genetic myopathy.

Genetic variants associated with cardiac hypertrophy-related sudden cardiac death and cardiovascular outcomes in a Finnish population

BACKGROUND

Hypertrophic cardiomyopathy is a common cause of non-ischaemic sudden cardiac death (SCD). Left ventricular hypertrophy (LVH) without cardiomyopathy-related myocardial disarray is a common autopsy finding and is often associated with prior hypertension in SCD subjects. Our aim was to investigate novel rare gene variants among SCD subjects with presumably hypertension-related LVH and myocardial fibrosis at autopsy.

METHODS

Whole exome sequencing was used to study rare variants (minor allele frequency<0.005) estimated to be deleterious in 96 non-ischaemic SCD subjects with presumably hypertension-related LVH and myocardial fibrosis. Associations of the identified variants with cardiac disease endpoints were replicated in the Finnish national genetic study (FinnGen) dataset.

RESULTS

18 variants were estimated likely to affect protein function and 14 of these were associated with cardiomyopathies, heart failure, conduction abnormalities, hypertension and/or cardiac arrest in Finnish population (FinnGen). Three of the variants were classified as pathogenic or likely pathogenic. These include the splice site variant NM_000449.3:c.234-1G>A in regulatory factor X5 and frameshift variants NM_000449.3:c.234-1G>A in dehydrogenase/reductase 7C and NM_015873.3:c.1164del in villin like.

CONCLUSIONS

We identified rare deleterious variants associated with LVH in SCD subjects. Several of the identified rare variants associated with cardiovascular endpoints including heart failure, cardiomyopathies, cardiac arrest and hypertension in general population.

Causes of mortality following PCI: the University of New Mexico hospital experience

BACKGROUND

Mortality after percutaneous coronary intervention (PCI) remains a problem. Clinical databases such as the American College of Cardiology National Cardiovascular Data CathPCI Registry do not contain enough information to determine the specific cause of death after PCI, and thus are not able to identify opportunities for improvement (OFIs) that might have prevented the death of specific patients. We reviewed cases of death after coronary intervention to identify specific OFIs.

METHODS

The University of New Mexico electronic medical record system was used to identify PCI patients who died before discharge from 1 January 2019 to 30 June 2021. Electronic medical records for each patient were reviewed by two physicians to identify presentation before PCI, procedural success of PCI, complications of PCI, contribution of PCI complications to death, and causes of death after PCI.

RESULTS

During the study period, 48 of 894 PCI patients died before discharge. Presentation was ST elevation myocardial infarction in 23 (48%) and out of hospital cardiac arrest in 17 (35%). PCI success rate was 90%. Causes of death were most frequently cardiac (80%), septic shock (4%), mixed cardiogenic and septic shock (4%), COVID (8%), and anoxic brain injury (4%).

CONCLUSION

All post-PCI deaths in this series occurred in acutely unstable patients, with cardiac comorbidities and myocardial infarction or cardiac arrest prior to catheterization. PCI reduced culprit stenosis to ≤50% in 96% of cases with an overall procedural success rate of 90% and only one major complication. No deaths were clearly related to operator error.

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.

Sudden Cardiac Death Reporting in US Patients on Dialysis: Comparison of United States Renal Data System and National Death Index Data

Key Points

For patients with ESKD treated with hemodialysis, the causes of death reported by the United States Renal Data System and the National Death Index show substantial disagreement. In particular, the proportion of sudden cardiac death was almost two-fold higher in the United States Renal Data System (42%) compared with the National Death Index (22%).

Background

Cause-specific mortality data from the United States Renal Data System (USRDS) form the basis for identifying cardiovascular disease (CVD), specifically sudden cardiac death (SCD), as the leading cause of death for patients on dialysis. Death certificate data from the National Death Index (NDI) is the epidemiological standard for assessing causes of death for the US population. The cause of death has not been compared between the USRDS and the NDI.

Methods

Among 39,507 adults starting dialysis in the United States, we identified 6436 patients who died between 2003 and 2009. We classified the cause of death as SCD, non-SCD CVD, cancer, infection, and others and compared the USRDS data with those from the NDI.

Results

The median age at the time of death was 70 years, 44% were female, and 30% were non-Hispanic Black individuals. The median time from dialysis initiation to death was 1.2 years. Most of the deaths occurred in hospital (N =4681, 73%). The overall concordance in cause of death between the two national registries was 42% (κ=0.23; 95% confidence interval, 0.22 to 0.24). CVD, including SCD and non-SCD CVD, accounted for 67% of deaths per the USRDS but only 52% per the NDI; this difference was mainly driven by the larger proportion of SCD in the USRDS (42%) versus the NDI (22%). Of the 2962 deaths reported as SCD by the USRDS, only 35% were also classified as SCD by the NDI. Out-of-hospital deaths were more likely to be classified as SCD in the USRDS (60%) versus the NDI (29%), compared with in-hospital deaths (41% in the USRDS; 25% in the NDI).

Conclusions

Significant discordance exists in the causes of death for patients on dialysis reported by the USRDS and the NDI. Our findings underscore the urgent need to integrate NDI data into the USRDS registry and enhance the accuracy of cause-of-death reporting.

Fasting plasma glucose level and in-hospital cardiac arrest in patients with acute coronary syndrome: findings from the CCC-ACS project

BACKGROUND

The prognosis of patients with coronary artery disease is adversely affected by elevated fasting plasma glucose (FPG) levels. However, the relationship between FPG levels and in-hospital cardiac arrest (IHCA) remains unclear.

OBJECTIVES

The objective of this study was to investigate the association between FPG levels and IHCA in patients diagnosed with acute coronary syndrome (ACS).

METHODS

Data from a total of 31,726 ACS patients fitted with inclusion and exclusion criteria across 241 hospitals in the Improving Care for Cardiovascular Disease in China-ACS project from November 2014 to July 2019 were collected. Different logistic regression models were utilized to examine the associations of FPG levels with IHCA. Sensitivity analyses were then conducted to assess the robustness of the findings. Marginal effect analyses were also employed to evaluate the impact of different therapies.

RESULTS

A total of 335 cases of IHCA and 293 in-hospital mortality were recorded throughout the study. A non-linear relationship between FPG levels and IHCA was identified after adjusting for the covariates. Specifically, a significant association was found between elevated FPG levels (≥6.1 mmol/L) and an increased risk of IHCA. These findings remained consistent across different subgroup analyses including both the diabetic and non-diabetic patients. Additionally, the marginal effect analyses revealed that percutaneous coronary intervention could lower the high FPG-related risk.

CONCLUSIONS

The study findings showed a positive correlation between FPG levels and a higher incidence of IHCA, irrespective of the presence of diabetes.

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.

Interstitial fibrosis and arrhythmic mitral valve prolapse: Unraveling sex-based differences

BACKGROUND

Interstitial fibrosis as quantified by cardiovascular magnetic resonance (CMR) has been demonstrated in arrhythmic mitral valve prolapse (AMVP), a condition with known female predominance. Prior studies of interstitial fibrosis in AMVP have only included cases with significant mitral regurgitation (MR) or mitral annular disjunction (MAD), limiting our understanding of alternative arrhythmic mechanisms in mitral valve prolapse (MVP). We sought to evaluate the association between interstitial fibrosis and AMVP, regardless of MAD and without severe MR, while also investigating the contribution of sex to this association.

METHODS

We performed research-based contrast CMR in consecutive individuals with MVP between 2019 and 2022. Extracellular volume fraction (ECV%), a surrogate marker for interstitial fibrosis, was quantified using T1 mapping in the basal and mid-left ventricular slices. Replacement fibrosis was assessed using late gadolinium enhancement (LGE). AMVP was defined as MVP with frequent premature ventricular contractions and/or non-sustained/sustained ventricular tachycardia (VT) or fibrillation (VF).

RESULTS

We identified 65 MVP cases without severe MR (30 [46%] women, 22 [34%] no/trace, 30 [44%] mild, and 13 [21%] moderate MR) and with adequate ECV% measurement. Among these, 38% were classified as AMVP, including two cases of aborted VF arrest, both in premenopausal females. Global ECV% was significantly higher in AMVP vs non-AMVP (31% [27-33] vs 27% [23-30], p = 0.002). In the AMVP group, higher segmental ECV% was not limited to the inferolateral/inferior walls, typically subject to myocardial traction by the prolapsing leaflets/MAD but was more diffuse and involved atypical segments such as the anterior/anterolateral walls (p < 0.05). The association between AMVP and global ECV% was driven by female sex (32% [30-34] vs 27% [25-30], p = 0.002 in females; 28% [23-32] vs 26% [23-30], p = 0.41 in males). ECV% remained independently associated with an increased risk of arrhythmic events, including VT/VF (p < 0.01), even after adjustment for cardiovascular risk factors, MAD, and LGE (p < 0.01).

CONCLUSION

In MVP without significant MR, interstitial fibrosis by CMR is associated with an increased risk of arrhythmic events, suggesting a primary myopathic process. The selective association between interstitial fibrosis and AMVP in females may explain why severe arrhythmic complications are more prevalent among women.

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.

Application of Digital Analysis for Assessment of Coronary Sub-Occlusions in Autopsy Pathology: It Is Time to Move beyond Histology Alone

Background: Coronary artery disease (CAD) underlies most cases of myocardial infarction (MI), causing or at least contributing to oxygen supply-demand mismatch and myocardial injury, so a careful and reliable evaluation of the main coronary arteries and large branches is a key moment of autopsy in order to establish the cause of death. The aim of this study is to evaluate the application of digital image analysis in the assessment of coronary artery sub-occlusions. Methods: A total of 50 coronary sections sampled during 11 consecutive autopsies, regardless of the cause of death, were analyzed. The ideal lumen and the percentage of the residual lumen were evaluated by digital pathology using QuPath v 4.3 and by an expert pathologist. The evaluations performed were compared using Lin's concordance correlation coefficient. Results: The Lin agreement index between the two evaluation methods for all measurements showed an excellent agreement rate [0.923, with confidence interval (0.866, 0.956)]. However, in the case of critical stenosis, from 60% to 80% and from 65% to 75%, the Lin agreement index between the two evaluation methods was, respectively, 0.798 [0.603, 0.904], corresponding to good agreement, and 0.516 [0.071, 0.725], corresponding to slight agreement. The digital system has superior performance in cases where lumen occlusion falls between 60% and 80% and provides an objective assessment of the residual lumen area. Conclusions: According to the widespread availability and ease of use of these technologies, we suggest that image analysis should be considered a routine tool and established as the diagnostic gold standard in this field.

Use of strain imaging to detect subtle myocardial involvement in post COVID-19 patients: An Indian perspective

BACKGROUND

The study assessed Global longitudinal strain imaging (GLS) to detect subtle myocardial dysfunction among patients clinically recovered from COVID-19.

METHODS

All patients (n = 101 76 % males, mean age 55.45 ± 11.14 years), and controls (n = 30), underwent clinical assessment and echocardiography, including GLS assessment.

RESULTS

The prevalence of diabetes mellitus, hypertension and dyslipidemia was comparable amongst patients and controls. The average GLS was significantly lesser in post COVID patients (-16.21 ± 1.96 vs -18.49 ± 1.64 respectively, p = 0.004) and significantly higher proportion of post COVID patients had GLS > -18 % (43 % vs 22.58 % respectively, p = 0.001) as compared to controls. The RV free wall longitudinal strain (RVFLS) was also lower in the patient group (22.35 ± 4.69 vs 24.19 ± 4.11, p = 0.004) and 21.7 % post COVID-19 patients had pathological RV FWLS (> -20 %) vs controls (6.6 %). Average GLS was significantly lesser in severe post COVID patients (viz -14.25 ± 1.92 vs -16.63 ± 1.61 vs -17.63 ± 1.91, p < 0.0001, respectively among severe, moderate and mild COVID-19 patients. On performing regression analysis, severity of COVID-19 (OR 7.762) was a significant predictor of impaired GLS.

CONCLUSION

Despite normal global LVEF, post COVID-19 recovered patients had significantly lower LV GLS and RV FWLS with severe COVID-19 infection, regardless of having a clinical recovery. This study reiterates the importance of speckle tracking echocardiography as an important imaging modality for detection of subclinical myocardial dysfunction in the post COVID-19 recovered patients.

Cardiac Arrest and Cardiopulmonary Resuscitation Outcome Reports: 2024 Update of the Utstein Out-of-Hospital Cardiac Arrest Registry Template

The Utstein Out-of-Hospital Cardiac Arrest Resuscitation Registry Template, introduced in 1991 and updated in 2004 and 2015, standardizes data collection to enable research, evaluation, and comparisons of systems of care. The impetus for the current update stemmed from significant advances in the field and insights from registry development and regional comparisons. This 2024 update involved representatives of the International Liaison Committee on Resuscitation and used a modified Delphi process. Every 2015 Utstein data element was reviewed for relevance, priority (core or supplemental), and improvement. New variables were proposed and refined. All changes were voted on for inclusion. The 2015 domains-system, dispatch, patient, process, and outcomes-were retained. Further clarity is provided for the definitions of out-of-hospital cardiac arrest attended resuscitation and attempted resuscitation. Changes reflect advancements in dispatch, early response systems, and resuscitation care, as well as the importance of prehospital outcomes. Time intervals such as emergency medical service response time now emphasize precise reporting of the times used. New flowcharts aid the reporting of system effectiveness for patients with an attempted resuscitation and system efficacy for the Utstein comparator group. Recognizing the varying capacities of emergency systems globally, the writing group provided a minimal dataset for settings with developing emergency medical systems. Supplementary variables are considered useful for research purposes. These revisions aim to elevate data collection and reporting transparency by registries and researchers and to advance international comparisons and collaborations. The overarching objective remains the improvement of outcomes for patients with out-of-hospital cardiac arrest.

Ischemic heart disease mortality in individuals with inflammatory bowel disease: A nationwide analysis of disparities in the United States

INTRODUCTION

Inflammatory bowel disease (IBD) is linked to immune-mediated pathogenesis and a pro-inflammatory state, leading to accelerated atherosclerosis. This earlier onset of clinical cardiovascular disease poses significant morbidity and mortality. We sought to identify IHD mortality trends in individuals with IBD in the United States (US).

METHODS

Mortality due to ischemic heart diseases (IHD) as the underlying cause of death with the IBD as a contributor of death were queried from death certificates using the CDC database from 1999 to 2020. Yearly crude mortality rates (CMR) were estimated by dividing the death count by the respective population size, reported per 100,000 persons. Mortality rates were adjusted for age using the Direct method and compared by demographic subpopulations. Log-linear regression models were utilized to assess temporal variation (annual percentage change [APC]) in mortality.

RESULTS

Age-adjusted mortality rates (AAMR) decreased from 0.11 in 1999 to 0.07 in 2020, primarily between 1999 and 2018 (APC -4.41, p < 0.001). AAMR was higher among male (AAMR 0.08) and White (AAMR 0.08) populations compared to female populations (AAMR 0.06) and Black (AAMR 0.04) populations, respectively. No significant differences were seen when comparing mortality between urban (AAMR 0.07) and rural (AAMR 0.08) regions. Southern US regions (AAMR 0.06) had the lowest mortality rates when compared to the other US census regions: Northeastern (AAMR 0.08), Midwestern (AAMR 0.08), and Western (AAMR 0.08).

CONCLUSION

Disparities in IHD mortality exist among individuals with IBD in the US based on demographic factors, with an overall decline in mortality during the 22-year period. Further investigation is warranted to confirm these findings and evaluate for contributors to the observed disparities.

Cardiac arrest and cardiopulmonary resuscitation outcome reports: 2024 update of the Utstein Out-of-Hospital Cardiac Arrest Registry template

The Utstein Out-of-Hospital Cardiac Arrest Resuscitation Registry Template, introduced in 1991 and updated in 2004 and 2015, standardizes data collection to enable research, evaluation, and comparisons of systems of care. The impetus for the current update stemmed from significant advances in the field and insights from registry development and regional comparisons. This 2024 update involved representatives of the International Liaison Committee on Resuscitation and used a modified Delphi process. Every 2015 Utstein data element was reviewed for relevance, priority (core or supplemental), and improvement. New variables were proposed and refined. All changes were voted on for inclusion. The 2015 domains-system, dispatch, patient, process, and outcomes-were retained. Further clarity is provided for the definitions of out-of-hospital cardiac arrest attended resuscitation and attempted resuscitation. Changes reflect advancements in dispatch, early response systems, and resuscitation care, as well as the importance of prehospital outcomes. Time intervals such as emergency medical service response time now emphasize precise reporting of the times used. New flowcharts aid the reporting of system effectiveness for patients with an attempted resuscitation and system efficacy for the Utstein comparator group. Recognizing the varying capacities of emergency systems globally, the writing group provided a minimal dataset for settings with developing emergency medical systems. Supplementary variables are considered useful for research purposes. These revisions aim to elevate data collection and reporting transparency by registries and researchers and to advance international comparisons and collaborations. The overarching objective remains the improvement of outcomes for patients with out-of-hospital cardiac arrest.

Intracerebral hemorrhage mortality in individuals with atrial fibrillation: a nationwide analysis of mortality trends in the United States

BACKGROUND

Atrial fibrillation (AF) is a risk factor for intracerebral hemorrhage (ICH), both with and without use of anticoagulation. Limited data exists on mortality trends and disparities related to this phenomenon. We aimed to assess ICH mortality trends and disparities based on demographic factors in individuals with atrial fibrillation in the United States (US).

METHODS

Our cross-sectional analysis utilized mortality data from the CDC database through death certificate queries from the years 1999 to 2020 in the US. We queried for all deaths with ICH as the underlying cause of death and atrial fibrillation as the multiple causes of death. Mortality data was obtained for overall population and demographic subpopulations based on sex, race and ethnicity, and geographic region. Trend analysis and average annual-mortality percentage change (AAPC) were completed using log-linear regression models.

RESULTS

ICH age-adjusted mortality rate (AAMR) in patients with AF increased from 0.27 (95% CI 0.25-0.29) in 1999 to 0.30 (95% CI 0.29-0.32) in 2020. A higher mortality rate was observed in males (AAMR 0.33) than in females (AAMR 0.26). The highest mortality was found in Asian/Pacific Islander (AAMR: 0.32) populations, followed by White (AAMR: 0.30), Black (AAMR: 0.15), and American Indian/Alaska Native (AAMR: 0.11) populations. Southern (AAPC: 1.3%) and non-metropolitan US regions (AAPC: + 1.9%) had the highest increase in annual mortality change.

CONCLUSION

Our findings highlight the disparities in ICH mortality in patients with AF. Further investigation is warranted to confirm these findings and evaluate for contributors to the observed disparities.

Predicting Out-of-Hospital Cardiac Arrest in the General Population Using Electronic Health Records

BACKGROUND

The majority of out-of-hospital cardiac arrests (OHCAs) occur among individuals in the general population, for whom there is no established strategy to identify risk. In this study, we assess the use of electronic health record (EHR) data to identify OHCA in the general population and define salient factors contributing to OHCA risk.

METHODS

The analytical cohort included 2366 individuals with OHCA and 23 660 age- and sex-matched controls receiving health care at the University of Washington. Comorbidities, electrocardiographic measures, vital signs, and medication prescription were abstracted from the EHR. The primary outcome was OHCA. Secondary outcomes included shockable and nonshockable OHCA. Model performance including area under the receiver operating characteristic curve and positive predictive value were assessed and adjusted for observed rate of OHCA across the health system.

RESULTS

There were significant differences in demographic characteristics, vital signs, electrocardiographic measures, comorbidities, and medication distribution between individuals with OHCA and controls. In external validation, discrimination in machine learning models (area under the receiver operating characteristic curve 0.80-0.85) was superior to a baseline model with conventional cardiovascular risk factors (area under the receiver operating characteristic curve 0.66). At a specificity threshold of 99%, correcting for baseline OHCA incidence across the health system, positive predictive value was 2.5% to 3.1% in machine learning models compared with 0.8% for the baseline model. Longer corrected QT interval, substance abuse disorder, fluid and electrolyte disorder, alcohol abuse, and higher heart rate were identified as salient predictors of OHCA risk across all machine learning models. Established cardiovascular risk factors retained predictive importance for shockable OHCA, but demographic characteristics (minority race, single marital status) and noncardiovascular comorbidities (substance abuse disorder) also contributed to risk prediction. For nonshockable OHCA, a range of salient predictors, including comorbidities, habits, vital signs, demographic characteristics, and electrocardiographic measures, were identified.

CONCLUSIONS

In a population-based case-control study, machine learning models incorporating readily available EHR data showed reasonable discrimination and risk enrichment for OHCA in the general population. Salient factors associated with OCHA risk were myriad across the cardiovascular and noncardiovascular spectrum. Public health and tailored strategies for OHCA prediction and prevention will require incorporation of this complexity.

Imaging for the assessment of the arrhythmogenic potential of mitral valve prolapse

Mitral valve prolapse (MVP) is the most common valve disease in the western world and recently emerged as a possible substrate for sudden cardiac death (SCD). It is estimated an annual risk of sudden cardiac death of 0.2 to 1.9% mostly caused by complex ventricular arrhythmias (VA). Several mechanisms have been recognized as potentially responsible for arrhythmia onset in MVP, resulting from the combination of morpho-functional abnormality of the mitral valve, structural substrates (regional myocardial hypertrophy, fibrosis, Purkinje fibers activity, inflammation), and mechanical stretch. Echocardiography plays a central role in MVP diagnosis and assessment of severity of regurgitation. Several abnormalities detectable by echocardiography can be prognostic for the occurrence of VA, from morphological alteration including leaflet redundancy and thickness, mitral annular dilatation, and mitral annulus disjunction (MAD), to motion abnormalities detectable with "Pickelhaube" sign. Additionally, speckle-tracking echocardiography may identify MVP patients at higher risk for VA by detection of increased mechanical dispersion. On the other hand, cardiac magnetic resonance (CMR) has the capability to provide a comprehensive risk stratification combining the identification of morphological and motion alteration with the detection of myocardial replacement and interstitial fibrosis, making CMR an ideal method for arrhythmia risk stratification in patients with MVP. Finally, recent studies have suggested a potential role in risk stratification of new techniques such as hybrid PET-MR and late contrast enhancement CT. The purpose of this review is to provide an overview of the mitral valve prolapse syndrome with a focus on the role of imaging in arrhythmic risk stratification. CLINICAL RELEVANCE STATEMENT: Mitral valve prolapse is the most frequent valve condition potentially associated with arrhythmias. Imaging has a central role in the identification of anatomical, functional, mechanical, and structural alterations potentially associated with a higher risk of developing complex ventricular arrhythmia and sudden cardiac death. KEY POINTS: • Mitral valve prolapse is a common valve disease potentially associated with complex ventricular arrhythmia and sudden cardiac death. • The mechanism of arrhythmogenesis in mitral valve prolapse is complex and multifactorial, due to the interplay among multiple conditions including valve morphological alteration, mechanical stretch, myocardial structure remodeling with fibrosis, and inflammation. • Cardiac imaging, especially echocardiography and cardiac magnetic resonance, is crucial in the identification of several features associated with the potential risk of serious cardiac events. In particular, cardiac magnetic resonance has the advantage of being able to detect myocardial fibrosis which is currently the strongest prognosticator.

Autopsy of all young sudden death cases is important to increase survival in family members left behind

Sudden cardiac death (SCD) is an important public health problem worldwide, accounting for an estimated 6-20% of total mortality. A significant proportion of SCD is caused by inherited heart disease, especially among the young. An autopsy is crucial to establish a diagnosis of inherited heart disease, allowing for subsequent identification of family members who require cardiac evaluation. Autopsy of cases of unexplained sudden death in the young is recommended by both the European Society of Cardiology and the American Heart Association. Overall autopsy rates, however, have been declining in many countries across the globe, and there is a lack of skilled trained pathologists able to carry out full autopsies. Recent studies show that not all cases of sudden death in the young are autopsied, likely due to financial, administrative, and organizational limitations as well as awareness among police, legal authorities, and physicians. Consequently, diagnoses of inherited heart disease are likely missed, along with the opportunity for treatment and prevention among surviving relatives. This article reviews the evidence for the role of autopsy in sudden death, how the cardiologist should interpret the autopsy-record, and how this can be integrated and implemented in clinical practice. Finally, we identify areas for future research along with potential for healthcare reform aimed at increasing autopsy awareness and ultimately reducing mortality from SCD.

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

Background

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

Methods

Using an electronic health record cohort of all individuals with HF within a municipal safety-net system from 2001-2019 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.

Results

Among people with HF (n=14,829), 697 individuals had HIV (4.7%). Persons with HIV (PWH) were diagnosed with HF ten years younger on average. A higher proportion of PWH had a reduced ejection fraction at diagnosis (37.9% vs 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 (HR 1.55; 95% CI 1.37-1.76; P<0.001) and lower odds of HF hospitalization (OR 0.51; 95% CI 0.39-0.66; P<0.001). Among PWH with HF, cause of death was less often attributed to cardiovascular disease (22.5% vs 54.6% uninfected; P<0.001) and more to substance use (17.9% vs 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 non-cardiovascular causes including substance-related and HIV-related mortality.

Accuracy of etiological classification of out-of-hospital cardiac arrest: A scoping review

INTRODUCTION

The Utstein reporting template classifies the etiology of OHCA into "presumed cardiac" and "obvious non-cardiac" or "medical" and "non-medical" categories; however, the accuracy of these classifications is unclear. Ascertaining more accurately the etiology of OHCA is important to tailor advanced life support and identify etiologically consistent patient cohorts for reporting incidence and outcome and enrollment in clinical trials. This scoping review was proposed to identify the state of agreement on etiological classification based on emergency medical service (EMS) data using the Utstein format against other sources.

METHOD

We searched Medline, EBM-Cochrane, and Embase databases from 1946-2023 to identify studies that reported initial and confirmed etiologies of OHCA. A descriptive review of the included studies was conducted.

RESULT

The search yielded 22,994 citations. After excluding duplicates, 16,932 citations were reviewed for titles and abstracts. Twelve studies met the inclusion criteria of this review. The frequency of presumed cardiac etiologies based on EMS data was higher than confirmed cardiac etiologies (88% vs 33%) with 83-94% sensitivity and 73-76% specificity. In contrast, the frequency of presumed non-cardiac etiologies was lower than confirmed non-cardiac etiologies (3% vs 27%) with 52-74% sensitivity and 90-97.7% specificity estimated for respiratory disease.

CONCLUSION

Major disparities exist between current etiological classifications based on the Utstein reporting template and robust sources such as autopsy and medical records. Data linkage and validation are necessary to confirm the etiology of OHCA. Further research is needed on how this misclassification affects reported incidence and outcomes, and how contributing factors may improve etiological classifications.

Toxicological profile using mass spectrometry in sudden cardiac arrest survivors admitted to a tertiary centre

BACKGROUND

There has been no previous thorough toxicological examination of a cohort of patients with resuscitated sudden cardiac arrest. We aimed to determine the qualitative and quantitative drug composition in a resuscitated sudden cardiac arrest population, using forensic toxicology, with focus on prescribed, non-prescribed, and commonly abused drugs.

METHODS

Individuals aged 18-90 years with resuscitated sudden cardiac arrest of presumed cardiac causes were prospectively included from a single tertiary center. Data from the sudden cardiac arrest hospitalization was collected from medical reports. Drugs used during resuscitation or before the blood sampling were identified and excluded in each patient. Mass spectrometry-based toxicology was performed to determine the absence or presence of most drugs and to quantify the findings.

RESULTS

Among 186 consecutively enrolled resuscitated sudden cardiac arrest patients (median age 62 years, 83% male), 90% had a shockable rhythm, and were primarily caused by ischemic heart disease (66%). In total, 90 different drugs (excluding metabolites) were identified, and 82% of patients had at least one drug detected (median of 2 detected drugs (IQR:1-4)) (polypharmacy). Commonly abused drugs were present in 16%, and QT-prolonging drugs were present in 12%. Polypharmacy (≥5drugs) were found in 19% of patients. Importantly, none had potentially lethal concentrations of any drugs.

CONCLUSION

In resuscitated sudden cardiac arrest patients with cardiac arrest of presumed cardiac cause, routine toxicological screening provides limited extra information. However, the role of polypharmacy in sudden cardiac arrest requires further investigation. No occult overdose-related cardiac arrests were identified.

The real incidence of sudden death: Fair estimations or futile speculations?

BACKGROUND

The true incidence of sudden death remains undetermined, with controversial results from various publications over time and countries.

AIM

To investigate if different estimations would reach the values usually reported for France.

METHODS

Three different kinds of estimations were used. First, the number of resuscitated sudden deaths and necropsies for sudden death in the Haute-Garonne French administrative department (i.e. county) over the last 10years was expanded to the national level. Second, sudden death coding of death certificates was collected at the national level. Third, the total number of out-of-hospital cardiac arrests leading to any emergency call (with/without intervention) in Haute-Garonne over the last 10years was expanded to the national level.

RESULTS

There was a mean of 26 resuscitated sudden deaths and 145 necropsies for sudden death each year in Haute-Garonne, i.e. 12 to 14 sudden deaths for 100,000 inhabitants, and 7700 to 9400 sudden deaths yearly when related to the whole French population, according to the year of inclusion. Based on death certificates, a mean of 6584 sudden deaths was registered each year in France. Finally, there were about 600 yearly calls/interventions for out-of-hospital cardiac arrests in Haute-Garonne, i.e. 40 to 50 sudden deaths for 100,000 inhabitants, and 16,000 to 27,000 sudden deaths yearly for the whole French territory, according to the year of inclusion.

CONCLUSIONS

The incidence of sudden death ranges from 6500 to 27,000 in France according to the calculation methods. This huge difference raises the question of the true current incidence of sudden death, which may have been overestimated previously or may be underestimated in France. More straight prospective surveys are needed to solve this question, because of relevant implications for priorities that should be given to sudden death.

Risk Prediction for Sudden Cardiac Death in the General Population: A Systematic Review and Meta-Analysis

Objective: Identification of SCD risk is important in the general population from a public health perspective. The objective is to summarize and appraise the available prediction models for the risk of SCD among the general population. Methods: Data were obtained searching six electronic databases and reporting prediction models of SCD risk in the general population. Studies with duplicate cohorts and missing information were excluded from the meta-analysis. Results: Out of 8,407 studies identified, fifteen studies were included in the systematic review, while five studies were included in the meta-analysis. The Cox proportional hazards model was used in thirteen studies (96.67%). Study locations were limited to Europe and the United States. Our pooled meta-analyses included four predictors: diabetes mellitus (ES = 2.69, 95%CI: 1.93, 3.76), QRS duration (ES = 1.16, 95%CI: 1.06, 1.26), spatial QRS-T angle (ES = 1.46, 95%CI: 1.27, 1.69) and factional shortening (ES = 1.37, 95%CI: 1.15, 1.64). Conclusion: Risk prediction model may be useful as an adjunct for risk stratification strategies for SCD in the general population. Further studies among people except for white participants and more accessible factors are necessary to explore.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Evaluation of MADIT-II Risk Stratification Score Among Nationwide Registry of Heart Failure Patients With Primary Prevention Implantable Cardiac Defibrillators or Resynchronization Therapy Devices

The current guidelines advocate prophylactic implantable cardioverter-defibrillator (ICD) for all patients with symptomatic heart failure (HF) with low left ventricular ejection fraction. Because many patients will never use their device, a score delineating subgroups with differential ICD benefit is crucial. We aimed to evaluate the MADIT-II-based Risk Stratification Score (MRSS) feasibility to delineate the ICD survival benefit in a nationwide registry of patients with HF with prophylactic ICDs. Accordingly, all Israeli patients with HF with prophylactic ICD/cardiac resynchronization therapy defibrillators were categorized into MRSS-based risk subgroups. The study end points included overall mortality, sustained ventricular arrhythmia (VA), and a competing risk of VA (potential preventable arrhythmic death, where ICD could benefit survival) versus nonarrhythmic death. Potential ICD survival benefit was estimated by the area between these cumulative incidence curves. In 2,177 patients with HF implanted prophylactic device, 189 patients (8.7%) had VA and 316 (14.5%) died during a median follow-up of 2.9 years. The MRSS risk subgroups were significantly associated with overall mortality (p <0.001) and weakly with VA (p = 0.3). The competing risk analysis of VA versus nonarrhythmic death revealed a significantly shorter duration (p <0.001) and smaller magnitude of ICD survival benefit with increased risk subgroups, yielding an estimated 76, 60, 38, and 0 life days gained from prophylactic ICD implant during a 5-year follow-up for the MRSS low-, intermediate-, high-, and very high-risk subgroups, respectively (p for trend <0.05). In conclusion, MRSS use in a nationwide registry of patients with ischemic and nonischemic cardiomyopathy, revealed subgroups with differing ICD survival benefit, suggesting it could help evaluate prophylactic ICD survival benefit.

Interstitial Fibrosis and Arrhythmic Mitral Valve Prolapse: Unravelling Sex-Based Differences

Background

Interstitial fibrosis as quantified by cardiac magnetic resonance (CMR) has been demonstrated in arrhythmic mitral valve prolapse (MVP), a condition with known female predominance. However, prior studies included only MVP cases with significant mitral regurgitation (MR) or mitral annular disjunction (MAD). We sought to evaluate the association between interstitial fibrosis and complex ventricular ectopy (ComVE) in MVPs unselected for MAD or severe MR, and to investigate the contribution of sex to this association.

Methods

We performed contrast CMR in consecutive individuals with MVP between 2020 and 2022. Extracellular volume fraction (ECV%), a surrogate marker for interstitial fibrosis, was quantified using T 1 mapping. Replacement fibrosis was assessed using late gadolinium enhancement (LGE). ComVE, defined as frequent premature ventricular contractions and/or non-sustained/sustained ventricular tachycardia (VT), was detected using ambulatory ECG monitoring.

Results

We identified 59 MVP cases without severe MR (49% women, 80% with mild or less MR) and available ECV% measurement. Among these, 23 (39%) had ComVE, including a case of aborted ventricular fibrillation (VF) and one with sudden arrhythmic death, both females. Global ECV% was significantly greater in ComVE versus non-ComVE (31%[27-33] vs 27%[23-30], p=0.002). In MVP-ComVE, higher segmental ECV% was not limited to the inferolateral/inferior LV wall, but was also demonstrated in atypical segments including the anterior/anterolateral wall (p<0.05). The association between ComVE and ECV% was driven by female sex (32%[30-33] vs 28%[26-30], p=0.003 in females; 31%[25-33] vs 26%[23-30], p=0.22 in males). ECV% remained independently associated with an increased risk of ComVE, including VT/VF, after adjustment for cardiovascular risk factors, MAD, and LGE (p<0.01).

Conclusion

In MVP without significant MR, interstitial fibrosis by CMR is associated with an increased risk of ComVE, suggesting a primary myopathic process. The stronger association between interstitial fibrosis and ComVE in females may explain why severe arrhythmic complications are more prevalent among women.

Abstract Figure

Characterization of cardiac involvement in patients with LMNA splice-site mutation-related dilated cardiomyopathy and sudden cardiac death

Introduction: LMNA splicing mutations occur in 9.1% of cases with cardiac involvement cases, but the phenotype and severity of disease they cause have not yet been systematically studied. The aim of this study was to understand the clinical and pathogenic characteristics of the LMNA splice-site mutation phenotype in patients with LMNA-related dilated cardiomyopathy (DCM) and sudden cardiac death (SCD). Methods and Results: First, we reported a novel family with LMNA-related DCM and SCD, and the clinical characteristics of all current patients with LMNA splicing mutations were further summarized through the ClinVar database. Seventeen families with a total of 134 individuals, containing a total of 15 LMNA splicing mutation sites, were enrolled. A total of 42 subjects (31.3%) had SCD. Compared without with the non-DCM group (n = 56), the patients within the DCM group (n = 78) presented a lower incidence of atrioventricular block (AVB) (p = 0.015) and a higher incidence rates of non-sustained ventricular tachycardia (p = 0.004),) and implantable cardioverter defibrillator (ICD) implantation (p = 0.005). Kaplan‒Meier survival analysis showed that the patients with pacemaker (PM) implantation had a significantly reduced the occurrence of SCD compared to patientswith those without PM implantation (log-rank p < 0.001), while there was no significant difference in ICD implantation between the two groups (log-rank p = 0.73). Second, we identified the family that we reported with a mutation in an LMNA c.513+1 G>A mutation in the reported family, and pathogenic prediction analysis showed that the mutation site was extremely harmful. Next, we conducted gene expression levels and cardiac pathological biopsy studies on the proband of this family. We found that the expression of normal LMNA mRNA from the proband was significantly downregulated in peripheral blood mononuclear cells than incompared with healthy individuals. Finally, we comprehensively summarized the pathological characteristics of LMNA-related DCM, including hypertrophy, atrophy, fibrosis, white blood cell infiltration, intercalated disc remodeling, and downregulation of desmin and connexin 43 (Cx43) expression. Discussion: Above all, Cardiaccardiac involvement in patients with LMNA splice-site mutation presented with a high rate of SCD. Implanting a pacemaker significantly reduced the SCD rate in non-DCM patients with AVB. The pathogenic characterization was not only haveinvolved suppressed the expression of the healthy LMNA allele, but was also associated with abnormal expression and distribution of desmin and Cx43.

Circulating Acylcarnitines Associated with Hypertrophic Cardiomyopathy Severity: an Exploratory Cross-Sectional Study in MYBPC3 Founder Variant Carriers

Hypertrophic cardiomyopathy (HCM) is a relatively common genetic heart disease characterised by myocardial hypertrophy. HCM can cause outflow tract obstruction, sudden cardiac death and heart failure, but severity is highly variable. In this exploratory cross-sectional study, circulating acylcarnitines were assessed as potential biomarkers in 124 MYBPC3 founder variant carriers (59 with severe HCM, 26 with mild HCM and 39 phenotype-negative [G + P-]). Elastic net logistic regression identified eight acylcarnitines associated with HCM severity. C3, C4, C6-DC, C8:1, C16, C18 and C18:2 were significantly increased in severe HCM compared to G + P-, and C3, C6-DC, C8:1 and C18 in mild HCM compared to G + P-. In multivariable linear regression, C6-DC and C8:1 correlated to log-transformed maximum wall thickness (coefficient 5.01, p = 0.005 and coefficient 0.803, p = 0.007, respectively), and C6-DC to log-transformed ejection fraction (coefficient -2.50, p = 0.004). Acylcarnitines seem promising biomarkers for HCM severity, however prospective studies are required to determine their prognostic value.

Homelessness and Incidence and Causes of Sudden Death: Data From the POST SCD Study

Importance

Over 580 000 people in the US experience homelessness, with one of the largest concentrations residing in San Francisco, California. Unhoused individuals have a life expectancy of approximately 50 years, yet how sudden death contributes to this early mortality is unknown.

Objective

To compare incidence and causes of sudden death by autopsy among housed and unhoused individuals in San Francisco County.

Design, Setting, and Participants

This cohort study used data from the Postmortem Systematic Investigation of Sudden Cardiac Death (POST SCD) study, a prospective cohort of consecutive out-of-hospital cardiac arrest deaths countywide among individuals aged 18 to 90 years. Cases meeting World Health Organization criteria for presumed SCD underwent autopsy, toxicologic analysis, and medical record review. For rate calculations, all 525 incident SCDs in the initial cohort were used (February 1, 2011, to March 1, 2014). For analysis of causes, 343 SCDs (incident cases approximately every third day) were added from the extended cohort (March 1, 2014, to December 16, 2018). Data analysis was performed from July 1, 2022, to July 1, 2023.

Main Outcomes and Measures

The main outcomes were incidence and causes of presumed SCD by housing status. Causes of sudden death were adjudicated as arrhythmic (potentially rescuable with implantable cardioverter-defibrillator), cardiac nonarrhythmic (eg, tamponade), or noncardiac (eg, overdose).

Results

A total of 868 presumed SCDs over 8 years were identified: 151 unhoused individuals (17.4%) and 717 housed individuals (82.6%). Unhoused individuals compared with housed individuals were younger (mean [SD] age, 56.7 [0.8] vs 61.0 [0.5] years, respectively) and more often male (132 [87.4%] vs 499 [69.6%]), with statistically significant racial differences. Paramedic response times were similar (mean [SD] time to arrival, unhoused individuals: 5.6 [0.4] minutes; housed individuals: 5.6 [0.2] minutes; P = .99), while proportion of witnessed sudden deaths was lower among unhoused individuals compared with housed individuals (27 [18.0%] vs 184 [25.7%], respectively, P = .04). Unhoused individuals had higher rates of sudden death (incidence rate ratio [IRR], 16.2; 95% CI, 5.1-51.2; P < .001) and arrhythmic death (IRR, 7.2; 95% CI, 1.3-40.1; P = .02). These associations remained statistically significant after adjustment for differences in age and sex. Noncardiac causes (96 [63.6%] vs 270 [37.7%], P < .001), including occult overdose (48 [31.8%] vs 90 [12.6%], P < .001), gastrointestinal causes (8 [5.3%] vs 15 [2.1%], P = .03), and infection (11 [7.3%] vs 20 [2.8%], P = .01), were more common among sudden deaths in unhoused individuals. A lower proportion of sudden deaths in unhoused individuals were due to arrhythmic causes (48 of 151 [31.8%] vs 420 of 717 [58.6%], P < .001), including acute and chronic coronary disease.

Conclusions and Relevance

In this cohort study among individuals who experienced sudden death in San Francisco County, homelessness was associated with greater risk of sudden death from both noncardiac causes and arrhythmic causes potentially preventable with a defibrillator.

Epidemiology of pediatric out-of-hospital cardiac arrest compared with adults

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is associated with ∼90% mortality rate. In the pediatric population, this would equate to a large number of years of life lost, posing a heavy medical and economic burden to society.

OBJECTIVE

The purpose of this study was to outline the characteristics and causes of pediatric OHCA (pOHCA) and associations with survival until discharge in patients enrolled in the End Unexplained Cardiac Death Registry.

METHODS

A prospective statewide multisource registry identified all pOHCAs cases in patients aged 1-18 years in Victoria, Australia (population 6.5 million), from April 2019 to April 2021. Cases were adjudicated using ambulance, hospital, and forensic records; clinic assessments; and interviews of survivors and family members.

RESULTS

The analysis included 106 cases after adjudication (62, 58.5% male), 45 (42.5%) of which were due to cardiac causes of OHCA, with unascertained (n = 33 [31.1%]) being the most common cardiac cause reported. Respiratory events (n = 28 [26.4%]) were the most common noncardiac cause of pOHCA. Noncardiac causes were more likely to present with asystole or pulseless electrical activity (P = .007). The overall survival to hospital discharge rate was 11.3% and associated with increasing age, witnessed cardiac arrest, and initial ventricular arrhythmias (P < .05).

CONCLUSION

The incidence of pOHCA in the study population was 3.69 per 100,000 child-years. In contrast to young adults with OHCA, the most common etiology was noncardiac in pediatric patients. Prognostic factors associated with survival to discharge included increasing age, witnessed arrest, and initial ventricular arrhythmias. Rates of cardiopulmonary resuscitation and defibrillation were suboptimal.

Predicting Risk of Cardiac Arrest in Young Asian Americans: Insights from an Artificial Neural Network Analysis of the Nationwide Cohort

We used the Artificial Neural Network (ANN) model to identify predictors of Sudden Cardiac Arrest (SCA) in a national cohort of young Asian patients in the United States. The National Inpatient Sample (2019) was used to identify young Asians (18-44-year-old) who were hospitalized with SCA. The neural network's predicted criteria for SCA were selected. After eliminating missing data, young Asians (n = 65,413) were randomly divided into training (n = 45,094) and testing (n = 19347) groups. Training data (70%) was used to calibrate ANN while testing data (30%) was utilized to assess the algorithm's accuracy. To determine ANN's performance in predicting SCA, we compared the frequency of incorrect prediction between training and testing data and measured the area under the Receiver Operating Curve (AUC). The 2019 young Asian cohort had 327,065 admissions (median age 32 years; 84.2% female), with SCA accounting for 0.21%. The exact rate of error in predictions vs. tests was shown by training data (0.2% vs 0.2%). In descending order, the normalized importance of predictors to accurately predict SCA in young adults included prior history of cardiac arrest, sex, age, diabetes, anxiety disorders, prior coronary artery bypass grafting, hypertension, congenital heart disease, income, peripheral vascular disease, and cancer. The AUC was 0.821, indicating an excellent ANN model for SCA prediction. Our ANN models performed excellently in revealing the order of important predictors of SCA in young Asian American patients. These findings could have a considerable impact on clinical practice to develop risk prediction models to improve the survival outcome in high-risk patients.