Toxicology Screening in Sports-Related Sudden Cardiac Death: A Multinational Observational Study

BACKGROUND

Knowledge of toxicological findings among sports-related sudden cardiac death (SrSCD) is scarce.

OBJECTIVES

This study aimed to describe postmortem toxicology findings in a multinational cohort of young SrSCD.

METHODS

Patients with sudden cardiac death (SCD) aged 12 to 49 years with a complete post mortem were included from Denmark, Spain, and Australia. Postmortem findings were compared between SrSCD and non-SrSCD, and toxicology findings in SrSCD were assessed.

RESULTS

We included 3,189 SCD, of which 219 (7%) were sports-related. SrSCD patients were younger (36 years vs 41 years; P < 0.001) and of male predominance (96% vs 75%; P < 0.001), and their death was more often caused by structural cardiac disease (68% vs 61%; P = 0.038). Positive toxicology screenings were significantly less likely among SrSCD than non-SrSCD (12% vs 43%; P < 0.001), corresponding to 82% lower odds of a positive toxicology screening in SrSCD. Patient characteristics were similar between SrSCDs with positive and negative toxicology screenings, but deaths were more often unexplained (59% vs 34%). Nonopioid analgesics were the most common finding (3%), and SCD-associated drugs were detected in 6% of SrSCD. SUD was more prevalent among the SrSCD with positive toxicology (59% vs 34%).

CONCLUSIONS

Sports-related SCD mainly occurred in younger men with structural heart disease. They had a significantly lower prevalence of a positive toxicology screening compared with non-SrSCD, and detection of SCD-associated drugs was rare.

Differences among young unwitnessed sudden cardiac death, according to time from last seen alive: Insights from a 15-year nationwide study

BACKGROUND

More than half of all sudden cardiac deaths (SCDs) are unwitnessed, but the composition of the unwitnessed SCD population is poorly described.

OBJECTIVE

The purpose of this study was to compare clinical and autopsy characteristics of young unwitnessed SCD subjects, based on the time from last contact to being found dead.

METHODS

All unwitnessed SCD subjects aged 1-35 years in Denmark from 2000-2014 identified through a multisource approach were included. Time from last seen alive to being found dead was dichotomized to <1 hour or 1-24 hours. Clinical characteristics and autopsy results were compared, and predictors of autopsy were assessed by logistic regression.

RESULTS

Of 440 unwitnessed SCD subjects, 366 (83%) had not been seen alive within 1 hour of being found dead. Comorbidities differed between the groups, with more epilepsy (17% vs 5%) and psychiatric diseases (13% vs 7%) in the 24-hour group. Patients in the 24-hour group died more frequently during sleep (64% vs 23%), the autopsy rate was higher (75% vs 61%), and deaths were more often unexplained after autopsy (69% vs 53%). Having been seen within 1 hour of death independently decreased the chance of being autopsied (odds ratio 0.51; 95% confidence interval 0.27-1.00; P = .0497).

CONCLUSION

The majority of unwitnessed SCD subjects had not been seen alive within 1 hour of being found dead. Clinical- and autopsy-related characteristics differed between the 2 groups. Differences were mainly attributable to death-related circumstances and comorbidities. Excluding SCD cases not seen alive within 1 hour of being found dead would severely underestimate the burden of SCD.

Outcomes after out-of-hospital cardiac arrest in immigrants vs natives in Denmark

AIMS

Ethnic disparities subsist in out-of-hospital cardiac arrest (OHCA) outcomes in the US, yet it is unresolved whether similar inequalities exist in European countries. This study compared survival after OHCA and its determinants in immigrants and non-immigrants in Denmark.

METHODS

Using the nationwide Danish Cardiac Arrest Register, 37,622 OHCAs of presumed cardiac cause between 2001 and 2019 were included, 95% in non-immigrants and 5% in immigrants. Univariate and multiple logistic regression was used to assess disparities in treatments, return of spontaneous circulation (ROSC) at hospital arrival, and 30-day survival.

RESULTS

Immigrants were younger at OHCA (median 64 [IQR 53-72] vs 68 [59-74] years; p < 0.05), had more prior myocardial infarction (15% vs 12%, p < 0.05), more diabetes (27% vs 19%, p < 0.05), and were more often witnessed (56% vs 53%; p < 0.05). Immigrants received similar bystander cardiopulmonary resuscitation and defibrillation rates to non-immigrants, but more coronary angiographies (15% vs 13%; p < 0.05) and percutaneous coronary interventions (10% vs 8%, p < 0.05), although this was insignificant after age-adjustment. Immigrants had higher ROSC at hospital arrival (28% vs 26%; p < 0.05) and 30-day survival (18% vs 16%; p < 0.05) compared to non-immigrants, but adjusting for age, sex, witness status, first observed rhythm, diabetes, and heart failure rendered the difference non-significant (odds ratios (OR) 1.03, 95% confidence interval (CI) 0.92-1.16 and OR 1.05, 95% CI 0.91-1.20, respectively).

CONCLUSIONS

OHCA management was similar between immigrants and non-immigrants, resulting in similar ROSC at hospital arrival and 30-day survival after adjustments.

Use of Nonrecommended Drugs in Patients With Brugada Syndrome: A Danish Nationwide Cohort Study

Background Patients with Brugada syndrome (BrS) are recommended to avoid drugs that may increase their risk of arrhythmic events. We examined treatment with such drugs in patients with BrS after their diagnosis. Methods and Results All Danish patients diagnosed with BrS (2006-2018) with >12 months of follow-up were identified from nationwide registries. Nonrecommended BrS drugs were grouped into drugs to "avoid" or "preferably avoid" according to http://www.brugadadrugs.org. Cox proportional hazards analyses were performed to identify factors associated with any nonrecommended BrS drug use, and logistic regression analyses were performed to examine associated risk of appropriate implantable cardioverter defibrillator therapy, mortality, and a combined end point indicating an arrhythmic event of delayed implantable cardioverter defibrillator implantation, appropriate implantable cardioverter defibrillator therapy, and mortality. During a median follow-up of 6.8 years, 93/270 (34.4%) patients with BrS (70.4% male, median age at diagnosis 46.1 years [interquartile range, 32.6-57.4]) were treated with ≥1 nonrecommended BrS drugs. No difference in any nonrecommended BrS drug use was identified comparing time before BrS diagnosis (12.6%) with each of the 5 years following BrS diagnosis (P>0.05). Factors associated with any nonrecommended BrS drug use after diagnosis were female sex (hazard ratio [HR]) 1.83 [95% CI, 1.15-2.90]), psychiatric disease (HR, 3.63 [1.89-6.99]), and prior use of any nonrecommended BrS drug (HR, 4.76 [2.45-9.25]). No significant association between any nonrecommended BrS drug use and implantable cardioverter defibrillator therapy (n=20/97, odds ratio [OR], 0.7 [0.2-2.4]), mortality (n=10/270, OR, 3.4 [0.7-19.6]), or the combined end point (n=38/270, OR, 1.7 [0.8-3.7]) was identified. Conclusions One in 3 patients with BrS were treated with a nonrecommended BrS drug after BrS diagnosis, and a BrS diagnosis did not change prescription patterns. More awareness of nonrecommended drug use among patients with BrS is needed.

Ethnic disparities in out-of-hospital cardiac arrest: A population-based cohort study among adult Danish immigrants

Background

Ethnicity might impact out-of-hospital cardiac arrest (OHCA) risk, but it has scarcely been studied in Europe. We aimed to assess whether ethnicity influenced the risk of OHCA of cardiac cause in Danish immigrants and its interplay with risk factors for OHCA and socioeconomic status.

Methods

This nationwide study included all immigrants between 18 and 80 years present in Denmark at some point between 2001 and 2020. Regions of origin were defined as Africa, Arabic countries, Asia, Eastern Europe, Latin America, and Western countries. OHCAs with presumed cardiac cause were identified from the Danish Cardiac Arrest Registry.

Findings

Overall, among 1,011,565 immigrants, a total of 1,801 (0.2%) OHCAs (median age 64 (Q1-Q3 53–72) years, 72% males) occurred. The age- and sex- standardized (reference: Western countries) incidence of OHCA (/1,00,000 person-years) was 34.6 (27.8–43.4) in African, 34.1 (30.4–38.4) in Arabic, 33.5 (29.3–38.2) in Asian, 35.6 (31.9–39.6) in Eastern European, and 16.2 (9.0–27.2) in Latin American immigrants. When selecting Western origin as a reference, and after adjusting on OHCA risk factors, Arabic (HR 1.18, 95%CI 1.04–1.35; P=0.01), Eastern European (HR 1.28, 95%CI 1.13–1.46; P<0.001), and African origin (HR 1.34, 95%CI 1.10–1.63; P<0.01) were associated with higher risk of OHCA, whereas Latin American origin (HR 0.58, 95%CI 0.35–0.0.96; P=0.03) was associated with lower risk of OHCA. Comparable results were observed when adjusting on education level and economic status.

Interpretation

This study emphasizes that ethnicity is associated with OHCA risk, even when considering traditional cardiac arrest risk factors.

Funding

R Garcia received a grant from the Fédération Française de Cardiologie for his post-doctoral fellowship and this work was supported by the Novo Nordisk Foundation Tandem Programme 2022 (grant# 31364).

Effect of time on characterics and cause of death in unwitnessed, young sudden cardiac death cases

Introduction

Around 50% of all sudden cardiac death (SCD) cases are unwitnessed. According to the World Health Organization's definition of sudden cardiac death, any unwitnessed death is considered SCD if the person was last seen alive and well within 24 hours of death and with confirmed or suspected cardiac cause of death. The length of this timespan has been debated, as the nature of death in unwitnessed cases is less certain compared to witnessed cases. The effect of time on the composition of the group of unwitnessed SCD cases has not previously been assessed.

Purpose

This study aimed to compare clinical characteristics and causes of death among unwitnessed SCD cases last seen alive within 1 hour or 24 hours.

Methods

This nationwide, retrospective study conducted in Denmark included all deceased persons aged 1–35 from 2000–2014. The highly descriptive Danish death certificates were utilized to identify all sudden and unexpected deaths. Through subsequent examination of autopsy reports and discharge summaries, we identified all SCD cases. In addition, witnessed status and time since last seen alive (1 vs. 24 hours) were recorded. Information on comorbidities was collected from the Danish Health Registries.

Results

During the 15-year study period, we identified 857 SCD. Of these, 353 (41%) were witnessed, and 441 (51%) were unwitnessed; 62 (7%) cases had unknown witnessed status. Among the unwitnessed SCD, 75 (17%) were last seen alive within 1 hour, and the remaining 366 (83%) were seen alive within 24 hours.

Comparison of clinical characteristics and cause of death revealed few but distinct differences. Cases seen within 1 hour were of male predominance (82% vs. 65%, p=0.005). The comorbidity burden was similar, except for epilepsy which was significantly more prevalent among the group last seen alive within 24 hours. Circumstances regarding death also differed among the groups: Cases seen alive within 1 hour were more often awake at the time of death (72% vs. 36%, p&lt;0.001) when compared to cases seen alive within 24 hours, and they were less often autopsied (61% vs. 75%, p=0.02). Among autopsied cases, structural heart disease was more often the cause of death among persons last seen alive within 1 hour (58% vs. 40%, p=0.02). In both groups. The most common cause of death was sudden unexpected death, but the proportion was significantly higher in the 24-hour group (60% vs 42%, p=0.03). Arrhythmogenic cardiomyopathy and thoracic aortic dissection were significantly more prevalent among cases seen within 1 hour (11% vs. 3%, p=0.002 for both).

Conclusions

In this 15-year nationwide study of SCD in Denmark, we found few, marked differences in cause of death and clinical characteristics between unwitnessed SCD last seen alive within 1 and 24 hours. Male sex predominated in cases seen within 1 hour, and the autopsy rate was significantly lower. In the autopsied cases structural heart disease was more common in cases seen alive within 1 hour.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Copenhagen

Use of non-recommended drugs in Brugada Syndrome: a Danish nationwide cohort study

Funding Acknowledgements

Type of funding sources: None.

Background

To lower the risk of sudden cardiac death, patients with Brugada Syndrome (BrS) are recommended to avoid intake of drugs known to increase the risk of arrhythmias or the development of type-1 BrS ECG. However, information on adherence to these recommendations among patients with BrS is limited.

Purpose

To examine treatment with non-recommended drugs before and after diagnosis with BrS, risk factors of treatment with these drugs, and whether treatment was associated with a higher risk of hospitalization with ventricular arrhythmias or death.

Methods

All patients diagnosed with BrS in Denmark (1995-2018) with &gt;12 months of follow-up were identified through nationwide registries using the ICD-10 diagnosis code DI472M (PPV 95.8%). Relevant BrS risk drugs were identified and grouped as drugs to "avoid" or "preferably avoid" in agreement with the likelihood of promoting arrhythmias and type-1 BrS ECG according to brugadadrugs.org(1) (accessed August 2021). Multiple logistic regression (adjusted for sex, age, year of diagnosis, and relevant comorbidities and drugs) was performed to identify factors associated with risk drug use during follow-up.

Results

We identified 270 patients with BrS. Median age at the time of diagnosis was 46.2 years [IQR 32.6-57.6], 70.4% were male. Before the time of diagnosis, 16 patients (5.9%) were treated with a drug to "avoid" or "preferably avoid" (n=5 and n=12, respectively). During a median follow-up of 79 months, 89 patients (33%) were treated with at least one BrS risk drug after the time of diagnosis (table). A total of 22 patients with BrS (8.1%) received ≥2 different drugs at any time during follow-up. There was no significant difference in proportions of patients receiving a risk drug the year prior to diagnosis (12.2%) compared to each of the five years following diagnosis (year 1-5, respectively: 12.2%; 9.7%; 12.3%; 13.6%; 13.5% (p&gt;0.05 for all)).

Females had an odds ratio (OR) of 2.21 [95% CI 1.21-4.03] for use of risk drugs. Also associated with a greater likelihood of risk drug use after diagnosis were having a psychiatric disease at baseline (OR=4.80 [1.72-13.41]) and any use of a risk drug within 90 days prior to diagnosis (OR=8.54 [2.13-34.31]) (figure).

During follow-up, six patients were hospitalized for ventricular arrhythmias; none had redeemed a prescription of a risk drug. In total, 12 patients died, of which five (41.7%) had redeemed a prescription of one or more risk drugs within 50 days of death.

Conclusions

1/3 patients with BrS received a risk drug at any time point after diagnosis. No change in proportions of patients treated with risk drugs was identified after time of diagnosis. 5/12 patients that died during follow-up had redeemed a prescription of one or more risk drugs within 50 days of death. Female sex, any psychiatric diagnosis, and use of a non-recommended drug before diagnosis with BrS were associated with a greater likelihood of risk drug use after diagnosis.

A positive toxicology screen is a rare finding in sports-related sudden cardiac deaths

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): University of Copenhagen

Introduction

Sports-related sudden cardiac deaths (SrSCD) are rare events often occurring in healthy individuals. An underlying cardiac disease may, in combination with strenuous exercise, trigger lethal arrhythmias. Intake of drugs (legal and illicit) increases the risk of sudden cardiac death (SCD), but knowledge on toxicological findings in SrSCD remains sparse.

Purpose

This study aimed to characterize the SrSCD population in an international consortium by investigating the epidemiology and autopsy findings in SrSCD.

Methods

Participating centers of the consortium (Denmark, Australia, England, Spain) provided data on all forensically autopsied SCDs aged 12—49 years in their respective cohorts, spanning from 2000—2019. Demographics, autopsy findings, and toxicology screen were assessed. A toxicology screen was considered positive if any drug was detected, except drugs related to resuscitation.

Results

Of all 5,029 SCDs, we identified 435 (9%) SrSCD. The majority (88%) died during sports while the remaining 12% died within one hour from exercise. SrSCD occurred more often in males (91% vs 71%, p&lt;0.001) who were younger (32 vs 36 years). In SrSCD, the autopsy more frequently revealed an underlying structural cardiac cause of death (64% vs 54%, p&lt;0.001); the most frequent causes of death among SrSCDs were sudden unexpected death (SUD), ischemic heart disease (IHD), and arrhythmogenic cardiomyopathy (ACM). Toxicological screens were performed in approx. 90% of cases, regardless of relation to sport. Among SrSCD cases, the rate of a positive toxicology was less than half compared to other SCDs (18% vs 44%, p&lt;0.001). The most frequent toxicological findings among SrSCDs were ethanol, central stimulants, cannabinoids, and non-opioid analgesics.

Conclusions

Sports-related SCD accounted for 9% of all SCDs in our population aged 12—49 years. The majority of sports-related deaths (88%) occurred during exercise activity. SrSCDs more often had an underlying structural cardiac disease, mainly IHD and ACM. Positive toxicology screens were half as frequent in SrSCDs compared with non-SrSCDs.

More than half of all sudden cardiac deaths occur in persons without a history of cardiovascular disease: A study of 54,028 deaths in Denmark

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Copenhagen University Hospital, Rigshospitalet

Background

Sudden cardiac death (SCD) is a major public health problem accounting for a large proportion of global mortality. Previous studies suggest that SCD often occurs in the general population in persons not previously diagnosed with cardiovascular disease. It is evidently challenging to identify high-risk persons in an overwhelmingly large population of mainly healthy individuals and studies are needed to further characterize these SCD cases.

Purpose

To estimate SCD burden in patients not previously diagnosed with cardiovascular disease and to characterize these SCD cases.

Methods

All deaths in Denmark (population of 5.5 million) in 2010 were manually reviewed case-by-case. Autopsy reports, death certificates, and information from nationwide health registries were systematically examined to identify all SCD in 2010. The Danish National Patient Register contains information on all in- and outpatient activities at Danish hospitals and emergency departments and was used to identify all SCD cases with a previous cardiovascular diagnosis.

Results

There were 54,028 deaths in Denmark in 2010, of which 6,867 (13%) were categorized as SCD. Overall incidence rate of SCD was 124 (95%-CI: 121-127) per 100,000 person-years. Of all SCD, 59% were not diagnosed with cardiovascular disease prior to death. SCD incidence in persons with and without a history of cardiovascular disease was 790 (95%-CI: 762-820) and 78 (95%-CI: 75-80) per 100,000 person-years, respectively. This corresponds to an incidence rate ratio of 10 (95%-CI: 10-11). SCD cases with no previously diagnosed cardiovascular diseases were younger (median age 75 vs. 80 years, p&lt;0.001), more often female (45 vs. 42%, p=0.019), and on average had a lower household income (p=0.002) (Table 1). SCD cases not diagnosed with cardiovascular disease prior to death in general had fewer comorbidities, except for psychiatric diseases, which were more common in the undiagnosed group (Table 1).

Conclusion

In this large and nationwide study of all SCD in Denmark in 2010, more than half of all SCD occurred in persons without a history of cardiovascular disease. This suggests that SCD is often first manifestation of disease. We currently do not have accurate tools for SCD risk stratification in the general population and future research is needed to identify modifiable and easily measured risk factors of SCD in the general population.

Nationwide study of mortality and sudden cardiac death in young persons diagnosed with chronic kidney disease

AIMS

The aim of this study was to compare short- and long-term risk of sudden cardiac death (SCD) among persons aged 18-49 years with and without chronic kidney disease (CKD).

METHODS AND RESULTS

Using Danish nationwide health registries, all persons aged 18-49 years diagnosed with earlier stages of CKD or chronic kidney failure from 1 July 1995 through 2009 were identified. Non-exposed subjects matched on sex and birth-year were identified. All SCD in the Danish population aged 18-49 years in 2000-2009 have previously been identified using information from the Danish nationwide health registries, death certificates, and autopsy reports. In total, 9308 incident cases of earlier stage CKD and 1233 incident cases of chronic kidney failure were included. Among patients with earlier stage CKD, the absolute risk of SCD 1, 5, and 10 years after diagnosis was 0.14%, 0.37%, and 0.68%, respectively. Compared with age- and sex-matched subjects the corresponding relative risk (RR) was 20.3 [95% confidence interval (CI) 8.4-48.8], 7.1 (95% CI 4.2-12.0), and 6.1 (95% CI 3.8-9.7), respectively. Among patients with chronic kidney failure, the absolute 1-, 5-, and 10-year risk of SCD was 0.17%, 0.56%, and 2.07%, respectively. The corresponding RR was 12.5 (95% CI 1.4-111.6), 7.9 (95% CI 2.3-27.0), and 10.1 (95% CI 4.5-22.6).

CONCLUSION

Persons with earlier stage CKD and chronic kidney failure had increased risk of SCD compared with the background population with a 6- to 20-fold increased risk of SCD. These findings underline the importance of early cardiovascular risk monitoring and assessment in persons with CKD.

Sex differences in sudden cardiac death in a nationwide study of 54 028 deaths

Objective

Sudden cardiac death (SCD) is a leading cause of death and is more common among males than females. Epidemiological studies of sex differences in SCD cases of all ages are sparse. The aim of this study was to examine differences in incidence rates, clinical characteristics, comorbidities and autopsy findings between male and female SCD cases.

Methods

All deaths in Denmark in 2010 (54 028) were reviewed. Autopsy reports, death certificates, discharge summaries and nationwide health registries were reviewed to identify cases of SCD. Based on the available information, all deaths were subcategorised into definite, probable and possible SCD.

Results

A total of 6867 SCD cases were identified, of which 3859 (56%) were males and 3008 (44%) were females. Incidence rates increased with age and were higher for male population across all age groups in the adult population. Average age at time of SCD was 71 years among males compared with 79 among females (p<0.01). The greatest difference in SCD incidence between males and females was found among the 35–50 years group with an incidence rate ratio of 3.7 (95% CI: 2.8 to 4.8). Compared with female SCD victims, male SCD victims more often had cardiovascular diseases and diabetes mellitus (p<0.01).

Conclusion

This is the first nationwide study of sex differences in SCD across all ages. Differences in incidence rates between males and females were greatest among young adults and the middle-aged. Incidence rates of SCD among older female population approached that of the male population, despite having significantly more cardiovascular disease and diabetes in male SCD cases.

Risk of sports-related sudden cardiac death in women

Sudden cardiac death (SCD) is a tragic incident accountable for up to 50% of deaths from cardiovascular disease. Sports-related SCD (SrSCD) is a phenomenon which has previously been associated with both competitive and recreational sport activities. SrSCD has been found to occur 5-33-fold less frequently in women than in men, and the sex difference persists despite a rapid increase in female participation in sports. Establishing the reasons behind this difference could pinpoint targets for improved prevention of SrSCD. Therefore, this review summarizes existing knowledge on epidemiology, characteristics, and causes of SrSCD in females, and elaborates on proposed mechanisms behind the sex differences. Although literature concerning the aetiology of SrSCD in females is limited, proposed mechanisms include sex-specific variations in hormones, blood pressure, autonomic tone, and the presentation of acute coronary syndromes. Consequently, these biological differences impact the degree of cardiac hypertrophy, dilation, right ventricular remodelling, myocardial fibrosis, and coronary atherosclerosis, and thereby the occurrence of ventricular arrhythmias in male and female athletes associated with short- and long-term exercise. Finally, cardiac examinations such as electrocardiograms and echocardiography are useful tools allowing easy differentiation between physiological and pathological cardiac adaptations following exercise in women. However, as a significant proportion of SrSCD causes in women are non-structural or unexplained after autopsy, channelopathies may play an important role, encouraging attention to prodromal symptoms and family history. These findings will aid in the identification of females at high risk of SrSCD and development of targeted prevention for female sport participants.

Sex differences in sudden cardiac death: a nationwide study of 54,028 deaths in Denmark

Background

Sudden cardiac death (SCD) is a leading cause of death. SCD is more common among males. In women SCD is, however, still the leading cause of death. The SCD epidemiology among women is less studied.

Purpose

The aim of this study was to examine how incidence rates, clinical characteristics and causes of SCD vary between males and females.

Methods

All deaths in Denmark in the 2010 (54,028) were included in the study. Autopsy reports, death certificates, discharge summaries and nationwide health registries were reviewed to identify cases of SCD. Sex and age specific SCD incidence rates in the general population were calculated, and age-adjusted clinical characteristics were compared using logistic regression.

Results

A total of 6,867 SCD cases were identified, of which 3,859 (56%) were males and 3,008 (44%) were females. Incidence rates increased with age and was higher for males across all age groups in the adult population. Average age of SCD was 71.3±14.3 years among males compared to 79.4±13.3 among females (mean ± standard deviation, p&lt;0.0001). The greatest difference in incidence between males and females was found among the 35–50-year group with an incidence rate ratio of 3.7 (95% confidence interval: 2.8–4.8). Although the males were younger, males more often had cardiovascular diseases and diabetes mellitus prior to SCD. Among autopsied cases, coronary artery disease (CAD) was the leading cause of death among both sexes. Structural causes of SCD, other than CAD, were more common among women (p&lt;0.01).

Conclusion

In this nationwide study of sex differences in SCD across all age groups, the differences in incidence rates between males and females were greatest among young adults and the middle-aged. Incidence rates of SCD among older females approached that of the male population, despite significantly more cardiovascular disease and diabetes mellitus in the male population in the 10 years prior to SCD.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark

Racial disparities in out-of-hospital cardiac arrest in Denmark

Introduction

American studies have pointed out racial disparities regarding sudden cardiac death occurrence and outcomes. Black individuals have higher sudden cardiac death rates and lower survival compared with white subjects (1). Although income and social status partly explain differences in outcomes (2), sudden cardiac death is 2-fold higher in black individuals after adjustment on these characteristics (3,4).

In Denmark, immigrants account for 9.1% of the population (5) but to date, no data exists regarding Out-of-Hospital Cardiac Arrest (OHCA) incidence.

Purpose

The main objective of this study was to compare the incidence of OHCA among native and immigrant individuals between 2001 and 2014 in Denmark.

Methods

This nationwide study included all patients identified from the Danish Cardiac Arrest Registry with OHCA of presumed cardiac cause between 18 and 80 years from 2001 to 2014 (6).

The primary outcome was OHCA occurrence defined as a clinical condition of cardiac arrest resulting in resuscitation efforts either by bystanders or by EMS personnel. The immigrant status was defined as native or immigrant according to the national database from Statistics Denmark. An immigrant was defined as a person born abroad whose both parents were either foreign citizens or born abroad.

The odds ratio of OHCA between immigrants and native Danes were adjusted according to age, sex, income, and education level.

Results

A total of 33,730 OHCA were recorded between 2001 and 2014. Among them, 1,684 occurred in immigrants and 32,046 in natives. Compared to natives, immigrant victims of OHCA were younger (62.0 [51.0, 71.0] vs. 66.0 [56.0, 74.0], p&lt;0.001), and more often had a history of diabetes (20.5% vs. 14.0; p&lt;0.001), myocardial infarction (11.9% vs. 8.7%; p&lt;0.001) and chronic heart failure (17.0% vs. 14.7%; p&lt;0.01). Female proportion was not statistically different between the two groups (30.2% vs. 31.3% of immigrants and natives respectively; p=0.32).

The incidence of OHCA was 61.0/100,000 person-years in natives and 35.0/100,000 person-years in immigrants (OR=0.57; 95% CI 0.54–0.60; p&lt;0.001). Between 2001 and 2014, the OHCA incidence decreased from 71.4 [67.9–75.0] to 70.9 [68.2–73.6]/100 000 person-years in natives (p=0.99) and from 40.2 [30.8–51.5] to 36.5 [31.1–42.6] /100,000 person-years in immigrants (p=0.91) (Figure).

After logistic regression, compared to natives, the immigrant status was associated with 0.61-fold odds of OHCA when adjusting on age and sex (OR=0.61; 95% CI 0.59–0.65; p&lt;0.001), and 0.65-fold odds of OHCA when adjusting on age, sex, income, and education level (OR=0.66; 95% CI 0.63–0.70; p&lt;0.001).

Conclusion

This is the first study assessing the incidence of OHCA in immigrants versus natives in a European country. Despite higher cardiovascular burden, the incidence of OHCA was lower in immigrants even when adjusted on sex, age, income, and education reflecting a selection of individuals migrating to Denmark.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Fédération Française de Cardiologie

Witnessed and unwitnessed sudden cardiac death: a nationwide study of persons aged 1-35 years

AIMS

The aim of this study is to compare clinical characteristics and causes of death among witnessed and unwitnessed sudden cardiac death (SCD) cases aged 1-35 years.

METHODS AND RESULTS

In this retrospective nationwide study, all deaths in persons aged 1-35 years in Denmark during 2000-09 were included (23.7 million person-years). Using the in-depth descriptive Danish death certificates and Danish nationwide registries, 860 cases of sudden, unexpected death were identified. Through review of autopsy reports and register data, we identified 635 cases of SCD of which 266 (42%) were witnessed and 326 (51%) were unwitnessed. In 43 cases (7%), witnessed status was missing. Clinical characteristics were overall similar between the two groups. We found a male predominance among unwitnessed SCD compared to witnessed SCD (71% and 62%, respectively, P-value 0.012), as well as more psychiatric comorbidity (20% and 13%, respectively, P-value 0.029). Unwitnessed SCD more often occurred during sleep whereas witnessed SCD more often occurred while the individual was awake and relaxed (P-value < 0.001). The autopsy rate among all SCD cases was 70% with no significant difference in autopsy rate between the two groups. Sudden unexplained death, which was the leading autopsy conclusion in both groups, was more frequent among unwitnessed SCD (P-value 0.001).

CONCLUSION

Several clinical characteristics and autopsy findings were similar between witnessed and unwitnessed SCD cases. Our data support the inclusion of both witnessed and unwitnessed cases in epidemiological studies of SCD cases aged 1-35 years, although the risk of misclassification is higher among unwitnessed and non-autopsied cases of SCD.

Symptoms Preceding Sports-Related Sudden Cardiac Death in Persons Aged 1-49 Years

PURPOSE OF REVIEW

Sports-related sudden cardiac death (Sr-SCD) is a leading natural cause of death in young athletes. To prevent Sr-SCD in athletes, it is important to identify individuals at risk. This review sought to summarize the current knowledge of symptoms prior to Sr-SCD in athletes aged 1-49 years.

RECENT FINDINGS

Cardiovascular screening of athletes is a subject of interest. However, the cost of ECG screening in a young population is relatively high compared to potential benefits, and systematic screening of athletes is heavily debated. In the background population, both cardiac and non-specific symptoms are often present prior to SCD. Both cardiac and non-specific symptoms are present in up to 74% prior to Sr-SCD. The main symptoms are syncope, chest pain, palpitations and dizziness. Knowledge of symptoms could potentially be used in combination with non-invasive prediction models to prevent Sr-SCD and treat athletes at risk.

Sudden cardiac death among persons with diabetes aged 1-49 years: a 10-year nationwide study of 14 294 deaths in Denmark

AIMS

The aim of this study was to compare nationwide incidence rate (IR) of sudden cardiac death (SCD) in persons aged 1-49 years with and without diabetes mellitus (DM).

METHODS AND RESULTS

The study population consisted of all persons in Denmark aged 1-49 years in 2000-09, which equals 27.1 million person-years. All 14 294 deaths in the 10-year period were included. By using the highly descriptive Danish death certificates, 1698 cases of sudden and unexpected death were identified. Through review of autopsy reports, discharge summaries, and the Danish registries, we identified 1363 cases of SCD. The Danish Register of Medicinal Product Statistics was used to identify persons with type 1 DM and type 2 DM. Among the 14 294 decedents, there were 669 with DM, of which 118 suffered SCD (9% of all SCD), making SCD the leading cause of death among young persons with DM. Among those aged 1-35 years, the IR of SCD-DM was 21.9 per 100 000 person-years compared to 2.6 per 100 000 person-years among persons without DM [IR ratio 8.6, 95% confidence interval (CI) 5.8-28.6]. Within the age range 36-49 years, the IR among persons with DM was 119.8 per 100 000 person-years compared to 19.7 per 100 000 person-years among persons without DM (IR ratio 6.1, 95% CI 4.7-7.8).

CONCLUSION

We found that young persons with DM aged 1-35 years had >8-fold higher SCD IR compared to young persons without DM. Our study highlights the need for early cardiovascular risk monitoring and assessment in young persons with DM.

Cause-specific mortality in children and young adults with diabetes mellitus: A Danish nationwide cohort study

Aims

Persons with diabetes mellitus have increased all-cause mortality compared with the general population. Nationwide studies on causes of death and mortality among young persons with diabetes mellitus are sparse. The aim of this study was to examine all-cause and cause-specific mortality in children and young adults with and without diabetes.

Methods and results

The study population consisted of all persons in Denmark aged 1–35 years in 2000–2009 and 36–49 years in 2007–2009, which equals 27.1 million person-years. All 14,294 deaths in the 10-year period were included and cause of death was established based on information from autopsy reports and death certificates. The Danish Register of Medicinal Product Statistics was used to identify persons with type 1 diabetes and type 2 diabetes. During the study period, which included 153,070 diabetic person-years, 669 (5% of all deceased) persons with diabetes mellitus died, of which 70% had type 1 and 30% had type 2 diabetes. Persons with diabetes mellitus had an all-cause mortality rate (ASMR) of 327 per 100,000 person-years compared with 74 per 100,000 person-years among persons without diabetes mellitus (ASMR ratio 4, p &lt; 0.001). The leading cause of death among persons with diabetes mellitus was cardiac diseases (n = 230, 34%) with an ASMR ratio of 8 (95% confidence interval 6–9).

Conclusions

Young persons with diabetes mellitus had four-fold increased all-cause mortality and eight-fold increased cardiovascular mortality compared with persons without diabetes mellitus. Focus on cardiovascular risk monitoring and management among young persons with diabetes mellitus is warranted to prevent premature death in diabetes mellitus.