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<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 >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>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<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<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<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<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.

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<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<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<0.001), and more often had a history of diabetes (20.5% vs. 14.0; p<0.001), myocardial infarction (11.9% vs. 8.7%; p<0.001) and chronic heart failure (17.0% vs. 14.7%; p<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<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<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<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