Causes of sudden cardiac death according to age and sex in persons aged 1-49 years.

BACKGROUND: Knowledge of causes of sudden cardiac death (SCD) according to age is important in clinical decision making and to lower the risk of SCD in family members of the deceased. OBJECTIVE: The purpose of this study was to report overall and sex-stratified causes of SCD according to age in persons aged 1-49 years. METHODS: 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. Danish death certificates, discharge summaries, autopsy reports, and data from nationwide registries were used to identify all SCD cases. The SCD cases were divided into 5-year age groups. RESULTS: In the 10-year study period, there were 14,294 deaths, of which 1362 (10%) were classified as SCD. Potentially inherited cardiac disease accounted for a high proportion (43%-78%) of autopsied SCD in all age groups. A significant proportion (19%-54%) of SCD was caused by sudden arrhythmic death syndrome in all age groups. Autopsy rates in both sudden unexpected death cases and SCD cases declined significantly with increasing age (74% in the youngest age group vs 35% in the oldest). CONCLUSION: The proportion of SCD cases that were identified with a potentially inherited cardiac disease postmortem was high in all studied age groups, while autopsy rates in sudden and unexpected death cases declined markedly with increasing age. Our findings indicate that diagnoses of inherited heart disease are likely missed in some SCD cases, along with the opportunity for treatment and prevention in surviving relatives.

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.

Nationwide burden of sudden cardiac death: A study of 54,028 deaths in Denmark.

BACKGROUND: A large proportion of all deaths are sudden cardiac deaths (SCDs). Reliable estimates of nationwide incidence of SCD, however, are missing. OBJECTIVES: The goals of this study were to estimate SCD burden across all age groups in Denmark and to compare it with the estimates of other common causes of death. 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 cases in 2010. According to the level of detail of the available information, all deaths were categorized as either non-SCD, definite SCD, probable SCD, or possible SCD. RESULTS: There were 54,028 deaths in Denmark in 2010, of which 6867 (13%) were categorized as SCD (591 (9%) definite SCD, 1568 (23%) probable SCD, and 4708 (68%) possible SCD). The incidence rate of definite SCD was 11 (95% confidence interval 10-12) per 100,000 person-years. Including definite, probable, and possible SCD cases, the highest possible overall SCD incidence rate was 124 (95% confidence interval 121-127) per 100,000 person-years. Estimated SCD burden was similar to or greater than the estimates of all other common causes of death. Of all SCD cases, 49% were not diagnosed with cardiovascular disease before death. CONCLUSION: SCD accounted for up to 13% of all deaths. Almost half of all SCD cases occurred in persons without a history of cardiovascular disease. Consequently, the optimization of risk stratification and prevention of SCD in the general population should be given high priority.

Decline in incidence of sudden cardiac death in the young: a 10-year nationwide study of 8756 deaths in Denmark.

AIMS: Sudden cardiac death in the young (SCDY) accounts for a significant proportion of deaths among the young. The aim of this nationwide study was to examine temporal changes in incidence and causes of SCDY in Denmark in 2000-2009. During this 10-year period, several public and private health initiatives were undertaken to decrease morbidity and mortality in Denmark. METHODS AND RESULTS: All deaths among persons aged 1-35 years in Denmark in 2000-2009 (23.7 million person-years) were included. Death certificates, autopsy reports, discharge summaries, and data from nationwide administrative registries were used to identify SCDY cases. Sudden cardiac death in the young incidence rates were age-adjusted and sex-adjusted using direct standardization. Temporal changes in standardized SCDY incidence rates were reported as average annual percent changes. In the 10-year study period, there were 8756 deaths, of which we identified 635 (7%) SCDY cases. For these SCDY cases, median age at death was 29 years and 68% were men. Standardized incidence of SCDY decreased from 3.1 per 100 000 person-years in 2000 [95% confidence interval (CI) 2.4-3.8] to 2.5 per 100 000 person-years in 2009 (95% CI 1.9-3.2). This corresponds to an average annual percent change of -3.0% (95% CI -5.8 to -0.1). The distribution of major causes of SCDY did not change significantly throughout the study period. CONCLUSION: Incidence of SCDY decreased significantly from 2000 through 2009 in Denmark with an average annual percent change of -3%. Further research is needed to elucidate underlying causes of this development.