Sudden cardiac death in young adult

Sudden death in young South European population: a cross-sectional study of postmortem cases

To describe the annual incidence and the leading causes of sudden non-cardiac and cardiac death (SCD) in children and young adult Portuguese population. We retrospectively reviewed autopsy of sudden unexpected deaths reports from the Portuguese National Institute of Legal Medicine and Forensic Sciences' database, between 2012 and 2016, for the central region of Portugal, Azores and Madeira (ages 1-40: 26% of the total population). During a 5-year period, 159 SD were identified, corresponding to an annual incidence of 2,4 (95%confidence interval, 1,5-3,6) per 100.000 people-years. Victims had a mean age of 32 ± 7 years-old, and 72,3% were male. There were 70,4% cardiac, 16,4% respiratory and 7,5% neurologic causes of SD. The most frequent cardiac anatomopathological diagnosis was atherosclerotic coronary artery disease (CAD) (33,0%). There were 15,2% victims with left ventricular hypertrophy, with a diagnosis of hypertrophic cardiomyopathy only possible in 2,7%. The prevalence of cardiac pathological findings of uncertain significance was 30,4%. In conclusion, the annual incidence of SD was low. Atherosclerotic CAD was diagnosed in 33,0% victims, suggesting the need to intensify primary prevention measures in the young. The high prevalence of pathological findings of uncertain significance emphasizes the importance of molecular autopsy and screening of first-degree relatives.

Predictive scores for identifying patients with type 2 diabetes mellitus at risk of acute myocardial infarction and sudden cardiac death

Introduction

The present study evaluated the application of incorporating non‐linear J/U‐shaped relationships between mean HbA1c and cholesterol levels into risk scores for predicting acute myocardial infarction (AMI) and non‐AMI‐related sudden cardiac death (SCD) respectively, amongst patients with type 2 diabetes mellitus.

Methods

This was a territory‐wide cohort study of patients with type 2 diabetes mellitus above the age 40 and free from prior AMI and SCD, with or without prescriptions of anti‐diabetic agents between January 1st, 2009 to December 31st, 2009 at government‐funded hospitals and clinics in Hong Kong. Patients recruited were followed up until 31 December 2019 or their date of death. Risk scores were developed for predicting incident AMI and non‐AMI‐related SCD. The performance of conditional inference survival forest (CISF) model compared to that of random survival forests (RSF) model and multivariate Cox model.

Results

This study included 261 308 patients (age = 66.0 ± 11.8 years old, male = 47.6%, follow‐up duration = 3552 ± 1201 days, diabetes duration = 4.77 ± 2.29 years). Mean HbA1c and low high‐density lipoprotein‐cholesterol (HDL‐C) were significant predictors of AMI on multivariate Cox regression. Mean HbA1c was linearly associated with AMI, whilst HDL‐C was inversely associated with AMI. Mean HbA1c and total cholesterol were significant multivariate predictors with a J‐shaped relationship with non‐AMI‐related SCD. The AMI and SCD risk scores had an area under the curve (AUC) of 0.666 (95% confidence interval (CI) = [0.662, 0.669]) and 0.677 (95% CI = [0.673, 0.682]), respectively. CISF significantly improves prediction performance of both outcomes compared to RSF and multivariate Cox models.

Conclusion

A holistic combination of demographic, clinical and laboratory indices can be used for the risk stratification of patients with type 2 diabetes mellitus for AMI and SCD.

Sudden Cardiac Death in the Young: Incidence, Trends, and Risk Factors in a Nationwide Study

BACKGROUND

Sudden cardiac death (SCD) in the young is devastating. Contemporary incidence remains unclear with few recent nationwide studies and limited data addressing risk factors for causes. We aimed to determine incidence, trends, causes, and risk factors for SCD in the young.

METHODS AND RESULTS

The National Coronial Information System registry was reviewed for SCD in people aged 1 to 35 years from 2000 to 2016 in Australia. Subjects were identified by the International Classification of Diseases, Tenth Revision code relating to circulatory system diseases (I00-I99) from coronial reports. Baseline demographics, circumstances, and cause of SCD were obtained from coronial and police reports, alongside autopsy and toxicology analyses where available. During the study period, 2006 cases were identified (median age, 28±7 years; men, 75%; mean body mass index, 29±8 kg/m²). Annual incidence ranged from 0.91 to 1.48 per 100 000 age-specific person-years, which was the lowest in 2013 to 2015 compared with previous 3-year intervals on Poisson regression model (P=0.001). SCD incidence was higher in nonmetropolitan versus metropolitan areas (0.99 versus 0.53 per 100 000 person-years; P<0.001). The most common cause of SCD was coronary artery disease (40%), followed by sudden arrhythmic death syndrome (14%). Incidence of coronary artery disease-related SCD decreased from 2001-2003 to 2013-2015 (P<0.001). Proportion of SCD related to sudden arrhythmic death syndrome increased during the study period (P=0.02) although overall incidence was stable (P=0.22). Residential remoteness was associated with coronary artery disease-related SCD (odds ratio, 1.44 [95% CI, 1.24-1.67]; P<0.001). For every 1-unit increase, body mass index was associated with increased likelihood of SCD from cardiomegaly (odds ratio, 1.08 [95% CI, 1.05-1.11]; P<0.001) and dilated cardiomyopathy (odds ratio, 1.04 [95% CI, 1.01-1.06]; P=0.005).

CONCLUSIONS

Incidence of SCD in the young and specifically coronary artery disease-related SCD has declined in recent years. Proportion of SCD related to sudden arrhythmic death syndrome increased over the study period. Geographic remoteness and obesity are risk factors for specific causes of SCD in the young.

Drug-induced life-threatening arrhythmias and sudden cardiac death: A clinical perspective of long QT, short QT and Brugada syndromes

Sudden cardiac death is a major public health challenge, which can be caused by genetic or acquired structural or electrophysiological abnormalities. These abnormalities include hereditary channelopathies: long QT, short QT and Brugada syndromes. These syndromes are a notable concern, particularly in young people, due to their high propensity for severe ventricular arrhythmias and sudden cardiac death. Current evidence suggests the involvement of an increasing number of drugs in acquired forms of long QT and Brugada syndromes. However, drug-induced short QT syndrome is still a rarely reported condition. Therefore, there has been speculation on its clinical significance, since few fatal arrhythmias and sudden cardiac death cases have been described so far. Drug-induced proarrhythmia is a growing challenge for physicians, regulatory agencies and the pharmaceutical industry. Physicians should weigh the risks of potentially fatal outcomes against the therapeutic benefits, when making decisions about drug prescriptions. Growing concerns about its safety and the need for more accurate predictive models for drug-induced fatal outcomes justify further research in these fields. The aim of this article is to comprehensively and critically review the recently published evidence with regard to drug-induced life-threatening arrhythmias and sudden cardiac death. This article will take into account the provision of data to physicians that are useful in the identification of the culprit drugs, and thus, contribute to the prompt recognition and management of these serious clinical conditions.

[Inverted takotsubo cardiomyopathy due to subarachnoid haemorrhage]

We present a case of a 34-year-old woman with cardiogenic shock after successful resuscitation. In the medical history migraine was known. Emergency echocardiography demonstrated left ventricular dysfunction with hypokinetic basal and midventricular segments and hyperkinetic apex. Cerebral computed tomography suggested a massive subarachnoid haemorrhage (SAH) with transtentorial herniation, so that taking into account the clinical history (severe headache) the diagnosis of a SAH-associated inverted takotsubo cardiomyopathy could be made. In the case of subarachnoid haemorrhage it should be noted that extracerebral organ dysfunction, e.g. inverted takotsubo cardiomyopathy, frequently occurs.