Bereavement of a child as a risk of heart failure

Heart failure (HF) is a leading cause of cardiovascular morbidity and mortality.1 In developed countries, 1%–2% of the population suffers from HF, with a prevalence of ≥10% among people aged 70 years or older.2 Despite improvements in the medical management of HF, the prognosis of HF patients continues to remain unfavourable. The risks of developing HF include traditional atherosclerotic factors such as hypertension, diabetes mellitus, dyslipidaemia, some modern factors such as kidney and pulmonary diseases, sleep disordered breathing,3 and socioeconomic factors (e.g. education, income levels, and social isolation).4 Psychological factors, including mental stress, may also act as risk factors for HF.5 A bereavement of a close family member can be a distressing experience that may induce a tremendous amount of mental stress. In particular, the death of a child is presumed to be an extremely devastating event for parents. In this issue of the Journal, Wei and colleagues provide novel findings regarding the death of a child in relation to the risk of HF for the parents in a large-scale population-based cohort study, using medical records of the Danish and Swedish Medical Birth Registers.6 During a median follow-up of 22 years, 129 829 out of 6 717 349 participants (1.9%) who participated in the study lost at least one child. The incidence rate of HF was 113.4 per 105 person-years in the bereaved parents, while that in non-bereaved parents was 44.3. The multivariable incidence rate ratio (IRR) (95% confidence interval) was 1.35 (1.29–1.41, p< 0.001) in the bereaved parents. The association between the death of a child and HF was observed regardless of the cause of death (i.e. cardiovascular, other natural, and unnatural causes) with relatively high IRR for cardiovascular deaths. The association was U-shaped when the bereaved parents were categorized in relation to the number of remaining live children when the parents had loss (the lowest IRR for 1–2 live children) or by the age of the deceased child (the lowest IRR for ages from 13 to 18 years). Stronger associations were observed in mothers as opposed to