Abstract
IMPORTANCE: Bereavement is a known risk factor for cardiovascular disease (CVD), but it remains unclear whether the COVID-19 pandemic-which disrupted health care and increased social isolation-altered this association. OBJECTIVE: To compare the association between bereavement and incident CVD before and during the pandemic. DESIGN, SETTING, AND PARTICIPANTS: This cohort study of Swedish national health registries included individuals aged 30 years or older in Sweden during the pre-COVID-19 (2018-2019) and COVID-19 (2020-2021) periods. Analyses were performed between September 2024 and August 2025. EXPOSURES: Bereavement exposure was defined as the loss of a partner, child, parent, or sibling. MAIN OUTCOMES AND MEASURES: The first diagnosis of any CVD event, identified from an outpatient hospital visit or hospitalization via the Swedish Patient Register or death via the Swedish Cause of Death Register. Cox regression was used to estimate hazard ratios (HRs) of incident CVD after bereavement by study period, type of loss, and age. RESULTS: Analysis included a total of 5 365 829 study participants (51.4% female; median [IQR] age, 51.6 [40.4-64.6] years) during the pre-COVID-19 period and 5 522 898 study participants (51.4% female; median [IQR] age, 49.8 [38.2-62.8] years) during the COVID-19 period. Overall, 372 477 (6.94%) and 368 902 (6.68%) incident CVD cases were identified during the pre-COVID-19 and COVID-19 periods, respectively. Bereavement was associated with increased CVD risk regardless of period or type of loss. However, the risk increment was greater during the COVID-19 period compared with the pre-COVID-19 period for loss of a partner (HR, 1.46 [95% CI, 1.41-1.51] vs 1.30 [95% CI, 1.26-1.35]; P for difference < .001) and sibling (HR, 1.23 [95% CI, 1.20-1.27] vs 1.16 [95% CI, 1.13-1.19]; P for difference = .003). No period difference was noted for the loss of a child or parent. The risk increment after loss of a partner or parent increased with age, while the risk after loss of a child or sibling decreased with age. CONCLUSIONS AND RELEVANCE: In this cohort study, bereavement was associated with increased CVD risk both before and during the COVID-19 pandemic; however, a stronger association for partner or sibling loss was noted during the pandemic. These findings suggest that bereavement may be a period of heightened cardiovascular vulnerability, underscoring the importance of targeted clinical monitoring and preventive care for bereaved individuals.