Bereavement was associated with higher risk of incident cardiovascular disease among Swedish adults before and during the COVID-19 pandemic, with the strongest pandemic-period association observed following partner loss, according to a nationwide cohort study published in JAMA Network Open.

Researchers analyzed Swedish national registry data from 5.4 million adults aged 30 years or older during 2018 to 2019 and 5.5 million during 2020 to 2021. Participants with prior cardiovascular disease (CVD), migration, or both during the preceding 3 years were excluded.

Bereavement was defined as the death of a partner, child, parent, or sibling and was modeled as a time-varying exposure. The primary endpoint was first diagnosis of any CVD event identified through hospital outpatient visits, hospitalization records, or mortality data. Secondary outcomes included myocardial infarction, cerebrovascular disease, heart failure, acute CVD events, and fatal CVD events.

Across both periods, bereavement was associated with higher adjusted rates of incident CVD. Following partner loss, the adjusted hazard ratio (HR) for incident CVD was 1.30 during 2018 to 2019 and 1.46 during the pandemic period — a statistically significant period difference on formal interaction testing. Following sibling loss, corresponding HRs were 1.16 and 1.23; however, formal interaction testing did not demonstrate a statistically significant period-related difference for sibling loss.

Associations were also observed following loss of a child or parent, though the magnitude did not significantly differ between periods.

Elevated CVD risk was apparent across myocardial infarction, cerebrovascular disease, heart failure, acute CVD events, and fatal CVD events. Risk was generally highest within 90 days following bereavement and was often greatest during the first 7 days — a finding the authors noted may identify the acute post-loss period as a clinically important window for monitoring and preventive intervention.

The study identified age-related differences by relationship type. CVD risk following partner or parent loss increased with age, whereas associations following child or sibling loss were stronger among younger adults. The researchers suggested these patterns may reflect differences in emotional dependency, caregiving responsibilities, social support structures, and competing mortality risks across life stages.

In subgroup analyses, individuals whose partner or child died from COVID-19 had some of the highest observed CVD risks, although confidence intervals overlapped with estimates for other causes of death.

The investigators cautioned that hazard ratios across bereavement categories should not be directly compared, as each relationship type was evaluated within a separate restricted cohort with distinct age distributions and baseline CVD risk profiles.

Models were adjusted for age, sex, educational attainment, household income, diabetes history, and psychiatric disorders. The study lacked data on smoking, obesity, and other cardiovascular risk factors, however, raising the possibility of residual confounding. The authors also noted that reduced hospital utilization during the pandemic may have contributed to underdiagnosis of CVD events, potentially biasing pandemic-period associations toward the null.

Generalizability outside Sweden may be limited given the country's universal welfare system and comparatively less restrictive pandemic mitigation policies, factors that could influence both the experience of bereavement and access to cardiovascular care.

"These findings suggest that bereavement may be a period of heightened cardiovascular vulnerability," wrote lead study author Fen Yang, MD, PhD, of Karolinska Institutet, and colleagues, "underscoring the importance of targeted clinical monitoring and preventive care for bereaved individuals."

Disclosures can be found in the study.

Source: JAMA Network Open