Out-of-hospital cardiac arrest associated with venous thromboembolism-a Swedish population-based cohort study

Venous thromboembolism (VTE) is a common and preventable cardiovascular disease but is potentially fatal if it presents as pulmonary embolism. There are few population-based studies on out-of-hospital cardiac arrest (OHCA) associated with VTE.

We aimed to investigate the prevalence and survival of VTE-associated OHCA in relation to sex, age, and presenting rhythm.

This population-based cohort included all individuals over 15 years registered with a medical OHCA in Sweden 2008-2018. Data from national registers were used. Association with presenting rhythm, 30-day survival, and sex was estimated using adjusted multinomial and binary logistic regression for odds ratios (ORs) with 95% CI.

OHCA was associated with VTE in 852 (2.0%) of 41 813 individuals. The median age for VTE-associated OHCA was 69, compared to 73 for the entire cohort, with a higher female prevalence (45% vs 34%). Younger women had a proportionally higher incidence of VTE-associated OHCA than men of the same age. Pulseless electrical activity and asystole had adjusted ORs of 17.2 (95% CI, 11.3-26.0) and 9.59 (95% CI, 6.37-14.4) for VTE-associated OHCA compared with the entire cohort. The 30-day survival was substantially lower in the VTE group compared with the overall medical OHCA group, 2.0% vs 12%, adjusted OR 0.25 (95% CI, 0.13-0.47).

This nationwide study confirms that VTE-associated OHCA is uncommon and almost always fatal. Despite fewer women experiencing OHCA, a higher proportion had VTE-associated OHCA, especially younger women. Our findings highlight the need for better prevention and identification of VTE-associated OHCA, particularly in women.