OUT-OF-HOSPITAL CARDIAC ARREST ASSOCIATED WITH VENOUS THROMBOEMBOLISM - A SWEDISH POPULATION-BASED COHORT STUDY

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

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

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

Results: 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% versus 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 (CI 11.3-26.0) and 9.59 (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 to the overall medical OHCA group, 2.0% versus 12%, adjusted OR 0.25 (CI 0.13-0.47).

Conclusion: 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.