Association between D-Dimer Trends and Intravascular Temperature Management-Related Venous Thromboembolism after Cardiac Arrest: A Single-Center Observational Study

Intravascular temperature management (IVTM) is widely used for temperature control after cardiac arrest, but its association with IVTM-related venous thromboembolism (VTE) remains clinically important. D-dimer is commonly used for VTE evaluation, although interpretation is challenging after cardiac arrest because coagulation and fibrinolytic abnormalities can elevate D-dimer values. We conducted a single-center retrospective cohort study of out-of-hospital cardiac arrest patients treated with IVTM between August 2021 and August 2024. D-dimer levels were measured daily for 7 days and reported in µg/mL D-dimer units. IVTM-related VTE diagnosed within 10 days after admission was identified from medical records. Delta D-dimer was defined as the increase from each baseline value on Days 1, 2, or 3 to the peak value within 7 days. Among 51 patients, 8 (15.7%) developed IVTM-related VTE; the median time to diagnosis was 5.5 days. Peak D-dimer was higher in patients with IVTM-related VTE than in those without IVTM-related VTE (56.0 vs. 17.4 µg/mL DDU). Delta D-dimer was associated with IVTM-related VTE in adjusted logistic regression models, with adjusted odds ratios ranging from 1.04 to 1.10 per 1 µg/mL increase. In post-cardiac arrest patients undergoing IVTM, increases in D-dimer from early-phase values to peak were associated with IVTM-related VTE. Serial D-dimer assessment may help identify patients who warrant targeted imaging when IVTM-related VTE is clinically suspected.