Inferior vena cava thrombosis associated with endovascular cooling catheters: impact on clinical outcomes

Endovascular cooling catheters are used to induce and maintain therapeutic hypothermia. While generally considered safe, complications have been reported, notably catheter-related inferior vena cava (IVC) thrombosis. We sought to determine the frequency and clinical impact of this complication in patients managed with therapeutic hypothermia following out-of-hospital cardiac arrest (OHCA).

We performed a post hoc analysis of the Effect of Moderate vs Mild Therapeutic Hypothermia on Mortality and Neurologic Outcomes in Comatose Survivors of Out-of-Hospital Cardiac Arrest (CAPITAL-CHILL) trial, which randomized 367 comatose OHCA survivors to mild (34 °C) vs moderate (31 °C) hypothermia using endovascular cooling catheters. Patients were routinely screened for IVC thrombosis using abdominal ultrasonography. Patients with IVC thrombosis were compared with patients without. The primary outcome was death or poor neurological outcome at 180 days.

We excluded 48 patients who died before ultrasonography. Amongst the remaining 319, 21 (6.6 %) developed IVC thrombosis. In patients who developed an IVC thrombosis versus those who did not, there was no difference in the primary outcome (47.6 % vs 38.3 %, P = 0.39). In-hospital bleeding was higher in the IVC thrombosis group, but not statistically significant (33.3 % vs 22.8 %, P = 0.24). Patients with IVC thrombosis were more likely to be discharged from hospital on an anticoagulant (76.9 % vs 22.5 %, P < 0.0001).

Despite intravenous anticoagulation, IVC thrombosis remains a relevant complication of endovascular cooling. Though not associated with death or poor neurological outcomes, it was associated with high in-hospital bleeding rates and anticoagulant use at discharge.