SARS-CoV-2 infection and venous thromboembolism after surgery: an international prospective cohortstudy

Abstract

SARS-CoV-2 has been associated with an increased rate of venous thromboembolism in critically ill patients.Since surgical patients are already at higher risk of venous thromboembolism than general populations, thisstudy aimed to determine if patients with peri-operative or prior SARS-CoV-2 were at further increased risk ofvenous thromboembolism. We conducted a planned sub-study and analysis from an international, multicentre,prospective cohort study of elective and emergency patients undergoing surgery during October 2020.Patients from all surgical specialties were included. The primary outcome measure was venousthromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS-CoV-2diagnosis was defined as peri-operative (7 days before to 30 days after surgery); recent (1–6 weeks beforesurgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre-operativeanti-coagulation for baseline comorbidities was not available. Postoperative venous thromboembolism ratewas 0.5% (666/123,591) in patients without SARS-CoV-2; 2.2% (50/2317) in patients with peri-operative SARS-CoV-2; 1.6% (15/953) in patients with recent SARS-CoV-2; and 1.0% (11/1148) in patients with previous SARS-CoV-2. After adjustment for confounding factors, patients with peri-operative (adjusted odds ratio 1.5 (95%CI1.1–2.0)) and recent SARS-CoV-2 (1.9 (95%CI 1.2–3.3)) remained at higher risk of venous thromboembolism,with a borderlinefinding in previous SARS-CoV-2 (1.7 (95%CI 0.9–3.0)). Overall, venous thromboembolism wasindependently associated with 30-day mortality (5.4 (95%CI 4.3–6.7)). In patients with SARS-CoV-2, mortalitywithout venous thromboembolism was 7.4% (319/4342) and with venous thromboembolism was 40.8% (31/76).Patients undergoing surgery with peri-operative or recent SARS-CoV-2 appear to be at increased risk ofpostoperative venous thromboembolism compared with patients with no history of SARS-CoV-2 infection.Optimal venous thromboembolism prophylaxis and treatment are unknown in this cohort of patients, and thesedata should be interpreted accordingly.