Incidence, patient characteristics, and treatment patterns of U.S. active-duty service members diagnosed with COVID-19-associated VTE in the outpatient setting

Abstract Background Venous Thromboembolism (VTE) is a well-established complication of acute coronavirus disease 2019 (COVID-19) infection. We sought to clarify the incidence, patient characteristics, and treatment patterns of VTE within United States active-duty service members (ADSM) diagnosed with COVID-19 infection in the outpatient setting. Methods Our team conducted a multicenter retrospective review of the outpatient healthcare records for all U.S. ADSM diagnosed COVID-19-associated VTE between January 1, 2020, and April 30, 2022. The data was obtained from the COVID-19 surveillance case list maintained by the Armed Services Health Surveillance Division (ASHSD) of the U.S. Defense Health Agency (DHA). The Defense Medical Surveillance System (a database containing inpatient and outpatient electronic medical records for active-duty service members) was used to capture all appropriate medical encounters using ICD-10 coding for venous thromboembolic events within 365 days of COVID-19 diagnosis. Chart review for data adjudication was performed by the physician investigator team. Results Among 365,788 ADSM who were diagnosed with COVID-19 in the outpatient setting, a total of 159 patients were identified as having COVID-19-associated VTE. The overall incidence rate of VTE was 43.47 per 100,000 people within 365 days of diagnosis (90-day incidence rate of 32.5/100,000). The median time from COVID-19 diagnosis to VTE was 23 days (IQR 13-87). Of 159 patients, 33 (20.7%) were diagnosed with DVT, 143 (90%) with PE, and 20 (12.5%) with both PE and DVT. The median age was 30 years old (IQR 23-38). The majority of patients were male (85%). 49% were white. The most common medical comorbidity was obesity (33%), 11% had a history of active tobacco use, and 9.4% of patients had a prior VTE diagnosis. Only 34% of patients were vaccinated for COVID-19 prior to their diagnosis (35 Pfizer–BioNTech, 13 Moderna, and 4 other). 148 (93%) of patients were treated with a direct oral anticoagulant, 10 (6.2%) were treated with low molecular weight heparin, and 1 (0.8%) was treated with a vitamin K antagonist. 96 (60.3%) required hospitalization with 4 (2.5%) requiring subsequent thrombectomy. None experienced major bleeding events. Only 2 (1.3%) of the patients died within 22 days from VTE diagnosis. The remaining 98.7% were alive at 875 days (SD 230) of follow-up. Conclusion The incidence of venous thromboembolism in active-duty military patients with COVID-19 was rare, affecting mostly unvaccinated, minority men in their 30s with risk factors such as obesity, prior VTE, and prior tobacco use. Of the women with VTE, 54% were non-white minorities. While VTE diagnosis was associated with a low mortality rate, the majority of patients required hospitalization.