Lower extremity arterial thrombosis associated with COVID-19 is characterized by greater thrombus burden and increased rate of amputation and death

BACKGROUND: During the peak of COVID-19 pandemic, we have noted an increase in positive lower extremity CT angiogram (CTA) exams in patients presenting with leg ischemia. The goal of this study was to determine whether lower extremity arterial thrombosis was associated with COVID-19 and whether it was characterized by greater severity in these patients. METHODS: In this IRB approved retrospective propensity score–matched study, 16 SARS-CoV-2 positive patients who underwent CTA of the lower extremities and 32 SARS-CoV-2 negative patients observed from January to April in 2018-2020 were compared using three scoring system: two systems including all vessels with weighting given in one system to more proximal vessel and in the other to more distal vessels, and a third system where only the common iliac through popliteal arteries were considered. Correlation with presenting symptoms and outcomes was computed. Fisher exact tests were used to compare COVID-19 positive to negative patients regarding presence of clots and presenting symptoms. A Mantel-Haenszel test was used to associate outcome of death/amputation with COVID-19 adjusted by the history of peripheral vascular disease (PVD). RESULTS: Sixteen patients with confirmed COVID-19 (70 +/- 14 years, 7 women) underwent CTA and 32 propensity-score matched control patients (71 +/- 15 years, 16 women) were included. All COVID-19 patients (100%, 95%CI: 79-100%) had at least one thrombus while only 69% (95%CI: 50-84%) of controls had thrombi (p=0.02). 94% (95%CI: 70-99.8%) of COVID-19 patients had proximal thrombi compared to 47% (95%CI: 29-65%) of controls (p<0.001). Mean thrombus score using any of the three scoring systems yielded greater scores in the COVID-19 patients (p<0.001). Adjusted for history of PVD, death or limb amputation was more common in COVID-19 patients (OR 25, 95%CI 4.3-147, p<0.001). COVID-19 patients presenting with symptoms of leg ischemia only were more likely to avoid amputation or death than patients presenting also with pulmonary or systemic symptoms (p=0.001). CONCLUSION: COVID-19 is associated with lower extremity arterial thrombosis characterized by greater clot burden and a more dire prognosis.