Outcomes of acute limb ischemia in COVID-19

Objective: The inflammatory cascade caused by severe acute respiratory syndrome coronavirus 2 infection may result in arterial thrombosis and acute limb ischemia (ALI) with devastating consequences. The aims of this study were to compare outcomes of ALI in the lower extremities in patients with and without coronavirus disease 2019 (COVID-19), and to determine if ALI development in the context of COVID-19 portends a worse prognosis compared with COVID-19 without ALI. Methods: Queries were built on TriNetX, a federated network of health care organizations across the United States that provides de-identified patient data. International Classification of Diseases, 10th revision diagnostic codes were used to identify patients with acute limb ischemia of the lower extremities and COVID-19. The study timeframe was defined as January 20, 2020 to May 20, 2021. Statistical analyses, including propensity-score matching, were done through TriNetX's internal software. Outcomes looked at are rates of mortality, stroke, myocardial infarction, major adverse limb events, re-intervention, respiratory failure, sepsis, mental health complications, and acute renal failure. Baseline cohort characteristics were also collected. Results: Patients with ALI with COVID-19 (ALI C19+; n = 526) were significantly less likely than patients with ALI without COVID-19 (ALI; n = 14,131) to have baseline comorbidities, including nicotine dependence (18% vs 33%; P <.0001). In contrast, ALI C19+ patients had significantly more comorbidities than hospitalized patients with COVID-19 without ALI (n = 275,903), including nicotine dependence (18% vs 10%; P <.0001). After propensity matching was performed, ALI C19+ patients had significantly higher rates of mortality (24.9% vs 9.2%; P <.0001), major adverse limb events (5.8% vs 2.9%; P =.0223), and acute renal failure (22.2% vs 14.9%; P =.0025) than patients with ALI. Compared with hospitalized patients with COVID-19 without ALI, ALI C19+ patients had higher propensity-matched rates of respiratory failure and being placed on assisted ventilation (32.9% vs 27%; P =.0369), sepsis (16.9% vs 12.2%; P =.0288), acute renal failure (22.1% vs 14.6%; P =.0019), and mortality (24.7% vs 14.4%; P <.0001). Conclusions: Patients who developed ALI following COVID-19 present with significantly different demographics and comorbidities from those who develop ALI without COVID-19. After controlling for these variables, higher rates of major adverse limb events, acute renal failure, and mortality in patients with ALI with COVID-19 suggest that not only may COVID-19 precipitate ALI, but it may also exacerbate ALI sequelae. Furthermore, development of ALI in COVID-19 portends worse prognosis compared with patients with COVID-19 without ALI.