Clinical Impact of Preoperative Anemia in Patients Undergoing Peripheral Vascular Interventions: A Systematic Review

Introduction: This systematic review aims to summarize the existing evidence relating to preoperative anemia and clinical outcomes in peripheral vascular surgery patients. Methods: The following databases were searched—PubMed, COCHRANE, LILACS, and Science Research—from 1 January 2010 up to 8 May 2020, with the last search performed on 1 January 2021. An additional manual search for potential primary studies was conducted on major journals (e.g., Anesthesiology, the British Journal of Anesthesia and the European Journal of Anaesthesiology) and reference lists of included studies. Google Scholar was also checked for additional eligible studies. Reviewers independently screened potentially eligible articles and extracted data from included studies on populations, interventions, comparisons, and outcomes. This review was registered at PROSPERO as CRD 180954. Results: In total, 6 observational studies with a combined total of 87,327 participants were analyzed. Data collected in this review suggest that preoperative anemia, especially when hemoglobin is <10 g/dL, is associated with an increased risk of red blood cell transfusions (OR: 7.5; 95% CI 6.3–8.9, p < 0.0001), limb amputation (OR: 5.2; 95% CI 3.1–8.6, p < 0.0001), and death (p < 0.0031). Conclusions: These data suggest an association between preoperative anemia, blood transfusion requirements, and other adverse clinical outcomes among patients subjected to peripheral vascular interventions. However, further investigations, particularly randomized controlled trials, are warranted to better understand the association between preoperative anemia and patients’ prognosis.