Prevalence, characterisation, and clinical impact of anaemia in patients with intermittent claudication: a retrospective analysis

IntroductionAnaemia prevalence and clinical significance in intermittent claudication patients remain poorly characterised, limiting evidence-based treatment strategies. This study investigated anaemia characteristics and clinical outcomes in patients with intermittent claudication. MethodsA retrospective analysis of 403 consecutive patients with intermittent claudication attending a tertiary vascular clinic over three months in 2023 was conducted. Primary outcomes included anaemia prevalence, characterisation, treatment patterns, and 24-month clinical outcomes: chronic limb-threatening ischaemia (CLTI) progression, major amputation, mortality, and symptom improvement following anaemia treatment. ResultsAmong 403 patients, 307 (76.2%) underwent anaemia investigation, with anaemia identified in 54 patients-- representing 17.6% of those investigated and 13.4% of the total cohort. Within the investigated group, anaemia was present in 19.5% of males and 13.0% of females. The highest prevalence was observed in males aged 70-79 years (32.3%), compared to 12.5% in those under 50 years (p<0.001). Normocytic normochromic anaemia predominated (79.6%), while iron deficiency was identified in only 11.1%, though limited iron studies (33.3% of anaemic patients tested). Treatment gaps were substantial: 77.8% received no anaemia treatment despite potential benefits. Oral iron therapy may be associated with trends towards symptom improvement (70.0% vs 37.9% in untreated, OR=3.82, 95% CI: 0.65-22.4, p=0.141; NNT=3.1). Anaemia showed a trend toward association with bilateral claudication (65.5% vs 52.4%, p = 0.078, r2 = 0.01), though this did not reach statistical significance. Survival analysis revealed significant composite endpoint differences (log-rank p=0.045), with trends toward increased amputation risk (5.6% vs 2.4%, RR=2.33, 95% CI: 0.52-10.4) and mortality (11.1% vs 6.3%, RR=1.79, 95% CI: 0.68-4.71) in anaemic patients. ConclusionAnaemia affects one in five intermittent claudication patients and represents a significant treatment gap with 77.8% receiving no therapy. Iron therapy shows promise for symptom improvement, while anaemia could be associated with worse clinical outcomes. A prospective randomised controlled trial evaluating the impact of anaemia and its treatment strategies in this cohort may help to improve understanding and guide clinical management.