Introduction Anaemia 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.

Methods A 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.

Results Among 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.

Conclusion Anaemia 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.

The authors have declared no competing interest.

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This retrospective study was conducted using routinely collected clinical data. Approval (or waiver of approval) was obtained from the Freeman Hospital Review Board]. Patient consent was waived as data were anonymised prior to analysis, in accordance with institutional and national regulations.

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