Anemia Prevalence, Characterization, and Clinical Impact in Intermittent Claudication

The prevalence and clinical impact of anemia in patients with intermittent claudication (IC) is unclear, and consequently, evidence-based treatment strategies are ambiguous. This study investigated anemia characteristics and clinical outcomes in patients with intermittent claudication.

A retrospective analysis of 403 consecutive patients with IC attending a tertiary vascular clinic over 3 months in 2023 was conducted. Primary outcomes included anemia prevalence, characterization, treatment patterns, and 24-month clinical outcomes: symptom improvement following anemia treatment, progression to chronic limb-threatening ischemia , major amputation, major adverse cardiovascular events (MACEs), and all-cause mortality.

Among 403 patients, 307 (76.2%) underwent anemia investigation, which identified anemia in 54 cases (17.6%), of whom 77.8% were male. Most patients had mild anemia (n = 48, 88.9%), with the remainder having moderate anemia (n = 6, 11.1%). Severe anemia was not observed in this cohort. Normocytic normochromic anemia predominated (79.6%, n = 43), and 14.8% (n = 8) had microcytic hypochromic anemia (P < 0.001), while iron deficiency was identified in only 11.1%, although only 33.3% of anemic patients underwent iron studies. Treatment gaps were substantial with 77.8% did not receive any anemia treatment. After adjustment for interval revascularization, anemia treatment showed a nonsignificant trend toward higher claudication improvement among anemic patients (adjusted odds ratio 4.82, 95% confidence interval [CI] 0.96-24.22; P = 0.056). Bilateral claudication was more frequent in anemic than nonanamic patients (66.7% vs. 52.2%, P = 0.052), but this did not reach statistical significance. Adjusted Cox models showed that anemia was associated with MACE (adjusted hazard ratio [HR] = 2.96, 95% CI 1.23-7.08; P = 0.015) and all-cause mortality (adjusted HR = 4.59, 95% CI 1.33-15.81; P = 0.016), but not limb loss-related outcomes.

Anemia affects approximately one in five patients with IC and represents a significant treatment gap, with 77.8% receiving no therapy, despite anemia was associated with higher MACE and mortality risk. A prospective randomized controlled trial evaluating the efficacy of anemia treatment strategies in this cohort may help to improve understanding and guide clinical management.