Monocyte Count as a Predictor of Major Adverse Limb Events in Aortoiliac Revascularization

<b>Background/Objectives:</b> Atherosclerosis is a leading cause of death, especially in the developed world, and is marked by chronic arterial inflammation and lipid accumulation. As key players in its progression, monocytes contribute to plaque formation, inflammation, and tissue repair. Understanding monocyte involvement is crucial for developing better therapeutic approaches. The objective of this study is to assess the prognostic value of monocytes for limb-related outcomes following revascularization for complex aortoiliac lesions, thereby emphasizing the central role of monocytes in atherosclerosis. <b>Methods:</b> This prospective cohort study-enrolled patients who had undergone elective aortoiliac revascularization at two hospitals between January 2013 and December 2023. Patients with TASC II type D lesions were included, excluding those with aneurysmal disease. Demographic, clinical, and procedural data were gathered, and patients were monitored for limb-related outcomes. Preoperative complete blood counts were analyzed, and statistical analyses, including multivariable Cox regression, were conducted to identify predictors of major adverse limb events (MALE). <b>Results:</b> The study included 135 patients with a mean age of 62.4 ± 9.20 years and predominantly male (93%). Patients were followed for a median of 61 IQR [55.4-66.6] months. Smoking history (91%) was the most prevalent cardiovascular risk factor. Preoperative monocyte count >0.720 × 10⁹/L was associated with worse 30-day limb-related outcomes (MALE: OR 7.138 95% CI: 1.509-33.764, <i>p</i> = 0.013) and long-term outcomes, including secondary patency (<i>p</i> = 0.03), major amputation (<i>p</i> = 0.04), and MALE (<i>p</i> = 0.039). Cox regression analysis confirmed an elevated monocyte count as an independent predictor of MALE (adjusted hazard ratio 2.149, 95% CI: 1.115-4.144, <i>p</i> = 0.022). <b>Conclusions:</b> This study demonstrated that patients with a higher absolute monocyte count may be more exposed to the risk of MALE in patients with aortoiliac TASC II type D lesions undergoing revascularization, with predictive accuracy in both the short and long term. Additionally, it was an independent predictor of major amputation. This new marker has the potential to serve as a cost-effective and easily available tool for risk stratification, helping identify patients at higher risk of MALE.