The inflammatory process and malnutrition play important roles in the pathogenesis and progression of atherosclerosis. C-reactive protein (CRP) is a commonly used clinical inflammatory marker in routine preprocedural blood tests that correlate with both disease severity and prognosis in patients with coronary artery disease. Serum albumin is expressed as a negative acute-phase protein and inversely correlated with the severity of the inflammatory response and reflects the nutritional status. Several studies regarding the clinical outcomes of cardiovascular disease have suggested that the CRP-to-albumin ratio (CAR), a simple value that reflects the balance between systemic inflammation and malnutrition, can be a novel indicator to predict disease progression and patients’ outcome. However, the relationship between CAR and the disease burden and the long-term clinical outcomes of patients with peripheral artery disease (PAD) after endovascular therapy (EVT) has not been well elucidated. Thus, the aim of this study was to evaluate the prognostic value of CAR in predicting the prevalence of complex lesions and multilevel involvement in patients with PAD treated with EVT. The secondary aim was to evaluate the association between CAR and clinical outcomes after EVT.

A total of 307 patients with PAD who underwent EVTwere retrospectively reviewed and categorized according to CAR tertiles; 1^sttertile, 0.022‒0.029; 2^nd tertile, 0.030‒0.628; and 3^rdtertile, 0.629‒13.917. The groups were compared for the prevalence of complex lesions and multilevel involvement as well as the incidence of major adverse cardiovascular events(MACEs) and major adverse limb events (MALEs). TASC type C or D lesions were considered as complex lesions. Multileveldisease was defined by the presence of severe disease in more than one categorical region (aortoiliac, femoropopliteal, or infrapopliteal) in the same limb.

The rates of complex lesions and multilevel involvement increased with increasing CAR tertiles (all p<0.001). These associations remained significant even after adjustment for other confounders(complex lesion odds ratio, 1.22 [1.03‒1.50], p=0.036; multilevel disease odds ratio, 1.20 [1.01‒1.44],p=0.041) (Figure 1). The third tertile of the CAR group showed a significantly higher incidence of MACEs and MALEs than the second and first tertile within a year (log-rank p<0.001) (Figure 2). A higher CAR as a continuous variable was also independently associated with the 4-year rate of MACE (hazard ratio, 1.20 [1.04‒1.38], p=0.015).

In conclusion, CAR, a novel marker of the inflammatory state measured in routine biochemical assessments, conveys valuable prognostic information that is independent of other conventional clinical risk factors in patients with PAD. Therefore, the high inflammatory conditions indicated by an elevated CAR should be considered as a risk factor for advanced disease and future MACEs in patients with PAD. Proper preventive strategies to reduce adverse events in these patients should be established in the future.