Impact of Nutritional and Inflammatory Status in Patients With Critical Limb-threatening Ischemia

The peripheral arterial disease (PAD) has been associated with all-cause and cardiovascular mortality. Despite minimally invasive endovascular techniques, patients with critical limb-threatening ischemia (CLTI) have a poor prognosis with a high mortality that is comparable that of cancer.

The inflammatory activity has a crucial role for the development and prognosis of atherosclerosis. Recently, different inflammatory biomarkers such as the neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and lymphocyte to monocyte ratio (LMR) have been associated with severity and prognosis in patients with PAD.

Additionally, patients with CLTI present several independent risk factors for malnutrition. For this reason, malnutrition represents an independent risk factor for mortality and post-operative complications. In this context, the Prognostic Nutritional Index (PNI) associates the nutritional and inflammatory status of patients.

This study shows the clinical applicability of the different pre-operative nutritional and inflammatory biomarkers in patients with CLTI. This study does not collect any patient identifiable information.

In order to show the relevance of patient's inflammatory status regarding the prognosis of PAD, this study establishes the correlation between pre-operative pro-inflammatory biomarkers represented by NLR, LMR and PLR with short-term mortality and major amputations at 6-months. Likewise, the association between the pre-operative PNI with short-term mortality and major amputation at 6-months revealing the impact of nutritional status.

- Data Collection: Demographic and clinical data. The initial surgical technique. The peri-operative outcomes Mortality and major amputation. The hemogram and biochemistry analysis were recorded preoperatively, at 48-hours after admission The inflammatory state was measured by the ratios of neutrophil/lymphocyte (NLR), lymphocyte/monocyte (LMR) and platelet/lymphocyte (PLR).

The nutritional status was estimated by the PNI = (serum albumin g/dL x 10) + (lymphocytes/μL + 0.005).

- Statistical Analysis: significant values p\<0.05. Descriptive analysis was presented as mean values and respective standard deviations.

The chi-squared test and Student t-test were used for variables that followed a normal distribution.

A non-parametric test was performed for the rest of variables (Mann-Whitney U). Spearman and Pearson correlations coefficients were calculated to determine the association between biomarkers and the hospital length-of-stay.

For the multivariate analysis a logistic regression was performed. A receiver operating characteristic (ROC) curve analysis was applied to establish a cut-off point with the corresponding area under the curve (AUC), 95% confidence interval (95%CI), sensitivity (S) and specificity (E) for short-term mortality and major amputation at six months.

Eligibility Criteria:
Inclusion Criteria:

* All patients diagnosed with a first episode of critical limb ischemia revascularized at our center from January 2016 to July 2019.

Exclusion Criteria:

* Patients with acute limb ischaemia.
* Patients with CLTI revascularized before 2016.
* Patients without serum albumin collected in the first 48 hours after admission.