Is prognostic nutritional index a predictive marker for estimating all-cause in-hospital mortality in COVID-19 patients with cardiovascular risk factors?

BACKGROUND: This study examined the possible association between the prognostic nutritional index (PNI) and in-hospital mortality rates in cases with a high cardiovascular risk burden and hospitalized with the diagnosis of coronavirus disease 2019 (COVID-19).

MATERIAL AND METHODS: This retrospective and cross-sectional study included 294 COVID-19 patients hospitalized in a tertiary referral pandemic center. The study cohort was grouped into tertiles based on the initial PNI values as T1, T2, and T3. The PNI was calculated for each case and the prognostic value of this index was compared to CURB-65 and 4C mortality risk scores in predicting in-hospital mortality.

RESULTS: Patients stratified into the T1 tertile had a lower lymphocyte count, serum albumin level, and PNI values. In a multivariate analysis, the PNI (OR: 0.688,%95CI: 0.586-0.808, p < 0.001) was an independent predictor for all-cause in-hospital death. After adjusting for confounding independent parameters, patients included in the T1 tertile were found to have 11.2 times higher rates of in-hospital mortality compared to the T3 group, which was presumed as the reference group. In addition, we found that the area under curve (AUC) value of PNI was significantly elevated than that of serum albumin level and total lymphocyte counts alone. [(AUC):0.79 vs AUC:0.75 vs AUC:0.69; respectively).

CONCLUSION: This study demonstrated that the PNI is independently related with in-hospital mortality in patient with COVID-19 and cardiovascular risk factors. The power of the PNI was also validated using well-accepted risk scores of COVID-19 such as CURB-65 and 4C mortality risk scores.