Abstract 9704: Role of Arterial Blood Gas Variables in the Prognostication of Patients With Acute Decompensated Heart Failure Admitted to Cardiac Intensive Care Unit

Abstract

Introduction: Several risk factors and scores have been studied to predict in-hospital mortality [IHM] and rehospitalization [RH] in patients with AHF. Hypothesis: The impact of the initial therapies implemented for AHF on the variables of the acid base gases (ABG) has not been evaluated for prognostication of IHM and RH. Methods: We prospectively evaluated 216 patients admitted in CICU with AHF from 2015 to 2021. Demographic, clinical and ABG variables were analyzed on admission and at 24 hours. Patients were grouped according to whether they presented improvement in respiratory failure, defined as improvement in SaO2, PaO2 and PaCO2 as well as de-escalation of respiratory support devices (NIV or high flow). The aim of the study was to identify whether the improvement in ABG variables, O2 requirement or respiratory support within 24 hours of admission is associated with lower IHM and RH at 60 days. Data was analyzed using bivariate and multivariate analyzes by logistic regression. Results: Mean age was 75 years (44% female), normal EF 62% and reduced 38%. Mean NT-pro-BNP was 9280 ng/dl. RH at 60 days was 25% and IHM was 8.7%. Mean PaO2 on admission was 75 mmHg and at 24 hours 82 mmHg, PaCO2 on admission was 38 mmHg and at 24 hours 40 mmHg, mean SaO2 on admission was 94% and at 24 hours 95%. In bivariate analysis, the highest elevation of the PaCO2 on admission as well as PaCO2 at 24 hours were identified as predictors of IHM (38.42 vs 40.26 mmHg, p = 0.025) and (40.17 vs 46.84 mmHg, p = 0.002) respectively. In multivariate analysis, AKI on CKD (p = 0.03), cardiogenic shock (p = <0.0001), acute myocardial infarction (p = <0.004), emergency PCI (p = <0.001), NIV failure (p = <0.001), NT-pro-BNP (p = <0.01), and elevated PaCO2 at 24 hours (p = 0.02) were identified as independent predictors for IHM. No association between the improvement in ABG variables and RH at 60 days was found. Conclusions: The lack of improvement in PaCO2 at 24 hours of admission to CICU for AHF identifies patients at higher risk for IHM. However, there was no association between the improvement ABG variables at 24 hours and the RH for AHF.