Objective: The aim of this study was to evaluate pro-gnostic implications of PaO2/FiO2 ratio at admission in acute heart failure patients.

Methods: In this study we have evaluated 114 consecu-tive patients, with a primary diagnosis of AHF admitted in the intensive care unit. PaO2/FiO2 ratio was deter-mined to all patients. Patients were divided into two groups: group 1 with a PaO2/FiO2 ratio <200 mmHg and group 2 with a ratio >200 mmHg. For statistical analysis we used independent t test for comparison of continuous values, Pearson x² test for comparison of categorical values, multivariate logistic regression, sur-vival curves and Cox regression for predictors of in-hospital mortality.

Results: Mean age was 68 ± 58 years and 49% were fe-male. Group 1 was associated with acute pulmonary edema (28%, p=0.002) while group 2 was associated with acute decompensated heart failure profile (26%, p=0.001). Patients with cardiogenic shock profile were more frequent seen in group 1 (10% vs. 6%, p=0.6) while patients with right heart failure profile were seen more frequent in group 2 (5.3% vs. 4.4%, p=0.5). A PaO2/FiO2 <200mmHg was correlated with respira-tory acidosis (pH=7.3, pCO2=56 mmol/L, p=0.022). Patients with a PaO2/FiO2 <200 mmHg had a signi-ficantly worse survival profile during hospitalization (log-rank test, p<0.045) and Cox proportional hazards modelling showed a crude HR=1.7 (95%CI [1-3.2], p<0.05) for in-hospital mortality.

Conclusions: Patients with acute pulmonary edema are more prone to develop lung injury. A PaO2/FiO2 ratio <200 mmHg at admission in patients with acute heart failure is responsible for worse in-hospital survi-val rates. Even though PaO2/FiO2 ratio is used to de-fine acute respiratory distress syndrome, it might also serve as a useful tool in stratifying risk of patients with acute heart failure.