Rapid Clinical Assessment of Patients with Acute Heart Failure: First Blood Pressure and Oxygen Saturation – Is That All We Need?

Abstract

The risk stratification of patients with acute heart failure (AHF) has been addressed repeatedly in recent years. Low oxygen saturation (SaO₂) and systolic blood pressure (SBP) are signs of impending respiratory and circulatory failure that can be obtained quickly in patients with AHF. Methods: Admissions for AHF (340 patients) in a city hospital were recorded and patients were followed for symptoms of heart failure, re-admission and mortality for 6 months. Results: Patients with low (<90%) SaO₂ had higher rates of worsening heart failure at 1 month and 6 months (p < 0.001 and p < 0.001, respectively) and higher rates of mortality (p = 0.013). SBP <120 mm Hg was not associated with a significant increase in worsening heart failure, but was associated with a statistically significant increase in mortality at 1 and 6 months (p < 0.001 and p < 0.001, respectively). Combined low SaO₂ and SBP had a particularly strong prognostic implication. Patients who developed frank respiratory failure and/or circulatory failure fared the worst. Patients requiring ventilatory support had a recurrent heart failure rate of 81% and a mortality of 41% at 1 month of follow-up. Patients requiring intravenous pressors without respiratory mechanical support had a recurrent heart failure rate of 72% and a mortality rate of 28% at 1 month (p < 0.001). Conclusions: Simple assessment of impending respiratory and circulatory failure at admission by measuring SaO₂ and SBP enables rapid and accurate risk stratification of patients admitted for AHF. This may enable more aggressive therapeutic interventions for stabilization and treatment of AHF.