Rapid clinical assessment of patients with acute heart failure: first blood pressure and oxygen saturation--is that all we need?

UNLABELLED: 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.