The Development of a Simple Risk Score to Predict Early Outcome in Severe Acute Acidotic Cardiogenic Pulmonary Edema

Abstract

Background— Acute cardiogenic pulmonary edema is a common medical emergency with high early mortality. Initial clinical assessment would benefit from accurate mortality prediction. We aimed to develop a simple clinical score based on presenting characteristics that would predict 7-day mortality in patients with acute cardiogenic pulmonary edema. Methods and Results— We used data from patients recruited to the 3CPO trial (a pragmatic multicenter trial comparing continuous positive airway pressure, noninvasive positive pressure ventilation, and standard oxygen therapy in emergency department patients with acute cardiogenic pulmonary edema) to investigate the association between baseline characteristics and 7-day mortality. Factors associated with mortality ( P <0.1) were entered into a multivariable model. Independent predictors of mortality from the multivariable model ( P <0.05) were assigned integer weights based on their coefficients and incorporated into a risk score. The discriminant ability of the score was tested by receiver operator characteristic analysis. Data from 1069 patients (78±10 years; 43% men; 7-day mortality, 9.6%) were analyzed. Multivariable analysis identified age ( P =0.003), systolic blood pressure ( P <0.001), and Glasgow Coma Scale motor component dichotomized and simplified to the ability to obey commands or not ( P =0.02) as the only independent predictors of 7-day mortality. These were weighted and used to develop a risk score ranging from 0 (7-day mortality, 1.9%; 95% CI, 0.8 to 4.5) to 7 (7-day mortality, 100%; 95% CI, 34.2 to 100). Receiver operator characteristic analysis demonstrated good risk prediction with a c-statistic of 0.794 (95% CI, 0.745 to 0.843). A simplified 3-point score with no weighting had a c-statistic of 0.754 (95% CI, 0.701 to 0.807). Conclusions— A simple clinical score based on age, systolic blood pressure, and the ability to obey commands predicts early mortality in patients with acute cardiogenic pulmonary edema. Clinical Trial Registration— clinicaltrials.gov Identifier: ISRCTN077448447.