Prevalence and Predictors of Pulmonary Embolism in Patients with Acutely Decompensated Heart Failure

Background: The prevalence of pulmonary embolism (PE) has not been reported in patients hospitalized due to classical findings of decompensated heart failure (HF). Objective: To describe the prevalence of PE and to assess the diagnostic accuracy of the Wells and Geneva scores in patients hospitalized due to HF. Methods: Patients hospitalized primarily due to HF underwent systematic ventilation-perfusion lung scan, and PE was defined by a result of high probability. Aiming at interpreting, low clinical probability of PE was defined as prevalence < 5%, according to the literature. When calculating the sample size, 49 patients were required to provide a 95% confidence interval with +/- 10% accuracy, estimating an a priori prevalence of 15%. Results: Of 51 patients studied, six had a high probability of PE on lung scan, resulting in 12% prevalence (95% CI = 5% - 23%). The Wells and Geneva scores had an area under the ROC curve of 0.53 (95% CI = 0.27 - 0.80; p = 0.80) and 0.43 (95% CI = 0.13 - 0.73; p = 0.56), respectively, indicating lack of accuracy for the diagnosis of PE. Alternatively, variables related to HF showed a tendency towards association with PE, and an exploratory model formed by that type of variable showed diagnostic accuracy for PE (ROC = 0.81; 95% CI = 0.66 - 0.96; p = 0.01). Conclusion: (1) Despite the lack of primary suspicion, patients admitted with HF have intermediate clinical probability of concomitant PE; (2) the scores usually used to estimate the clinical probability of PE do not apply to the population with HF, and future predictive models should consider variables related to that syndrome. (Arq Bras Cardiol 2012; 98(2): 120-125)