Pulmonary Embolism in Heart Failure

Abstract

Case Presentation: A 71-year-old man with coronary artery disease, left ventricular (LV) systolic dysfunction (ejection fraction, 30%), and recent admission for heart failure presented with acute dyspnea and hypoxemia. A pro-brain–type natriuretic peptide level was elevated at 2450 pg/mL (normal <350 pg/mL). Chest x-ray demonstrated cardiomegaly and small bilateral pleural effusions. After an hour of diuresis, the patient developed systemic arterial hypotension and worsened hypoxemia, prompting cardiology consultation. Based on the absence of rales on physical examination and lack of pulmonary edema on chest x-ray, an alternative diagnosis of pulmonary embolism (PE) was suggested, and contrast-enhanced chest tomography (CT) was obtained. Chest CT demonstrated large bilateral proximal PE. Venous thromboembolism (VTE), which encompasses deep vein thrombosis and PE, is an increasingly common and challenging complication of heart failure. The relative risk of PE is at least double that of patients without heart failure and increases as LV systolic function declines.1 PE patients with heart failure have a higher overall mortality rate than those without heart failure (17% versus 10%).2 In addition, PE is an independent predictor of death or rehospitalization among heart failure patients.3 ### Risk Factors Heart failure patients often have a high medical acuity and multiple risk factors that amplify the risk of VTE.4 The increased risk of VTE observed with heart failure itself has been attributed to reduced flow caused by low cardiac output and abnormalities of hemostasis, platelet function, and endothelial function. Central venous catheters and leads from implantable cardiac defibrillators and pacemakers are common among heart failure patients and have been shown to increase the risk of upper-extremity deep vein thrombosis. Heart failure patients tend to be older, and VTE in the elderly is problematic.5 ### Hemodynamics Acute PE increases pulmonary vascular resistance and right ventricular (RV) afterload through direct physical obstruction, hypoxemia, and pulmonary …