Management of Submassive Pulmonary Embolism

Case presentation : A 58-year-old woman with a history of cigarette smoking, chronic obstructive pulmonary disease, and recent intensive care unit admission for pneumonia presented with sudden onset of right-sided chest discomfort and dyspnea. On physical examination, she was tachycardic (heart rate 110 beats per minute), normotensive (blood pressure of 128/72 mm Hg), tachypneic (24 breaths per minute), and hypoxemic (oxygen saturation 88% on room air). She had jugular venous distension to the angle of her mandible, a grade 2/6 holosystolic murmur that increased to grade 3/6 with inspiration at the left lower sternal border, lung fields clear to auscultation bilaterally, and mild symmetrical lower-extremity edema. The ECG was notable for sinus tachycardia and T-wave inversions across the anterior precordium. Laboratory evaluation was remarkable for a D-dimer level of 1104 ng/mL (normal <500 ng/mL) and a cardiac troponin I level of 1.4 ng/mL (normal <0.1 ng/mL). Contrast-enhanced chest computed tomography demonstrated thrombus that filled the right main pulmonary artery and moderate right ventricular (RV) enlargement (RV-to-left ventricular [LV] dimension ratio=1.2). Bedside transthoracic echocardiography documented moderately severe RV hypokinesis, moderate tricuspid regurgitation, and an estimated pulmonary artery systolic pressure of 55 mm Hg. These clinical, laboratory, and imaging findings established the diagnosis of submassive pulmonary embolism (PE). The principal management question was whether to treat with anticoagulation alone (a “watch and wait” strategy) or to administer fibrinolysis immediately.Venous thromboembolism is the third most common cardiovascular disorder after myocardial infarction and stroke.1 The mortality rate for acute PE exceeds 15% in the first 3 months after diagnosis and surpasses that of myocardial infarction.2 Death most commonly results from progressive RV failure that culminates in cardiovascular collapse.3 Survivors of acute PE remain at risk for chronic thromboembolic pulmonary hypertension.4Acute PE represents a spectrum of clinical syndromes with …