A 68-year-old man comes to the emergency department due to chest pain. The patient was hospitalized 2 weeks ago with chest pain and was diagnosed with a non-ST elevation myocardial infarction. Percutaneous coronary intervention was performed with placement of a drug-eluting stent in the left circumflex artery. The patient has taken all medications as prescribed, including aspirin and clopidogrel, and has limited physical activity to prevent "overexerting the heart." He was feeling well until last night when he began having sharp, left-sided chest pain, which worsens with deep inspiration. The patient also feels short of breath but has had no fever or cough. Other medical conditions include hypertension and hyperlipidemia. He smokes half a pack of cigarettes daily but has not smoked over the past 2 weeks. Temperature is 38.1 C (100.6 F), blood pressure is 116/84 mm Hg, pulse is 110/min, and respirations are 20/min. Oxygen saturation is 92% on room air. BMI is 30.2 kg/m2. The patient appears in mild respiratory distress. The lungs are clear on auscultation and there are no cardiac murmurs. There is mild right lower extremity edema, and the distal pulses are full. ECG shows sinus tachycardia with nonspecific T wave changes. Serum creatinine is 0.8 mg/dL and troponin I is 0.4 ng/mL (normal: <0.01). Chest x-ray shows normal cardiac size, small left pleural effusion, and no lung opacities. Which of the following is the best next step in management of this patient?
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Causes of pleuritic chest pain include costochondritis, pericarditis, malignancy, and infection (eg, pneumonia). Pulmonary embolism (PE) is a relatively common, life-threatening cause of pleuritic chest pain and should be strongly considered in patients with risk factors (eg, recent hospitalization with prolonged immobilization). The evaluation of suspected PE requires an assessment of pretest probability.
This patient has several features that are highly suggestive of PE including dyspnea, tachycardia, tachypnea, and unilateral lower extremity edema. Pleural effusion, low-grade fever (due to an inflammatory response to tissue damage), and troponin elevations (due to myocardial demand ischemia) can also be seen. These features all make PE a likely explanation of his presentation. Therefore, using the modified Wells criteria, this patient has a high (likely) probability for PE (heart rate >100/min, recent hospitalization/prolonged immobilization, alternate diagnosis less likely than PE), and CT pulmonary angiography is indicated as it has high diagnostic accuracy in such patients. Ventilation-perfusion scan is a less accurate alternative for patients with significant renal impairment, morbid obesity, or contrast allergy.
D-dimer testing is useful in excluding PE in patients with low pretest probability, but it has no utility in the setting of high pretest probability due to an unacceptable rate of false-negative results in such patients.
(Choices B, D, and E) This patient is at risk for recurrent acute coronary syndrome (ACS). Emergency coronary angiography is indicated for ST-elevation myocardial infarction (MI) (eg, due to stent thrombosis); however, this should present with ST elevation on ECG and ischemic (ie, pressure-like, unchanged with breathing) chest pain, rather than pleuritic chest pain. Serial ECGs and troponin levels or stress testing are indicated for suspected non-ST elevation MI or unstable angina, but these ACS manifestations should also present with ischemic, rather than pleuritic, chest pain.
(Choice C) Postcardiac injury (Dressler) syndrome is an immune-mediated pericarditis that can occur several weeks following MI or cardiac surgery, and it is treated with nonsteroidal anti-inflammatory drugs and colchicine. It typically presents with pleuritic chest pain and fever but often causes diffuse ST elevation on ECG and would not explain this patient's unilateral lower extremity edema. Acute PE is more likely and must be evaluated.
Educational objective:
Pulmonary embolism (PE) is the most common, life-threatening cause of pleuritic chest pain and should be strongly considered in patients with risk factors (eg, prolonged immobilization) and suggestive clinical features (eg, dyspnea, tachycardia, tachypnea, unilateral lower extremity edema). Patients with high pretest probability of PE are best evaluated with CT pulmonary angiography.