A 55-year-old woman comes to the office due to exertional dyspnea for 3 months. The patient has had no chest pain. Medical history is significant for hypertension and chronic kidney disease. Medications include furosemide, amlodipine, and lisinopril. The patient has never smoked cigarettes. Temperature is 37 C (98.6 F), blood pressure is 128/80 mm Hg, and pulse is 80/min. Oxygen saturation is 98% on room air. BMI is 27 kg/m². There is no jugular venous distension. Cardiopulmonary examination is normal. Trace bilateral pedal edema is present. Laboratory studies are as follow: ECG is unremarkable. Chest x-ray reveals clear lung fields. Which of the following is the most appropriate next step in management of this patient?

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Explanation: Chronic kidney disease (CKD) independently increases the risk for coronary artery disease (CAD) and cardiovascular events. This association may be due to following: Altered calcium balance (eg, secondary hyperparathyroidism) leading to arterial calcium deposition and accelerated atherosclerosis Loss of protein in the urine facilitating an unfavorable lipid profile (ie, high LDL/HDL ratio) Increased systemic inflammation contributing to accelerated atherosclerosis and instability of atherosclerotic plaques Although symptomatic CAD usually presents with typical symptoms (ie, anginal chest pain), patients with CKD, particularly women, are more likely to have atypical symptoms (eg, anginal equivalents such as dyspnea or nausea). Therefore, high suspicion should exist for stable angina in this patient with several months of exertional dyspnea (a possible "anginal equivalent") in the setting of CKD and other risk factors for CAD (eg, hypertension). Cardiac stress testing in the form of stress echocardiography or treadmill stress testing is most appropriate. (Choice A) CT pulmonary angiography is used to diagnose pulmonary embolism (PE). Subacute PE may present with exertional dyspnea but is unlikely in this patient with a normal heart rate and oxygen saturation. (Choice B) Anemia is common in CKD and, when severe, may cause dyspnea and contribute to an increased risk for cardiovascular events. However, this patient's hemoglobin >10 g/dL is consistent with relatively mild anemia that is unlikely to cause dyspnea. In patients with CKD, the initiation of an erythropoiesis-stimulating agent (eg, epoetin) is indicated only for hemoglobin <10 g/dL. (Choice C) The initiation of chronic hemodialysis for CKD is typically delayed until the estimated glomerular filtration rate reaches 7.5-15 mL/min/1.73 m² (sometimes lower) or complications of CKD (eg, uremic symptoms, volume overload) become unmanageable with medications alone. This patient has no indication for hemodialysis. (Choice D) Pulmonary function testing can be used to diagnose chronic obstructive pulmonary disease and can assist in the diagnosis of interstitial lung disease, both common causes of dyspnea. However, this patient's normal cardiopulmonary examination and absence of cough and smoking history make pulmonary disease highly unlikely. Pulmonary testing can be considered if cardiac stress testing is negative. Educational objective: Patients with chronic kidney disease (CKD) are at increased risk of coronary artery disease (CAD) and cardiovascular events. Physicians should have a low threshold for pursuing cardiac stress testing (eg, stress echocardiography) in CKD patients with atypical CAD symptoms (eg, exertional dyspnea). References: Kidney disease as a risk factor for development of cardiovascular disease: a statement from the American Heart Association Councils on Kidney in Cardiovascular Disease, High Blood Pressure Research, Clinical Cardiology, and Epidemiology and Prevention. (http://www.ncbi.nlm.nih.gov/pubmed/14581387) Differential symptoms of acute myocardial infarction in patients with kidney disease: a community-wide perspective. (http://www.ncbi.nlm.nih.gov/pubmed/16490615)

A 55-Year-Old Woman Comes to the Office Due to Exertional