Large-vessel vasculitis with persistent exertional dyspnea in a 75-year-old woman

Excerpt

A 75-year-old woman presented with low-grade fever, and pain and numbness in her upper extremities that worsened on exertion, for over three months, (Raynaud’s phenomenon) (Figure 1). She also had persistent exertional dyspnea. Her electrocardiographic and transesophageal echocardiographic findings were within the normal ranges. Computed tomography (CT) angiography revealed multiple stenoses in both mid-subclavian arteries and occlusion from the axillary to the brachial arteries bilaterally (Figure 2). Subsequent invasive coronary angiography demonstrated intermediate stenotic lesions at the ostium of the right and left coronary arteries (Figure 3). ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT revealed an increased FDG uptake in the thoracoabdominal aorta and along the carotid and subclavian arteries (Figure 4A). Laboratory examination showed a white blood cell count of 8200/mm³ and erythrocyte sedimentation rate of 81 mm·h. Blood cultures and serologic tests were negative for hepatitis B, hepatitis C, human immunodeficiency virus, and syphilis. The above findings were suggestive of Takayasu’s arteritis. Her stress/rest perfusion ¹³N-ammonia PET/CT demonstrated (Figure 5A) a significantly low global myocardial flow reserve (MFR) of 1.82. However, myocardial perfusion imaging appeared normal, suggesting coronary microvascular dysfunction (CMD). She was treated with oral prednisone. Inflammatory parameters normalized within three weeks, and the numbness and pain in her arms disappeared. On repeated FDG-PET/CT, no remarkable uptake along the aortic wall and subclavian arteries was noted (Figure 4B). Three months after the initiation of corticosteroid therapy, she still complained of dyspnea on exertion. A repeat ¹³N-ammonia PET/CT (Figure 5B) revealed a low global MFR of 2.09. These findings imply that conventional corticosteroid treatment may not improve angina and CMD over the short-term. CMD has been described in similar chronic inflammatory conditions, such as systemic lupus erythematosus, where prolonged vascular inflammation contributes to endothelial dysfunction and reduced MFR.1 However, this is the first report that associates large-vessel vasculitis with CMD, as evidenced by perfusion PET.

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