MEDizzy - A 75-year-old man underwent a diagnostic coronary

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Disorders of the cardiovascular system 2

A 75-year-old man underwent a diagnostic coronary angiography after an abnormal stress test. Arterial access was obtained easily in the right femoral artery, and the angiography was completed with 35 mL of iodinated contrast dye. Fortunately, no signifcant coronary stenoses were noted. Seven days later, the man presents to the emergency department with abdominal pain and nausea. He reports that his urine output has been poor recently. Examination reveals a slight fever (38.3°C) and livedo reticularis on his lower extremities. Laboratory studies show a creatinine of 2.7 mg/dL (previously 1.1 mg/dL), a white blood cell count of 10,500/mL with 21% eosinophils, and an erythrocyte sedimentation rate of 92 mm/hr. What is the most likely diagnosis?

ExplanationThis patient’s clinical scenario is most consistent with other embolic renal disease. Atheroemboli in the kidney is strongly associated with aortic aneurysmal disease and renal artery stenosis. Most clinical cases can be linked to precipitating events, such as angiography, vascular surgery, anticoagulation with heparin, thrombolytic therapy, or trauma. Clinical manifestations of this syndrome commonly develop between 1 and 14 days after an inciting event and may continue to develop for weeks thereafter. Systemic embolic disease manifestations, such as fever, abdominal pain, and weight loss, are present in less than half of patients, although cutaneous manifestations including livedo reticularis and localized toe gangrene may be more common. Worsening hypertension and deteriorating kidney function are common. Typical laboratory findings include rising creatinine, transient eosinophilia (60%–80% of cases), elevated erythrocyte sedimentation rate (ESR), and hypocomplementemia (15% of cases). Contrast-induced nephropathy is not associated with fever, high ESR, eosinophilia, or livedo reticularis of the lower extremities. It would be unusual to develop interstitial nephritis without exposure to a new medication, and other than eosinophilia, the laboratory abnormalities are not supported in this case. Likewise, the sudden development of hypereosinophilic syndrome in a 75-year-old man would be highly unlikely. Finally, although Churg-Strauss syndrome is a small- to medium-vessel vasculitis associated with renal dysfunction and eosinophilia, almost all patients experience atopy and asthma-like lung disease, which are absent in this patient.