Acute Kidney Cortical Necrosis following Cardiac Catheterization: A Diagnostic Challenge

Introduction: Atheroembolic renal disease is a rare but serious cause of renal failure among patients who underwent cardiac catheterization. It can lead to ischemic renal cortical necrosis due to microvascular injury. Renal biopsyis the gold standard for the definitive diagnosis, however, this is not possible for patients who are at high risk of bleeding. We present a case of a patient who developed severe acute kidney injury (AKI) following cardiac catheterization. He was diagnosed with renal cortical necrosis using a nuclear dimercaptosuccinic acid (DMSA) renal scan. Case Description: A 61-year-old male with a past medical history of hypertension and coronary artery disease was sent to the emergency department after a routine Cardiology follow-up for evaluation and management of AKI. His laboratory test showed elevated BUN of 57 mg/dL and serum creatinine of 15.14 mg/dL from a baseline of 1 mg/dL. 3 weeks prior, the patient underwent left heart catheterization and drug-eluting stent (DES) placement for NSTEMI. His hospital course was uncomplicated and he was discharged with a stable renal function. On presentation, the patient reported decreased urine output, otherwise the history and physical examination were unremarkable. His work-ups including a renal ultrasound were unrevealing. A renal biopsy was planned, however, the patient was at high risk for bleeding due to his dual antiplatelet therapy for a recent coronary DES placement. Upon discussion with the Nuclear Medicine department, a DMSA renal scan was obtained to assess the kidney function and to help in the diagnosis of possible cortical infarction. The patient’s results showed heterogeneity of uptake compatible with suspected cortical necrosis. The patient had a good renal recovery after undergoing a few treatments with hemodialysis. Discussion: The diagnosis of atheroembolic renal disease following cardiac catheterization is challenging as the patients may present with non-specific symptoms and unrevealing AKI workups. Renal biopsyis the gold standard to confirm the diagnosis, however, this is a diagnostic challenge as there is a high risk of bleeding for patients who are receiving dual anti-platelet therapy following DES. DMSA, a renal nuclide scan, can provide both functional and anatomic information. This case highlights that radionuclide studies may be utilized in such cases when kidney biopsy is not possible.