A 60-year-old woman presents to the emergency department complaining of general malaise with a new elevated creatinine of 260 µmol/L. She has no past medical history. Vital signs include a heart rate of 82, blood pressure 195/100, respiratory rate 18, temperature 36.7, oxygen saturation 97% on room air. Physical exam is unremarkable. She appears euvolemic with no evidence of pulmonary or peripheral edema. Urinalysis demonstrates 2+ protein and 2+ red blood cells. Which of the following is likely the cause of her acute kidney injury?