A 58-year-old man with diabetes mellitus type 2 and hypertension presents to the emergency department with acute kidney injury. His serum creatinine has risen from baseline 1.2 mg/dL to 3.8 mg/dL over 48 hours. Urinalysis shows muddy brown casts and fractional excretion of sodium (FENa) is 2.1%. What is the most common cause of acute kidney injury in hospitalized patients in India?