Acute Renal Infarct Caused by Atrial Fibrillation: A Case Report and Literature Review

Introduction: Acute renal infarction (ARI) is a major medical emergency that can cause irreversible kidney damage. It is a rare but serious condition, often caused by embolism or thrombosis. We report a new case of renal infarct in a 43-year-old male patient who presented with right flank pain. Case Description: A 43-year-old Indian male presented to the emergency department with sudden onset, severe right sided flank pain radiating towards the groin. There was no fever, hematuria or dysuria. He had a past history of hypertension for 5 years and new onset fast atrial fibrillation (CHA2DS2-VASC score 1) which had been electrically cardioverted 9 months ago. The electrical cardioversion was followed by oral anticoagulation for 1 month. Vital signs were stable. The laboratory investigations revealed acute kidney injury with a serum creatinine of 129 umol/L and leukocytosis. Full septic screen was negative. His renal immunology and virology screen were normal. There was no haemato-proteinuria or pyuria.. A CT angiogram of the abdomen revealed multiple areas of renal infarction in the right kidney. The renal arteries were patent. A subsequent Echocardiogram showed no intracardiac thrombi. The patient was started on oral anticoagulation and his kidney function was closely monitored. The pain resolved and there was no further decline in the kidney function. Discussion: Acute renal infarction (ARI) is an infrequently encountered and underdiagnosed clinical entity, often due to its nonspecific presentation and overlap with more common causes of flank pain. Atrial fibrillation is a well-established risk factor for systemic embolism. Although the patient had a low CHA2DS2-VASC score of 1, his episode of renal infarction highlights an important consideration: the score may not fully capture embolic risk in all individuals. Existing literature supports this observation. Hence a more nuanced risk assessment may be necessary, especially for non-cerebral embolic events. This case illustrates a potential gap in guidelines regarding the duration of anticoagulation after cardioversion in low-risk patients. While current recommendations suggest short-term anticoagulation in low CHA2DS2-VASC patients, this case raises the question of whether extended or indefinite anticoagulation might be warranted in selected individuals.