Clinical Characteristics and Outcomes of Renal Infarction

Abstract

Background: Renal infarction is a rare condition resulting from an acute disruption of renal blood flow, and the cause and outcome of renal infarction are not well established.

Study design: Case series.

Setting & participants: 438 patients with renal infarction in January 1993 to December 2013 at 9 hospitals in Korea were included. Renal infarction was defined by radiologic findings that included single or multiple wedge-shaped parenchymal perfusion defects in the kidney.

Predictor: Causes of renal infarction included cardiogenic (n=244 [55.7%]), renal artery injury (n=33 [7.5%]), hypercoagulable (n=29 [6.6%]), and idiopathic (n=132 [30.1%]) factors.

Outcomes: We used recurrence, acute kidney injury (AKI; defined as creatinine level increase ≥ 0.3mg/dL within 48 hours or an increase to 150% of baseline level within 7 days during the sentinel hospitalization), new-onset estimated glomerular filtration rate (eGFR)<60mL/min/1.73m(2) (for >3 months after renal infarction in the absence of a history of decreased eGFR), end-stage renal disease (ESRD; receiving hemodialysis or peritoneal dialysis because of irreversible kidney damage), and mortality as outcome metrics.

Results: Treatment included urokinase (n=19), heparin (n=342), warfarin (n=330), and antiplatelet agents (n=157). 5% of patients died during the initial hospitalization. During the median 20.0 (range, 1-223) months of follow-up, 2.8% of patients had recurrent infarction, 20.1% of patients developed AKI, 10.9% of patients developed new-onset eGFR<60mL/min/1.73m(2), and 2.1% of patients progressed to ESRD.

Limitations: This was a retrospective study; it cannot clearly determine the specific causal mechanism for certain patients or provide information about the causes of mortality. 16 patients were excluded from the prognostic analysis.

Conclusions: Cardiogenic origins were the most important causes of renal infarction. Despite aggressive treatment, renal infarction can lead to AKI, new-onset eGFR<60mL/min/1.73m(2), ESRD, and death.

Keywords: Renal infarction; acute kidney injury (AKI); cardiogenic etiology; case series; end-stage renal disease (ESRD); kidney function; mortality; outcomes; parenchymal perfusion defect; reduced glomerular filtration rate; renal blood flow.