Systematic Review of Renal Infarction Clinical Presentation, Causes, and Outcomes

Renal infarction is rare with only retrospective cohort studies published. To better understand renal infarction, we conducted a systematic review and metaanalysis of proportions for i) incidence and prevalence, ii) patient characteristics and symptoms, iii) causes, and iv) outcomes.

Web of Science, PubMed, and Scopus databases were searched. Articles were screened and data extracted with pooled measures determined by random effects metaanalysis of proportions with 95% confidence interval (95% CI). Heterogeneity was examined through I ² .

We screened 4010 abstracts and included 34 retrospective cohort studies with 12,727 cases of renal infarction. Pooled incidence was 0.3 per 10,000 patient-years (95% CI, 0.04-2.3; I ² = 99%) and prevalence 0.017% (95% CI, 0.004-0.038; I ² = 99%). Comorbidity burden was high, with hypertension the most prevalent (0.47; 95% CI, 0.43-0.51; I ² = 74%). Antithrombotic therapy was used in almost a third of patients (0.32; 95% CI, 0.21-0.45; I ² = 88%). The most common symptom was flank or abdominal pain (0.64; 95% CI, 0.46-0.81; I ² = 89%). Causes of renal infarction included embolic (0.42; 95% CI, 0.35-0.50; I ² = 97%), hypercoagulable state (0.12; 95% CI, 0.08-0.18; I ² = 85%), renal artery damage (0.11; 95% CI, 0.06-0.16, I ² = 97%), trauma (0.03; 95% CI, 0.01-0.06; I ² = 87%) and other or idiopathic (0.31; 95% CI, 0.25-0.37; I ² = 98%). Outcomes following a renal infarction included acute dialysis (0.04; 95% CI, 0.02-0.07, I ² = 39%), inpatient mortality (0.05; 95% CI, 0.03-0.09; I ² = 69%), chronic kidney disease (CKD) (0.25; 95% CI, 0.16-0.34; I ² = 89%), and kidney failure (0.04; 95% CI, 0.02-0.08; I ² = 77%).

Renal infarction is rare and can present with unspecific symptoms. Antithrombotic use should not exclude renal infarction from the differential and 25% develop CKD. There is a need to better standardize the classification.