Acute renal infarction: Clinical characteristics and prognostic factors

Acute renal infarction (ARI) is an uncommon disease, whose real incidence is probably higher than expected. It is associated with poor prognosis in a high percentage of cases.

To describe the main clinical, biochemical and radiologic features and to determine which factors are associated with poor prognosis (death or permanent renal injury).

The following is a retrospective, observational, single-hospital-based study. All patients diagnosed with ARI by contrast-enhanced computed tomography (CT) over an 18-year period were included. Patients were classified according to the cardiac or non-cardiac origin of their disease. Clinical, biochemical and radiologic features were analysed, and multiple logistic regression model was used to determine factors associated with poor prognosis.

A total of 62 patients were included, 30 of which had a cardiac origin. Other 32 patients with non-cardiac ARI were younger, had less comorbidity, and were less frequently treated with oral anticoagulants. CT scans estimated mean injury extension at 35%, with no differences observed between groups. A total of 38% of patients had an unfavourable outcome, and the main determinants were: Initial renal function (OR=0.949; IC 95% 0.918-0.980; p=0.002), and previous treatment with oral anticoagulants (OR=0.135; IC 95% 0.032-0.565; p=0.006).

ARI is a rare pathology with non-specific symptoms, and it is not associated with cardiological disease or arrhythmias in more than half of cases. A substantial proportion of patients have unfavourable outcomes, and the initial renal function is one of the main prognostic factors.