Effects of plasma aldosterone concentration and treatment with eplerenone on the survival of cats with chronic kidney disease.

This study investigated the plasma aldosterone concentration (PAC) in cats with chronic kidney disease (CKD) and retrospectively evaluated the survival of cats with high PAC. Furthermore, this study prospectively examined eplerenone's effect on survival time in CKD cats with high PAC. The PAC was measured retrospectively in blood samples obtained from 156 client-owned cats that visited a veterinary hospital. The cats were designated into 2 groups: clinically healthy (n = 101) and those with CKD (n = 55). The PAC was measured by solid-phase radioimmunoassay; median (minimum-maximum) PAC in healthy cats was 97 pg/mL (range: 10 to 416 pg/mL) and the upper limit (95th percentile) was 243 pg/mL. In the CKD group, PAC [126 pg/mL (range: 10 to 981 pg/mL)] was higher (P < 0.01) than in the clinically healthy group. In cats with CKD, the survival time of those with high PAC (n = 16) (> 243 pg/mL) was shorter (P = 0.019) than that of those (n = 39) with normal PAC. Administering an aldosterone antagonist, eplerenone, at 2.5 to 5 mg/kg body weight prolonged survival (P = 0.005) in CKD cats with high PAC (n = 8). In conclusion, PAC could be a prognostic marker of CKD in cats and eplerenone may prolong survival in cats with CKD and a high PAC.