Cardiovascular‐renal axis disorder and acute‐phase proteins in cats with congestive heart failure caused by primary cardiomyopathy

Abstract Background Currently, the pathogenesis of congestive heart failure (CHF) in cats is not fully understood. Objective To identify novel biomarkers for CHF in cats caused by primary cardiomyopathy, particularly related to cardiovascular‐renal axis disorder and systemic inflammatory response. Animals Twenty‐five cats in CHF caused by primary cardiomyopathy, 12 cats with preclinical cardiomyopathy, and 20 healthy controls. Methods Case control and observational case series. The following serum biomarkers were compared among the 3 cat groups: a cardiorenal profile that included N‐terminal pro‐brain natriuretic peptide (NT‐proBNP), symmetric dimethylarginine (SDMA), and creatinine and an inflammatory profile that included 7 acute‐phase proteins (APPs). Survival analyses and longitudinal studies were performed in CHF cats. Results All cardiorenal biomarkers were positively correlated and higher in CHF cats, and high NT‐proBNP and SDMA were associated with poor clinical outcome. Cats with CHF had significantly higher leucine‐rich alpha‐2‐glycoprotein 1, serum amyloid A, and ceruloplasmin, and these APPs were positively correlated with NT‐proBNP and left atrial size. In a multivariable survival analysis, alpha‐1‐acid glycoprotein concentration (P = .01), body weight (P = .02) and left atrial‐to‐aortic root ratio (P = .01) were independent prognostic factors for CHF in these cats. Conclusions and Clinical Importance In cats, CHF is an inflammatory disorder and outcome in CHF may be determined by the extent of inflammation and possibly the amount of residual renal function. These novel biomarkers have potential use for the clinical management, prognosis, and future research into CHF and cardiomyopathy in cats.