Prognostic value of plasma cortisol concentration in dogs with congestive heart failure

The association of plasma cortisol concentration with prognosis for dogs with congestive heart failure (CHF) is unknown.

To determine whether higher plasma cortisol concentration was independently associated with greater risk of cardiac mortality in dogs with CHF. Additional study aims were to evaluate the associations between other clinical, neurohormonal, and echocardiographic indices and cardiac mortality.

Thirty-one client-owned dogs with CHF secondary to myxomatous mitral valve disease (MMVD).

Prospective cohort observational study. Plasma cortisol measurement, urine cortisol-to-creatinine ratio, renal function test results, serum electrolytes, biomarkers of the renin-angiotensin-aldosterone system, N-terminal pro-B-type natriuretic peptide, and echocardiography were performed in dogs with MMVD at first onset of CHF. Plasma cortisol was repeated 7-14 days later. Association between plasma cortisol and other covariates with survival was determined using a proportional hazards regression model.

Plasma cortisol concentration was not associated with cardiac (P = .112; hazard ratio [HR] 1.01; 95% CI, 0.998-1.02) or all-cause mortality (P = .143; HR 1.01; 95% CI, 0.998-1.02). Treatment with angiotensin-converting enzyme inhibitors (P = .021; HR 0.058; 95% CI, 0.0052-0.66) was associated with longer survival to cardiac mortality. Treatment with spironolactone (P = .038; HR 0.36; 95% CI, 0.14-0.94), percent fractional shortening (P = .034; HR 0.0018; 95% CI, 5.44 × 10-6 to 0.61), and lower serum potassium (P = .048; HR 2.07; 95% CI, 1.01-4.27) at diagnosis were associated with longer survival to all-cause mortality. Spironolactone treatment at baseline was associated with all-cause mortality on multivariable regression analysis.

Plasma cortisol concentrations were not associated with cardiac mortality in this sample of dogs with CHF.