Effect of prespecified therapy escalation on plasma NT-proBNP concentrations in dogs with stable congestive heart failure due to myxomatous mitral valve disease.

Background: Therapy targeted to achieve reduction in N-terminal pro-B-type natriuretic peptide (NT-proBNP) improves outcomes in human congestive heart failure (CHF) patients. Hypothesis: A pre-specified therapeutic algorithm that increased diuretic or pimobendan usage will reduce plasma NT-proBNP concentrations in dogs with CHF secondary to myxomatous mitral valve disease (MMVD). Animals: Twenty-six dogs with clinically stable CHF secondary to MMVD. Methods: Prospective, controlled before-and-after study. Dogs were examined up to 3 times over 21 days. Treatment was prescribed based on NT-proBNP as follows: <1500 pmol/L at baseline, no therapy adjustment at any point during the study (group 1); ≥1500 pmol/L and creatinine ≤3.0 mg/dL at baseline or subsequent visits, therapy escalated according to the algorithm (group 2); ≥1500 pmol/L at baseline, no therapy adjustment (group 3). Results: NT-proBNP decreased significantly in group 2 (mean change=-1,736 pmol/L (95% CI, -804 to -2,668), P<0.001) but not in groups 1 or 3 (623 pmol/L (-631 to 1877 pmol/L), P=0.14 and 685 pmol/L (-304 to 1068 pmol/L), P=0.46, respectively). Serum BUN and creatinine did not change significantly between visit 0 and visit 2 in group 1 (median=23 mg/dL (range 13-32) vs. 19 mg/dL (12-38), P=0.72 and1.15 mg/dL (0.70 – 1.40) vs. 0.95 mg/dL (0.70 – 1.10), P=0.10, respectively) or group 2 (28 mg/dL (18-87) vs. 43.5 mg/dL (21-160), P=0.092 and 1.10 mg/dL (0.90 – 2.50) vs.1.55 mg/dL (0.90 – 3.30), P=0.062, respectively). Conclusions and clinical importance: Use of this treatment escalation algorithm allows effective targeting of therapy for CHF in dogs against an objective criterion.