Dr Atkinson is presently affiliated with Cardiology Northwest, Portland, OR. This work was previously presented as an abstract at the 26th Annual Meeting of the American College of Veterinary Internal Medicine, San Antonio, TX, June 2008.
Evaluation of Pimobendan and N-Terminal Probrain Natriuretic Peptide in the Treatment of Pulmonary Hypertension Secondary to Degenerative Mitral Valve Disease in Dogs
Article first published online: 22 SEP 2009
Copyright © 2009 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 23, Issue 6, pages 1190–1196, November/December 2009
How to Cite
Atkinson, K.J., Fine, D.M., Thombs, L.A., Gorelick, J.J. and Durham, H.E. (2009), Evaluation of Pimobendan and N-Terminal Probrain Natriuretic Peptide in the Treatment of Pulmonary Hypertension Secondary to Degenerative Mitral Valve Disease in Dogs. Journal of Veterinary Internal Medicine, 23: 1190–1196. doi: 10.1111/j.1939-1676.2009.0390.x
- Issue published online: 27 OCT 2009
- Article first published online: 22 SEP 2009
- Submitted February 26, 2009; Revised July 24, 2009; Accepted August 13, 2009.
- Heart failure;
Background: Pimobendan is a positive inotrope and vasodilator that may be useful in the treatment of pulmonary hypertension (PHT) secondary to degenerative mitral valve disease.
Hypothesis: Pimobendan decreases the severity of PHT measured echocardiographically and improves quality-of-life scores. Changes in N-terminal probrain natriuretic peptide (NT-proBNP) concentrations will reflect improvement in severity of PHT.
Animals: Ten client-owned dogs with peak tricuspid regurgitant flow velocity (TRFV) ≥3.5 m/s.
Methods: Prospective short-term, double-blinded, crossover design, with a long-term, open-label component. Short term, dogs were randomly allocated to receive either placebo or pimobendan (0.18–0.3 mg/kg PO q12 h) for 14 days. After a 1-week washout, they received the alternative treatment for 14 days, followed by pimobendan open-label for 8 weeks.
Results: Short-term comparison: peak TRFV decreased in all dogs on pimobendan compared with placebo from a median of 4.40 (range, 3.2–5.6) to 3.75 (range, 2.4–4.8) m/s (P < .0001). NT-proBNP concentration decreased after treatment with pimobendan from a median of 2,143 (range, 450–3,981) to 1,329 (range, 123–2,411) pmol/L (P= .0009). All dogs improved their quality-of-life score (P= .006). In the long-term comparisons, peak TRFV decreased in all dogs from a median of 4.28 (range, 3.5–5.7) to 3.52 (range, 2.4–5.0) m/s (P < .0001). No significant changes in NT-proBNP or quality-of-life scores were detected.
Conclusions and Clinical Importance: Pimobendan lowered severity of measurable PHT, improved quality-of-life scores, and decreased NT-proBNP concentrations short-term. Long term, only the reduction in TRFV was maintained.