Evaluation of novel diagnostic and therapeutic modalities for treatment of canine pulmonary hypertension
Abstract
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Pimobendan, a phosphodiesterase III inhibitor and calcium channel sensitizing agent, was hypothesized to decrease the severity of pulmonary hypertension (PHT) in a prospective short-term, double-blinded, crossover design, with a long-term, open-label component. Ten dogs with a peak tricuspid regurgitant pressure gradient (TRPG) [greater than or equal to] 50 mmHg on echocardiogram were enrolled. PHT was secondary to myxomatous valve disease in 8 of the dogs, and chronic pulmonary disease in 2. Dogs were examined on days 0, 14, 21, 35, and 91. In the 35-day short-term phase, dogs were randomly allocated to receive either placebo or pimobendan (0.18-0.3 mg/kg, PO q12h) for 14 days. Following a 1 week washout, the dogs received the alternative treatment for 14 days. All dogs then received pimobendan for 8 weeks. Data was analyzed using a two-period crossover design. Short-term comparison of pimobendan vs. placebo: All dogs had a decreased peak TRPG on pimobendan therapy in comparison to placebo (p=0.0061), with a mean decrease of 16.37 [plus or minus] 12.89 mmHg. All dogs demonstrated a significant decrease in NT-proBNP levels while receiving pimobendan (p=0.0023), with a mean difference of 708.8 [plus or minus] 508.6 pmol/L. A significant improvement in the summed QOL score was noted in 9/10 dogs (p=0.016). Long-term comparison of day 0 vs. 91: 9/10 dogs showed a decreased peak TRPG (p=0.03), with a mean decrease of 14.0 [plus or minus] 15.6 mmHg. No significant changes in NT-proBNP levels (p=0.34) or the summed QOL scores (p=0.41) were seen. Failure to show improvement may be secondary to progressive disease or the small sample size.
Degree
M.S.
Thesis Department
Rights
Access is limited to the campus of the University of Missouri--Columbia.