Podcasts

Using pimobendan in cats with hypertrophic cardiomyopathy | VETgirl Veterinary CE Podcasts

In today’s VETgirl online veterinary continuing education podcast, we review a study published out of North Carolina State University on the use of pimobendan in cats with hypertrophic cardiomyopathy (HCM) and congestive heart failure (CHF). Should we use it?

Pimobendan, a calcium sensitizer and phosphodiesterase III inhibitor, is considered an inodilator due to its effects as a positive inotrope (via sensitization of the myocardium to the effects of calcium) and vasodilator (via phosphodiesterase type 3 inhibition). It has become a standard treatment for dogs with congestive heart failure (CHF) due to dilated cardiomyopathy (DCM) or chronic vavular heart disease (CVHD); however, data on the effects of pimobendan in cats with CHF secondary to HCM is limited and the drug is not currently licensed for use in cats.

Is pimobendan safe to use in cats? There’s significant debate over its safety and indications for use in cats due to the poorly defined effects of the drug on diastolic heart failure, particularly in those cats with the obstructive form of HCM (HOCM). The obstruction in HOCM cats is dynamic in nature (e.g., not fixed) and associated with systolic anterior motion (SAM) of the anterior mitral valve leaflet.

So, Reina-Doreste Y et al out of NC State wanted to retrospectively evaluate this using a case control study (e.g., cases on pimobendan versus control cats). Overall, the median dose of pimobendan used for the case group of cats was 0.49 mg/kg/day. Overall, no significant differences were detected between the two groups for additional cardiac medications used or any other variables at the start or completion of the study. What they did find however, was that case group cats on pimobendan lived significantly longer: for a median of 626 days as compared to control cats at 103 days.

So, this VETgirl podcast discusses whether or not it’s worth considering for use in cats with HCM or HOCM. The results of this study certainly have the potential to change the way we think about treating cats with CHF secondary to HCM, and suggests that addition of pimobendan to CHF therapy in cats with HOCM and HCM may provide significant improvement in survival time. That said, there are some limitations of the study, and larger, prospective studies are warranted to investigate this conclusion.

For more information, check out our previous podcast on the use of pimobendan in cats with congestive heart failure here.

Suggested reading:

1. MacGregor JM, Rush JE, Laste NJ, et al. Use of pimobendan in 170 cats (2006-2010). J Vet Cardiol 13:251-260, 2011.

2. Gordon SG, Saunders AB, Roland RM, et al. Effects of oral administration of pimobendan in cats with heart failureJ Am Vet Med Assoc 2012;241:89–94.

3. Reina-Doreste Y, Stern JA, Keene BW, et al. Case-control study of the effects of pimobendan on survival time in cats with hypertrophic cardiomyopathy and congestive heart failure. J Am Vet Med Assoc 2014;245(5):534-539.

4. Wainberg S. Use of pimobendan in feline congenital heart failure. Can Vet J 2013; 54(12): 1164–1166.

 

Only VETgirl members can leave comments. Sign In or Join VETgirl now!