Effect of oral administration of pimobendan in cats with heart failure.
OBJECTIVE
To determine the effect of PO administration of pimobendan on clinical and echocardiographic variables and survival time in cats with heart failure characterized by ventricular systolic dysfunction.


METHODS
Retrospective cohort study.


METHODS
27 client-owned cats (16 male and 11 female) with heart failure, treated with pimobendan (mean ± SD dosage, 0.26 ± 0.08 mg/kg [0.118 ± 0.036 mg/lb], PO, q 12 h).


METHODS
Information on medical history, laboratory results, diagnostic imaging findings, treatments received, and survival time were obtained from medical records of cats that received pimobendan because of cardiac disease. When possible, additional follow-up information was obtained through telephone interviews with referring veterinarians and owners.


RESULTS
The mean ± SD age of all 27 cats was 8.9 ± 5.2 years. All cats had received several cardiac medications. Types of heart disease represented included unclassified cardiomyopathy (CM; n = 11 [41%]), dilated CM (8 [30%]), arrhythmogenic right ventricular CM (4 [15%]), congenital heart disease (3 [11 %]), and hypertrophic CM with regional hypokinesis (1 [4%]). All cats had ventricular systolic dysfunction. One cat with systolic anterior motion of the mitral valve became severely hypotensive after initial administration of pimobendan and was excluded from the survival analysis. Median survival time was 167 days (95% confidence interval, 32 to 339 days).


CONCLUSIONS
Pimobendan appeared to be well tolerated in cats with heart failure characterized by ventricular systolic dysfunction of various etiologies. Cats with systolic anterior motion of the mitral valve may develop systemic hypotension when treated with pimobendan. Additional studies are needed to establish dosages for pimobendan and its effects before it can be recommended for treatment of cats with CHF.
Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, College of Science, Texas A&M University, College Station, TX 77843, USA. sgordon@cvm.tamu.edu
Sonya G
SG
Gordon
Ashley B
AB
Saunders
Risa M
RM
Roland
Randolph L
RL
Winter
Lori
L
Drourr
Sarah E
SE
Achen
Crystal D
CD
Hariu
Ryan C
RC
Fries
May M
MM
Boggess
Matthew W
MW
Miller
D000284:Administration, Oral; D000818:Animals; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002371:Cat Diseases / Q000188:drug therapy* / Q000401:mortality; D002415:Cats; D015331:Cohort Studies; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000401:mortality / Q000662:veterinary*; D008297:Male; D011724:Pyridazines / Q000008:administration & dosage / Q000627:therapeutic use*; D012189:Retrospective Studies; D016896:Treatment Outcome; D018754:Ventricular Dysfunction / Q000188:drug therapy / Q000662:veterinary*
D002316:Cardiotonic Agents; D011724:Pyridazines; C041648:pimobendan