Veterinary Medical Center

This study is closed (8/29/2012)

Purpose of the study:

The purpose of this study is to determine whether chronic oral administration of pimobendan in dogs with evidence of increased heart size secondary to preclinical myxomatous mitral valve disease, can delay the onset of signs of congestive heart failure.

Background:

Currently there is no cardiac drug licensed for the treatment of preclinical myxomatous mitral valve disease. Pimobendan has been proven to be safe and to reduce mortality as well as morbidity associated with congestive heart failure (CHF) due to myxomatous mitral valve disease. The combination of preload and afterload reduction in combination with inotropic support may result in a reduction in cardiac size and filling pressures in dogs with significant remodelling secondary to myxomatous mitral valve disease. These effects are considered to be cardioprotective and therefore, in dogs with preclinical myxomatous mitral valve disease, would be anticipated to delay the onset of pulmonary oedema and clinical signs.

Inclusion criteria:

To qualify for enrollment in this study, dogs must have:

• A moderate to high intensity systolic heart murmur with maximal intensity over the mitral area (≥ grade 3/6[a1] ).
• Animals must be at least six years of age.
• Animals must have a body weight ≥ 4.1 and ≤ 15 kg (≥ 9 and ≤ 33.1 lb)
• Radiographic evidence of cardiomegaly (VHS score > 10.5)
• Echocardiographic evidence of myxomatous mitral valve disease defined as characteristic valvular lesions of the mitral valve apparatus (leaflet thickening, valve prolapse, ruptured chordae tendineae)
• Presence of mitral regurgitation on the colour Doppler echocardiogram

Exclusion criteria

• Chronic treatment (> 14 days) for cardiovascular disease (enalapril, furosemide, etc.) within 30 days of Day 0, then the dog is not eligible for screening or enrolment. 

Study design

This is a multi-center, placebo controlled, double blinded study.  On Day 0 dogs will have  physical examination, auscultation, radiographs, echocardiography, labwork, and blood pressure performed. Dogs meeting enrolment criteria will be randomized to either receive Pimobendan or Placebo, and will be reevaluated at day 35 ± 7, 4 Months, 8 Months, and every 4 months thereafter following entry and again at the time of clinical signs related to CHF.

Client cost

• Clients are responsible for paying for charges related to laboratory tests and other exams that may be requested beyond study design

Client compensation

• The study will cover for approximately 80% or more of the client’s bill

• Adverse events confirmed to be directly related to the medication will be covered by the study


 Contact information

For more information on this study contact Nicole Stingle or Tamra Mathie at clinicaltrials [at] cvm [dot] osu [dot] edu