About QUEST

The QUEST trial is the largest clinical study of its kind to be conducted amongst dogs with congestive heart failure due to myxomatous mitral valve disease (MMVD) – also sometimes referred to as “endocardiosis” or “chronic valvular insufficiency”. QUEST stands for Quality of Life and Extension of Survival Time, and is an international, multi-centre clinical trial comparing the effects of two different treatments used to treat congestive heart failure due to MMVD in dogs. To watch leading cardiologists discuss the study objectives, please click on the video link below.

Overview

• The study is a comparison of  pimobendan (Vetmedin®) and benazepril hydrochloride (an ACE-inhibitor treatment) in the treatment of dogs with congestive heart failure due to myxomatous mitral valve disease (MMVD)
• 260 dogs were enrolled across 11 countries
• The clinical phase of the study lasted three years.

What were the aims of the study?

• Primary: To assess the effect of pimobendan therapy on survival time, in comparison with benazepril hydrochloride, in dogs with congestive heart failure due to MMVD.
• Secondary: To assess the effect of pimobendan in comparison with benazepril hydrochloride on quality of life measures  in dogs with congestive heart failure due to MMVD

What sorts of patients were enrolled in the study?

Inclusion criteria for patients in the QUEST study were:

• The presence of congestive heart failure due to MMVD, confirmed by ultrasound of the heart chambers and valves and by radiography (x-ray)
• The presence of pulmonary oedema (fluid build-up in the lungs)
• Clinical signs of heart failure
• Dogs aged 5 years or older
• Dogs within a  body weight range of 5- 20kg (MMVD is primarily a disease of small to medium-sized dogs)

Reasons for patients being excluded from the study included:

• Other significant conditions, e.g. heart, kidney, liver, stomach or intestinal disease
• Pregnant or lactating female dogs

Trial Design

QUEST was a randomised, positive-controlled, multi-centre trial conducted at 28 sites across Australia, Canada and Europe. Patients were recruited over a two year period and randomly allocated to either the pimobendan or benazepril hydrochloride treatment group, each group consisting of 130 dogs. The trial spanned three years and followed dogs through to death, euthanasia or treatment failure leading to withdrawal from the trial.

Dosing Schedule

Dogs in the pimobendan treatment group received a daily dose of 0.4-0.6mg/kg, using a suitable number of 1.25mg or 2.5mg capsules depending on weight, which were administered twice daily. The benazepril hydrochloride group received 0.25-0.5mg/kg daily, given using the appropriate number of 5mg tablets, according to the manufacturer’s recommendation - this dose could be doubled at the request of the Investigator.

Which symptoms and quality of life measures were used?

Quality of life observations

• Appetite
• Demeanour
• Exercise tolerance

Clinical considerations

• Respiratory: respiratory effort, coughing, shortness of breath or coughing at night
• Circulatory measures: heart rate, heart failure score, electrocardiography and  ultrasound measures.
• Blood testing: clinical chemistry and haematology