Study Start Date: 05/01/2007
Study End Date: 6/1/2010

Pulmonic stenosis (PS) is one of the most common congenital heart defects in dogs.  Dogs with severe PS often have a shortened life span and develop clinical signs including exercise intolerance, syncope, abdominal distension and sudden death.  Pulmonic stenosis is most often caused by abnormal pulmonic valve leaflets resulting in a narrowing of the pulmonary outflow tract at the valvular level and elevated right ventricular pressures for which balloon dilation is an effective treatment.  Less commonly, pulmonic stenosis is a result of a hypoplastic pulmonic annulus or a coronary anomaly in which an interventional procedure such as balloon dilation cannot be performed.  Elevations in specific cardiac biomarkers including troponin I and C-reactive protein are associated with increased morbidity and mortality in human patients with cardiovascular disease and have been shown to be elevated in dogs with severe PS.  Fatty acid supplementation in humans with various cardiac diseases consistently results in resolution of inflammatory patterns and may be able to curtail myocardial damage.  We hypothesize that fatty acid supplementation will improve clinical signs of disease in dogs with severe PS and may curtail significant elevations in cardiac biomarkers following balloon dilation to improve long-term outcome.

Study Design:
Randomized clinical trial

Inclusion Criteria:

• Echocardiographic evidence of severe pulmonic stenosis, (peak pressure gradient across the stenotic region >80mmHg in conjunction with right ventricular hypertrophy). 
• Dogs will be entered into one of two groups depending on whether or not balloon dilation can be performed.  Therefore, dogs with annular hypoplasia and/or coronary artery anomalies can be enrolled.
• No evidence of any other underlying systemic or metabolic disease.
• No evidence of other congenital heart defects.
• Not already receiving fatty acid supplements.
• Patients need to be presented to Texas A&M University for the procedure (if performed) and follow-up

Exclusion Criteria:

• Dogs without pulmonic stenosis, or with pulmonic stenosis that has already been treated with balloon valvuloplasty

Study Endpoints:
Biomarker changes and survival. 

Samples:
Patients need to be presented to Texas A&M University for the procedure (if performed) and follow-up

Costs/Reimbursements
Patients included in the trial receive at no charge: physical exam, echocardiogram, blood pressure at initial evaluation and all expenses (except atenolol therapy) associated with recheck exams at 3 months, 6 months, and 1 year post-balloon valvuloplasty or following enrollment into the study. Should patients be examined and inclusion criteria are not met, owners are responsible for cost of initial evaluation including physical exam and echocardiogram ($300-400).

Full Disclosure information:

• The study is funded by a grant from Nestle Purina PetCare Company.
• The investigator does not have a conflict of interest.
• The study will be published if results are negative
• The study will be reported on VIN
• The authors will acknowledge VIN if the study is published with sufficient case recruitment.