C07 - Comparison of Low- and High-pressure Balloon Valvuloplasty in Dogs with Severe Pulmonary Valve Stenosis

Abstract: Background- Balloon valvuloplasty (BVP) is standard treatment for severe valvular pulmonic stenosis (PS) in dogs. Efficacy and safety of low-pressure balloon catheters (LP) and high-pressure balloon catheters (HP) for BVP has not been compared. Hypothesis/Objectives- There will be no difference in pressure gradient reduction between HP and LP. Cardiac troponin I (cTnI) will be higher with HP compared to LP immediately following BVP. Animals- Twenty-five (25) client owned dogs with severe PS. Methods- Prospective, randomized study. Patients matched based on pulmonic annulus size. Echocardiographic measures of PS severity included transvalvular pressure gradient (PGmax) and aorta-to-pulmonary artery velocity time integral ratio (Ao/PAVTI) at baseline, 18-24 hours following BVP and at 3-month recheck. Serum cTnI was measured at each time point.Results- There were 13 dogs in the LP group and 12 in the HP group with no difference in sex, weight or age between groups. There was no significant difference in PS severity between groups at baseline [(Ao/PAVTI; p=0.376), (PGmax; p=0.406)], 18-24 hours post-BVP [(Ao/PAVTI; p=0.270), (PGmax; p=0.263)], or at 3-month recheck [(Ao/PAVTI; p=0.418), (PGmax; p=0.184)]. There was no significant difference in serum cTnI between groups at baseline (p=0.069), 18-24 hours post-BVP (p=0.378), or at 3-month recheck (p=0.705). Major complications were rare with no difference between HP and LP.Conclusions and clinical importance - There was no difference in reduction of PS severity between HP and LP. The use of HP is not expected to provide superior reduction in PS severity compared to LP or be associated with increased myocardial injury.