Comparison of low- and high-pressure balloon valvuloplasty in dogs with severe pulmonary valve stenosis.

INTRODUCTION/

OBJECTIVES

Balloon valvuloplasty (BVP) is considered a standard treatment for severe pulmonary valve stenosis (PS) in dogs. The efficacy and safety of low-pressure (LP) and high-pressure (HP) balloon catheters for BVP have not been compared. It was hypothesized there would be no difference in pressure gradient reduction between HP and LP, while cardiac troponin I would be higher with HP than with LP immediately following BVP.

ANIMALS, MATERIALS AND

METHODS

Twenty-five client-owned dogs with severe PS were included in the study. A prospective, randomized study with animals matched based on pulmonic annulus size was conducted. Echocardiographic measures of PS severity included peak transvalvular pressure gradient (PGmax) and aorta-to-pulmonary artery velocity time integral ratio at baseline, 18-24 h following BVP, and at the initial follow-up. Serum cardiac troponin I was measured at each time point.

RESULTS

No differences were found between groups in sex, age, weight, or PS severity at any time point (baseline, 18-24 h post BVP, and follow-up; all P>0.9). Only three dogs had annular hypoplasia. Cardiac troponin values did not differ between LP and HP groups at any stage (P>0.1). Complication rates were also comparable (P=0.201).

STUDY LIMITATIONS: The limited sample size may have reduced statistical power to detect modest yet clinically relevant differences. Small and homogeneous sample, lack of standardized HP catheters, inconsistent atenolol use, and variable follow-up timing may have influenced results.

CONCLUSIONS

No significant difference between LP and HP catheters was observed in PS severity reduction or myocardial injury. High-pressure catheters offer no added benefit over LP catheters for treating severe PS in dogs without annular hypoplasia.