Veterinary Student University of Georgia College of Veterinary Medicine Athens, Georgia, United States
Abstract:
Background: Pulmonary valve stenosis (PS) is often treated with balloon pulmonary valvuloplasty (BPV) if moderate or severe. While Doppler echocardiographic assessment of transpulmonary pressure gradient (PG) serves as a surrogate for catheter-based measurements and helps determine transcatheter indication, the agreement of these techniques have not been systemically evaluated in dogs. Objective/Hypothesis: The objective of this study was to describe agreement between Doppler echocardiographic methods of transpulmonary pressure gradient estimation and peak-to-peak pressure gradient at catheterization (PGcath) in dogs. We hypothesized that with reference to PGcath, mean echocardiographic PG (PGecho-mean) would have less bias than peak modal instantaneous echocardiographic PG (PGecho-peak). Animals: Dogs with congenital PS that underwent BPV at one of two teaching hospitals.
Methods: Cases that underwent echocardiography and subsequent BVP separated by < 30 days were retrospectively identified. For each echocardiogram, measurements from Doppler recordings were used to determine average PGecho-mean and PGecho-peak from 3-5 consecutive beats. Peak-right-ventricular-to-peak-pulmonary-artery pressure gradients (PGcath) were obtained from catheterization reports. Bland-Altman analysis was used to assess agreement between echocardiographic and catheterization data.
Results: Data from 205 cases were evaluated. Relative to PGcath, bias (95% limits of agreement) for PGecho-mean and PGecho-peak were -19.9 mmHg (-93.9 to 54.0 mmHg) and 37.92 mmHg (-39.8 to 115.7 mmHg), respectively. Proportional bias, greater at higher gradients, was observed for both methods. Conclusions and clinical importance: On average, PGecho-mean and PGecho-peak under- and over-estimated PGcath, respectively, with wide limits of agreement for both. Over-reliance on echocardiographic PG for assessment of PS severity might be problematic.
