Diameter-based echocardiographic methods showed wide limits of agreement and systematic bias compared to the Disc method, overestimating regurgitant volume and fraction in dogs with advanced MMVD.
Observational (n=186)
Do diameter-based echocardiographic methods agree with the modified Simpson's method of discs for quantifying mitral regurgitation in dogs with myxomatous mitral valve disease?
Diameter-based echocardiographic methods are not interchangeable with the modified Simpson's method of discs for absolute quantification of mitral regurgitation severity in dogs with myxomatous mitral valve disease.
Quantitative assessment of mitral regurgitation (MR) in dogs with myxomatous mitral valve disease (MMVD) is influenced by the method used to estimate left ventricular volume. This study aimed to evaluate the impact of different left ventricular volume estimation methods on quantitative MR assessment, using the modified Simpson’s method of discs (Disc method) as a reference. Echocardiographic data from 167 dogs with MMVD and 19 healthy control dogs were analyzed. Regurgitant volume (RVol), body size-normalized RVol, and regurgitant fraction (RF) were calculated using diameter-based methods (Cube, Gibson, Meyer, and Teichholz) and compared with values obtained using the Disc method. All diameter-based methods showed significant positive correlations with the Disc method. However, Bland–Altman analyses demonstrated wide limits of agreement and systematic bias. Between-method discrepancies increased with advancing disease stage, with diameter-based methods tending to overestimate RVol and RF, particularly in dogs classified as American College of Veterinary Internal Medicine (ACVIM) stages B2 and C/D. Although relative trends in regurgitant indices were consistent across methods, substantial differences were observed in absolute values. These findings indicate that diameter-based methods are not interchangeable with the Disc method for absolute quantification of MR severity in dogs with MMVD, especially in advanced disease stages.
Kawai et al. (Sat,) conducted a observational in Myxomatous mitral valve disease (MMVD) in dogs (n=186). Diameter-based echocardiographic volumetric methods (Cube, Gibson, Meyer, Teichholz) vs. Modified Simpson's method of discs (Disc method) was evaluated on Regurgitant volume (RVol), body size-normalized RVol, and regurgitant fraction (RF). Diameter-based echocardiographic methods showed wide limits of agreement and systematic bias compared to the Disc method, overestimating regurgitant volume and fraction in dogs with advanced MMVD.