The effect of myxomatous mitral valve disease severity on packed cell volume in dogs

Abstract

Objectives The aim of this study was to examine whether associations between disease severity and packed cell volume exist in dogs with myxomatous mitral valve disease. Materials and Methods Data were selected from 289 dogs that had been examined at a research clinic (2004–2017) on multiple occasions (n=1465). American College of Veterinary Internal Medicine stage and echocardiographic measurements were entered in separate multivariable linear mixed effects models with packed cell volume as the dependent variable. Age, breed, sex, weight and blood urea nitrogen concentrations were additionally tested in these analyses to control for patient characteristics. Results Packed cell volume (% whole blood) in stages B1 and B2 (B1: 42.62 ±0.27, P=0.001; B2: 41.77± 0.42, P < 0.001) was lower than stage A (44.57 ±0.53). In stage C, packed cell volume was greater than both preclinical stages (C: 43.84 ±0.46). When the administration of loop diuretics was included in statistical models, packed cell volume was inversely related to normalised left ventricular internal diameters (β: −2.37; 95% confidence intervals: −3.49, −1.25; P < 0.001). Clinical Significance Dogs with myxomatous mitral valve disease may develop reductions in packed cell volume as their disease progresses. Although this finding was statistically significant at a population level, it should be noted that the differences described are relatively small. This, along with other causes of variation in packed cell volume, means that changes would be challenging to appreciate within individual patients. Plasma volume depletion following diuretic administration may explain why findings differed in stage C.

Platelet hyperresponsiveness and increased platelet‐neutrophil aggregates in dogs with myxomatous mitral valve disease and pulmonary hypertension

“…Interestingly, dogs with MMVD and PH had significantly higher leukocyte and monocyte count, and lower red blood cell count, hemoglobin concentration and hematocrit compared with MMVD dogs without PH. Iron deficiency anemia has been commonly reported in dogs 68,69 and humans with mitral valve disease 70 and appears to be commensurate with disease severity. A previous study found that dogs with congestive heart failure, including 44/72 dogs with MMVD, had significantly increased neutrophils, band neutrophils, and monocyte compared with healthy dogs, although cell counts remained within normal reference range 71 .…”

Serum Proteomic Changes in Dogs with Different Stages of Chronic Heart Failure

“…The dogs who did not show a clinical complaint but had a systolic heart murmur over the mitral valve area and radiographic and echocardiographic evidence of cardiac remodeling due to MMVD were considered as stage B2 that refers asymptomatic phase of CHF. Dogs who displayed one or more clinical signs, such as coughing, hyporexia, tachypnea, and/or exercise intolerance in combination with a systolic murmur due to CHF caused by MMVD were categorized as symptomatic stages (stage C and D groups) of CHF, as reported in our [ 11 ] and other previous studies [ 12 , 13 , 22 ]. The group including stage B1 dogs (asymptomatic) was not included due to insufficient material during the specimen collection period.…”

“…MMVD was diagnosed by trans-thoracic echocardiography including the following criteria: the presence of mitral valve prolapse (MVP) and/or thickening of the mitral valve anterior leaflet by 2-D echocardiography, and identification of mitral valve regurgitation by color Doppler examination as reported in our [ 11 ] and other previous studies [ 13 , 22 ].…”