Plasma Homocysteine Concentrations in Horses with Left-Sided Valvular Heart Disease

Figures

• 

  Figure 1. Long-term stability of plasma homocysteine concentrations ([HCY]p). Timepoint 0 measured at the time of blood collection and timepoint 2 measured 2 years later after being stored at −80 °C. The median difference between timepoint 0 and 2 was 0.68 µmol/L (range: −0.1 to 4.4 µmol/L, * p = 0.0156).

• 

  Figure 2. Influence of different anticoagulants on homocysteine concentration [HCY] in 19 horses. The [HCY] in sodium citrate samples was lower compared to all other samples. No significant differences were detected in [HCY] between LH plasma, EDTA plasma and serum.

• 

  Figure 3. Plasma homocysteine concentrations ([HCY]p) over 5 freeze–thaw cycles. No statistical difference in [HCY]p was noted between any of the time points (F-test, p = 0.059).

• 

  Figure 4. Plasma homocysteine concentrations ([HCY]p) grouped by valvular regurgitation severity assessed by color Doppler receiving chamber analysis. Horses with trivial (n = 17), mild (n = 70), moderate (n = 65) or severe (n = 17) left-sided regurgitation (mitral, aortic or both) were grouped together. Box-and-whisker plot represents median, quartiles and 5th/95th percentiles. Outliers (<5%/>95%) are displayed as individual points. The dotted line represents the upper reference interval for [HCY]p in healthy horses [28]. No significant differences in [HCY]p were detected between groups (Supplementary Table S2).

• 

  Figure 5. (A–D) Representative echocardiography indices of (A) left ventricular volume (LVIVd [500]), (B) maximal left atrial area in short axis (LAArsx-max [500]), (C) left ventricular ejection fraction (% LV EF) and (D) aortic sinus diameter (AoDrlx-ed [500]) and the association with plasma homocysteine concentrations ([HCY]p). The horizontal dashed line represents the relevant limits of the reference interval in Warmblood horses [39,40], and the vertical dashed line represents the upper reference limit for [HCY]p from healthy Warmblood horses [28]. The red shaded areas indicate horses that had both an echocardiographic variable measuring outside of the reference interval and elevated [HCY]p. The gray shaded areas include individuals with an increased echocardiographic variable but normal [HCY]p or a normal echocardiographic variable and elevated [HCY]p. The solid line represents regression line, and the dotted lines either side represent the 95% confidence intervals of the regression line. Abbreviations: % LV EF, % left ventricular ejection fraction; AoDrlx-ed [500], aortic sinus diameter in a right parasternal long-axis view of the left ventricular outflow tract at end-diastole,…

• 

  Figure 6. (A), Correlation between plasma homocysteine concentration ([HCY]p) and plasma creatinine concentration ([Crea]p) (n = 169). (B), Correlation between [HCY]p and age (n = 169). ρ, Spearman’s correlation coefficient, R2, linear regression coefficient of determination. The solid line represents regression line, and the dotted lines either side represent the 95% confidence intervals of the regression line.