2017 ACVIM Forum Research Abstract Program

All dogs had structural heart disease, 31/46 were in congestive heart failure, 44/46 were receiving anti-arrhythmic drugs. MeanHR was 125 bpm (range 62-203 bpm), minHR was 82 bpm (range 37-163 bpm) and maxHR was 217 bpm (range 126-307 bpm). Sex, age, weight, cardiac diagnosis, and study site had no significant impact on survival. For every 10 bpm increase in meanHR, the risk of all-cause mortality increased by 35% (hazard ratio 1.35; 95% CI 1.17-1.55; P < 0.001). Median survival time of dogs with meanHR < 125 bpm (n = 23) was significantly longer (1037 days; range 524-open) than dogs with meanHR ≥ 125 bpm (n = 23) (105 days; range 67-267 days) (P = 0.0012). Only meanHR was independently associated with survival time (P < 0.003) by multivariate regression. Our results suggest that aggressive rate control in dogs with AF leads to reduced mortality and prospective studies targeting meanHR of 125 bpm or lower are indicated. This study aimed to evaluate left atrial volume (LAV) in dogs in different stages of chronic mitral valve disease (CMVD), and to evaluate the association of these values with congestive heart failure (CHF). Our hypothesis was that LAV increases with severity of CMVD and can be used to detect CHF in dogs with CMVD. Eighty dogs were included in a prospective crosssectional clinical study, grouped according to the staging of CMVD proposed by the American College of Veterinary Internal Medicine (A, B1, B2 and C), based on clinical signs and echocardiographic evaluation. Left atrial volume was calculated using the biplane area-length method from the left apical two and four chamber views at the end of ventricular systole. The LAV was indexed to body weight. LAV/kg showed high values (P 25%-75% =3.91-6.81) compared with groups A (0.82 mL/kg, P 25%-75% =0.64-0.95), B1 (0.91 mL/kg, P 25%-75% =0.47-1.29) and B2 (2.23 mL/kg, P 25%-75% =1.93-2.85). Analysis of ROC curve for CHF diagnosis showed area under curve of 0.92 for LAV/ kg. A LAV/kg >3.26 mL/kg was the optimal cut-off identified for detecting CHF in dogs with CMVD with a sensitivity and specificity of 90%. In addition, when LAV is greater than this cut-off, it increases to 90% the probability to detect CHF (an increase of 40% in diagnostic capacity than pre-test), which allows for the decision to treat for CHF. In conclusion, left atrial volume increases with severity of CMVD and helps the detection of CHF in these dogs. The soluble fraction of ST2 (sST2) is the circulating isoform of ST2, a member of the interleukin-1 (IL-1) receptor family. The sST2 is induced when cardiomyocytes and cardiac fibroblasts undergo mechanical strain, making it a promising biomarker of fibrosis and cardiac remodeling. sST2 has been widely studied in human medicine, and characterized as an important prognostic biomarker and an independent mortality predictor. However, there are no studies determining reference values or evaluating the influence of gender and age on sST2 in healthy dogs. Therefore, this study aimed to measure serum levels of sST2 in healthy dogs, in order to determine normal values for the study population and to evaluate the influence of gender and age on this biomarker concentration for future assessment of dogs with heart disease. With this purpose, a prospective cross-sectional clinical study was conducted, and included a sample of 60 healthy small-to-medium size dogs, males and females, adults of different ages. There was no significant difference in sST2 serum levels betwe