Evaluation of serum cardiac troponin-I concentrations for diagnosis of infective endocarditis in dogs.

BACKGROUND: Infective endocarditis (IE) in dogs is associated with severe disease and a high case fatality rate but often presents with nonspecific clinical signs. HYPOTHESIS/OBJECTIVES: Serum concentration of cardiac troponin-I (cTnI) is elevated in dogs with IE and can differentiate dogs with IE from dogs with other diseases with similar clinical features. Concentration of serum cTnI is negatively correlated with survival time in dogs with IE. ANIMALS: Seventy-two client-owned dogs; 29 with IE, 27 with stage-B myxomatous mitral valve disease (MMVD), and 16 with immune-mediated disease (IMD). METHODS: Retrospective clinical cohort study. Concentration of serum cTnI was measured in all dogs at time of diagnosis. Clinical findings and echocardiographic interpretation were also recorded. Statistical analyses included Kruskal-Wallis test, pairwise Mann-Whitney U tests, receiver operator characteristic, and Cox proportional hazards. RESULTS: Serum concentration of cTnI was significantly higher in the IE group (0.69 ng/mL [0.03-80.8]) than in the MMVD (0.05 ng/mL [0.02-0.11], P < .001) and IMD groups (0.05 ng/mL [0.03-0.57], P < .001). Increased cTnI was a moderately accurate predictor of IE (area under the curve 0.857 (95% confidence interval [CI] 0.745-0.968, P < .001). A cTnI cutoff of 0.625 ng/mL had 100% specificity (95% CI 90%-100%) and 52% sensitivity (95% CI 33%-70%) in this study sample. There was no association between cTnI concentration and survival time in dogs with IE (hazard ratio 1.013, 95% CI 0.993-1.034, P = .2). CONCLUSIONS AND CLINICAL IMPORTANCE: Cardiac troponin-I concentrations are higher in dogs with IE compared to dogs with preclinical MMVD or IMD. In dogs with a compatible clinical presentation, serum cTnI concentrations >0.625 ng/mL are supportive of IE.

Biomarker changes with systolic anterior motion of the mitral valve in cats with hypertrophic cardiomyopathy.

BACKGROUND: N-terminal pro B-type natriuretic peptide (NT-proBNP) and cardiac troponin-I (cTnI) are biomarkers commonly evaluated in cats with suspected heart disease. Many cats with hypertrophic cardiomyopathy (HCM) have systolic anterior motion of the mitral valve (SAM), but its influence on circulating NT-proBNP or cTnI concentrations is currently unknown. HYPOTHESIS/OBJECTIVES: Cats with HCM and SAM (HCMSAM+ ) have higher NT-proBNP and cTnI concentrations than do cats with HCM but without SAM (HCMSAM- ). ANIMALS: One hundred forty cats with HCM: 70 with SAM and 70 without SAM. METHODS: Retrospective case-to-case study. Cats were recruited if diagnosed with HCM by echocardiography and results were available for NT-proBNP or cTnI concentrations or both. Cats with SAM were matched to those without SAM for clinical presentation, left atrial (LA) size and left ventricular (LV) fractional shortening. RESULTS: A total of 119 NT-proBNP and 123 cTnI results were available. The HCMSAM+ cats had higher median concentrations than did HCMSAM- cats for NT-proBNP (729 pmoL/L; interquartile range [IQR], 275-1467 versus 65 pmoL/L; IQR, 25-271; P < .001) and cTnI (0.27 ng/mL; IQR, 0.10-0.81 versus 0.07 ng/mL; IQR, 0.01-0.43; P = .002). In general linear models for both NT-proBNP and cTnI, the independent explanatory variables were SAM, congestive heart failure, maximal LV wall thickness, and LA size. CONCLUSIONS AND CLINICAL IMPORTANCE: For cats with HCM and equivalent LA size and LV systolic function, those with SAM had higher NT-proBNP and cTnI concentrations than did those without SAM. Presence of SAM should be considered when interpreting biomarker concentrations in cats with HCM.

Prognostic value of mitral annular systolic plane excursion and tricuspid annular plane systolic excursion in cats with hypertrophic cardiomyopathy.

INTRODUCTION: Hypertrophic cardiomyopathy (HCM) has a variable prognosis; left atrial size, presence of clinical signs and left ventricular systolic function have been shown to predict outcomes. Mitral annular plane systolic excursion (MAPSE) and tricuspid annular plane systolic excursion (TAPSE) assess longitudinal ventricular systolic function and are decreased in cats with HCM. The aim of the study was to ascertain whether MAPSE and TAPSE have prognostic value in HCM and if cats with pleural effusion have lower MAPSE and TAPSE than cats with pulmonary oedema. ANIMALS: One hundred eighty-four client-owned cats diagnosed with HCM. METHODS: This is a retrospective study. Echocardiography was used to diagnose HCM (end-diastolic left ventricular wall thickness ≥ 6 mm) and to measure MAPSE and TAPSE. Survival information was obtained. RESULTS: No multivariable model including MAPSE or TAPSE could be generated in this population. Cats with pleural effusion ± pulmonary oedema had lower MAPSE measured at the interventricular septum (MAPSE IVS) and TAPSE, compared with cats with pulmonary oedema only. MAPSE IVS was the only factor predicting pleural effusion on multivariable regression model. CONCLUSIONS: Lower MAPSE and TAPSE were not independently associated with outcomes on multivariable analysis. Cats with pleural effusion ± pulmonary oedema had lower TAPSE and MAPSE IVS than cats with pulmonary oedema, and MAPSE IVS was the only predictive factor associated with the development of pleural effusion in this population.