Cardiac Troponin I and T as Prognostic Markers in Cats with Hypertrophic Cardiomyopathy

Background Hypertrophic cardiomyopathy (HCM) is the most common cardiac disease in cats. However, most cats are not diagnosed until they develop congestive heart failure, arterial thromboembolism (ATE), or sudden cardiac death. Thus, an affordable screening test for early detection of HCM is desirable. Hypothesis/Objectives Evaluation of a sensitive cardiac troponin I (cTnI) assay as a screening test for HCM in cats and determination of a cutoff for its early detection. Animals One hundred sixty‐six client‐owned cats (male, n = 97) of various breeds were evaluated and classified using echocardiography as being healthy (n = 87), equivocal (n = 15), or having HCM (mild, n = 16; moderate, n = 10; severe, n = 34) or ATE (n = 4). Methods All cats were prospectively evaluated by echocardiography, and serum cTnI concentration was determined using the currently most sensitive assay (Siemens ADVIA Centaur TnI‐Ultra). Results The median cTnI concentration was significantly different between study groups ( P < .000001). A cutoff of 0.06 ng/mL provided good discrimination between healthy cats and cats with HCM (sensitivity, 91.7%; specificity, 95.4%; area under the curve [AUC], 0.95; 95% confidence interval [CI], 0.899‐0.978). Even for asymptomatic cats with HCM, sensitivity and specificity for a cutoff of >0.06 ng/mL remained high at 87.8% and 95.4%, respectively (AUC, 0.93; 95% CI, 0.864‐0.964). Conclusions and clinical importance Cardiac troponin I can be used as a sensitive and specific screening test for the diagnosis of HCM in otherwise healthy cats (cutoff, >0.06 ng/mL). However, echocardiography is needed to confirm the diagnosis.

Section: Discussionsupporting

confidence: 92%

Evaluation of a sensitive cardiac troponin I assay as a screening test for the diagnosis of hypertrophic cardiomyopathy in cats

Hertzsch

Roos

Wess

2019

“…By contrast, the detection limit of the current cTnI assay is 0.006 ng/mL. A previous study reported that the mean serum cTnI concentration in 23 pure‐bred healthy cats was 0.012 (range, 0.003‐0.09) ng/mL . In our study, the median concentration was 0.027 (IQR, 0.012‐0.048) ng/mL in healthy cats.…”

Section: Discussioncontrasting

confidence: 74%

Diagnostic utility of cardiac troponin I in cats with hypertrophic cardiomyopathy

Hori

Iguchi²,

Heishima

et al. 2018

BackgroundCardiac troponin I (cTnI) is useful for assessing hypertrophic cardiomyopathy (HCM) in cats.ObjectiveTo measure plasma cTnI concentrations in healthy cats and evaluate the clinical utility of cTnI in determining the severity of HCM.AnimalsClinically healthy cats (n = 88) and cats with HCM (n = 93).MethodsMulticenter prospective study. Cats with HCM, including hypertrophic obstructive cardiomyopathy at various stages, were diagnosed using echocardiography. Plasma cTnI concentrations were analyzed by a commercial laboratory. Receiver‐operating characteristic curve analysis was used to evaluate the accuracy of plasma cTnI concentrations to detect HCM.ResultsThe median cTnI concentration was 0.027 ng/mL (interquartile range, 0.012‐0.048 ng/mL) in healthy cats. Concentrations were significantly higher in diseased cats than in healthy controls, and concentrations were significantly higher in cats with heart failure than in asymptomatic cats. A plasma cTnI concentration of 0.163 ng/mL had a sensitivity of 62.0% and specificity of 100% when used to distinguish normal cats from asymptomatic HCM cats without left atrial dilatation. A cutoff of 0.234 ng/mL had high sensitivity (95.0%) and specificity (77.8%) for assessing heart failure. The areas under the receiver‐operating characteristic curves were 0.85 and 0.93, respectively.Conclusions and Clinical ImportanceIncreased cTnI concentrations reflect the severity of HCM. If other causes of cardiac injury are ruled out, plasma cTnI concentration may be useful for predicting the severity of HCM in cats.

“…Previously reported variables that have been shown to have an association with survival time in cats with CHF or HCM include body weight, age, body temperature at the time of hospital admission, left atrial size and function, extreme left ventricular hypertrophy, left ventricular systolic function, presence of systolic anterior motion, and cardiac troponin I 35, 36, 37, 44, 45, 46. Although troponin I was not measured, none of the other variables were found to be associated with survival time in the current study, which may be due to the small sample size or to a true lack of association in this population of cats.…”

Section: Discussionmentioning

confidence: 99%

Association between Survival Time and Changes inNT‐proBNPin Cats Treated for Congestive Heart Failure

Pierce

Freeman

Cunningham

et al. 2017

BackgroundReductions in N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) concentrations after treatment have been associated with improved survival in people with congestive heart failure (CHF), but have not been reported in cats with CHF.ObjectivesTo evaluate changes in NT‐proBNP concentrations in cats with CHF after treatment and determine whether serial NT‐proBNP measurements provide prognostic information.AnimalsThirty‐one client‐owned cats.MethodsProspective, observational study in cats with new onset CHF secondary to cardiomyopathy. Concentrations of NT‐proBNP were measured within 4 hours of admission to the hospital, on the day of discharge, and at re‐evaluation 7–10 days later.ResultsMedian NT‐proBNP concentrations decreased significantly from admission (1,713 pmol/L [range, 160–3,784 pmol/L]) to discharge (902 pmol/L [range, 147–3,223 pmol/L]); P = .005) and from admission to re‐evaluation (1,124 pmol/L [range, 111–2,727 pmol/L]; P = .024). Median survival time was 109 days (range, 1–709 days), with 5 cats still alive at the time of analysis. Cats with a larger percent decrease in NT‐proBNP from admission to discharge had a longer survival time (P = .048). Cats with evidence of active CHF at the time of re‐evaluation (P = .010) and cats whose owners had difficulty administering medications (P = .045) had shorter survival times.Conclusions and clinical importanceCats with a larger percent decrease in NT‐proBNP during hospitalization and no evidence of CHF at the time of re‐evaluation had longer survival times. Additional studies are needed to determine whether NT‐proBNP can help guide treatment in cats with CHF.