Long-term outcome and troponin I concentrations in Great Danes screened for dilated cardiomyopathy: an observational retrospective epidemiological study.

Abstract

INTRODUCTION: Dilated cardiomyopathy (DCM) is common in Great Danes (GDs) but screening for this condition can be challenging. We hypothesised that cardiac troponin-I (cTnI) concentration is elevated in GDs with DCM and/or ventricular arrhythmias (VAs), and is associated with reduced survival time in GDs. ANIMALS: One hundred and twenty-four client-owned GDs assigned echocardiographically as normal (n&#xa0;=&#xa0;53), equivocal (n&#xa0;=&#xa0;37), preclinical DCM&#xa0;(n&#xa0;=&#xa0;21), or clinical DCM&#xa0;(n&#xa0;=&#xa0;13). MATERIALS AND METHODS: A retrospective epidemiological study. Echocardiographic diagnosis, VAs, and contemporaneous cTnI concentrations were recorded. Diagnostic accuracy and cTnI cut-offs were determined with receiver operating characteristic analyses. Effects of the cTnI concentration and disease status on survival and cause of death were explored. RESULTS: Median cTnI was greater in clinical DCM (0.6&#xa0;ng/mL [25th-75th percentiles: 0.41-1.71&#xa0;ng/mL]) and GDs with VAs (0.5&#xa0;ng/mL [0.27-0.80&#xa0;ng/mL], P<0.001). Elevated cTnI detected these dogs with good accuracy (area under the curve: 0.78-0.85; cut-offs 0.199-0.34&#xa0;ng/mL). Thirty-eight GDs (30.6%) suffered a cardiac death (CD); GDs suffering CD (0.25&#xa0;ng/mL [0.21-0.53&#xa0;ng/mL]) and specifically sudden cardiac death (SCD) (0.51&#xa0;ng/mL [0.23-0.72&#xa0;ng/mL]) had higher cTnI than GDs dying of other causes (0.20&#xa0;ng/mL [0.14-0.35&#xa0;ng/mL]; P<0.001). Elevated cTnI (>0.199&#xa0;ng/mL) was associated with shorter long-term survival (1.25 years) and increased risk of SCD. Great Danes with VAs had shorter survival times (0.97 years). CONCLUSIONS: A cardiac troponin-I concentration is a useful adjunctive screening tool. Elevated cTnI is a negative prognostic indicator.