Serum and plasma cardiac troponin I concentrations in clinically normal Thoroughbreds in training in Australia

Area of Science:

• Veterinary Cardiology
• Equine Sports Medicine
• Biomarker Analysis

Background:

• Cardiac troponin I (cTnI) is a specific indicator of myocardial injury.
• Assessing cardiac health in performance horses is crucial for diagnosing poor performance.
• Non-invasive diagnostic tools are needed for equine cardiac assessment.

Purpose of the Study:

• To evaluate the utility of cardiac troponin I as a biomarker for cardiac muscle damage in horses.
• To determine reference ranges for cardiac troponin I in clinically normal Thoroughbred horses.
• To assess the potential of cardiac troponin I testing in diagnosing exercise-induced cardiac conditions in horses.

Main Methods:

• Serum and heparinised plasma samples were collected from 23 Thoroughbred horses in race training.
• Cardiac troponin I concentrations were measured using the ADVIA Centaur Assay at a commercial laboratory.
• The assay was validated using macerated equine myocardium.

Main Results:

• All samples from clinically normal horses showed cardiac troponin I concentrations below the assay's lower limit of quantification (< 0.15 microg/L).
• The assay demonstrated capability to detect cardiac troponin I when validated with equine cardiac tissue.
• This suggests a low baseline level of cardiac troponin I in healthy, racing Thoroughbreds.

Conclusions:

• Cardiac troponin I concentrations are very low in healthy, racing Thoroughbred horses.
• Cardiac troponin I testing shows potential for identifying cardiac muscle damage in horses.
• This biomarker may aid in differentiating poor performance causes related to active myocardial disease.