A nurse is caring for a client who came to the emergency department reporting chest pain. The provider suspects a myocardial infarction. While waiting for the troponin levels report, the client asks what this blood test will show. Which of the following explanations should the nurse provide the client?

Troponin is a protein that helps transport oxygen throughout the body.

Troponin is a lipid whose levels reflect the risk for coronary artery disease.

Troponin is a heart muscle protein that appears in the bloodstream when there is damage to the heart.

Troponin is an enzyme that indicates damage to brain, heart, and skeletal muscle tissues.