Troponin elevation indicates which condition in ACS evaluation?

• A. Pericarditis
• B. Unstable angina
• C. Troponin elevation indicates myocardial necrosis
• D. CHF

Answer: (C)

Troponin elevation signals myocardial necrosis from ischemia. Cardiac troponin I and T are highly specific to heart muscle, and when cardiomyocytes die, their contents leak into the bloodstream. In acute coronary syndrome, a rise and/or fall of troponin with clinical symptoms and ECG changes indicates that myocardial cells have been irreversibly damaged, i.e., a myocardial infarction. Unstable angina involves reversible ischemia without cell death, so troponin is usually not elevated. Pure pericarditis doesn't show myocardial necrosis, though troponin can be modestly elevated if the myocardium is involved; otherwise it remains normal. Congestive heart failure can cause troponin elevations in some scenarios due to increased demand or injury, but in ACS the key point is that troponin elevation reflects myocardial necrosis.