Which cardiac marker is consistently increased in patients with unstable angina?

Troponin T is the cardiac marker that is consistently increased in patients with unstable angina. Troponins are proteins found in heart muscle and are released into the bloodstream when there is damage to heart tissue. In the context of unstable angina, which is characterized by chest pain due to inadequate blood flow to the heart but not necessarily leading to myocardial infarction, elevated levels of troponins indicate that there may be myocardial injury occurring or at increased risk.

Troponin T has high specificity and sensitivity for cardiac injury, making it a reliable marker for diagnosing various forms of acute coronary syndromes, including unstable angina. Elevated troponin levels help distinguish unstable angina from other types of chest pain where muscle damage may not be present.

Other markers listed, such as CK-MB and LDH, may also be indicative of cardiac damage but are not as consistently or specifically increased in unstable angina compared to troponin T. Myoglobin, while it can rise quickly following myocardial injury, lacks the specificity for cardiac muscle damage, as it is released from skeletal muscle as well.