Which statement about unstable angina is true?

Which statement about unstable angina is true?

• A. It does not cause elevated CK-MB or troponin
• B. It always causes elevated CK-MB and troponin
• C. It always shows ST elevation on ECG
• D. It is not part of acute coronary syndrome

Answer: (A)

Unstable angina is a form of acute coronary syndrome where ischemia occurs but there is no myocardial cell death. Because there’s no necrosis, cardiac enzymes such as CK-MB and troponin are not elevated. That makes the statement about not causing elevated CK-MB or troponin true. In contrast, if troponin is elevated, the picture is NSTEMI, a different ACS presentation. ST-segment elevation is not a defining feature of unstable angina; persistent ST elevation characterizes STEMI, while unstable angina may have no ST changes or only transient ones. So unstable angina is indeed part of the acute coronary syndrome spectrum, with normal enzyme levels, distinguishing it from NSTEMI and STEMI.

Unstable angina is a form of acute coronary syndrome where ischemia occurs but there is no myocardial cell death. Because there’s no necrosis, cardiac enzymes such as CK-MB and troponin are not elevated. That makes the statement about not causing elevated CK-MB or troponin true. In contrast, if troponin is elevated, the picture is NSTEMI, a different ACS presentation. ST-segment elevation is not a defining feature of unstable angina; persistent ST elevation characterizes STEMI, while unstable angina may have no ST changes or only transient ones. So unstable angina is indeed part of the acute coronary syndrome spectrum, with normal enzyme levels, distinguishing it from NSTEMI and STEMI.