A 65-year-old man with chest pain and rising troponin but no ST elevations on ECG most likely has which diagnosis?

• A. NSTEMI
• B. Prinzmetal angina
• C. STEMI
• D. Unstable angina

Answer: (B)

Rising troponin means there has been myocardial injury. The ECG finding of ST elevations is what classically defines a STEMI, a full-thickness infarct. When troponin is elevated but the ECG does not show ST elevations, the scenario fits a non-ST-elevation myocardial infarction.

Think through the other possibilities: Prinzmetal (vasospastic) angina typically causes chest pain with transient ST-segment elevations during the episode; between episodes, troponin is not elevated unless there has been an infarct. Unstable angina can present with angina at rest or new/worsening angina but without troponin release. NSTEMI, on the other hand, presents with chest pain or equivalent symptoms plus a rising (and/or falling) troponin in the absence of persistent ST elevations.

So the combination of chest pain with rising troponin but no ST elevations on ECG best fits NSTEMI.