ACS with initially negative troponin: Next step?

• A. Serial troponin testing (3–6 hours) with monitoring
• B. Discharge home
• C. Immediate thrombolysis
• D. Only imaging, no labs

Answer: (B)

In suspected ACS, an initial negative troponin does not rule out myocardial infarction. Troponin is a marker of myocardial injury that often becomes elevated hours after symptoms begin, so early tests can be falsely reassuring.

The best next step is to keep the patient under continuous monitoring and obtain serial troponin measurements, typically repeating the test several hours after presentation (about 3–6 hours) while you observe for any new or evolving signs of ischemia on the ECG and in the clinical picture. This approach detects a rising troponin pattern that would indicate NSTEMI or UA and guides timely management.

Immediate thrombolysis is not appropriate for non–ST-elevation ACS unless there is a STEMI pattern on the ECG. Imaging studies are helpful as an adjunct but cannot replace serial troponin testing to identify ongoing myocardial injury. Discharging home immediately would risk missing an evolving infarction, so observation with serial labs is the right course.