Troponin elevations are not reliable until after how many hours?

Troponin elevations are not reliable until after how many hours?

• A. 2 hours
• B. 4 hours
• C. 6 hours
• D. 8 hours

Answer: (C)

Troponin rises only after a delay following myocardial injury because it needs time to be released from damaged heart cells and reach detectable levels in the blood. With conventional troponin assays, this rise is often not reliably seen in the very early hours after chest pain. By about six hours after onset, troponin elevations become reliably detectable, with levels continuing to rise and then remaining elevated for days. This is why early single measurements can miss an acute MI and why serial sampling is used. (High-sensitivity assays can detect smaller amounts earlier, but for standard testing, six hours is the reliable time point.)

Troponin rises only after a delay following myocardial injury because it needs time to be released from damaged heart cells and reach detectable levels in the blood. With conventional troponin assays, this rise is often not reliably seen in the very early hours after chest pain. By about six hours after onset, troponin elevations become reliably detectable, with levels continuing to rise and then remaining elevated for days. This is why early single measurements can miss an acute MI and why serial sampling is used. (High-sensitivity assays can detect smaller amounts earlier, but for standard testing, six hours is the reliable time point.)