Interpreting changes in troponin--clinical judgment is essential.

A 51-year-old woman with a history of mild hypertension and mild hyperlipidemia presented with a 2-h episode of substernal chest discomfort for the first time. She was receiving a statin but refused treatment for hypertension. She was an avid runner and had never had chest discomfort previously. The discomfort occurred at rest and radiated to her arms and her neck. Her electrocardiogram revealed minor ST-segment and T-wave changes in the inferior and lateral leads. Her initial cardiac troponin T (cTnT) concentration was 0.04 μg/L (99th-percentile upper reference limit, 0.01 μg/L) but increased to 0.32 μg/L and then to 0.76 μg/L. An emergent coronary angiogram was interpreted as normal with the exception of slow flow in the circumflex coronary artery. An echocardiogram was normal.