Presence of Macrotroponin for Over 2 Years in a Young Woman.

We present the case of a 28-year-old woman who presented with nonspecific symptoms with a high-sensitivity troponin I level > 10,000 ng/L, which led to extensive investigations and a hospital stay. Follow-up testing using an alternate troponin assay yielded undetectable levels. Two years later, the patient had a high-sensitivity troponin I level > 1500 ng/L, with experiments confirming the presence of a macrocomplex. We advocate for communication with laboratory professionals to expedite identification of macrotroponin complexes, so that patients and clinicians can reduce the number of unwarranted investigations. Novel teaching points include the importance of identifying macrocomplexes as a source of persistent false elevations and ensuring that a process is instituted to investigate troponin-level elevations when false-positive results are suspected.