Background
Cancer therapy-related cardiac dysfunction (CTRCD) is an important adverse effect in patients receiving potential cardiotoxic cancer therapies. Interpretation of cardiac troponin
Conclusions
Clinicians should be cautious of benign hs-cTn elevations resulting from macrotroponin presence, as it can complicate CTRCD assessment.
Methods
A total of 20 serum samples from 12 ERBB2 + breast cancer patients (median age: 55 years, range: 30-69 years) who exhibited a significant increase in high-sensitivity cardiac troponin I (hs-cTnI) from baseline to post-anthracycline (~ 2 months after therapy initiation) and/or 3-months into trastuzumab therapy (~ 5 months after therapy initiation) and/or who had at least one hs-cTnI value above the female-specific 99th percentile (hs-cTnI > 16 ng/L) and had available banked blood for analysis were included in this pilot study. Samples were analyzed using the Abbott STAT High-Sensitive Troponin-I and Roche Elecsys Troponin T hs STAT assays. Macrotroponin was detected by treating the sample with protein G and re-measuring hs-cTn. Macrotroponin presence was defined as a hs-cTnI or hs-cTnT recovery of < 40% or 85%, respectively.
Results
Macrotroponin was not identified after anthracycline treatment but was present in four patients 3-months into trastuzumab therapy, two of which had hs-cTnI concentrations above the 99th percentile. None of these patients exhibited a significant reduction in LVEF and/or GLS despite having significant elevations in hs-cTnI. Conclusions: Clinicians should be cautious of benign hs-cTn elevations resulting from macrotroponin presence, as it can complicate CTRCD assessment.