Troponin and natriuretic peptide monitoring during cancer treatment

What they measure. Cardiac troponin leaks from injured heart muscle cells; the high-sensitivity assays now standard in emergency departments detect rises far below those of a heart attack. B-type natriuretic peptide and its precursor fragment NT-proBNP are released when the heart's chambers are stretched, rising with fluid overload and failing pump function. Both are cheap, automated, and available in any hospital laboratory.

Who should have them. The 2022 European Society of Cardiology cardio-oncology guideline recommends a baseline troponin and natriuretic peptide in every patient starting anthracyclines, HER2-targeted therapy, or other cardiotoxic treatment, then a schedule of repeats that depends on baseline risk: after every cycle or two for high-risk patients on anthracyclines, at intervals for others. Troponin is also the front-line test when immune checkpoint inhibitor myocarditis is suspected, because it is raised in nearly all cases and a normal result argues strongly against the diagnosis; some centres check it at each of the first few infusions.

What changes. A troponin rise on anthracyclines identifies the patients who will later lose pump function, and in the Milan studies starting an ACE inhibitor in those patients prevented that loss. A rise on a checkpoint inhibitor triggers urgent electrocardiography, echocardiography, cardiac MRI, pausing the drug and high-dose steroids. A natriuretic peptide rise prompts an earlier echocardiogram, fluid and blood pressure review, and often starting heart failure medicines. Neither test replaces imaging; they choose who needs it and when. Cost is a few pounds per test, and the barrier is remembering to order them and having a pathway for the result.