Table 1.

Strengths and weaknesses of Cardiac Biomarkers for ICI Related Myocarditis.

Biomarkers	Strengths	Weaknesses
Troponin-I	High sensitivity Early increase to peak levels within hours of initial presentation. Good for early diagnosis. Widely available	Can indicate myocardial injury from other causes e.g. ACS Macrotroponins can cause false positive troponin measurements Confounders e.g. renal function may complicate interpretationLow specificity
Troponin- T	High sensitivity Peak within days after initial presentation, increase persist for months. Good for late diagnosis.Stronger prognosticator for MACE compared to troponin I and CK	Can indicate myocardial injury from other causes e.g. ACS Less available than Tropinin I Macrotroponins can cause false positive troponin measurements Confounders e.g. renal func-tion may complicate inter-pretationLow specificity
Creatinine kinase	High sensitivityEarly increase to peak levels within hours of initial presentation. Good for early diagnosis.	Low specificity
Natriuretic peptides	Widely availableHigh sensitivity	Low specificity e.g. can be increased in supraventricular arrhythmias
CK-MB	Widely available Early increase Shorter time courseMore specific for myocardial damage than CK	Low sensitivity
AST	High sensitivity Routinely measured Can be helpful with detecting ICI-induced hepatotoxicityElevated in ICIRM	Low specificity
ALP	High sensitivity Routinely measured Can be helpful with detecting ICI-induced hepatotoxicityElevated in ICIRM	Low specificity
CPK	High sensitivity for acute myocarditis Moderate specificity Early increase to peak levels within hours of initial presentation, thus providing early indication for development of myocarditis Routinely measured Associated with rapid decline following initiation of immunosuppressive treatment, therefore useful to monitor effectiveness of treatmentElevated in ICIRM	Decreases rapidly with acute episodes
LDH	Routinely measuredMarkedly elevated in ICIRM	Low specificity