Table 3. Summary of study characteristics and results of included studies on myocardial function.

Author [ref], study period, country	Study design	Intervention	Number of patients	Myocardial parameters assessed	Time of measurement	Results	Quality assessment
Eicher et al. [17], ND, Canada; USA	Multicentre; randomized controlled trial	Whole body cooling	31 cooled vs. 31 non-cooled	cTnI, CK-MB	48h	No significant reduction in cTnI; significant increase in CK-MB in hypothermia group	Moderate
Liu et al. [24], ND, UK	Retrospective cohort study	Whole body cooling (n = 58), head cooling (n = 4)	61 cooled vs. 14 non-cooled	cTnI	First 3 days	Significant reduction in peak level and AUC of cTnI within 24h in hypothermia group	Moderate
Nestaas et al. [25], 2010–2011, Norway	Single centre; prospective cohort study	Whole body cooling	44 cooled vs. 20 non-cooled	Tissue doppler measurements, peak cTnT	Day 1, 3, 4	Similar impairment during days 1–3, significant improvement in myocardial function in hypothermia group at day 4 (after rewarming) with a better myocardial function than at day 3 in the non-cooled group; higher median peak cTnT in hypothermia group	High
Rakesh et al. [26], 2014–2016, India	Single centre; randomized controlled trial	Whole body cooling	60 cooled vs. 60 non-cooled	CK-MB, cTnI, ECG, ECHO	0, 24 and 72h	Significant increase in median of difference of CK-MB and cTnI in hypothermia group; less findings of myocardial dysfunction on ECG and ECHO at 72h in hypothermia group	High
Vijlbrief et al. [27], 2006–2008, The Netherlands	Single centre; prospective cohort study	Whole body cooling	20 cooled vs. 28 non-cooled	cTnI, BNP	0, 24, 48 and 84h	Significant reduction in BNP at 48 and 84h in hypothermia group; no difference in cTnI between the two groups	Moderate

ND = not described; cTnI = cardiac troponin I; BNP = brain natriuretic peptide; CK-MB = creatinekinase MB; ECG = electrocardiography; ECHO = echocardiography; AUC = area under the curve; cTnT = cardiac troponin T.