High-sensitivity troponin-T as a prognostic marker after out-of-hospital cardiac arrest - A targeted temperature management (TTM) trial substudy.

AIM OF THE STUDY

Predicting outcome of unconscious patients after successful resuscitation is challenging and better prognostic markers are highly needed. Ischemic heart disease is a common cause of out-of-hospital cardiac arrest (OHCA). Whether or not high-sensitivity troponin T (hs-TnT) is a prognostic marker among survivors of OHCA with both ischemic and non-ischemic aetiologies remains to be determined. We sought to evaluate the ability of hs-TnT to prognosticate all-cause mortality, death due to cardiovascular causes or multi-organ failure and death due to cerebral causes after OHCA. The influence of the level of target temperature management on hs-TnT as a marker of infarct size was also assessed.

METHODS

A total of 699 patients from the targeted temperature management (TTM) trial were included and hs-TnT was analyzed in blood samples from 24, 48 and 72h after return of spontaneous circulation (ROSC). The endpoints were 180 day all-cause mortality, death due to cardiovascular causes or multi-organ failure and death due to cerebral causes. Subgroups based on the initial ECG after ROSC (STEMI vs all other ECG presentations) were analyzed.

RESULTS

Hs-TnT was independently associated with all-cause mortality which was driven by death due to cardiovascular causes or multi-organ failure and not cerebral causes (at 48h: OR 1.10, CI 1.01-1.20, p<0.05). Hs-TnT was also an independent predictor of death due to cardiovascular causes or multi-organ failure (at 48h: OR 1.13, CI 1.01-1.26, p<0.05). In patients with STEMI, hs-TnT was independently associated with death due to cardiovascular causes or multi-organ failure (at 48h: OR 1.47, CI 1.10-1.95, p<0.01). Targeted temperature management at 33°C was not associated with hs-TnT compared to 36°C.

CONCLUSIONS

After OHCA due to both ischemic and non-ischemic causes, hs-TnT is an independent marker of both all-cause mortality and death due to cardiovascular causes or multi-organ failure. Targeted temperature management at 33°C did not reduce hs-TnT compared to 36°C. Hs-TnT may be a marker of poor prognosis after OHCA and this should be taken into consideration in patients that present with high troponin levels.

TRIAL REGISTRATION

The TTM-trial is registered and accessible at Clinicaltrials.gov (identifier: NCT01020916).