Association of early elevated cardiac troponin I concentration and longitudinal change after off-pump coronary artery bypass grafting and adverse events: a prospective cohort study.

BACKGROUND

The elevation of troponin after coronary artery bypass grafting (CABG) is common This study aimed to investigate the association between very early cardiac troponin I (cTnI) concentration and its longitudinal change within 24 hours after CABG and 30-day adverse events.

METHODS

This study prospectively enrolled 633 patients who underwent isolated off-pump CABG from January 2019 to May 2019. Serum cTnI levels were measured in all patients at two examinations within 24 hours postoperatively (1 hour and 12-18 hours), and a proportional hazards model was used to determine the association between cTnI levels and their change with adverse events, which were defined as a composite of 30-day mortality, stroke, heart failure, myocardial infarction (MI), and ventricular fibrillation.

RESULTS

cTnI levels of the two examinations and absolute change of cTnI levels were significantly higher in the event group than in the non-event group (P<0.01, both). Earlier and later cTnI concentrations were associated with 30-day complications [adjusted hazard ration (HR) 1.598, 95% confidence interval (CI), 1.158-2.204 and HR 1.499, 95% CI, 1.228-1.831, respectively]. With regard to longitudinal change in cTnI levels, participants with persistently high levels of cTnI and those with progression from a low level to high level concentration experienced a significantly increased risk of adverse events than did participants who had a trend of persistently low cTnI levels (HR 3.105, 95% CI, 1.748-5.517 versus HR 2.944, 95% CI, 1.488-5.824).

CONCLUSIONS

Longitudinal change in cTnI levels within 24 hours and early cTnI concentrations, even less than 1 hour after CABG, are associated with adverse events. These data will be useful in identifying patients at an increased risk of complications.