Abstract 14169: Implications of Elevated Troponin on Time-to-Surgery in Non-ST Elevation Myocardial Infarction (NIHR Health Informatics Collaborative: Trop-CABG Study)

Background: The optimal timing of coronary artery bypass grafting(CABG) in patients with non-ST elevation myocardial infarction (NSTEMI) and the utility of pre-operative troponin levels in decision-making remains unclear. We investigated (a)the association between peak pre-operative troponin and survival post-CABG in a large cohort of NSTEMI patients and (b)the interaction between troponin and time-to-surgery. Methods: Our cohort consisted of 1746 NSTEMI patients(mean age 69±11 years, 21% female) with recorded troponins that had CABG at five United Kingdom centers between 2010 and 2017. Time-segmented Cox regression was used to investigate the interaction of peak troponin and time-to-surgery on early(within 30 days) and late(beyond 30 days) survival. Results: Average interval from peak troponin to surgery was 9±15 days, with 1466(84.0%) patients having CABG during the same admission. Sixty patients died within 30-days and another 211 died after a mean follow-up of 4±2years(30-day survival 0.97±0.004 and 5-year survival 0.83±0.01). Peak troponin was a strong predictor of early survival(adjusted P=0.002) with a significant interaction with time-to-surgery(P interaction=0.007). For peak troponin levels <100 times the upper limit of normal, there was no improvement in early survival with longer time-to-surgery. However, in patients with higher troponins, early survival increased progressively with a longer time-to-surgery, till day 10. Peak troponin did not influence survival beyond 30 days(adjusted P=0.64). Conclusions: Peak troponin in NSTEMI patients undergoing CABG was a significant predictor of early mortality, strongly influenced the time-to-surgery and may prove to be a clinically useful biomarker in the management of these patients.