Abstract 977: Baseline Troponin Levels Predict 30 Day CV Mortality in STEMI Independent of Clinical and Electrocardiographic Factors: Analysis from CLARITY-TIMI 28
Background: Cardiac troponin is the preferred biomarker for risk stratification in non-ST-elevation ACS. The incremental prognostic utility of the initial magnitude of troponin elevation and its value in conjunction with ST segment resolution in ST-elevation MI is less well-defined.
Methods: Troponin T (TnT, detection limit 0.01 ng/ml) was measured in 1250 patients at presentation undergoing lysis for STEMI in CLARITY-TIMI 28. ST segment resolution (STRes) was measured at 90 min. Multivariable logistic regression was used to examine the independent association between TnT levels, STRes, and 30-d cardiovascular (CV) mortality.
Results: Patients were classified into undetectable TnT at baseline (n=594), detectable but below the median of 0.12 ng/ml (n=330), and above the median (n=326). Patients w/higher baseline TnT levels were older, more likely to have a hx of HTN and diabetes, and present later after symptom onset (2.0, 2.7, 3.8 h respectively), with anterior MI, and Killip Class II-IV. Rates of 30-d CV death were 1.5%, 4.5%, and 9.5%. Compared with those with undetectable levels and adjusting for baseline factors incl. time to presentation, the OR for 30-d CV death were 2.79 (1.13– 6.88, P=.026) and 6.21 (2.64 – 14.58, P<.0001) for those below and above the median respectively. When combined with STRes, there was a significant gradient of risk, and in a multivariable model both baseline TnT and STRes at 90 min were significant predictors of 30-d CV death (Fig⇓).
Conclusions: Baseline TnT and 90-min ST segment resolution are independent predictors of 30-d CV death in patients with STEMI. Use of these two simple, readily available tools can aid clinicians in early risk stratification.