Defining the Optimal Cardiac Troponin T Threshold for Predicting Death Caused by Periprocedural Myocardial Infarction After Percutaneous Coronary Intervention
Background—There is controversy about the diagnostic and prognostic significance of percutaneous coronary intervention–related myocardial infarction, especially with the use of cardiac troponin T (cTnT). This analysis was designed to address the question of the presence and the level of a prognostic cTnT threshold.
Methods and Results—We evaluated 5268 consecutive patients who underwent nonemergent percutaneous coronary intervention between 2000 and 2009 with a preprocedural cTnT level below the upper limit of normal (ULN, ≤0.01 ng/mL). Postprocedural cTnT and creatine kinase-MB mass levels (ULN, 6.7 ng/mL in men and 3.8 ng/mL in women) were found to be associated with 3-month mortality in Cox proportional hazard models (hazard ratio per doubling of cTnT, 1.24; 95% confidence interval, 1.08–1.43; P=0.003 and hazard ratio per doubling of creatine kinase-MB, 1.30; 95% confidence interval, 1.05–1.60; P=0.018), adjusted for the Mayo Clinic risk scores for in-hospital and postdischarge mortality. The optimal prognostic threshold for 3-month mortality was 25× ULN for cTnT (hazard ratio, 4.53; 99% confidence interval, 1.59–12.9; P<0.001), which provided similar information as a value of 5× ULN for creatine kinase-MB (hazard ratio, 4.31; 99% confidence interval, 1.27–14.6; P=0.002). The cumulative mortality rate was 0.6% at 91 days.
Conclusions—A significant association of postpercutaneous coronary intervention cardiac biomarker elevation with a small number of postpercutaneous coronary intervention outcomes was noted for the early (first 91 days) follow-up period with an identifiable optimal threshold of 25× ULN (0.25, ng/mL) for cTnT, which provided similar early outcome information as a cutoff of × ULN for creatine kinase-MB.
- Received February 15, 2013.
- Accepted June 20, 2014.
- © 2014 American Heart Association, Inc.