Comparative prognostic value of postprocedural creatine kinase myocardial band and high‐sensitivity troponin T in patients with non‐ST‐segment elevation myocardial infarction undergoing percutaneous coronary intervention

Objectives We aimed to assess the prognostic value of postprocedural creatine kinase myocardial band (CK‐MB) and cardiac troponin (cTn) in patients with non‐ST‐segment elevation myocardial infarction (NSTEMI). Background : Whether postprocedural CK‐MB or cTn is a better biomarker to stratify the risk after percutaneous coronary intervention (PCI) remains unknown. Methods : This study included 2,077 patients with NSTEMI undergoing early PCI. Peak postprocedural values of CK‐MB and high‐sensitivity cTn T (hs‐cTnT) were analyzed. The primary outcome was 3‐year mortality. Results : The median values of peak postprocedural CK‐MB and hs‐cTnT were 18.3 U L −1 and 0.140 µg L −1 , respectively. Overall, 211 patients died during follow‐up. There were 129 deaths in patients with CK‐MB >the median value and 82 deaths in those with CK‐MB ≤the median value (Kaplan–Meier estimates of 3‐year mortality, 18.9% and 14.0%, respectively; hazard ratio [HR] = 1.52, 95% confidence interval [CI] 1.16–2.01; P < 0.001). There were 134 deaths in patients with hs‐cTnT >the median value and 77 deaths in patients with hs‐cTnT ≤the median value (Kaplan–Meier estimates of 3‐year mortality, 19.9% and 13.2%, respectively; HR = 1.90 [1.44–2.52]; P < 0.001). After adjustment, peak postprocedural CK‐MB (adjusted HR = 1.05 [1.02–1.07], P < 0.001 for each 24 U L −1 increment) and hs‐cTnT (adjusted HR = 1.12 [1.01–1.25], P = 0.037 for each unit higher log hs‐cTnT) remained independently associated with the risk of 3‐year mortality. The C‐statistic(s) of the model with CK‐MB and hs‐cTnT were 0.789 [0.757–0.817] and 0.793 [0.762–0.821], respectively ( P = 0.585). Conclusion : In patients with NSTEMI undergoing early PCI, peak postprocedural CK‐MB and hs‐cTnT are independently associated with the risk of 3‐year mortality.