Impact of Periprocedural Myocardial Biomarker Elevation on Mortality Following Elective Percutaneous Coronary Intervention

Objectives: This study sought to explore the association between biomarker elevation, with creatine kinase–myocardial band (CK-MB) or cardiac troponin (cTn), following percutaneous coronary intervention (PCI) and mortality in patients undergoing PCI for stable angina with normal baseline values. Background: Several studies have shown a strong association between post-PCI CK-MB elevation and subsequent mortality. However, the prognostic significance of troponin elevation following coronary intervention is still debated. Methods: Patient-level data from 5 contemporary coronary stent trials and 1 large registry were pooled. Mortality of patients with stable angina, with normal baseline biomarkers, was compared between patients with and those without different cutoff values of cTn and CK-MB. Results: A total of 13,452 patients were included in this pooled analysis. The overall percentage of patients with elevated biomarkers following PCI was 23.9% for CK-MB and 68.4% for cTn. In the patient cohort for whom both assays were available (n = 8,859), 2.4% had both CK-MB ≥5 × the upper limit of normal (ULN) and cTn ≥35 × ULN, while 92% had both CK-MB <5 × ULN and cTn <35 × ULN. Among patients with CK-MB ≥5 × ULN (n = 315), 212 (67.3%) also had cTn ≥35 × ULN. Conversely, 390 of patients (64.8%) who had cTn ≥35 × ULN did not have CK-MB ≥5 × ULN. A total of 259 patients (1.9%) died at 1 year; 20 (7.7%) had CK-MB ≥5 × ULN, and 23 (8.8%) had cTn ≥35 × ULN. In the Cox multivariate analysis, in which the CK-MB and cTn ratios post-procedure were forced into the model, age, prior myocardial infarction, lesion complexity, hyperlipidemia, and CK-MB ratio (≥10) post-procedure were associated with increased 1-year mortality. Conclusions: Following elective PCI in patients in stable condition treated with second-generation drug-eluting stent, CK-MB and cTn elevations remain common. After multivariate adjustment, there was an increased mortality rate with elevation of CK-MB after PCI, whereas cTn elevation was not independently associated with mortality at 1 year.