Incidence, correlates, and significance of abnormal cardiac enzyme rises in patients treated with surgical or percutaneous based revascularisation

Aims The aim of the present investigation was to determine the long-term prognostic association of post-procedural cardiac enzyme elevation within the randomised Synergy between Percutaneous Coronary Intervention (PCI) with TAXUS and Cardiac Surgery (SYNTAX) Trial. Methods 1800 patients with unprotected left main or de novo three-vessel coronary artery disease were randomised to undergo coronary artery bypass graft (CABG) surgery or PCI. Per protocol patients underwent post-procedural blood sampling with creatine kinase (CK), and the cardiac specific MB iso-enzyme (CK-MB) only if the preceding CK ratio was ≥2× the upper limit of normal (ULN). An independent chemistry laboratory evaluated all collected blood samples. Results Post-procedural CK sampling was available in 1629 of 1800 patients (90.5%). As per protocol, CK-MB analyses were undertaken in 474 of 491 patients (96.5%) in the CABG arm, and 53 of 61 patients (86.9%) in the PCI arm. Within the CABG arm, despite the limitations of incomplete data, a post-procedural CK-MB ratio <3/≥3 ULN separated 4-year mortality into low- and high-risk groups (2.3% vs. 9.5%, p=0.03). Additionally, in the CABG arm, a post-procedural CK-MB ratio ≥3 ULN was associated with an increased frequency of a high SYNTAX Score (≥33) tertile (high [≥33] SYNTAX Score: 39.5%, intermediate [23–32] SYNTAX Score 31.0%, low [≤22] SYNTAX Score 29.5%, p=0.02). Within the PCI arm, a post-procedural CK ratio of <2 or ≥2 ULN separated 4-year mortality into low- and high-risk groups (10.8% vs. 23.3%, p=0.001). Notably, there was an early (within 6months) and late (after 2years) peak in mortality in patients with a post-PCI CK ratio of ≥2 ULN. Lack of pre-procedural thienopyridine, carotid artery disease, type 1 diabetes, and presence of coronary bifurcations were independent correlates of a CK ratio ≥2 ULN post-PCI. Conclusion Cardiac enzyme elevations post-CABG or post-PCI are associated with an adverse long-term mortality; the causes of which are multifactorial.