Incidence, correlates, and significance of abnormal cardiac enzyme rises in patients treated with surgical or percutaneous based revascularisation: A substudy from the Synergy between Percutaneous Coronary Interventions with Taxus and Cardiac Surgery (SYN

AimsThe 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.Methods1800 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.ResultsPost-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 6 months) and late (after 2 years) 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.ConclusionCardiac enzyme elevations post-CABG or post-PCI are associated with an adverse long-term mortality; the causes of which are multifactorial.