Kotoku, Nozomi

Background Recently, machine learning algorithms have identified preprocedural γ‐glutamyl transferase (GGT) as a significant predictor of long‐term mortality after coronary revascularization in the SYNTAX (Synergy Between PCI [Percutaneous Coronary Intervention] With Taxus and Cardiac Surgery) trial. The aim of the present study is to investigate the impact of preprocedural GGT on 10‐year all‐cause mortality in patients with complex coronary artery disease after revascularization. Methods and Results The SYNTAX trial was a randomized trial comparing PCI with coronary artery bypass grafting in 1800 patients with complex coronary artery disease. The present report is a post hoc subanalysis of the SYNTAXES (Synergy Between PCI With Taxus and Cardiac Surgery Extended Survival) trial, an investigator‐driven extended 10‐year follow‐up of the SYNTAX trial. The association between preprocedural GGT and 10‐year all‐cause mortality was investigated. The mean values of GGT for men and women were 43.5 (SD, 48.5) and 36.4 (SD, 46.1) U/L, respectively. In multivariable Cox regression models adjusted by traditional risk factors, GGT was an independent predictor for all‐cause death at 10‐year follow‐up, and each SD increase in log‐GGT was associated with a 1.24‐fold risk of all cause death at 10‐year follow‐up (95% CI, 1.10–1.40). According to previously reported sex‐related GGT thresholds, patients with higher GGT level had a 1.74‐fold risk of all‐cause death at 10‐year follow‐up (95% CI, 1.32–2.29) compared with patients with lower GGT level. Conclusions Preprocedural GGT is an independent predictor of 10‐year mortality after coronary revascularization in patients with complex coronary artery disease. In patients with elevated GGT, strong secondary prevention may be required after revascularization and must be studied prospectively. Registration URL: https://clinicaltrials.gov/study/NCT03417050 .

Abstract Background/Introduction Over the last decade, epidemiology and pathology studies have suggested that gamma-glutamyl transferase (GGT) has an independent role in the pathogenesis and clinical evolution of cardiovascular diseases associated with atherosclerosis. Recently, machine learning (ML) algorithms have identified pre-procedural GGT as a significant predictor of long-term mortality after coronary revascularization in the SYNTAX trial. Purpose The aim of this study is to investigate the impact of pre-procedural GGT on 10-year all-cause mortality in patients with three-vessel disease (3VD) and/or left main coronary artery disease (LMCAD) following revascularization. Methods The SYNTAX trial was a randomized trial comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) in 1,800 patients with complex CAD. The present report is a post-hoc sub-analysis of the SYNTAXES study, an investigator-driven extended 10-year follow-up of the SYNTAX trial. Before revascularization, blood samples were taken for GGT as well as other biological markers and analyzed by an independent central chemistry laboratory. The primary endpoint was all-cause mortality at 10-years. The changes in hazard for all-cause mortality in GGT over time were modelled using restricted cubic spline functions in a Cox regression model adjusted by age and sex. Subsequently, we compared survival in four groups defined by gender specific GGT thresholds of <32 IU and ≥32 IU for females and <64 IU and ≥64 IU for males, in accordance with prior studies. Results Out of 1,800 patients enrolled in the SYNTAX study, 167 (9.3%) did not have a GGT available at baseline and 1,633 (90.7%) patients were included in the present study. The mean values of GGT for males and females were 43.5±48.5 and 36.4±46.1 U/L, respectively. In the overall population a 10 U/L increase in GGT was significantly associated with 10-year all-cause death (adjusted hazard ratio [HR] 95% confidence interval [CI]: 1.03 [1.02–1.04], p <0.001, Figure A). For Kaplan–Meier analysis, patients were stratified into four groups according to previously reported sex related GGT thresholds. Ten-year mortality was numerically higher in males (adjusted HR 1.31, 95% CI: 0.90–1.91), and significantly higher in females (adjusted HR 1.88, 95% CI: 1.16–3.05) among patients with higher versus lower GGT (Figure B). Furthermore, GGT was significantly associated with CRP, a surrogate-marker of inflammation, as well as established cardiovascular risk biomarkers such as TG, total cholesterol, and glucose. Conclusions Preprocedural GGT is an independent predictor of 10-year mortality following coronary revascularization in patients with 3VD and/or LMCAD. This long-term association has been identified using ML algorithms and should be corroborated using data from large biobanks.Figure AFigure B