Gamma-glutamyl transferase and prognosis in patients with coronary artery disease

Background: The association between gamma-glutamyl transferase (GGT) activity and outcome of patients with coronary artery disease (CAD) remains poorly investigated.

Methods: The study included 5501 patients with CAD treated with percutaneous coronary intervention and GGT measurements available. The primary outcome was 3-year mortality.

Results: GGT activity tertiles were: 1st tertile (GGT<28.10U/L; n=1866), 2nd tertile (GGT≥28.10U/L to49.50U/L; n=1804) and 3rd tertile (GG>49.50U/L; n=1831). There were 110 deaths in the 1st, 111 deaths in the 2nd and 216 deaths in the 3rd GGT tertile (mortality estimates, 7.1%, 7.2% and 13.9%; P<0.001). GGT was independently associated with the increased risk of 3-year all-cause (adjusted hazard ratio [HR]=1.30, 95% confidence interval [CI] 1.18 to 1.44, P<0.001), cardiac (HR=1.21 [1.06-1.39], P=0.005) and non-cardiac (HR=1.42 [1.23-1.63], P<0.001) mortality (all risk estimates calculated per standard deviation increase in the log GGT activity). GGT improved prediction of all-cause (P<0.001) and non-cardiac mortality (P<0.001) but not cardiac mortality (P=0.155).

Conclusions: In patients with CAD, elevated GGT activity is associated with increased risk of 3-year all-cause, cardiac and non-cardiac mortality. GGT provided incremental prognostic information on top of cardiovascular and metabolic risk factors for prediction of all-cause and non-cardiac mortality but not cardiac mortality.