Prognostic value of serum gamma-glutamyl transferase activity after myocardial infarction.
OBJECTIVE
Serum gamma-glutamyl transferase activity (gamma-GT) is able to catalyse low-density lipoprotein oxidation and has been detected in coronary atherosclerotic plaques. gamma-GT has been documented as an independent risk factor for cardiac mortality in middle-aged men. The purpose of this study is to determine the prognostic value of gamma-GT in patients with coronary artery disease.


RESULTS
In a prospective study, gamma-GT and other cardiac risk factors were evaluated in 469 consecutive subjects with angiographically documented coronary artery disease, using mortality and mortality plus non-fatal myocardial infarction as end-points. gamma-GT showed an independent prognostic value beyond known established risk factors in the subgroup of 262 patients with previous myocardial infarction. At a 6-year follow-up, cardiac mortality was 25.2% in patients with gamma-GT >40 U x l(-1)vs 13.9% in those with gamma-GT <40 U x l(-1)(P=0.038). When both cardiac mortality and non-fatal myocardial infarction were considered as end-points, these events were recorded in 32.7% of patients with gamma-GT >40 U x l(-1)and in 20.4% of those with levels <40 U x l(-1)(P=0.031). Excess mortality and non-fatal infarction in patients with high gamma-GT levels were concentrated in the first 2 years of follow-up (P=0.014). The association of gamma-GT values >40 U x l(-1), previous myocardial infarction, and multiple vessel disease identified a subgroup of 168 patients with the highest risk of cardiac events at 6 years (P=0.024). The relationship between gamma-GT levels and cardiac events remained significant after adjustment for cardiac risk factors, and possible confounders, including alcohol consumption. gamma-GT did not show significant prognostic value in the 207 patients without previous myocardial infarction.


CONCLUSIONS
gamma-GT is an independent cardiac risk factor in ischaemic patients with established coronary atherosclerosis and previous myocardial infarction.
Emdin
M
M
CNR Institute of Clinical Physiology, National Research Council, Pisa, Italy.
Passino
C
C
Michelassi
C
C
Titta
F
F
L'abbate
A
A
Donato
L
L
Pompella
A
A
Paolicchi
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003324:Coronary Artery Disease / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000201:enzymology* / Q000401:mortality; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012372:ROC Curve; D012044:Regression Analysis; D012307:Risk Factors; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D005723:gamma-Glutamyltransferase / Q000097:blood*
D005723:gamma-Glutamyltransferase