Protein Z levels and prognosis in patients with acute coronary syndromes.
BACKGROUND
Protein Z, a vitamin K-dependent glycoprotein, serves as a cofactor for the inhibition of activated coagulation factor X. During recent years, a role for low levels of protein Z in prothrombotic disorders such as ischemic stroke and acute coronary syndromes (ACS) has been reported. The aims of this study were to test changes in protein Z and their association with outcome at 1-year follow-up in 193 (150 male, 43 female) patients with ACS.


RESULTS
Protein Z plasma levels were significantly lower (p<0.0001) after 1 year [1,600 (28-3,736) ng/mL] compared to the baseline [1,695 (294-4,068) ng/mL]. Regression analysis showed a significant association between baseline protein Z below the 5th percentile of our control group and subsequent adverse cardiac events at follow-up (odds ratio 3.3; 95% CI 1.04-10.7; p=0.04). Moreover, Cox regression analysis showed that low protein Z levels at admission were significant predictors of major adverse cardiac events (cardiac death, non-fatal recurrent myocardial infarction, and need for target lesion revascularization) after 1 year (hazard risk 2.5; 95% CI 1.02-6.5, p=0.04).


CONCLUSIONS
Our results show that in patients with ACS: 1) protein Z decreases moving from the acute to the convalescent phase; and 2) low levels of baseline protein Z are significantly associated with adverse outcome at 1-year follow-up.
Sofi
Francesco
F
Department of Medical and Surgical Critical Care, Thrombosis Center, University of Florence, Florence, Italy. francescosofi@gmail.com
Cesari
Francesca
F
Marcucci
Rossella
R
Fatini
Cinzia
C
Gori
Anna Maria
AM
Giglioli
Cristina
C
Valente
Serafina
S
Fedi
Sandra
S
Abbate
Rosanna
R
Gensini
Gian Franco
GF
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D001798:Blood Proteins / Q000032:analysis* / Q000378:metabolism; D003327:Coronary Disease / Q000097:blood* / Q000209:etiology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012044:Regression Analysis; D018570:Risk Assessment; D012720:Severity of Illness Index
D015415:Biomarkers; D001798:Blood Proteins; C026080:plasma protein Z