Additive prognostic value of interleukin-6 at peak phase of dobutamine stress echocardiography in patients with coronary artery disease. A 6-year follow-up study.
BACKGROUND
Interleukin-6 (IL-6) and tissue factor (TF) are elevated after myocardial ischemia during dobutamine stress echo (DSE). We examined the incremental prognostic value of IL-6 or TF measured during DSE over echocardiographic and clinical factors in patients with chronic coronary artery disease (CAD).


METHODS
We studied 106 patients with angiographically documented CAD. IL-6 and TF were measured at rest, peak, and during recovery. A wall motion score index was calculated.


RESULTS
Fifty-seven (54%) patients had ischemia at DSE. During follow-up (63.7 +/- 20 months), 36 patients (33%) had an adverse event (12 cardiac deaths, 24 acute coronary events). Patients with events had a higher peak IL-6 (P = .02) but similar rest and recovery IL-6 than those without. Patients with peak IL-6 > or =3.14 pg/mL (upper tertile) had a hazard ratio of 2.7 (95% CI 1.44-5.37) (P < .01 for an adverse event). The addition of peak wall motion score index in a multivariable model including risk factors, ejection fraction, revascularization, and multivessel disease increased the model's c statistic from 0.66 to 0.70 (P = .04). The addition of peak IL-6 further increased the model's c statistic to 0.75 (P = .04). Tissue factor was not related with cardiac events.


CONCLUSIONS
Interleuikin-6 levels measured during the peak phase of DSE incrementally contribute to risk stratification in patients with chronic CAD.
Ikonomidis
Ignatios
I
2nd Cardiology Department, Attikon Hospital, University of Athens, Athens, Greece. ignoik@otenet.gr
Athanassopoulos
George
G
Stamatelopoulos
Kimon
K
Lekakis
John
J
Revela
Ioanna
I
Venetsanou
Kiriaki
K
Marinou
Margarita
M
Monaco
Claudia
C
Cokkinos
Dennis V
DV
Nihoyannopoulos
Petros
P
D000368:Aged; D006328:Cardiac Catheterization; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging; D025401:Echocardiography, Stress; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D013925:Thromboplastin / Q000032:analysis*
D015850:Interleukin-6; D013925:Thromboplastin