Prognostic relations between inflammatory markers and mortality in diabetic patients with non-ST elevation acute coronary syndrome

Abstract

Objective: To determine the differences in the inflammatory status between diabetic and non-diabetic patients and to evaluate the usefulness of C reactive protein, fibrinogen, and leucocyte count as predictors of death in diabetic patients with unstable coronary disease.

Design: Nested case-control comparisons of the inflammatory status between diabetic and non-diabetic patients. Prospective cohort analysis of C reactive protein concentration, fibrinogen concentration, and leucocyte count as predictors of cardiovascular death in diabetic patients.

Setting: Coronary care unit in Spain.

Participants: 83 diabetic patients with non-ST elevation acute coronary syndrome and 83 sex and aged matched patients selected from 361 non-diabetic patients with non-ST elevation acute coronary syndrome.

Main outcome measures: Plasma concentrations of C reactive protein and fibrinogen, and leucocyte count. Investigators contacted patients to assess clinical events.

Results: Concentrations of C reactive protein and fibrinogen, and leucocyte count on admission were higher in diabetic than in non-diabetic patients (7 mg/l v 5 mg/l, p = 0.020; 3.34 g/l v 2.90 g/l, p = 0.013; and 8.8 x 10(9)/l v 7.8 x 10(9)/l, p = 0.040). Among diabetic patients, these values were also higher in those who died during the 22 month follow up (13 mg/l v 6 mg/l, p = 0.001; 3.95 g/l v 3.05 g/l, p < 0.001; and 11.4 x 10(9)/l v 8.4 x 10(9)/l, p = 0.005). After adjustment for confounding factors, diabetic patients in the highest tertile of C reactive protein had a hazard ratio for cardiovascular death of 4.51 (95% confidence interval (CI) 1.62 to 12.55). Similar hazard ratios were for fibrinogen 3.74 (95% CI 1.32 to 10.62) and for leucocyte count 3.64 (95% CI 1.37 to 9.68).

Conclusions: Inflammation appears more evident in diabetic than in non-diabetic patients with acute coronary syndrome. C reactive protein concentration, fibrinogen concentration, and leucocyte count constitute independent predictors of cardiovascular death in diabetics with unstable coronary disease.

Figure 1

Kaplan-Meier survival estimates for diabetic patients divided into tertiles according to (A) C reactive protein concentrations, (B) fibrinogen concentrations, and (C) leucocyte count on admission.

Figure 2

Cardiovascular death hazard ratios in diabetic patients based on the number of increased inflammatory markers.