[Relationship between antithrombin-III value with acute coronary syndrome and preprocedural TIMI flow grade].

Objective: To explore the differences of antiprothrombin-III (AT-III) value in patients with acute coronary syndrome (ACS) and stable angina pectoris (SAP) and examine the association of AT-III value with preprocedural thrombolysis in myocardial infarction (TIMI) flow in ACS patients.

Methods: This study prospectively included 121 hospitalized ACS patients between February 2011 to June 2011, including ST-segment elevation myocardial infarction (STEMI, n = 50), non-ST segment elevation myocardial infarction (NSTEMI, n = 32) and unstable angina (UAP, n = 39). Meanwhile, 50 SAP cases during the same period were selected as the control group. The AT-III levels were measured by chromogenic substrate method before coronary angiography for all patients.

Results: (1) The AT-III levels were significantly lower in the ACS patients than those in the SAP cases. (2) In the STEMI subgroup, the AT-III levels were markedly lower in the patients with preprocedural TIMI flow grade ≤ 2 versus those with preprocedural TIMI flow grade 3 (86% ± 11% vs 93% ± 9%, P < 0.05). (3) In the USTEMI/UAP subgroup, the mean levels of AT-III were obviously lower in the patients with preprocedural TIMI flow grade ≤ 2 than those with preprocedural TIMI flow grade 3 (85% ± 8% vs 95% ± 8%, P < 0.01) and were notably lower in the patients with the culprit lesion stenosis ≥ 70% versus those with stenosis < 70% (88% ± 9% vs 94% ± 9%, P < 0.01). (4) Multivariable analysis identified AT-III value as an independent predictor of impaired preprocedural TIMI flow grade of culprit coronary artery in ACS patients.

Conclusion: The AT-III levels were significantly lower in the ACS patients than those in the SAP patients. The activity of AT-III is positively correlated with the TIMI flow grade in ACS patients. In contrast, the activity of AT-III is negatively correlated with the severity of culprit vessel stenosis in the patients with NSTEMI. Thus AT-III level may be used to distinguish high-risk populations in ACS patients at an early stage.