Thrombin generation after the abrupt cessation of intravenous unfractionated heparin among patients with acute coronary syndromes
Potential mechanisms for heightened prothrombotic potential
Richard C. Becker, MD*,
Frederick A. Spencer, MD, FACC*,
Youfu Li, MD*,
Steven P. Ball, RN*,
Yunsheng Ma, MD, MPH ,
Thomas Hurley, MS and
James Hebert, ScD
* Laboratory for Vascular Biology Research, Division of Cardiovascular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
Department of Behavioral Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Figure 1 Thrombin generation (F1.2 concentrations) at baseline, 1 h, 4 h and 24 h for the overall patient population and patients randomized to either immediate discontinuation of heparin (D/C heparin), intravenous (IV) heparin weaning or subcutaneous (SC) heparin weaning. Thrombin generation was evident by 1 h and increased steadily over time. Thrombin generation was greatest with abrupt heparin cessation and was least with IV heparin weaning. D/C = discontinue; IV = intravenous; SC = subcutaneous.
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Figure 2 Factor VIIa concentration over time in the heparin strategy groups. An increase was observed in all patients; however, the greatest increase (from baseline) was observed with abrupt heparin cessation. D/C = discontinue; IV = intravenous; SC = subcutaneous.
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Figure 3 Tissue factor pathway inhibitor (TFPI) (total) concentration over time in the heparin strategy groups. There was a progressive increase in all patients; however, IV heparin weaning preserved TFPI levels. D/C = discontinue; IV = intravenous; SC = subcutaneous; TFPI = tissue factor pathway inhibitor.
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