Thrombelastographic measures of clot propagation: A comparison of alpha with the maximum rate of thrombus generation

Truitt C. Ellis, Vance G. Nielsen, Marisa B. Marques, James K. Kirklin

Research output: Contribution to journalArticlepeer-review

42 Scopus citations


The alpha angle α (degrees) is a thrombelastographic measure of clot propagation. A parametric measurement of clot propagation [maximum rate of thrombus generation (MRTG), dynes/cm per s], however, has recently been utilized. Thus, the relationship of changes in α with changes in MRTG were determined. α and MRTG values obtained from 859 thrombelastograms was collected from nine studies. Data were analyzed and the relationship between α and MRTG defined with commercially available software. Additional comparisons were made retrospectively from whole-blood and plasma data obtained from 33 normal individuals. Data from the nine studies demonstrated that MRTG increased in an exponential fashion compared with increases in α (R = 0.88, P < 0.001). Whole-blood α values were in the range 66.7-74.7 whereas MRTG values were 5.5-10.8, and plasma α values were 65.1-77.9 with corresponding MRTG values of 3.5-12.0. Assessment of clot propagation utilizing MRTG provides a more parametric evaluation than the determination of α. While normal α values may vary by only 12-20%, MRTG values vary by approximately 200-300%. The MRTG should be progressively utilized to a greater extent in both laboratory and clinical settings to parametrically quantify clot growth kinetics with thrombelastography.

Original languageEnglish (US)
Pages (from-to)45-48
Number of pages4
JournalBlood Coagulation and Fibrinolysis
Issue number1
StatePublished - Jan 2007


  • Alpha
  • Coagulation kinetics
  • Maximum rate of thrombus generation
  • Measurement techniques
  • Thrombelastography

ASJC Scopus subject areas

  • Hematology


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