Role of homocysteine for thromboembolic complication in patients with non-valvular atrial fibrilation

Blood Coagul Fibrinolysis. 2002 Oct;13(7):609-13. doi: 10.1097/00001721-200210000-00005.


Thromboembolism is the most important complication in patients with atrial fibrilation (AF). Homocysteine is a toxic amino acid that has been recently accepted as a risk factor for atherosclerosis and stroke. The aim of the present study is to show whether there is a relation between hyperhomocysteinemia and thromboembolic complications in patients with non-valvular AF. We admitted 38 patients with non-valvular AF. The patients were divided into two groups: group A (n = 20; mean age, 75.7 +/- 10.4 years; three males/17 females), and group B (n = 18; mean age, 68.0 +/- 10.6 years; 11 males/seven females). While group A consisted of the patients with AF and stroke, group B was composed of the patients with AF but without stroke. The patients having sinus rhythm (15 subjects) were used as the reference group to obtain the cut-off value. Homocysteine was measured by the immunoassay method. The means of the homocysteine levels were 12.4 +/- 3.3 micromol/l in group A, 8.3 +/- 2.3 micromol/l in group B and 9.3 +/- 1.8 micromol/l in the reference group. The cut-off value was 10.6 micromol/l. Group A had a statistically higher homocysteine level than not only group B, but also the reference group (P < 0.05). While 60% of group A (n = 12) had the elevated homocysteine level, the rate was only 22% for group B (n = 4). In conclusion, hyperhomocysteinemia may be one of the explanations for the increased rate of thromboembolic complications in older patients with AF.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Atrial Fibrillation / complications*
  • Case-Control Studies
  • Female
  • Homocysteine / blood*
  • Homocysteine / physiology*
  • Humans
  • Male
  • Middle Aged
  • Risk Factors
  • Stroke / etiology
  • Thromboembolism / etiology*


  • Homocysteine