Dementia in subjects with atrial fibrillation: hemostatic function and the role of anticoagulation.
BACKGROUND
Atrial fibrillation (AF) is associated with cognitive impairment and dementia, perhaps through encouraging a prothrombotic state and cardioembolism.


OBJECTIVE
We wished to test the hypotheses that hemostatic function is altered in subjects with AF who develop dementia, and that long-term warfarin anticoagulation is protective against this complication.


METHODS
Recruitment was from an observational cohort study of AF. Baseline assessment included measurement of plasma fibrinogen, fibrin D-dimer, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complexes (TAT), von Willebrand factor and tissue plasminogen activator. We assessed cognitive function after 3 years' follow-up using the 13-item modified Telephone Interview for Cognitive Status (TICSm) and the short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE).


RESULTS
Of the 218 subjects assessed, 145 (66%) were prescribed warfarin. Forty-nine (22%) met TICSm/IQCODE criteria for dementia. D-dimer, F1+2 and TAT levels were higher in AF subjects with dementia compared with those without (medians 81 vs. 60 ng mL(-1), P = 0.008; 0.76 vs. 0.49 nmol L(-1), P = 0.006; and 1.78 vs. 1.44 microg L(-1), P = 0.003, respectively). These associations became of borderline statistical significance following adjustment for age. Logistic regression showed a trend towards warfarin use being independently associated with reduced prevalence of dementia (odds ratio 0.52, P = 0.08).


CONCLUSIONS
We found evidence of increased thrombin generation and fibrin turnover in subjects with AF and dementia compared with those without dementia. Long-term warfarin use may be protective against the development of dementia in subjects with AF.
Barber
M
M
University Section of Clinical Gerontology and Vascular Medicine and Department of Haematology, Royal Infirmary, Glasgow, UK. m.barber@clinmed.gla.ac.uk
Tait
R C
RC
Scott
J
J
Rumley
A
A
Lowe
G D O
GD
Stott
D J
DJ
D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000494:pharmacology* / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000097:blood / Q000150:complications* / Q000188:drug therapy*; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003704:Dementia / Q000097:blood* / Q000209:etiology / Q000517:prevention & control; D004341:Drug Evaluation; D005260:Female; D005500:Follow-Up Studies; D006487:Hemostasis / Q000187:drug effects / Q000502:physiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D011237:Predictive Value of Tests; D015995:Prevalence; D011795:Surveys and Questionnaires
D000925:Anticoagulants; D015415:Biomarkers