Background and purpose: Abnormalities in blood coagulation and the fibrinolytic system have been associated with increased risk of stroke, but few prospective studies have studied the associations in older adults. We have examined the associations between fibrin D-dimer, tissue-type plasminogen activator, and von Willebrand factor (vWF) and risk of stroke in older men and examined their predictive roles separately in normotensive and hypertensive men.
Methods: Prospective study of 3358 men aged 60 to 79 years with no previous diagnosis of myocardial infarction or stroke and without atrial fibrillation followed-up for an average of 9 years, during which there were 187 incident stroke events.
Results: Increased levels of D-dimer and vWF were associated with significantly increased risk of major stroke events after adjustment for potential confounders, including systolic blood pressure (adjusted hazard ratios and 95% confidence interval per standard deviation increase in D-dimer and vWF were 1.24 [95% confidence interval, 1.08-1.44] and 1.25 [95% confidence interval, 1.09-1.45], respectively). No associations were seen with tPA after adjustment. The positive associations between D-dimer and vWF and incident stroke remained after additional adjustment for markers of inflammation (C-reactive protein, IL-6). D-dimer was associated with stroke in both normotensive and hypertensive men; vWF showed stronger associations in normotensive than in hypertensive men (test for interaction: P=0.52 for D-dimer; P<0.01 for vWF).
Conclusions: Fibrin D-dimer and vWF are associated with increased risk of stroke in older men. These associations were not explained by their associations with inflammation. D-dimer may be a useful marker to identify those at high risk for stroke among hypertensive men.