Dipyridamole in stroke prevention: effect of dipyridamole on blood pressure.
OBJECTIVE
Trial data suggest that dipyridamole, with or without aspirin, is more efficacious in the secondary prevention of stroke than of coronary events. This selective effect might be attributed to blood pressure lowering by dipyridamole. Therefore, we aimed to assess the effect on blood pressure in the setting of a randomized clinical trial in patients with cerebral ischemia of presumed arterial origin.


METHODS
In this study, 591 patients with recent cerebral ischemia of arterial origin were randomly allocated to treatment with aspirin 30 to 325 mg/d or with the combination of aspirin and dipyridamole 400 mg/d in the European/Australian Stroke Prevention in Reversible Ischemia Trial. In an on-treatment analysis, the change in blood pressure measurements from baseline to values after at least 6 months of follow up was assessed with linear regression analysis.


RESULTS
After an average period of 15 months, systolic blood pressure dropped 6.2 mm Hg in the aspirin plus dipyridamole group (n=273) and 6.2 mm Hg in the aspirin group (n=318), for a difference of 0.0 mm Hg (95% confidence interval, -3.8 to 3.7). Diastolic blood pressure dropped 3.6 mm Hg in the aspirin plus dipyridamole group compared with 2.7 mm Hg in the aspirin group, for a difference of 0.9 mm Hg (95% confidence interval, -1.0 to 2.9).


CONCLUSIONS
It is unlikely that dipyridamole leads to a permanent reduction in blood pressure and that this would explain why this drug might prevent strokes rather than coronary events.
De Schryver
E L L M
EL
Department of Neurology, University Medical Center Utrecht, H 02.128, PO Box 85500, 3508 GA Utrecht, The Netherlands. e.deschryver@neuro.azu.nl
D001241:Aspirin / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D002545:Brain Ischemia / Q000188:drug therapy; D004176:Dipyridamole / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D020521:Stroke / Q000517:prevention & control*; D013995:Time; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000627:therapeutic use*
D010975:Platelet Aggregation Inhibitors; D014665:Vasodilator Agents; D004176:Dipyridamole; D001241:Aspirin