Is aspirin plus dipyridamole better than aspirin alone in preventing recurrent cerebral ischemia?

In this unblinded study, the combination of aspirin plus dipyridamole is more effective than aspirin alone in preventing death from all vascular causes, nonfatal stroke, nonfatal myocardial infarction, or major bleeding complications. However, patients taking dipyridamole are much more likely to experience headaches sufficient to stop taking it. (LOE = 2b)

The ESPRIT Study Group; Halkes PH, van Gijn J, Kappelle LJ, Koudstaal PJ, Algra A. Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial. Lancet 2006;367:1665-1673.  [PMID:16714187]

Randomized controlled trial (nonblinded)

Government

Concealed

Outpatient (specialty)

Patients referred to a participating hospital within 6 months of a transient ischemic attack or a minor ischemic stroke (grade 3 or less on the modified Rankin Scale) were randomly assigned to receive aspirin alone (average dose = 75 mg; n=1376) or the same dose of aspirin plus dipyridamole 200 mg twice daily (average dose = 75 mg; n=1363). The patients were evaluated every 6 months for up to 5 years, either by phone or in person. The primary outcome -- a composite of death from all vascular causes, nonfatal stroke, nonfatal myocardial infarction, or major bleeding complication, blindly determined -- was assessed by intention to treat. The mean length of follow-up was 3.5 years. At the end of the study period, 15.7% of patients taking aspirin alone experienced the composite outcome compared with 12.7% of patients taking aspirin and dipyridamole (number needed to treat = 34 for 3.5 years; 95% CI, 18-257). Patients taking the combination therapy, however, stopped taking it more often than those taking aspirin alone (34% vs 13%; number needed to treat to harm = 5; 4-6), mainly because of headache.