Most stroke recurrences after embolic stroke of undetermined source (ESUS) are embolic and often of undetermined source, reveals a secondary analysis of data from the NAVIGATE-ESUS trial, published in JAMA Neurology.
The trial compared the efficacy of rivaroxaban 15 mg daily and aspirin 100 mg daily, in patients with recent ESUS (n=7,213). This secondary analysis examined recurrent ischaemic stroke during follow-up (median 11 months).
Ischaemic stroke was validated in 309 patients (205 males) and classified into ESUS or non-ESUS. Of 270 classifiable ischaemic strokes, 156 (58%) were ESUS and 114 (42%) were non-ESUS (37 cardioembolic, 26 atherosclerotic, 35 lacunar, and 16 other determined cause).
Annualised rates of recurrent ischaemic stroke were 4.7 per cent and 4.6 per cent in those assigned rivaroxaban and aspirin, respectively. Recurrent ischemic strokes associated with cardioembolic subtype were more disabling as measured by the modified Rankin scale score and were associated with a higher mortality rate than other stroke subtypes. Cardioembolic stroke was less frequent in the rivaroxaban group. Participants not assigned to aspirin tended to have a higher risk for atherosclerotic and lacunar stroke, although none were statistically significant.
Specific sources of embolism in individual patients should be determined, or the establishment of antithrombotic therapies addressing different pathways of embolus formation.