Does all single infarction have lower risk of stroke recurrence than multiple infarctions in minor stroke?

BACKGROUND: Single acute infarction (SAI) usually had lower risk of stroke recurrence than multiple acute infarctions (MAIs) in minor stroke. To evaluate whether all SAI had lower risk of stroke recurrence than MAIs in minor stroke. METHODS: We derived data from the imaging subgroup of the Clopidogrel in High-risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. Minor stroke were categorized into SAI and MAIs by infarction numbers in diffusion weighted imaging. SAI were classified as lacunar infarction and non-lacunar infarction. The outcome was stroke recurrence within one-year follow-up. We assessed the associations between infarction patterns and stroke recurrence using multivariable Cox regression models. RESULTS: Overall, 834 patients with minor stroke were included in this subgroup, 553 SAI (381 lacunar infarction, 172 non-lacunar infarction) and 281 MAIs. The rate of stroke recurrence was 7.6%, 15.1% and 15.3% in lacunar infarction of SAI, non-lacunar infarction of SAI and MAIs at one year, respectively. Compared with MAIs, lacunar infarction of SAI had lower risk of stroke recurrence (hazard ratio [HR] 0.41, 95% confidence interval [CI] 0.21-0.80, P = 0.009), but not in non-lacunar infarction of SAI (HR 1.01, 95% CI 0.60-1.69, P = 0.98). CONCLUSIONS: Lacunar infarction of SAI have lower risk of stroke recurrence than MAIs, while non-lacunar infarction of SAI might have similar risk as MAIs. Except for the number of infarctions, size and location should also be considered to stratify risk of stroke recurrence in minor stroke. TRIAL REGISTRATION: http://www.clinicaltrials.gov Unique identifier: NCT00979589 . Date of registration: September 2009.