Clinical and Prognostic Characteristics of Acute BAD–Related Stroke: A Multicenter MRI–Based Prospective Study

BACKGROUND: Branch atheromatous disease (BAD)-related stroke has emerged as a meaningful subtype of ischemic stroke yet remained understudied. We aimed to investigate the demographic, clinical, therapeutic, and prognostic characteristics of BAD-related stroke. METHODS: The BAD-study was a nationwide, multicenter, prospective, observational cohort study in 20 Chinese hospitals from June 2021 to June 2023, enrolling patients aged 18 to 80 years with BAD-related stroke within 72 hours of onset. Eligible single subcortical infarct in the territory of lenticulostriate artery and paramedian pontine artery was included. Clinical, laboratory, and treatment data were collected at baseline. The primary outcome was a proportion of good outcomes (modified Rankin Scale score, 0-2) at 90 days. Main secondary outcomes included early neurological deterioration (END), cerebrovascular event, major bleeding, and excellent outcome (modified Rankin Scale score, 0-1) during 90-day follow-up. RESULTS: We finally enrolled 476 patients, with a median age of 60 (interquartile range, 53-68) years, and 70.2% were male. The median National Institutes of Health Stroke Scale score was 3 (interquartile range, 2-6) at enrollment. Involvement of the lenticulostriate artery was more common than the paramedian pontine artery (60.7% versus 39.3%). END occurred in 14.7% of patients, with a median time from onset of 38 (interquartile range, 22-62) hours. The rates of good and excellent outcomes were 86.5% and 72%, respectively. Its 90-day stroke recurrence rate was 1.9%. Acute-phase therapy (from onset to 7 days of enrollment) showed heterogeneity and was not associated with prognosis. Multivariable logistic regression analysis identified the National Institutes of Health Stroke Scale score ≥4 at admission and END as negative predictors and extracranial artery stenosis as a positive predictor of good outcomes. Age ≥60 years, National Institutes of Health Stroke Scale score ≥4 at admission, and END were negative predictors of excellent outcomes. CONCLUSIONS: With distinct demographic, clinical, and prognostic characteristics, along with a high incidence of END and a low risk of stroke recurrence, BAD-related stroke could be categorized as a separate disease entity. Moreover, its acute-phase treatment strategies were undetermined, awaiting further high-quality studies.