STRIVE-2 MRI-defined brain frailty and functional outcomes after thrombectomy: A multicenter study.

Abstract

Background and objectives: Mechanical thrombectomy (MT) is the standard of care for large vessel occlusion (LVO) stroke, yet nearly half of patients fail to achieve functional independence. Cerebral small vessel disease (CSVD) represents a marker of brain frailty that may impair recovery. We aimed to evaluate whether comprehensive magnetic resonance imaging (MRI)-defined CSVD markers before MT predict 90-day functional outcomes and hemorrhagic transformation.

Methods: This retrospective, multicenter cohort study analyzed consecutive patients with anterior circulation LVO treated with MT (2015-2022) at two tertiary centers. CSVD markers (white matter hyperintensities (WMHs), lacunes, cerebral microbleeds (CMBs), enlarged perivascular spaces (EPVS), and brain atrophy) were assessed on pre-treatment MRI according to STRIVE-2 criteria. The primary outcome was functional dependence or death at 90 days (modified Rankin Scale (mRS) score 3-6). Bayesian logistic regression models estimated adjusted odds ratios (aORs) and 95% credible intervals (CrI), adjusting for age, sex, thrombolysis, infarct volume, time-to-puncture, and reperfusion status. A composite CSVD score including all five markers was also evaluated.

Results: Among 479 patients (median age 72 years (interquartile range = 59-80); 46% female), successful reperfusion (modified thrombolysis in cerebral infarction 2b-3) was achieved in 83% and 47% had 90-day mRS 3-6. Functional dependence was independently associated with the presence of lacunes (aOR = 2.07; 95% CrI = 1.22-3.59; posterior probability (PP) > 99%), moderate-to-severe brain atrophy (aOR 1.92; 95% CrI = 1.09-3.40; PP 99%), and moderate-to-severe WMH (aOR = 1.63; 95% CrI = 0.94-2.84; PP = 96%). Furthermore, every 1-point increase in the five-item composite CSVD score demonstrated a dose-dependent increase in the odds of functional dependence (aOR = 1.44; 95% CrI = 1.23-1.69; PP > 99%) and symptomatic intracerebral hemorrhage (aOR = 1.33; 95% CrI = 0.92-1.93; PP = 94%).

Discussion: Pre-existing lacunes, atrophy, and WMH are independent determinants of worse functional recovery after MT. Importantly, cumulative total CSVD burden acts as a strong, dose-dependent predictor of functional outcomes and symptomatic hemorrhage. While these findings support that CSVD assessment improves post-thrombectomy prognostication, they do not support CSVD be used as a criterion to preclude patients from MT eligibility.