Predictors and clinical impact of infarct progression rate in the ESCAPE-NA1 trial

Background: Determining infarct progression rate in acute ischemic stroke (AIS) is important for patient triage, treatment decision-making, and outcome prognostication.

Objective: To estimate infarct progression rate in patients with AIS with large vessel occlusion (LVO) and determine its predictors and impact on clinical outcome.

Methods: Data are from the ESCAPE-NA1 Trial. Patients with AIS with time from last known well to randomization <6 hours and near-complete reperfusion following endovascular treatment were included. Infarct growth rate (mL/h) was estimated by dividing 24 hour infarct volume (measured by non-contrast CT or diffusion-weighted magnetic resonance imaging) by time from last known well to reperfusion. Multivariable linear regression was used to assess the association of patient baseline variables with log-transformed infarct progression rate. The association of infarct progression rate and good outcome (modified Rankin Scale score 0-2) was determined using multivariable logistic regression.

Results: Four hundred and nine patients were included in the study. Median infarct progression rate was 4.74 mL/h (IQR 1.25-14.84). Collateral status (β: -0.81 (95% CI -1.20 to -0.41)), Alberta Stroke Program Early CT Score (ASPECTS, β: -0.34 (95% CI -0.46 to -0.23)), blood glucose(β: 0.09 (95% CI 0.02 to 0.16)), and National Institutes of Health Stroke Scale (NIHS score (β: 0.07 (95% CI 0.04 to 0.10)) were associated with log-transformed infarct progression rate. Clinical and imaging baseline variables explained 23% of the variance in infarct progression rate. Infarct progression rate was significantly associated with good outcome (aOR per 1 mL/h increase: 0.96 (95% CI 0.95 to 0.98)).

Conclusion: In this sample of patients presenting within the early time window with LVO and near-complete recanalization, infarct progression rate was significantly associated with good outcome. A significant association between ASPECTS, collateral status, blood glucose, and NIHSS score was observed, but baseline imaging and clinical characteristics explained only a small proportion of the interindividual variance. More research on measurable factors affecting infarct growth is needed.