Seven-Day Modified Rankin Scale Score as an Early Predictor of 90-Day Functional Outcome After Mechanical...

We hypothesized that the modified Rankin Scale (mRS) score after mechanical thrombectomy (MT) could predict subsequent functional improvement.

We retrospectively analyzed consecutive patients with acute ischemic stroke who underwent MT at our institution between January 2020 and December 2024. The association between the 7‑day and 90-day mRS scores was evaluated in all eligible patients (N = 432). Analyses of functional improvement were performed in patients with a 7-day mRS score of 3-5 (n = 290). Functional improvement was defined as a decrease of ≥ 1 point in the mRS score from day 7 to day 90, and patients were classified into improvement and non-improvement groups.

There was a strong correlation between the 7‑day and 90-day mRS scores (r = 0.86), with moderate agreement (weighted κ = 0.48). Functional improvement was observed in 95 (32.8%) of 290 patients with a 7-day mRS score of 3-5. Compared with the non-improvement group, the improvement group was significantly younger (median age, 79 versus 84 years; P < 0.0001), had a higher proportion of prestroke mRS score of 0-2 (82.1% versus 58.0%; P < 0.0001), and a higher prevalence of current smoking (17.9% versus 6.7%; P = 0.003). In multivariable logistic regression analysis, younger age (OR 0.96 per 1‑year increase; 95% CI, 0.93-0.99; P = 0.0030) and a prestroke mRS score of 0-2 (OR 2.7; 95% CI, 1.42-4.98; P = 0.0023) were identified as independent predictors of functional improvement.

The 7‑day mRS score after MT was strongly associated with the 90-day mRS score. Among patients with a 7-day mRS score of 3-5, younger age and a prestroke mRS score of 0-2 were independent predictors of functional improvement.