The proximal occlusion site and thrombus length were shown to be two independent predictors of early neurological deterioration of presumed ischemic origin (ENDi) after intravenous thrombolysis (IVT) in patients with minor strokes, according to the study results published in JAMA Neurology.
A 4-point score derived from these variables – 1 point for the thrombus length and 3 points for the occlusion site – showed good discriminatory power for ENDi in a cohort of 729 patients with mild stroke and was successfully validated in an independent cohort of 347 patients.
The study’s researchers sought to provide doctors with a predictive value for assessing the risk of post-IVT ENDi in patients with acute but disabling stroke and large vascular occlusion (LVO) so that they could best select candidates for bridging therapy .
The researchers used data from the MINOR-STROKE collaboration, which had retrospectively collected data from acute stroke patients admitted to French stroke centers between 2006 and 2018 for a lead cohort and used data from prospectively collected databases from 6 stroke centers in France and 3 from Switzerland for a validation cohort of 347 patients. Patients scheduled directly for an additional mechanical thrombectomy (MT) or who had isolated internal carotid artery occlusion without central carotid artery occlusion were excluded.
In the lead cohort, early neurological deterioration (END) occurred in 96 patients (13.2%; 95% CI, 10.7-15.7) and in 88 patients (12.1%; 95% CI, 9.7- 14.4) an ENDi. Patients with ENDi treated with rescue MT had better outcomes than those without (common odds ratio (OR), 3.72; 95% CI, 1.67-8.32; P = 0.001).
In a univariate analysis, the researchers found that the association of thrombus length with ENDi in patients with magnetic resonance imaging (unmatched OR per 1 mm increase, 1.11; 95% CI, 1.06-1.16) and computed tomography / computed tomography Angiography was similar (unmatched OR per 1 mm increase, 1.12; 95% CI, 0.98-1.29; P for interaction = 0.83).
In a multivariable analysis, the researchers found that a more proximal occlusion site and longer thrombus length were associated with a higher likelihood of ENDi. The association of the thrombus length with ENDi did not vary across the occlusion sites. They constructed an integer rating based on the size of the regression coefficients observed in the multivariable analysis: less than 7% for ratings of 0 or 1, which accounted for two-thirds of the total sample, but more than 18% for ratings of 2 to 4, with 35% for scores of 3 or 4 have been achieved. The C statistic of the score was 0.76 (95% CI, 0.70-0.82).
Internal cross-validation based on 2000 bootstrap replicates showed a similar C statistic (0.75; 95% CI, 0.69-0.82). In the external validation cohort, the ENDi-Score showed good discrimination (C-statistic = 0.78; 95% CI, 0.70-0.86) and calibration (Hosmer-Lemeshow test, P = 0.78) ENDi to predict.
The limitations of the study included the non-direct information on whether bridging therapy is superior to IVT alone and possible selection biases due to the exclusion of 262 patients with mild stroke and LVO who were treated with first-line bridging therapy.
Ultimately, the study’s authors concluded that “the significant ENDi rates observed in these cohorts underscore the current debate over whether to transfer patients with IVT-treated stroke and LVO directly for an additional thrombectomy.” that “the simple score derived from these associations and successfully validated in an independent cohort provides good discriminatory power for the ENDi prediction, which can ultimately help clinicians make decisions”.
Disclosure: Several authors of the study have stated that they belong to the pharmaceutical industry. For a full list of the authors’ information, see the original reference.
Seners P., Ben Hassen W., Lapergue B. et al. Predicting early neurological deterioration in subjects with mild stroke and large vascular occlusion intended for intravenous thrombolysis only. JAMA Neurol. Published online January 11, 2021. doi: 10.1001 / jamaneurol.2020.4557