Postthrombolysis hemorrhage risk is affected by stroke assessment bias between hemispheres

Stroke Laterality Did Not Modify Outcomes in the HERMES Meta-Analysis of Individual Patient Data of 7 Trials

Background and Purpose—

There is contradictory evidence on the impact of the stroke side (hemisphere) on outcomes. We investigated any effect modification by laterality on stroke patients’ outcomes in recent endovascular trials.

Methods—

Individual patient-level data were combined in this meta-analysis of all patients included in randomized trials comparing endovascular thrombectomy predominantly done with stent retrievers with standard care in anterior circulation ischemic patients with stroke (HERMES [Highly Effective Reperfusion Using Multiple Endovascular Devices] Collaboration). We stratified the 90-day functional outcome assessed by ordinal analysis of the modified Rankin Scale according to the stroke side of patients treated with endovascular therapy versus standard care, adjusted for important prognostic variables.

Results—

The meta-analysis included 1737 patients (871 right hemispheric strokes and 866 left hemispheric) from 7 trials. Baseline median National Institutes of Health Stroke Scale scores were significantly higher in left (20) versus right (16) hemispheric strokes ( P <0.001). Other clinical and radiological baseline characteristics were similar. The beneficial response to endovascular therapy assessed by 90-day modified Rankin Scale shift was not modified by the side of the stroke. There were no significant differences between right and left hemispheric stroke in the 90-day functional outcome (modified Rankin Scale score ≤2; 40.7% [95% CI, 37.4%–44.1%] versus 37.6% [95% CI, 37.4%–44.1%]; P =0.19), median final infarct volumes (45 versus 39.5 mL, P =0.51), nor 90-day mortality (15.1% vs 16.8%, P =0.31).

Conclusions—

Stroke side was not a prognostic factor and did not modify the treatment effect among patients treated in the endovascular or control groups in recent endovascular thrombectomy trials.

The Association between Diffusion MRI-Defined Infarct Volume and NIHSS Score in Patients with Minor Acute Stroke

BACKGROUND

Prior studies have shown a correlation between the National Institutes of Health Stroke Scale (NIHSS) and stroke volume on diffusion weighted imaging (DWI); data are more limited in patients with minor stroke. We sought to determine the association between DWI lesion(s) volume and the (1) total NIHSS score and (2) NIHSS component scores in patients with minor stroke.

METHODS

We included all patients with minor stroke (NIHSS 0-5) enrolled in the Stroke Warning Information and Faster Treatment study. We calculated lesion(s) volume (cm³ ) on the DWI sequence using Medical Image Processing, Analysis, and Visualization (MIPAV, NIH, Version 7.1.1). We used nonparametric tests to study the association between the primary outcome, DWI lesion(s) volume, and the predictors (NIHSS score and its components).

RESULTS

We identified 894 patients with a discharge diagnosis of minor stroke; 709 underwent magnetic resonance imaging and 510 were DWI positive. There was a graded relationship between the NIHSS score and median DWI lesion volume in cm³ : (NIHSS 0: 7.1, NIHSS 1: 8.0, NIHSS 2: 17.1, NIHSS 3: 11.6, NIHSS 4: 19.0, and NIHSS 5: 23.6, P < .01). The median lesion volume was significantly higher in patients with neglect (105.6 vs. 12.5, P = .025), language disorder (34.6 vs. 11.9, P < .001), and visual field impairment (185.6 vs. 11.6, P < .001). Other components of the NIHSS were not associated with lesion volume.

CONCLUSION

In patients with minor stroke, the nature of deficit when used with the NIHSS score can improve prediction of infarct volume. This may have clinical and therapeutic implications.

Oxfordshire Community Stroke Project classification improves prediction of post-thrombolysis symptomatic intracerebral hemorrhage

Background

The Oxfordshire Community Stroke Project (OCSP) classification is a simple stroke classification system with value in predicting clinical outcomes. We investigated whether and how the addition of OCSP classification to the Safe Implementation of Thrombolysis in Stroke (SITS) symptomatic intracerebral hemorrhage (SICH) risk score improved the predictive performance.

Methods

We constructed an extended risk score by adding an OCSP component, which assigns 3 points for total anterior circulation infarcts, 0 point for partial anterior circulation infarcts or lacunar infarcts. Patients with posterior circulation infarcts were assigned an extended risk score of zero. We analyzed prospectively collected data from 4 hospitals to compare the predictive performance between the original and the extended scores, using area under the receiver operating characteristic curve (AUC) and net reclassification improvement (NRI).

Results

In a total of 548 patients, the rates of SICH were 7.3% per the National Institute of Neurological Diseases and Stroke (NINDS) definition, 5.3% per the European-Australasian Cooperative Acute Stroke Study (ECASS) II, and 3.5% per the SITS-Monitoring Study (SITS-MOST). Both scores effectively predicted SICH across all three definitions. The extended score had a higher AUC for SICH per NINDS (0.704 versus 0.624, P = 0.015) and per ECASS II (0.703 versus 0.612, P = 0.016) compared with the SITS SICH risk score. NRI for the extended risk score was 22.3% (P = 0.011) for SICH per NINDS, 21.2% (P = 0.018) per ECASS II, and 24.5% (P = 0.024) per SITS-MOST.

Conclusions

Incorporation of the OCSP classification into the SITS SICH risk score improves risk prediction for post-thrombolysis SICH.