Severe cerebral hypovolemia on perfusion CT and lower body weight are associated with parenchymal haemorrhage after thrombolysis

Predicting Penumbra Salvage and Infarct Growth in Acute Ischemic Stroke: A Multifactor Survival Game

BACKGROUND

Effective treatment of acute ischemic stroke requires reperfusion of salvageable tissue. We investigated the predictors of penumbra salvage (PS) and infarct growth (IG) in a large cohort of stroke patients.

METHODS

In the ASTRAL registry from 2003 to 2016, we selected middle cerebral artery strokes <24 h with a high-quality CT angiography and CT perfusion. PS and IG were correlated in multivariate analyses with clinical, biochemical and radiological variables, and with clinical outcomes.

RESULTS

Among 4090 patients, 551 were included in the study, 50.8% male, mean age (±SD) 66.3 ± 14.7 years, mean admission NIHSS (±SD 13.3 ± 7.1) and median onset-to-imaging-time (IQR) 170 (102 to 385) minutes. Increased PS was associated with the following: higher BMI and lower WBC; neglect; larger penumbra; absence of early ischemic changes, leukoaraiosis and other territory involvement; and higher clot burden score. Reduced IG was associated with the following: non-smokers; lower glycemia; larger infarct core; absence of early ischemic changes, chronic vascular brain lesions, other territory involvement, extracranial arterial pathology and hyperdense middle cerebral artery sign; and higher clot burden score. When adding subacute variables, recanalization was associated with increased PS and reduced IG, and the absence of haemorrhage with reduced IG. Collateral status was not significantly associated with IG nor with PS. Increased PS and reduced IG correlated with better 3- and 12-month outcomes.

CONCLUSION

In our comprehensive analysis, multiple factors were found to be responsible for PS or IG, the strongest being radiological features. These findings may help to better select patients, particularly for more aggressive or late acute stroke treatment.

Use of MRI to predict symptomatic haemorrhagic transformation after thrombolysis for cerebral ischaemia

BACKGROUND AND OBJECTIVE

Predictors of symptomatic haemorrhagic transformation (s-HT) of cerebral ischaemia after intravenous recombinant tissue-plasminogen activator (rt-PA) were identified in studies using CT scans. We evaluated whether MRI can identify other predictors.

METHOD

We analysed predictors of s-HT in a cohort of consecutive patients who received intravenous rt-PA for cerebral ischaemia after MRI at baseline. We used receiver operating characteristic curves considering an area under the curve (AUC) of 0.70 or higher as indicating acceptable discrimination.

RESULTS

Of 944 patients, 49 patients (5.2%) developed s-HT. Clinical factors independently associated with s-HT were age (adjusted OR (adjOR) 1.03 for 1 year increase; 95% CI 1.01 to 1.05), excessive alcohol consumption (adjOR 3.13; 95% CI 1.32 to 7.42), recent transient ischaemic attack (adjOR 2.88; 95% CI 1.04 to 7.95) and baseline national institutes of health stroke scale score (adjOR 1.06 for 1 point increase; 95% CI 1.02 to 1.10). MRI predictors were vascular hyperintensities (adjOR 3.89; 95% CI 1.50 to 10.08), old infarcts (adjOR 2.01; 95% CI 1.11 to 3.66) and volume of diffusion-weighted imaging (DWI) abnormality (adjOR 1.02 for 1 cm³ increase; 95% CI 1.01 to 1.03). The only variable with an acceptable discrimination was volume of DWI abnormality (AUC 0.72; 95% CI 0.64 to 0.79), a value of 4 cm³ predicting s-HT with a 78% sensitivity and 58% specificity. Variables that can be assessed only with MRI did not predict s-HT.

CONCLUSION

Although the volume of DWI abnormality predicts s-HT, other imaging characteristics that can only be assessed with MRI were not significantly associated with s-HT. Trial registration number NCT01614080.

Perfusion CT for prediction of hemorrhagic transformation in acute ischemic stroke: a systematic review and meta-analysis

OBJECTIVE

To investigate the diagnostic performance of perfusion CT for prediction of hemorrhagic transformation in acute ischemic stroke.

METHODS

A computerized literature search of Ovid MEDLINE and EMBASE was conducted up to October 29, 2018. Search terms included acute ischemic stroke, hemorrhagic transformation, and perfusion CT. Studies assessing the diagnostic performance of perfusion CT for prediction of hemorrhagic transformation in acute ischemic stroke were included. Two reviewers independently evaluated the eligibility of the studies. A bivariate random effects model was used to calculate the pooled sensitivity and pooled specificity. Multiple subgroup analyses were performed.

RESULTS

Fifteen original articles with a total of 1134 patients were included. High blood-brain barrier permeability and hypoperfusion status derived from perfusion CT are associated with hemorrhagic transformation. The pooled sensitivity and specificity were 84% (95% CI, 71-91%) and 74% (95% CI, 67-81%), respectively. The area under the hierarchical summary receiver operating characteristic curve was 0.84 (95% CI, 0.81-0.87). The Higgins I² statistic demonstrated that heterogeneity was present in the sensitivity (I² = 80.21%) and specificity (I² = 85.94%).

CONCLUSION

Although various perfusion CT parameters have been used across studies, the current evidence supports the use of perfusion CT to predict hemorrhagic transformation in acute ischemic stroke.

KEY POINTS

• High blood-brain barrier permeability and hypoperfusion status derived from perfusion CT were associated with hemorrhagic transformation. • Perfusion CT has moderate diagnostic performance for the prediction of hemorrhagic transformation in acute ischemic stroke. • The pooled sensitivity was 84%, and the pooled specificity was 74%.