Identifying Patients at High Risk for Poor Outcome After Intra-Arterial Therapy for Acute Ischemic Stroke

Abstract

Background Intra-arterial recanalization therapy (IAT) is increasingly utilized for acute stroke. Despite high rates of recanalization the outcome is variable. We attempted to identify predictors of outcome that will enable better patient selection for IAT. Methods All patients who underwent IAT at the UT Houston Stroke Center were reviewed. Poor outcome was defined as modified Rankin Scale score 4–6 on hospital discharge. Findings were validated in an independent dataset of 175 patients from UCLA Stroke Center Results 190 patients were identified. Mean age 62, median baseline NIHSS .18. Recanalization rate 75%, symptomatic hemorrhage rate 6%, and poor outcome rate 66%. Variables associated with poor outcome were: age, baseline NIHSS, admission glucose, diabetes, heart disease, previous stroke and the absence of mismatch on the pre-treatment MRI. Logistic regression identified three variables independently associated with poor outcome: age (p=0.049, OR=1.028), NIHSS (p=0.013, OR=1.084), admission glucose (p=0.031, OR=1.011). Using this data, we devised the Houston IAT (HIAT) score: 1 point for age>75; 1 for NIHSS>18 and 1 point for glucose>150mg/dL (range 0 to 3). The percentage of poor outcome by HIAT score was: score of 0: 44%; 1: 67%; 2: 97%; 3: 100%. Recanalization rates were similar across the scores (p=0.4). Applying HIAT to the external cohort showed comparable trends in outcome and nearly identical rates in the HIAT 3 tier. Conclusions The HIAT score estimates the chances of poor outcome after IAT even with recanalization. It may be useful in comparing cohorts of patients and when assessing the results of clinical trials.

Predicting Long-Term Outcome after Endovascular Stroke Treatment: The Totaled Health Risks in Vascular Events Score

“…When DM was replaced in the above analyses with admission hyperglycemia (glucose Ͼ 150 mg/dL 9 ) the results were not substantially altered (data not shown).…”

“…Because other studies have found that hyperglycemia on initial glucose measurement at acute stroke presentation is associated with poor outcome after endovascular stroke treatment, 9 we also examined whether admission hyperglycemia yielded different results from a history of DM. When DM was replaced in the above analyses with admission hyperglycemia (glucose Ͼ 150 mg/dL 9 ) the results were not substantially altered (data not shown).…”

“…13 A 3-point score encompassing age, NIHSS, and admission hyperglycemia that predicts poor outcome by the time of hospital discharge was recently developed and validated. 9 Of the 3 variables included in this score, age and NIHSS are included in the THRIVE score, and admission hyperglycemia was found to have an effect in the CDS similar to a Age trichotomized as shown in Table 4. b NIHSS trichotomized as shown in Table 4.…”

Improving patient selection for endovascular treatment of acute cerebral ischemia: a review of the literature and an external validation of the Houston IAT and THRIVE predictive scoring systems

“…Researchers from Houston and UCLA developed the HIAT score, which is composed of 3 factors found to be significant and independent predictors of patient outcome subsequent to IAT regardless of patient recanalization status: age, NIHSS score, and admission glucose level. 26 Patients treated with IAT at the University of Texas Houston Stroke Center were retrospectively assigned 1 point for each of the following factors: age > 75 years, NIHSS score > 18, and glucose level > 150 mg/dl. The median NIHSS score for good outcome was 16, while the median NIHSS score for poor outcome was 20.…”

“…As previously mentioned, the authors of the HIAT study found that the median baseline NIHSS score for patients with good outcomes after IAT was 16, while the median baseline NIHSS score for poor outcomes was 20; the rate of recanalization did not differ significantly between the good and poor outcome groups (p = 0.4). 26 The THRIVE score author group trichotomized NIHSS scores (≤ 10, 11-20, and ≥ 21) and concluded that the breakdown of the scale could effectively predict those very likely, moderately likely, and least likely to experience good outcome subsequent to endovascular stroke treatment, respectively. 20 Yet another analysis reports that patients who experienced futile recanalization, defined as successful removal of the thrombus without corresponding clinical improvement, had higher median baseline NIHSS scores (19) compared with those with nonfutile recanalization pursuant to IAT (14).…”