Matthew Edwardson, MD

Sarraj A, Albright K, Barreto AD, Boehme AK, Sitton CW, Choi J, et al. Optimizing Prediction Scores for Poor Outcome After Intra-ArterialTherapy in Anterior Circulation Acute Ischemic Stroke. Stroke. 2013

Results of recent clinical trials suggest no benefit from endovascular therapy over IV-TPA alone. The search continues to identify subgroups of patients who may respond better to endovascular therapy, thereby justifying the use of this costly but potentially beneficial intervention. To this end, Sarraj and colleagues developed the HIAT2 score to identify patients who would respond poorly to endovascular therapy regardless of recanalization rate.

The authors retrospectively selected 163 stroke patients at UT Houston with ICA or MCA occlusion who underwent intervention with IA-TPA and/or mechanical clot removal. Using logistical regression, they identified variables that predicted poor outcome to come up with the HIAT2 score: age (≤59=0, 60-79=2, ≥80 years=4), glucose (<150=0, ≥150 mg/dl=1), NIHSS (≤10=0, 11-20=1, ≥21=2) and ASPECTS (8-10=0, ≤7=3). More than 80% of patients with a HIAT2 score ≥ 5 had a poor outcome (mRS 4-6). The HIAT2 outperformed all prior scores predicting outcome following endovascular therapy.

By adding neuroimaging findings in the form of the ASPECTS to the prediction score, the HIAT2 improves our ability to identify those who will respond poorly to endovascular therapy. The HIAT2 validates what most of us were already doing in clinical practice, that is, taking patient age, exam severity, and poor prognostic signs on neuroimaging into account when selecting patients for further intervention. Considering the number of points allotted for patients with age ≥ 80, the HIAT2 also validates the practice of many centers not to consider patients ≥ 80 for endovascular therapy. Whether the HIAT2 score will change clinical management in the future remains uncertain. The HIAT2 holds promise to aid in patient selection for future clinical trials so that we can identify patients who might benefit from endovascular therapy.