Nirali Vora, MD

Yoo A, O Zaidat O, Chaudhry Z, Berkhemer O, Ganzolez R, Goyal M, et al. Impact of Pretreatment Noncontrast CT Alberta Stroke Program Early CTScore on Clinical Outcome After Intra-Arterial Stroke Therapy. Stroke. 2014

How many times does early hypodensity or the ASPECTSscore on a patient’s CT influence your choice to pursue intra-arterial therapies? In the era post-IMS III, MR Rescue, and Synthesis, we are very careful to select the “right” patients for the cath lab. Ideally, a patient with a small infarct core (and larger mismatch) is the right patient, as evidenced by recently published DEFUSE 2. However, not all patients undergo acute MRI or perfusion imaging. Everyone does get a head CT and in those patients, where do you draw the line? Standard ASPECTS <7? ASPECTS <5?

Penumbra funded this pooled analysis of 249 patients treated with IA therapy from their single-arm Pivotal trial and post-marketing PICS registry. Yoo et al studied the relationship between modified ASPECTS score and functional independence at 90 days. Good outcomes were significantly less in ASPECTS 0-4 (5%) compared to 5-7 (38.6%) or 8-10 (46%).  One confounder was time to reperfusion, which was faster among those with better ASPECTS scores.  However, the authors report higher ASPECTs score independently predicted good outcome.

It’s hard to draw the firm conclusion that ASPECTS >5 will have good outcomes, since there was no control arm/study of patients who did not go on to IA therapy. However, I agree with the authors that this study further supports that we should NOT take patients with ASPECTS 0-4 to the cath lab due to poor outcomes (5% independent at 90 days and 55% mortality). 

Should ASPECTS 0-4 be a standard exclusion criteria in future IA studies? A quick glance at SWIFT PRIME’s exclusion criteria suggest it’s not at present. They are using the standard  >1/3 MCA territory exclusion.  Thought it’s cumbersome to ensure appropriate training, optimizing selection will be the cornerstone in the saga to prove IA therapy!