Rohan V, Baxa J, Tupy R, Cerna L, Sevcik P, Friesl M, et al. Length of Occlusion Predicts Recanalization and Outcome After Intravenous Thrombolysis in Middle Cerebral Artery Stroke. Stroke. 2014
In a recent article, Rohan et al explore predictors of successful IV-tPA recanalization and outcome in patients with proximal MCA occlusion as measured by 4D CTA imaging. They looked at 80 patients with M1-M2 occlusion (the majority had isolated M1 occlusions), calculated the length of the occlusion, recorded the NIHSS at presentation and at 24 hours after tPA and assessed clinical outcome at three months using the mRS (favorable outcome=mRS 0-2). Successful recanalization was defined as a TIMI grade 2 or 3. With univariate analysis, they found that a lower baseline NIHSS, length of occlusion and ASPECTS score were significant predictive factors of favorable outcome. In multivariate analysis, only baseline NIHSS and length of occlusion in the M1 segment were significant independent predictors of favorable outcome.
I really enjoyed this article. It speaks to our desire to improve our practice and deliver better care. We’ve been administering IV-tPA to treat acute stroke for years but we’re still learning about how it performs in different situations. We are facing a newer, similar challenge in the endovascular world: trying to identify the patients who will benefit most from the interventional reperfusion. Overall, the results of this study are not surprising: patients with better NIHSS, smaller lengths of occlusion and less area of ischemia benefit more from IV-tPA than their counterparts.
One of the limitations of the study is that it cannot be applied at the bedside at this point. The imaging modalities used to determine the length of the occlusion are not yet feasible or practical in the acute setting. Even if we know the length of the occlusion at the time we’re considering administering tPA , it would most likely not affect our decision as to whether or not to give the medication. But, just as meaningfully, knowing the relationship between occlusion length, IV-tPA and clinical outcome with more certainty would surely help us when speaking with patients and families about potential outcomes and expectations.
It’s important to constantly evaluate how we can deliver care more effectively and this article is an example of that pursuit. It brings up an interesting topic and although the results are not yet ready for prime-time clinical use, as more information is gathered, it may factor into our treatment decisions and it will certainly factor in to our discussions with patients and their families.