Endovascular Therapy for Stroke: What Has Changed?

Last week’s International Stroke Conference (ISC) in Nashville, TN, renewed hopes that endovascular therapy for stroke can work.

No fewer than 3 trials—ESCAPE, EXTEND-IA, and SWIFT PRIME—came down in favor of the treatment. Specifically, they found that adding mechanical thrombectomy to IV thrombolysis alone for acute ischemic stroke caused by large proximal intracranial occlusions improved both reperfusion and functional outcomes. Additional subanalyses of prior trials provided some clarity about the influence of stroke severity, time to reperfusion, and anesthesia type. 

But clinical practice does not occur within the confines of a trial. Many of the same obstacles for endovascular therapy that existed nearly 2 years ago in late 2013, when I made an ill-fated attempt to write a TCTMD feature on the topic, continue to exist today. 

At the time, the larger endovascular “story” felt unfinished, and I struggled with how to express that uncertainty. IMS III, MR RESCUE, and SYNTHESIS Expansion all were published in the New England Journal of Medicine and presented at ISC 2013, and all were negative. Sources I spoke with said that delays to treatment might be to blame as well as the use of outdated devices and inclusion of patients for whom intervention is futile. 

Stroke itself also presents challenges, they stressed.

It is hard to quickly and definitively select stroke patients for endovascular therapy. Stroke is much more heterogeneous than ACS, including MI, and its lesions can be harder to access. While ECGs are common and familiar, the imaging needed to diagnose stroke is less straightforward and requires dedicated software. Finally, stroke patients—often not in pain—may be less likely to seek prompt medical care than MI patients. 

In short, we do not know for sure either how or who to treat, I was told. Not only that, but there are systemic challenges—patients must quickly reach the correct hospital, and the center’s endovascular team must be ready for them. 

Reacting to the ISC 2015 news in a recent blog post, neurologist Mark N. Rubin, MD, of the Mayo Clinic (Scottsdale, AZ), spoke to the clinical challenges of endovascular stroke care: “How many of our patients are premorbid [modified Rankin scale] 0-1, onset to treatment 110 minutes? Is that your average patient? Do you routinely get acute noninvasive angiography, let alone score collaterals, in your acute stroke patients? Can you mobilize your endovascular team within 1 hour of counseling/trial enrollment? Do you have software that provides you with a discrete visual and numerical representation of the penumbra? Do you only see anterior circulation strokes? What of the many, many patients [who] do not fall within the careful clinical and neuroimaging selection criteria of these trials?” 

I, too, feel skeptical. When doubting the findings of research studies, we cite their limitations. When welcoming positive results, we tend to downplay what is required to bring the right therapy to the right patient at the right time. 

What has changed in the past 2 years? Aside from our enthusiasm for promising data, are we any more ready to be using these devices?