Highly Anticipated COMPASS Results Boost Aspiration for Acute Ischemic Stroke

LOS ANGELES, CA—Using the direct aspiration first pass technique (ADAPT) provides patients with functional outcomes that are noninferior to those achieved by using stent retrievers as a frontline approach in the setting of acute ischemic stroke caused by large-vessel occlusions, the COMPASS trial shows.

Other variables, including safety and time to and quality of reperfusion, were shown to be similar with each strategy, with information on cost—which is expected to be lower with aspiration—forthcoming, J Mocco, MD (Mount Sinai Hospital, New York, NY), reported at the International Stroke Conference here.

“With ASTER and COMPASS now, I believe there’s . . . level I evidence that stent retrievers and primary aspiration have noninferior clinical outcomes in the treatment of [large-vessel occlusion],” Mocco said during his presentation. “I think that both are important and valuable therapies for our patients, and I hope that it’s counted as a real positive that our physicians have the option to use the therapy that they think is best for their patients.”

Several recent trials have demonstrated that mechanical thrombectomy on top of standard medical therapy improves functional outcomes in patients with acute strokes caused by large-vessel occlusions, with recent evidence emerging that the benefit can be achieved up to 24 hours after stroke onset in carefully selected patients.

Most patients in those studies were treated with stent retrievers, but there are some data indicating that similar results can be achieved with aspiration alone. The randomized ASTER and Penumbra Separator 3D trials, for example, have both shown that comparable results could be achieved with either ADAPT or stent retrievers. Smaller studies have suggested that using aspiration alone as a first-line approach can reduce procedure time and costs, he said.

I hope that it’s counted as a real positive that our physicians have the option to use the therapy that they think is best for their patients. J Mocco

The COMPASS trial was designed to see whether using ADAPT would prove to be noninferior to stent retrievers. Conducted at 15 centers, the trial enrolled 270 patients with acute ischemic strokes caused by large-vessel occlusions in the anterior circulation who could be treated within 6 hours of symptom onset with any US Food and Drug Administration-approved thrombectomy device. When the study was conducted, the only commercially available aspiration system was Penumbra’s, with Medtronic’s Riptide system gaining approval just last month.

Mocco said the trial results—which became available to the investigators only 3 days ago—included one patient who might have to be excluded from the final analysis due to an issue with consent; the situation is still being investigated.

In terms of procedural characteristics, there was a high rate of concomitant use of distal aspiration in the stent-retriever arm (85%). Roughly one in every five patients in the aspiration arm (21%) were treated with a stent retriever at some point. Mocco noted that just over 80% of patients in each study arm achieved at least TICI 2b reperfusion using the assigned modality.

The primary efficacy outcome was functional independence at 90 days, defined as a modified Rankin Scale score of 0 to 2. That was achieved by 49% of patients in the stent retriever arm and 52% of those in the ADAPT arm, a difference that met criteria for noninferiority (P = 0.0014).

Secondary outcomes included the distribution of mRS scores at 90 days, achievement of TICI 2c or greater or TICI 3 or greater reperfusion within 45 minutes of puncture, and the time from puncture to TICI 2b or greater; although there were some hints of an advantage for aspiration, there were no significant differences between trial arms. Similarly, no between-group differences were seen in final TICI scores.

Safety endpoints—including all-cause mortality and total and symptomatic intracranial hemorrhages—occurred at nearly identical rates with aspiration or stent retrievers.

Expanding Options

At a press conference, Mocco said that there is room for both aspiration systems and stent retrievers in acute stroke therapy.

“All of these tools are helpful. The question is: what do you start with? Do you have to open the stent retriever or not? And what COMPASS unequivocally shows is that you don’t have to open the stent retriever,” he said, noting, however, that stent retrievers still were required in about 20% of cases started with aspiration. “This isn’t about reducing options. It’s about expanding and giving physicians the ability to choose between their options.”

Choosing between aspiration or stent retrievers as a frontline approach could come down to anatomy in some cases and to physician experience and preference in others.

During the press conference, American Stroke Association spokesperson Ralph Sacco, MD (University of Miami, FL), a former president of the American Heart Association, noted that clot composition could be a deciding factor. If the stroke is cardioembolic and there is a fresh clot, aspiration might be better, but if the stroke is due to atherosclerotic disease and there is a fibrous clot, a stent retriever might be better, he said, adding that further studies are needed to work those issues out.

Aspiration is expected to be less costly when compared with stent retrievers, and multiple experts raised that as a consideration when choosing between the two approaches, which have been shown to provide similar outcomes.

Maarten Lansberg, MD, PhD (Stanford University, CA), indicated that a cost benefit could be especially important in parts of the world with fewer resources than in the United States.

“The ability maybe to provide this treatment in countries outside of the US, where cost may be even more of an issue than here to provide this treatment to more patients who may have to pay cash for this type of treatment, is a real opportunity,” he said.

A cost analysis tied to COMPASS is ongoing, Mocco said.