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Outcomes after stroke thrombectomy were not better with tissue plasminogen activator (tPA) withheld, according to the trial.

Of more than 500 acute stroke patients with large vessel occlusion (LVO), those randomized to endovascular therapy (EVT) alone did not meet criteria for superior functional outcomes on the modified Rankin Scale (mRS) at 90 days compared with those getting IV thrombolysis on top of EVT (adjusted common OR 0.88, 95% CI 0.65-1.19).

In fact, direct EVT failed to meet noninferiority as the lower 95% CI bound crossed 0.8, reported Yvo Roos, MD, PhD, of Academic Medical Center Amsterdam, during a late-breaking scientific session at the American Stroke Association's International Stroke Conference.

Moreover, 90-day functional independence (mRS 0-2) was numerically lower among people getting EVT without lytics (adjusted OR 0.95, 95% CI 0.65-1.40).

"Thus, [I] don't see much evidence to change current practice of IV thrombolytics prior to EVT for patients who come directly to [thrombectomy-capable] sites. And certainly thrombolytics are critical at those hospitals where transfer to thrombectomy center is going to take some time," said Joseph Broderick, MD, of University of Cincinnati, who was not involved with the trial.

Broderick called MR CLEAN-NO IV a "well-done" trial that adds the highest-quality evidence yet to the literature on ; results have been inconclusive based on the earlier DEVT, SKIP, and DIRECT-MT studies.

During the same ISC session, the SHRINE study, which pooled individual patient-level data from the DEVT and SKIP trials, was shown to have come close but ultimately failed to demonstrate noninferiority of direct thrombectomy over the bridging strategy.

Nevertheless, the SHRINE group cautioned against a one-size-fits-all approach, and identified people with atrial fibrillation, time to puncture over 3 hours, and intracranial internal carotid artery occlusions as the subgroups most likely to benefit from EVT without tPA bridging.

As for safety, taking away IV alteplase in MR CLEAN-NO IV made no difference in intracerebral hemorrhage (ICH; 35.9% vs 36.4%, adjusted OR 0.99, 95% CI 0.70-1.41) or symptomatic ICH (5.9% vs 5.3%, adjusted OR 1.31, 95% CI 0.61-2.84). Mortality rates were also similar between groups (20.5% vs 15.8%, adjusted OR 1.39, 95% CI 0.84-2.30).

Study investigators were part of the original MR CLEAN group that had reported the clinical benefit of EVT on top of IV alteplase in 2014.

MR CLEAN-NO IV was conducted at multiple centers across France and the Netherlands from 2018 t0 2020. Investigators randomized 547 people, all tPA- and EVT-eligible, to IV alteplase followed by EVT (0.9 mg/kg) or thrombectomy alone. The final analysis included the 539 people who consented to participate in the study.

Between the two groups, median age was about 70, and more than half were men.

Median stroke onset to randomization time was just over 90 minutes among both direct EVT and usual care arms; stroke onset to groin puncture took 130 minutes without alteplase and 135 minutes with the lytic.

Broderick said that tPA's delay of only 5 minutes suggests "they didn't waste any time giving them lytics," which is "very good and makes me confidant in trial results."

In the study, EVT operators trended towards less successful reperfusion with direct EVT (78.3% vs 83.1%, adjusted OR 0.72, 95% CI 0.45-1.13). NIH Stroke Scale scores separated after 24 hours to also favor the tPA-EVT combination (3 vs 5 after 5-7 days or at discharge).

Although MR CLEAN-NO IV was conducted in Europe, the results may be expected to apply to U.S. stroke centers, Broderick speculated.

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