Mixed results for mechanical thrombectomy alone in acute ischemic stroke
Two studies published in JAMA of mechanical thrombectomy alone vs. mechanical thrombectomy plus IV thrombolysis in patients with acute ischemic stroke contradicted each other.
In the SKIP trial, mechanical thrombectomy alone did not meet noninferiority criteria for favorable functional outcome compared with mechanical thrombectomy plus IV thrombolysis, but in the DEVT trial, it did. However, the SKIP researchers could not conclude inferiority, either.
“Together, the trial findings demonstrate that the treatment strategies of [endovascular treatment alone and of IV thrombolysis before [endovascular treatment] (when performed soon after one another at thrombectomy-capable stroke centers) yield numerically similar results” in patients with acute ischemic stroke and large-vessel occlusions, Jeffrey L. Saver, MD, professor of neurology at UCLA David Geffen School of Medicine, and Opeolu Adeoye, MD, MS, associate professor of emergency medicine and neurosurgery at University of Cincinnati Medical Center, wrote in an accompanying editorial.
For the SKIP trial, researchers randomly assigned 204 patients (median age, 74 years; 63% men) with acute ischemic stroke due to large vessel occlusion to mechanical thrombectomy alone or mechanical thrombectomy plus IV thrombolysis.
The primary endpoint of favorable outcome, defined as modified Rankin Scale score of 0 to 2 at 90 days, occurred in 59.4% of mechanical thrombectomy alone group and 57.3% of the mechanical thrombectomy plus IV thrombolysis group (difference, 2.1 percentage points; one-sided 97.5% CI, 11.4 to infinity; OR = 1.09; one-sided 97.5% CI, 0.63 to infinity; P = .18 for noninferiority).
The noninferiority margin of OR = 0.74 was not met, Kentaro Suzuki, MD, PhD, neurologist at Nippon Medical School, Tokyo, and colleagues wrote.
“However, the wide confidence intervals around the effect estimate also did not allow a conclusion of inferiority,” the researchers wrote.
There were no differences between the groups in most secondary endpoints, including 90-day all-cause mortality. However, intracerebral hemorrhage occurred less often in the mechanical thrombectomy alone group (OR = 0.5; 95% CI, 0.28-0.88; P = .02), although the groups were similar in symptomatic intracerebral hemorrhage.
For the DEVT trial, researchers assigned 234 patients (mean age, 68 years; 44% women) who presented with proximal anterior circulation intracranial occlusion stroke within 4.5 hours of symptom onset to endovascular treatment alone or endovascular treatment plus IV thrombolysis.
The trial was planned for 970 patients but was stopped early due to efficacy, Wenjie Zi, MD, neurologist at Xinqiao Hospital and The Second Affiliated Hospital, Army Medical University (Third Military Medical University), Shapingba District, Chongqing, China, and colleagues wrote.
“Different from the prior trials, this present trial excluded participants with middle cerebral artery M2 segment occlusion and used a full dose of alteplase,” Zi and colleagues wrote.
The primary endpoint of functional independence, defined as modified Rankin Scale score of 0 to 2, at 90 days occurred in 54.3% of the endovascular treatment alone group and 46.6% of the combined treatment group (difference, 7.7 percentage points; one-sided 97.5% CI, 5.1 to infinity; P for noninferiority = .003).
There were no differences in symptomatic intracerebral hemorrhage or all-cause mortality at 90 days, according to the researchers.
Saver and Adeoye wrote that the trials “have enriched the current therapeutic options, even if applying these findings to individual patients will sometimes be challenging. For stroke clinicians caring for patients with [acute ischemic stroke with large vessel occlusion], it now will sometimes be reasonable to avoid using two therapeutic approaches, pharmacologic and mechanical, and instead proceed with a single strategy of rapid direct endovascular thrombectomy.”