Balloon Angioplasty ‘Lite’ Improves Key Intracranial Stenosis Outcomes

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Trial from China provides proof-of-concept for stroke risk reduction in symptomatic cases

by
Crystal Phend, Contributing Editor, MedPage Today

September 5, 2024

Submaximal balloon angioplasty for symptomatic intracranial atherosclerotic stenosis (ICAS) improved outcomes over aggressive medical management alone, the BASIS trial from China showed.

The incidence of the composite of any stroke or death within 30 days or any ischemic stroke or revascularization of the qualifying artery from 30 days to 12 months after enrollment was lower with the procedure compared with medical management alone (4.4% vs 13.5%; HR 0.32, 95% CI 0.16-0.63, P<0.001).

Even when excluding the softer endpoint of revascularization from that composite endpoint, the procedure held the advantage (3.6% vs 9.1%; HR 0.39, 95% CI 0.18-0.85), reported Zhongrong Miao, MD, PhD, of Beijing Tiantan Hospital in China, and colleagues in JAMA.

“Although the study has limitations, the results provide important proof-of-concept evidence that endovascular treatments still have the potential to improve stroke risk in ICAS,” wrote Tanya Turan, MD, MSCR, of the Medical University of South Carolina in Charleston, and Colin Derdeyn, MD, of the University of Virginia in Charlottesville, in an accompanying editorial.

“Prior endovascular trials comparing percutaneous angioplasty and stenting with medical therapy failed largely due to unacceptably high rates of periprocedural complications, primarily ischemic stroke and brain hemorrhage,” they explained.

And indeed, BASIS showed that angioplasty with a smaller-diameter balloon and no stenting paid a price in early events, with 3.2% of patients having any stroke or death from any cause within 30 days compared with 1.6% in the medical therapy-alone group.

While the editorialists called that an acceptable rate, the researchers noted that it’s a risk that “should be considered in clinical practice.”

In addition, 17.4% of patients in the balloon angioplasty group had procedural complications, and 14.5% had arterial dissection. Symptomatic intracranial hemorrhage occurred in 1.2% compared with 0.4% in the medical management group.

“Submaximal balloon angioplasty without stenting has long been proposed as a ‘gentler’ procedure that results in less trauma to the arterial wall but provides sufficient reduction of stenosis to potentially restore flow and reduce the risk of recurrent stroke,” Turan and Derdeyn noted. Many of those strokes after angioplasty and stenting are from local perforator occlusion, which submaximal angioplasty may address, along with lower hemorrhage risk from the smaller-diameter balloon, fewer devices, and less manipulation.

The trial included 512 adults ages 35 to 80 from 31 centers across China who had an ischemic stroke in the prior 14 to 90 days or a transient ischemic attack (TIA) within 90 days due to severe ICAS (70% to 99% stenosis of a major intracranial artery) and who were on treatment with at least one antithrombotic drug or standard risk factor management.

Aggressive medical management included 100-mg aspirin daily for the duration of follow-up; clopidogrel 75 mg daily for the first 90 days, or ticagrelor (Brilinta) or cilostazol (Pletal) for patients with clopidogrel resistance; and risk factor management, including blood pressure control to 140/90 mm Hg, a low-density lipoprotein cholesterol target under 70 mg/dL, and a hemoglobin A1C target under 7.0% for those with diabetes, along with smoking cessation and physical activity.

The balloon angioplasty group was recommended to undergo the procedure with a dedicated intracranial balloon under general anesthesia with the Neuro RX and Neuro LPS devices (approved in China but not the U.S.) inflated to a balloon diameter 50% to 70% of the proximal artery diameter.

Driving the primary endpoint benefits with balloon angioplasty were lower rates of any ischemic stroke in the qualifying artery territory past 30 days through 1 year after enrollment (0.4% vs 7.5%) and less revascularization of the qualifying artery in that same timeframe (1.2% vs 8.3%).

The editorialists noted that revascularization is a controversial component “because it is typically performed for a TIA, and the decision to perform revascularization in this setting is subjective, which is particularly problematic in an unblinded trial.”

They also cautioned that aspects of the study design might have biased the results in favor of the angioplasty group, including exclusion of patients with ischemic stroke within the first 2 weeks after the qualifying event to decrease the risk of periprocedural complications despite the “very high” early recurrent stroke risk in this population, as well as inclusion of a large proportion of patients presenting with border zone infarcts, suggesting hypoperfusion as the mechanism of stroke.

The editorialists also pointed to generalizability questions raised by participation requirement for “very experienced” centers with an annual volume of at least 50 angioplasty cases, but uneven enrollment of more than half of the patients at the main site, while one-third of the remaining sites enrolled only one patient each.

The primary endpoint rate in the balloon angioplasty group was lower at that main center than the rest combined (2.9% vs 6.3%), suggesting “either neurointerventionist or clinical site experience likely played an important role in the low event rate in the angioplasty group,” Turan and Derdeyn wrote. “Therefore, it remains to be seen whether angioplasty would be superior to medical therapy alone if studied in an international cohort with a lower prevalence of ICAS and less ICAS angioplasty experience.”

They called for additional studies comparing angioplasty with medical therapy in high-risk patients, particularly in more diverse populations, noting that this is “imperative before angioplasty is widely adopted as an alternative treatment for ICAS in the U.S. and worldwide.”