BASIS Trial(2024)
Balloon Angioplasty vs Medical (ICAS)
Primary Outcome: Composite stroke/death/revascthrough 12 Months
Clinical Context
BASIS tested whether adding submaximal balloon angioplasty (without stent placement) to aggressive medical management reduces stroke in symptomatic 70–99% intracranial atherosclerotic stenosis. It enrolled patients with a TIA within 90 days or an ischemic stroke 14 to 90 days earlier at 31 experienced Chinese centers, using a strategy deliberately gentler than the initial stenting that failed in SAMMPRIS and CASSISS.
Trial Summary
Randomized open-label trial, blinded endpoint (PROBE) · 31 centers, China · 1:1 allocation (submaximal balloon angioplasty + AMM vs AMM alone) · Enrolled 2018 to 2022; final follow-up 2023
501 Analyzed (512 randomized)
Submaximal balloon angioplasty (balloon undersized to the normal vessel diameter, slow low-pressure inflation) plus aggressive medical management vs Aggressive medical management alone (dual antiplatelet therapy, high-intensity statin, plus blood-pressure and risk-factor control)
Composite stroke/death/revasc through 12 Months
4.4% with Balloon angioplasty + AMM vs 13.5% with Aggressive Medical Management (AMM) (4.4% vs 13.5%: HR 0.32; Angioplasty better: <0.001)
⚠️ Safety Profile
Balloon angioplasty vs medical management. Procedural hemorrhage risk is front-loaded.
Clinical Pearls
- 1First positive endovascular ICAS RCT: the 12-month composite of any stroke or death, territory ischemic stroke, or revascularization was 4.4% with balloon angioplasty plus medical management vs 13.5% with medical management alone (HR 0.32, 95% CI 0.16 to 0.63; P<.001).
- 2Balloon, not stent: BASIS tested submaximal balloon angioplasty without stent placement, a deliberately gentler strategy than the initial Wingspan stenting that failed in SAMMPRIS and CASSISS.
- 3Benefit held in the hard endpoint: territory ischemic stroke from 30 days to 1 year was 0.4% with angioplasty vs 7.5% with medical management, so the result does not rest on the operator-influenced revascularization component (1.2% vs 8.3%).
- 4Upfront procedural risk is real: 30-day stroke or death was 3.2% with angioplasty vs 1.6% with medical management, and symptomatic ICH was 1.2% vs 0.4%. The harm is front-loaded against a later benefit.
- 5Procedural complications 17.4%, with arterial dissection in 14.5%: submaximal technique reduces but does not eliminate vessel injury.
- 6Population: TIA within 90 days or ischemic stroke 14 to 90 days, 70–99% intracranial atherosclerotic stenosis, age 35 to 80; enrolled at 31 experienced Chinese centers.
- 7Not yet guideline-endorsed: BASIS is single-country, open-label, and operator-experienced. It does not license stenting, and it awaits US and multinational replication before it changes AHA/ASA or ESO practice. Aggressive medical management remains first-line.
Conclusion
BASIS numerically favored Aggressive Medical Management (AMM) over Balloon angioplasty + AMM for Composite stroke/death/revasc through 12 Months (13.5% vs 4.4%). Even with a complex trial design, the clinical takeaway is caution against adopting the intervention as a new default.
Source: Sun et al. (JAMA 2024;332(13):1059–1069)
Trial Design
- •Randomized open-label trial, blinded endpoint (PROBE)
- •31 centers, China
- •1:1 allocation (submaximal balloon angioplasty + AMM vs AMM alone)