BASIS Trial: Balloon Angioplasty vs Medical (ICAS)
In patients with symptomatic 70–99% intracranial atherosclerotic stenosis, does adding submaximal balloon angioplasty to aggressive medical management reduce the 12-month composite of stroke, death, territory ischemic stroke, or revascularization compared with aggressive medical management alone? (First positive endovascular ICAS trial; experienced Chinese centers.)
Sun et al. (JAMA 2024;332(13):1059–1069) · doi:10.1001/jama.2024.12829 · 501 patients
Population
Included
- TIA within 90 days or ischemic stroke 14 to 90 days before enrollment
- 70–99% atherosclerotic stenosis of a major intracranial artery
- Age 35 to 80 years
- Symptomatic ICAS in the target territory
Eligible patients
- Age 35 to 80 years
- Transient ischemic attack within 90 days OR ischemic stroke 14 to 90 days before enrollment
- Symptoms attributed to 70% to 99% atherosclerotic stenosis of a major intracranial artery
Excluded
- Nonatherosclerotic stenosis (dissection, vasculitis, moyamoya)
- Qualifying ischemic stroke within 14 days of enrollment
- Additional criteria per the published study protocol
Lesion and mechanism
- Nonatherosclerotic cause of stenosis (dissection, vasculitis, moyamoya)
- Qualifying ischemic stroke within 14 days of enrollment
Other (per published study protocol)
- Additional criteria are described in the study protocol available with the full text in JAMA
Source: Sun X et al., JAMA 2024;332(13):1059–1069· Retrieved 2026-07-22
Primary Outcome
POSITIVE, WITH CAVEATS: First endovascular ICAS trial to beat medical therapy on its primary endpoint (4.4% vs 13.5%; HR 0.32, 95% CI 0.16–0.63; P below 0.001), but it tested submaximal BALLOON ANGIOPLASTY (not stenting), at experienced Chinese centers, and the composite includes revascularization. Procedural risk is front-loaded: 30-day stroke/death 3.2% vs 1.6%, symptomatic ICH 1.2% vs 0.4%, arterial dissection 14.5%. Not yet endorsed by AHA/ASA or ESO; awaits US or multinational replication.
Event-free at 12 Months
Study Arms
- Agent
- Submaximal balloon angioplasty (balloon undersized to the normal vessel diameter)
- Dose
- Balloon sized below the normal luminal diameter; slow, low-pressure inflation to limit dissection
- Route
- Endovascular (intracranial angioplasty), no stent placement
- Frequency
- Single procedure
- Duration
- One-time procedure; aggressive medical management continued as in the control arm
- Co-interventions
- Aggressive medical management in both arms: dual antiplatelet therapy, high-intensity statin, plus blood-pressure and risk-factor control
Submaximal angioplasty is deliberately gentler than stenting. Procedural complications occurred in 17.4%, with arterial dissection in 14.5%. 30-day stroke or death 3.2%; symptomatic ICH 1.2%. Source: Sun JAMA 2024.
- Agent
- Aggressive medical management
- Route
- Oral antiplatelet and statin plus risk-factor and lifestyle management
- Frequency
- Daily
- Duration
- Ongoing
- Co-interventions
- Dual antiplatelet therapy, high-intensity statin, plus blood-pressure and risk-factor control
Control-arm 12-month composite 13.5%; 30-day stroke or death 1.6%; symptomatic ICH 0.4%. First-line strategy for symptomatic intracranial atherosclerotic stenosis.
Safety
Symptomatic ICH
1.2%
0.4%
Balloon angioplasty vs medical management. Procedural hemorrhage risk is front-loaded.
Procedural complications (angioplasty arm)
17.4%
0%
Arterial dissection 14.5%. The medical arm had no procedure.
Trial Design
Type
- Randomized open-label trial, blinded endpoint (PROBE)
- 31 centers, China
- 1:1 allocation (submaximal balloon angioplasty + AMM vs AMM alone)
Timeline
Enrolled 2018 to 2022; final follow-up 2023
N
501
Enrollment
512 randomized, 501 analyzed (249 balloon angioplasty, 252 medical) at 31 centers in China. Enrolled Nov 2018 to Apr 2022 with 12-month follow-up. Submaximal balloon angioplasty with primary stenting avoided by design; arterial dissection occurred in 14.5%. Open-label with blinded endpoint. Published JAMA 2024.
ClinicalTrials.gov
NCT03703635Bedside Pearl
BASIS is the first randomized endovascular therapy to beat aggressive medical management in symptomatic 70–99% intracranial stenosis: the 12-month composite was 4.4% vs 13.5% (HR 0.32). It tested submaximal balloon angioplasty, not stenting, at experienced Chinese centers, with real upfront risk (30-day stroke or death 3.2% vs 1.6%, symptomatic ICH 1.2% vs 0.4%). It is not yet guideline-endorsed. Keep aggressive medical management first-line; consider balloon angioplasty only at expert centers pending replication.