Subgroup analysis based on the main study (NCT05692882), not registered separately.

This study is a prospective, multicenter, open-label, randomized controlled clinical trial, aims to assess the clinical non-inferiority of 3 months (short-term) vs 6 months (long-term) of Dual Anti-Platelet Therapy (DAPT) in patients after implanted NOVA intracranial sirolimus-eluting stent system. All participants met the inclusion criteria will be 1:1 randomized to 3 months or 12 months of DAPT at index procedure.

This study will recruit 478 subjects with intracranial atherosclerotic stenosis (ICAS) in China. All participants met the inclusion criteria will be 1:1 randomized to 3 months or 6 months of DAPT after implanting NOVA stent. Clinical follow-up will be carried out at 30 days, 3 months, 6 months, 12 months, 1 year, 2 years, 3 years, 4 years and 5 years after index procedure. The primary endpoint is the composite endpoint of any stroke, death and major bleeding (intracranial or systemic bleeding requiring hospitalization, blood transfusion or surgery) at 1 year.

Inclusion criteria

1. Males or females between 35 and 80 years of age.
2. Symptomatic intracranial arteriosclerosis stenosis with reference diameter 2.25-4.00mm;.
3. Intracranial artery stenosis (≥70%) conformed by DSA.
4. Subjects who voluntarily participate in the study and sign informed consent form.

Exclusion Criteria:

1. Subjects who have surgery within previous 30 days or plan to perform major surgery in the next 90 days (surgery grade 3 and above).
2. Subjects of acute hemorrhagic stroke within 3 months.
3. Disabling stroke with a baseline mRS score ≥3.
4. Lesion artery with severe calcification and close neighbour stenosis.
5. Non-atherosclerotic diseases (e.g. arterial dissection, Moya Moya disease, vascular inflammatory lesions caused by infection, autoimmune diseases, post-irradiation, postpartum status; developmental or genetic abnormalities such as fibromuscular dysplasia, sickle cell anemia, suspected vasospasm).
6. The ischaemic event that is highly suspected to be due to vascular embolism from an extracranial arterial segment such as ipsilateral neck/chest arterial occlusion) or cardio embolism such as atrial fibrillation, mitral stenosis, left ventricular thrombus, patent foramen ovale, myocardial infarction within 6 weeks, etc.
7. More than 50% stenosis of the supplying artery of the lesion artery: 1) MCA severe stenosis (lesion artery) with more than 50% stenosis of ipsilateral ICA (supplying artery). 2) Basilar artery severe stenosis (lesion artery) with more than 50% stenosis of dominant VA (supplying artery) stenosis.
8. Accompanied by intracranial tumours or intracranial arteriovenous malformations.
9. The patient who is allergy response to heparin, aspirin, clopidogrel, rapamycin, contrast agents, anaesthetics, or drug eluted stent components.
10. Women who are pregnant or lactating.
11. Due to cognitive or emotional disorders or mental illness, the patient who cannot finish the follow-up.
12. Investigators consider the patient who is not suitable for enrolling in the present trial.