Intracerebral hemorrhage (ICH) in patients with non-valvular atrial fibrillation (NVAF) poses a particular dilemma for thromboprophylaxis. Left atrial appendage occlusion (LAAO) is a non-pharmacological approach to prevent cardiac embolism in NVAF. The risk-benefit ratio of LAAO in patients with NVAF after ICH is unknown. The aim of STROKECLOSE is to assess the effect of LAAO to reduce the incidence stroke, bleeding and cardiovascular mortality in patients with NVAF and prior ICH.

Methods/design: A multicenter prospective randomized open-label clinical trial with blinded outcome evaluation (PROBE design) and blinded safety outcome assessment. The active comparison LAAO is tested against medical therapy in a 2:1 stratified randomization.

Study population: Patients should have had an ICH within 12 months prior to enrollment and have NVAF with increased risk of stroke or systemic embolism, as indicated by a CHA2DS2VASc score >2. In total 750 patients will be included. Active enrollment ensues over 3 years followed by 5 years follow-up and a long-term follow-up at 10 years.

Intervention and control: The intervention group will be treated by LAAO, using the Amplatzer Amulet device. Implantation requires a catheterization procedure using venous access and transseptal puncture and is guided by angiography, fluoroscopy and transesophageal echocardiography (TEE) or intracardiac echocardiography (ICE). Recommended post-implant antithrombotic therapy includes aspirin (ASA) therapy for at least 6 months, with or without clopidogrel for the first 45 days after implantation. The control group will receive medical therapy, delivered according to national standards and guidelines at the treating physicians' discretion. This may include oral anticoagulation (OAC) (vitamin-K antagonists, VKA), non-VKA OAC, antiplatelet therapy or no antithrombotic therapy at all.

Main study outcomes: The primary outcome is the composite endpoint of stroke (ischemic and hemorrhagic), systemic embolism, life-threatening or major bleeding and all-cause mortality, assessed over at least two years. Secondary outcome examines various early and late safety outcome parameters.

Inclusion Criteria:

• A diagnosis of paroxysmal, persistent or long-standing NVAF with CHA2DS2VASc score >2.
• Clinical and CT/MRI evidence of ICH within 12 months but not less than 4 weeks prior to enrollment.
• Age > 18 years.
• Signed informed consent.

Exclusion Criteria:

• ICH secondary to vascular malformation or tumors
• Estimated life expectancy of less than 1 year at eligibility assessment
• mRS > 3 at enrollment
• Prior surgical LAA excision
• Planned combined interventional procedures at the time of enrollment

The full study protocol, statistical plan and informed consent form will be publicly available when results are published. Data will be available on patient level; data will be pseudonymized. The full dataset will be available upon request.

Starting after publication and for 36 months.

A full description of the intended use of the data must be sent to the corresponding author for review and approval. Participant consent for data sharing is conditioned and new ethics approval may be required.