Prospective, single-center, clinical registry of patients with symptomatic/critical carotid artery stenosis at risk of stroke coexisting with unstable or multivessel severe coronary artery disease and/or severe valvular heart disease undergoing endovascular treatment of carotid atherosclerosis using a mesh stent in combination with cardiac surgery (coronary artery bypass grafting (CABG) and/or valve surgery). A study involving clinical data evaluation of truly simultaneous treatment outcomes in patients deemed to require carotid revascularization at the time of surgical cardiac intervention (single-stage, simultaneous treatment). An open-label study, without randomization - a single arm study.

Academic Registry - scientific activity of the Faculty of Medicine, Collegium Medicum, Jagiellonian University and John Paul II Hospital.

The coexistence of symptomatic or unstable stroke-threatening carotid atherosclerotic stenosis with cardiac disease requiring urgent / fast-track cardiac surgery (such as advanced unstable or multivessel coronary artery disease, recent myocardial infarction or pulmonary edema, severely impaired myocardial contractility, and/or severe valvular disease requiring surgical treatment) represents a major medical and therapeutic/logistics challenge.

According to current guidelines, in absence of prospective randomized evidence, the most appropriate management strategy for a given patient should be determined by a multispecialty team. In hemodynamically compromised patients sequential treatment (i.e., first carotid stenosis repair followed by surgery or first cardiac surgery followed by carotid stenosis treatment, either surgical or endovascular) is associated with a high risk of cardiac complications in case of first-stage carotid stenosis treatment and a high risk of neurological complications in case of the first-stage cardiac surgery.

In this challenging patient group, we have introduced single-stage, truly simultaneous procedure. The fundament of the strategy is to establish extracorporeal circulation back-up ("CEC standby") prior to the minimally invasive (endovascular) treatment of stroke-threatening carotid artery stenosis in the hybrid room under single anesthesia.

For CAS (proximal or distal protected), in case of suboptimal femoral access (or lack of femoral access), a direct access via carotid artery is used (transcervical or transcarotid revascularization), this is immediately followed by cardiac surgery.

The procedure, each time, follows recommendation of the Multispecialty Team (Heart Team + NeuroVascular Team) as the lowest-deemed risk management in patients with indications for both urgent both carotid revascularization and cardiac surgery. Both carotid and cardiac treatment are performed under single anesthesia with the feasibility of immediate extracorporeal circulation support during carotid revascularization in case of hemodynamic collapse.

Eligibility for treatment is based on the decision (recommendation) of a multidisciplinary Heart Team along with a NeuroVascular Team consisting of a cardiac surgeon, cardiologist, anesthesiologist, angiologist, neurologist, and vascular surgeon, with the concomitant use of routine pharmacotherapy and non-pharmacological prevention - according to current guidelines.

Inclusion Criteria:

• Patients eligible for concomitant carotid artery stenting in conjunction with cardiac surgery based on Heart Team and NeuroVascular Team reccomendation and according to local standards of practice.
• Signed informed consent form
• Consent to (routinely performed in this group of patients) follow-up visits and tests performed (routinely) during long-term follow-up
• De novo atherosclerotic lesions or neo-atherosclerosis.
• Symptomatic patients (with a history of ipsilateral transient cerebral ischemia, stroke or amaurosis fugax within the past 6 months) with carotid artery stenosis ≥50% as assessed by NASCET angiography or
• Asymptomatic patients with carotid artery stenosis ≥70-80% as assessed by angiography (NASCET method).
• Coronary angiography-confirmed multivessel disease or left main stem stenosis with the symptoms of unstable angina or non-ST-segment elevation myocardial infarction.
• Severe symptomatic valvular disease detected by echocardiography.

Exclusion Criteria:

• Expected survival time <1 year (e.g., cancer).
• Renal failure with GFR < 20 ml/min/1.73 m2 as calculated by the CKD-EPI formula
• Women who are pregnant (pregnancy test).
• Coagulopathies.
• History of hypersensitivity to a contrast agent that does not respond to pharmacotherapy.
• Total carotid artery occlusion.
• Stent in the carotid artery that protrudes into the aortic arch.
• Anatomic variants that preclude stent implantation.
• Significant stenosis of the common carotid artery proximal to the target lesion.
• Mobile atherosclerotic plaques in the aortic arch.
• Anatomy of the coronary arteries unsuitable for bypass grafting.
• Lack of available vascular material for grafting.
• Porcelain aorta.

All-comers registry of patients with Heart and NeuroVascular Team recommendation for single-stage simultaneous surgical and endovascular procedure.

The SIM-GUARD single arm registry design and exploratory nature precluded sample size calculation. The number of patients to be enrolled is selected based on the number of procedures at the Center and the average typical size of studies/registries in this field of interventional treatment.