The Coronary Sinus Balloon Pump in STEMI

Prior treatment

• Presence of an implant or foreign body within the coronary sinus.
• Known allergy or contraindication to drugs or materials required during PCI and the use of the investigational device (including, but not limited to, sirolimus, dual antiplatelet therapy drugs, polyamide, polyurethane, polytetrafluoroethylene, or stainless steel).
• Intracardiac thrombus detected by echocardiography within 30 days prior to enrollment.
• Prior coronary artery bypass graft (CABG) surgery.
• Current participation in another clinical drug or device study where the primary endpoint has not been reached, or planned participation in another investigational drug or device clinical trial within 12 months after the baseline procedure.
• Subjects with chronic obstructive pulmonary disease (COPD) who are on home oxygen therapy or receiving chronic steroid therapy.
• Any vascular PCI treatment received within 1 week prior to enrollment.
• Fibrinolytic therapy received within 24 hours prior to enrollment.

Other illness

• Presence of pericardial effusion (moderate or greater), cardiac tamponade, hemodynamically significant left/right shunt, or severe valvular heart disease.
• History of acute myocardial infarction, or documented history of hospitalization for Q-wave infarction.
• History of cerebral infarction, intracerebral hemorrhage, transient ischemic attack (TIA), or reversible ischemic neurologic deficit within the past 6 months, or presence of permanent neurological deficit.
• Subjects experiencing cardiac arrest or cardiopulmonary resuscitation (CPR) for more than 5 minutes preoperatively (baseline) or intraoperatively.
• Known contraindications to cardiac magnetic resonance imaging (CMR), such as claustrophobia, presence of non-CMR compatible foreign bodies or implants, or allergy/intolerance to gadolinium-based contrast agents.
• History of treatment for malignancy within the past 12 months.

Lab values

• Known hemoglobin level below 90 g/L, platelet count below 80×10⁹/L, history of bleeding diathesis or coagulation disorder, or unwillingness to receive blood transfusion.
• Known severe renal disease (estimated glomerular filtration rate (eGFR) \<30 mL/(min·1.73m²) as calculated by the MDRD formula\*) or undergoing hemodialysis.

Other

• The target lesion involves the left main coronary artery, or there is a ≥50% stenosis in the left main coronary artery.
• Subjects requiring circulatory support or assisted ventilation.
• Subjects unsuitable for femoral or jugular venous access.
• Visible well-developed collateral circulation distal to the target lesion in the target vessel.
• Impaired consciousness during PCI, cardiogenic shock (persistent systolic blood pressure ≤90 mmHg despite conservative treatment), or pulmonary edema (peripheral oxygen saturation \<90% with rales).
• -target lesions in vessels other than the left anterior descending artery and its branches requiring treatment during this PCI or within one week thereafter.
• Known pregnancy or breastfeeding, or female subjects planning pregnancy within 1 year post-procedure and unable to complete follow-up as required.
• Subjects judged by the investigator to have poor compliance and unable to complete the study as required, or any other reason the investigator deems the subject unsuitable for enrollment.

• General Inclusion Criteria:
• Subjects aged ≥18 and ≤80 years, clinically diagnosed with ST-segment elevation myocardial infarction (STEMI).
• Left ventricular ejection fraction (LVEF) ≤50% and ≥35% as assessed by echocardiography or left ventriculography prior to PCI.
• Symptoms of myocardial infarction (e.g., persistent chest pain, with or without shortness of breath, nausea/vomiting, profuse sweating, dyspnea, syncope) consistent with the timing of myocardial ischemia, with symptom onset within 24 hours.
• Electrocardiographic evidence of acute anterior wall myocardial infarction, defined as ST-segment elevation ≥1 mm (0.1 mV) in at least two contiguous precordial leads on a 12-lead ECG. For leads V2 or V3, the following gender- and age-specific cutoffs apply:
  • 2 mm (0.2 mV) in men ≥45 years old.
  • 2.5 mm (0.25 mV) in men \<40 years old.
  • 1.5 mm (0.15 mV) in women.
• Subject is eligible for primary percutaneous coronary intervention (primary PCI).
• Subject is able to understand the purpose of the study, voluntarily agrees to participate by signing the informed consent form acknowledging the risks and benefits described therein, and is willing and able to comply with the required clinical follow-up procedures.
  • Angiographic Inclusion Criteria:
• The target lesion is located in the proximal or mid segment of the left anterior descending artery (LAD).
• TIMI flow grade of the target vessel is 0, 1, or 2 prior to PCI treatment.