Cardiac Shock Wave Therapy for the Treatment of Myocardial Infarction With Non-obstructive Coronary Arteries

Myocardial infarction with non-obstructive coronary arteries (MINOCA) accounts for 15% of all myocardial infarctions and its mortality rate approaches that of large vessel myocardial infarction, but there are currently no effective treatment options. Coronary microvascular dysfunction is an important mechanism of MINOCA and is closely related to adverse cardiovascular outcomes.

The prospective trial aimed to verify the safety and effectiveness of cardiac shock wave therapy (CSWT) in the treatment of Myocardial infarction with non-obstructive coronary arteries (MINOCA), and to expand the scope of clinical indications for CSWT and provide new treatment strategy for MINOCA.

All participants will be fully informed of the study protocol, and informed consent will be obtained from each patient before the study. The inclusion criteria include: 1) Aged between 18 and 85 years old; 2) The initial diagnosis is acute myocardial infarction; 3) Coronary angiography shows coronary stenosis \<50%; 4) Abnormal D-SPECT myocardial perfusion images; 5) Voluntary informed consent signed.

The exclusion criteria include: 1) Previous history of coronary heart disease, received percutaneous coronary intervention, coronary artery bypass surgery or myocardial infarction (MI); 2) Hemodynamic instability; 3) Acute heart failure; 4) Severe valvular heart disease requiring surgical treatment; 5) Severe liver and kidney diseases; 6) Malignant tumors with an expected survival of less than one year; 7) Patients with severe bleeding tendency; 8) Pregnant women; 9) Intervening coronary ischemic events.

Based on the literature and the number of participants with myocardial infarction in the hospital, the sample size calculated according to the formula is about 50 cases. Considering the dropout rate of 10%, the sample size should be 56 cases.

56 patients are randomly divided 1:1 by computer into the CSWT group and Control group, with 28 MINOCA participants in each group. Participants in the CSWT group are treated with conventional medical therapy (including antiplatelet drugs, statins, and antianginal drugs), combined with CSWT, and those in the Control group were treated with conventional medical therapy and sham CSWT. Care providers and physicians who follow participants (parameters of this study) should be blinded to group assignment. CSWT is performed according to the recommended protocol on shock wave output and the number of shots delivered per point developed by Tohoku University, Japan, and with protocol equipment (Modulith SLC; Storz Medical, Switzerland) developed by the University of Essen, Germany. CSWT is performed three times a week (days 1, 3, and 5) in a session with a 3-month interval between sessions or 1-month intensive treatment. 40 The participants underwent CSWT for 3 months and 9 CSWT sessions were performed in total. Participants in the control group received sham CSWT, the energy of cardiac shock wave therapy was the lowest, and the water bladder was in contact with the skin but not close to the skin.

Examinations in this prospective trial include D-SPECT, blood biochemical examination, myocardial marker, and cardiopulmonary exercise testing. During follow-up, investigators will record major adverse cardiovascular events, and adverse events caused by other treatments. The safety and effectivity of CSWT will be verified by clinical parameters, D-SPECT, and peak oxygen consumption in CPET.

Eligibility Criteria:
Inclusion Criteria:

* Aged between 18 and 85 years old
* The initial diagnosis is acute myocardial infarction
* Coronary angiography shows coronary stenosis \<50%
* Abnormal D-SPECT myocardial perfusion images
* Voluntary informed consent signed

Exclusion Criteria:

* Previous history of coronary heart disease, received percutaneous coronary intervention, coronary artery bypass surgery or myocardial infarction (MI)
* Hemodynamic instability
* Acute heart failure
* Severe valvular heart disease requiring surgical treatment
* Severe liver and kidney diseases
* Malignant tumors with expected survival of less than one year
* Patients with severe bleeding tendency
* Pregnant women
* Intervening coronary ischemic events