Summary of Main Research Content:

This study was a randomized, controlled, sham-intervention, proof-of-concept trial and the aim of this study was designed to evaluate the efficacy and safety of six months of chronic remote ischemic conditioning (CRIC) in improving myocardial perfusion and angina symptoms in patients with chronic stable angina (CSA). A total of 220 patients were enrolled and randomly assigned to either the intervention group, receiving CRIC for six months（Figure1）, or the control group, receiving sham-CRIC treatment.

The primary endpoint was the change in myocardial flow reserve (MFR) as measured by single-photon emission computed tomography (SPECT). Secondary endpoints included the improvement rate of angina symptoms (assessed by CCS angina classification, Seattle Angina Questionnaire, and six-minute walk test distance) and the incidence of major adverse cardiovascular and cerebrovascular events (MACCEs). The results demonstrated that six months of CRIC significantly improved MFR（Figure2）, angina symptoms（Figure3）, and exercise tolerance in CSA patients without increasing the incidence of MACCEs, with good treatment tolerability. The beneficial effects of CRIC may be attributed to its ability to enhance microcirculatory function, promote angiogenesis, and reduce myocardial oxygen consumption at rest. This non-invasive, safe, simple and effective intervention is a novel therapeutic approach for CSA patients.

Research Commentary:

The prevalence and mortality rates of coronary artery disease (CAD) in China continue to rise. Despite great progresses in drug therapy, coronary artery interventions and bypass surgery, there remains a significant number of patients who are either ineligible for these procedures or have experienced procedural failure. These late-stage CAD patients, even with optimal medical therapy, often suffer from persistent symptoms that severely impact their quality of life and prognosis, presenting a formidable clinical challenge. Recurrent angina and heart failure lead to frequent hospitalizations, imposing a substantial psychological and economic burden on individuals and society, ultimately hindering national economic development. Thus, finding effective treatment options for these patients is of urgent and significant clinical value.

Professor Li Muwei’s team has conducted extensive clinical research on such patients over the past few years. Their findings indicated that when epicardial coronary arteries are not able to intervention, improving microcirculatory function can significantly enhance myocardial perfusion and alleviate angina symptoms. Based on this concern, the concept of CRIC was proposed to improve myocardial ischemia by enhancing coronary microcirculation and promoting neovascularization, thereby increasing myocardial blood supply. This study has validated the feasibility and clinical utility of this concept. The research findings, with Dr. Quan Guo as the first author, were published in the BMC Medicine in 2023. This study offers a safe, effective and simple treatment method for late-stage CAD patients, distinct from traditional pharmacological or surgical approaches, anesising angina symptoms, avoiding the risks associated with complex surgeries, and reducing the costs of recurrent hospitalizations.