Recently, Professor Shaoping Nie and Professor Xiao Wang from Beijing Anzhen Hospital, Capital Medical University, published a cutting-edge research article titled "Coronary angiography-derived index of microcirculatory resistance and evolution of infarct pathology after ST-segment-elevation myocardial infarction" in a top-tier journal. The study revealed the immediate diagnostic and long-term predictive value of the caIMR system for microvascular injury after primary percutaneous coronary intervention (PPCI). Microvascular obstruction (MVO) is an upstream problem and is potentially reversible, but severe microvascular injury progresses to irreversible intramyocardial haemorrhage (IMH). IMH drives infarct expansion after reperfusion and compromises myocardial salvage. This study confirmed that caIMR can objectively reflect the degree and evolution of postoperative infarct pathology in acute myocardial infarction patients, provide a risk stratification index for microcirculation injury diagnosis and treatment, and maximize clinical benefits for patients.

This is the first study to explore the relationship between the caIMR index and the degree and evolution of infarct pathology through continuous cardiac magnetic resonance imaging. The article was accepted by the internationally renowned SCI journal "European Heart Journal - Cardiovascular Imaging" (IF 9.130). Data shows that approximately onehalf of patients with ST-segment elevation myocardial infarction (STEMI) have failed myocardial reperfusion, as reflected by MVO and IMH. The detection of MVO at the acute setting by cardiac magnetic resonance imaging (CMR) is dynamic and may resolve or persist and evolve into irreversible IMH. The caIMR system can detect microvascular injury in emergency PCI patients immediately within a very short rescue time, predict the evolution or regression trend of infarct characteristics, identify high-risk patients, and strive for the best prognosis by providing early auxiliary treatment.

Patients with STEMI undergoing PPCI were prospectively enrolled between October 2019 and August 2021. A total of 286 STEMI patients with both angio-IMR and cardiac magnetic resonance (CMR) at baseline were included. Patients were grouped using caIMR=40U as the cut-off value, with caIMR>40U as the high caIMR group and caIMR≤40U as the low caIMR group. Patients were followed up for 3 months, and the results showed:

1. caIMR can predict the prevalence rate and degree of coronary microvascular obstruction. A significant correlation was observed between post-procedural angio-IMR and MVO at index admission (ρ= 0.228, P < 0.001). Patients with angio-IMR >40 U had a higher prevalence of MVO (84.5% vs. 48.5%, P < 0.001) compared with those with angio-IMR ≤40 U.

2. aIMR can predict the infarct size and regression after procedure. An angio-IMR >40 U indicated extensive microvascular damage with less regression of infarct size and more persistent iron at follow-up. Both caIMR as a continuous variable and caIMR>40 U were predictive factors for final infarct size and myocardial iron deposition. An angio-IMR >40 U was a multivariable predictor of infarct size with a three-fold higher risk of final infarct size >25% and it can significantly predict the presence and extent of myocardial iron at follow-up.

Previous studies published in journals such as "JACC: CARDIOVASCULAR INTERVENTIONS" and "Cardiovascular Diabetology" have confirmed the important clinical diagnostic value of the caIMR system. Among them, a clinical study published by Samsung Medical Center in the journal "Rev Esp Cardiol" preliminarily verified the feasibility of using cardiac magnetic resonance imaging to measure microcirculation injury immediately after surgery with the caIMR system. This study further revealed the relationship between the caIMR index and infarct evolution through cardiac magnetic resonance imaging, making it more clinically informative and practical.

Coronary microcirculation dysfunction is an important factor leading to reperfusion failure and is commonly encountered in daily clinical practice. RainMed Medical has broken through the high operational barriers and high clinical risks of traditional guidewire-derived IMR and independently developed the caIMR system. Currently, the caIMR system has successfully entered the special approval channel for innovative medical devices of the National Medical Products Administration (NMPA) and has obtained NMPA certification in China, becoming the world's first non-invasive microcirculation diagnostic system to achieve commercialization. The caIMR system is the world's first non-invasive IMR system. The large-scale clinical application of this product provides a safer and more reliable diagnostic and treatment method for comprehensive assessment of myocardial ischemia in clinical practice.

Currently, the caIMR system and the previously commercialized caFFR system jointly serve as the core products of functional diagnostic modules, integrated on the FlashBot vascular intervention robot. As a platform-level robot product, FlashBot continues to integrate more cutting-edge treatment technologies, aiming to provide remote, integrated diagnosis and treatment solutions for complex vascular diseases and promote high-quality, balanced development of medical standards across regions!