A Prospective, Multi-center Clinical Trial for Evaluating the Effectiveness and Safety of Online Coronary Angiography-Derived Index of Microcirculatory Resistance (caIMR)
Condition: Coronary Microvascular Dysfunction
Study type: Observational

Summary: 
      More than 50% of patients with stable or unstable angina pectoris have no obstructive
      coronary arteries by angiographic visual estimation, in which coronary microvascular
      dysfunction (CMD) is one of the causes of myocardial ischemia and chest pain. A coronary
      angiography-derived index of microcirculatory resistance (caIMR) is proposed for
      physiological assessment of microvascular diseases in coronary circulation. The aim of the
      trial is to assess diagnostic performance of caIMR, using wire-derived index of
      microcirculatory resistance (IMR) as the reference standard.
    

Detailed description: 
      More than 50% of patients with stable or unstable angina pectoris have no obstructive
      coronary arteries by angiographic visual estimation, in which coronary microvascular
      dysfunction (CMD) is one of the causes of myocardial ischemia and chest pain. Presently, the
      index of microcirculatory resistance (IMR) measured by the pressure wire is recognized as
      standard for evaluating coronary microcirculatory function. A coronary angiography-derived
      index of microcirculatory resistance (caIMR) is proposed for physiological assessment of
      microvascular diseases in coronary circulation without pressure wire, hyperemic agents, or
      thermodilution method.

      This study is a prospective, multi-center clinical trial. In the study, IMR (measured by
      pressure wire) will be used as a reference standard to evaluate the feasibility, accuracy and
      safety of caIMR measured by a non-invasive diagnosis system (FM21a) based on angiography
      images and aortic pressure wave. 116 patients eligible for inclusion criteria will be
      enrolled in the study. Both IMR and caIMR measurement will be performed in the same patient
      in a random order after angiography. The definitions of IMR and caIMR for coronary
      microcirculatory ischemia are IMR≥25 and caIMR≥25. The primary endpoint is the diagnostic
      accuracy of caIMR. The secondary endpoint is caIMR's sensitivity, specificity, positive
      predictive value, negative predictive value, ROC curve and AUC of caIMR diagnosis, and the
      diagnostic characteristics of caIMR at the vascular level.
    

Intervention name(s): Angiography-derived Index of Microcirculatory Resistance; Pressure wire-based Index of Microcirculatory Resistance
Intervention type(s): Device; Device
Intervention description(s): caIMR will be measured by pressure sensors which are produced by Suzhou Rainmed Medical Technology Co., Ltd.
caIMR is calculated based on angiography images and Hyperemic Pa estimated from resting Pa according to prespecified equation.; IMR will be measured by thermodilution method with pressure wire and arterial physiological detector which are produced by St. Jude Medical.
IMR = Pd ∙Tmn
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients with stable or unstable angina, or suspected myocardial ischemia.
      
Keywords: Hemodynamics; Computational fluid dynamics; Index of microcirculatory resistance; Fractional flow reserve; Angiography-derived IMR