About 60% of patients with hypertrophic cardiomyopathy have microvascular dysfunction. Microvascular dysfunction is directly related to prognosis in hypertrophic cardiomyopathy. This new measurement method is microcirculation resistance (MR) based on quantitative flow ratio (QFR), which does not need a pressure guide wire on the basis of angiography. The QFR system is used to evaluate the blood vessels distal pressure and blood flow, and their ratio is microcirculation resistance (MR). The quantitative blood flow fraction measurement system was analyzed by interventional laboratory platform image analysis software (AngioPlus 2.0). This study is a single-center retrospective cohort study. Participants were selected from patients who were diagnosed with hypertrophic obstructive cardiomyopathy in Fuwai Hospital from January 2020 to November 2021. The risk factor is whether there is microcirculation resistance disorder. The outcome was the major adverse cardiovascular events related to HCM (including all-cause death, heart transplantation, left ventricular pacemaker, and heart failure readmission) that were followed up one year after angiography. Aim To further clarify whether there is a certain correlation between microvascular resistance and adverse cardiovascular prognosis.

Inclusion criteria:

1. Aged 18-80 years old;
2. Patients with hypertrophic obstructive cardiomyopathy undergoing coronary angiography. Diagnosis criteria that meet the diagnostic guidelines for hypertrophic obstructive cardiomyopathy: It usually refers to the thickness of the ventricular septum or left ventricular wall measured by two-dimensional echocardiography > 15 mm, or the thickness of > 13mm in patients with a clear family history, usually without enlargement of the left ventricular cavity, and the thickening of the left ventricular wall caused by increased loads, such as hypertension, aortic stenosis, and congenital subvalvular septum should be excluded; LVOTG>30 mmHg under quiet or exercise conditions.
3. The informed consent form for the use of sample data of patients admitted to the hospital has been signed;

Exclusion criteria:

1. No contrast examination is performed for various reasons;
2. Missing baseline important information indicators;
3. Loss of follow-up;

From January 2017 to November 2021, patients with hypertrophic obstructive cardiomyopathy underwent coronary angiography in Fuwai Hospital.