Objectives:Coronary slow flow(CSF)has long been regarded as a marker of coronary microvascular dysfunction(CMD).This study aims to evaluate the diagnostic value of CSF for CMD in patients with angina and nonobstructive coronary arteries(ANOCA).Methods:The study data were derived from the ANOCA-CMD prospective cohort study.All enrolled patients underwent coronary angiography and concurrent coronary physiological assessments in the left anterior descending artery using pressure-wire and thermodilution techniques to obtain coronary flow reserve(CFR)and the index of microcirculatory resistance(IMR).Based on the results,CMD was classified into four subtypes:CMD with elevated IMR(IMR≥25),CMD with reduced CFR(CFR<2.5),CMD with either reduced CFR or elevated IMR(CFR<2.5 or IMR≥25),and CMD with both reduced CFR and elevated IMR(CFR<2.5 and IMR≥25).The corrected thrombolysis in myocardial infarction(TIMI)frame count(CTFC)in the left anterior descending artery was calculated from coronary angiography images,with CSF defined as CTFC>27.This study evaluated the correlation between CTFC,CFR,and IMR,and investigated the diagnostic value of CSF for CMD in ANOCA patients.Results:A total of 103 ANOCA patients were enrolled in this study,with a mean age of(64.2±10.6)years,and 53.4％were female.Among them,57 patients(55.3％)were diagnosed with coronary slow flow.Patients with slow flow had higher IMR(P<0.001)and CFR(P=0.041).Similarly,the proportion of CMD with elevated IMR was higher in the slow flow group(P<0.001),while the proportion of CMD with reduced CFR was lower(P=0.044).There was no significant difference between the groups in the proportions of CMD with either reduced CFR or elevated IMR or CMD with both reduced CFR and elevated IMR(all P>0.05).CTFC was positively correlated with hyperemic mean transit time(r=0.424,P<0.001),IMR(r=0.430,P<0.001),and CFR(r=0.211,P=0.032).The area under the curve(AUC)of CTFC for diagnosing CMD with elevated IMR was 0.721(95％CI:0.623-0.819)with an accuracy of 67％(57％,76％),for diagnosing CMD with reduced CFR was 0.610(95％CI:0.499-0.720)with an accuracy of 60％(50％,70％),for diagnosing CMD with either reduced CFR or elevated IMR was 0.549(95％CI:0.425-0.673)with an accuracy of 47％(37％,57％),and for diagnosing CMD with both reduced CFR and elevated IMR was 0.582(95％CI:0.471-0.693)with an accuracy of 47％(37％,57％).Thus,CSF demonstrated limited diagnostic values across all subtypes of CMD.Conclusions:In ANOCA patients,CSF cannot serve as an effective diagnostic marker for CMD.Therefore,in clinical practice,the slow flow phenomenon should not be directly equated with the presence of coronary microvascular dysfunction in ANOCA patients.

Objectives:Coronary slow flow(CSF)has long been regarded as a marker of coronary microvascular dysfunction(CMD).This study aims to evaluate the diagnostic value of CSF for CMD in patients with angina and nonobstructive coronary arteries(ANOCA).Methods:The study data were derived from the ANOCA-CMD prospective cohort study.All enrolled patients underwent coronary angiography and concurrent coronary physiological assessments in the left anterior descending artery using pressure-wire and thermodilution techniques to obtain coronary flow reserve(CFR)and the index of microcirculatory resistance(IMR).Based on the results,CMD was classified into four subtypes:CMD with elevated IMR(IMR≥25),CMD with reduced CFR(CFR<2.5),CMD with either reduced CFR or elevated IMR(CFR<2.5 or IMR≥25),and CMD with both reduced CFR and elevated IMR(CFR<2.5 and IMR≥25).The corrected thrombolysis in myocardial infarction(TIMI)frame count(CTFC)in the left anterior descending artery was calculated from coronary angiography images,with CSF defined as CTFC>27.This study evaluated the correlation between CTFC,CFR,and IMR,and investigated the diagnostic value of CSF for CMD in ANOCA patients.Results:A total of 103 ANOCA patients were enrolled in this study,with a mean age of(64.2±10.6)years,and 53.4％were female.Among them,57 patients(55.3％)were diagnosed with coronary slow flow.Patients with slow flow had higher IMR(P<0.001)and CFR(P=0.041).Similarly,the proportion of CMD with elevated IMR was higher in the slow flow group(P<0.001),while the proportion of CMD with reduced CFR was lower(P=0.044).There was no significant difference between the groups in the proportions of CMD with either reduced CFR or elevated IMR or CMD with both reduced CFR and elevated IMR(all P>0.05).CTFC was positively correlated with hyperemic mean transit time(r=0.424,P<0.001),IMR(r=0.430,P<0.001),and CFR(r=0.211,P=0.032).The area under the curve(AUC)of CTFC for diagnosing CMD with elevated IMR was 0.721(95％CI:0.623-0.819)with an accuracy of 67％(57％,76％),for diagnosing CMD with reduced CFR was 0.610(95％CI:0.499-0.720)with an accuracy of 60％(50％,70％),for diagnosing CMD with either reduced CFR or elevated IMR was 0.549(95％CI:0.425-0.673)with an accuracy of 47％(37％,57％),and for diagnosing CMD with both reduced CFR and elevated IMR was 0.582(95％CI:0.471-0.693)with an accuracy of 47％(37％,57％).Thus,CSF demonstrated limited diagnostic values across all subtypes of CMD.Conclusions:In ANOCA patients,CSF cannot serve as an effective diagnostic marker for CMD.Therefore,in clinical practice,the slow flow phenomenon should not be directly equated with the presence of coronary microvascular dysfunction in ANOCA patients.

Objective: To analyze the clinical features and summarize the experience on the diagnosis and treatment of aortic stenosis caused by Takayasu arteritis in pediatric patients. Methods: This study was a retrospective study. Five pediatric patients diagnosed as aortic stenosis caused by Takayasu arteritis in Fuwai Hospital of Chinese Academy of Medical Sciences from January 2016 to August 2018 were included. The clinical features, methods of examination, treatment and outcome were analyzed. Results: There were 2 male and 3 female patients in this cohort. The age of onset ranged from 10 to 13 years. The main clinical symptoms were as follows: intermittent claudication and hypertension (5 patients), heart failure (3 patients). Three patients with heart failure were misdiagnosed with dilated cardiomyopathy in other hospitals. Except 1 patient died due to disease aggravation before operation, the other 4 patients received interventional therapy for severe heart failure or refractory hypertension on the basis of hormone anti-inflammatory treatment, including 2 patients treated with aortic balloon dilatation and 2 patients treated with aortic balloon dilatation and stent implantation. In post-operational follow-up, clinical symptoms and laboratory examination values of the 4 patients treated with interventional therapy were significantly improved. Conclusions The clinical symptoms of pediatric patients with aortic stenosis caused by Takayasu arteritis mainly present with intermittent claudication, hypertension and heart failure. Aortic intervention strategy should be applied for pediatric patients with severe heart failure or refractory hypertension as early as possible.

Objective To analyze the clinical features and summarize the experience on the diagnosis and treatment of aortic stenosis caused by Takayasu arteritis in pediatric patients. Methods This study was a retrospective study. Five pediatric patients diagnosed as aortic stenosis caused by Takayasu arteritis in Fuwai Hospital of Chinese Academy of Medical Sciences from January 2016 to August 2018 were included. The clinical features, methods of examination, treatment and outcome were analyzed. Results There were 2 male and 3 female patients in this cohort. The age of onset ranged from 10 to 13 years. The main clinical symptoms were as follows: intermittent claudication and hypertension (5 patients), heart failure (3 patients). Three patients with heart failure were misdiagnosed with dilated cardiomyopathy in other hospitals. Except 1 patient died due to disease aggravation before operation, the other 4 patients received interventional therapy for severe heart failure or refractory hypertension on the basis of hormone anti?inflammatory treatment, including 2 patients treated with aortic balloon dilatation and 2 patients treated with aortic balloon dilatation and stent implantation. In post?operational follow?up, clinical symptoms and laboratory examination values of the 4 patients treated with interventional therapy were significantly improved. Conclusions The clinical symptoms of pediatric patients with aortic stenosis caused by Takayasu arteritis mainly present with intermittent claudication, hypertension and heart failure. Aortic intervention strategy should be applied for pediatric patients with severe heart failure or refractory hypertension as early as possible.

Objective: To evaluate the effect of stenting for proximal atherosclerotic extracranial vertebral artery stenosis. Methods: A total of 204 proximal atherosclerotic extracranial vertebral artery stenosis patients underwent stent implantation at Fuwai Hospital were enrolled consecutively between August 2007 and June 2014 prospectively. Medical records were collected and the clinical results were obtained through outpatient and telephone follow up. Results: (1) The patients were (64.1±7.9) years old, and 179 were male (87.7%). (2) Stent implantation was performed on 210 proximal atherosclerotic extracranial vertebral artery stenosis lesions with 210 stents (156 on the left, 54 on the right), and 6 patients received both sides stent implantations. Technical success rate was 100%(210/210). The stenosis of the lesions was decreased from (85.1±6.4) % to (6.5±3.2) % after the stent implantation (P<0.01). (3) Three (1.5%) patients experienced transient ischemic attack during the procedure, and two (1.0%) patients suffered from minor posterior circulation ischemic strokes on the 2nd and 10th day after the procedure, respectively. (4)The median follow-up was 1.5 (0.8-2.5) years. Three(1.5%) patients died (two non-vacular deaths, and the other one due to sudden cardiac death). Three (1.5%) patients developed stroke (one case ipsilateral posterior circulation stroke, and two cases unrelated area stroke). Four (2.0%) patients experienced transient ischemic attack. One patient suffered nonfatal myocardial infraction. In-stent restenosis occurred in thirty nine (19.4%) patients, of which fourteen (35.9%) patients were totally occluded and four (10.3%) patients with symptomatic restenosis. Kaplan-Meier survival curve showed that the primary patency rate of the vertebral artery were 85.6%, 78.6%, 72.2% and 64.4% at 1, 2, 3 and 5 years, respectively. Conclusions Stenting for proximal atherosclerotic extracranial vertebral artery stenosis is safe and feasible, with a good middle to long-term patency rate. However, further trials are required to validate the effective results found in this patients cohort.