Retrospective analysis of OCT on MB characteristics and 1-year follow-up of the ISR incidence after the DES implantation in patients with MB

We used optical coherence tomography (OCT) to analyze the "half-moon" like phenomenon and its characteristics and observe 1-year follow-up of the in-stent restenosis (ISR) incidence after the drug eluted stent (DES) implantation in patients with the myocardial bridge (MB). Patients were retrospectively analyzed from January 2013 to December 2019. We used OCT to check 45 patients with MB and found a visible muscle layer (VML) around the vessel adventitia with the same or high density compared to the vessel media layer. There was not any significant difference in maximal thickness, maximal arch, and total length between the half-moon layer and the visible muscle layer groups (p > 0.05). Maximal thickness, arch, and total length of the half-moon layer were significantly positively related to VML, respectively (r = 0.962, 0.985, 0.742, p < 0.01). Of these 626 patients with MB seen by OCT, only 300 could be checked out by coronary angiography (CAG). Besides, the larger the thickness and arch of the VML around the vessel adventitia, the more severe the MB in these patients (p < 0.05). After the OCT use, there was no coronary perforation in these patients with MB covered with DES. After 1-year follow-up, ISR in MB covered with DES showed a notable difference among no MB, mild MB, moderate MB, and severe MB groups (p < 0.05), and ISR in DES aggravated with the MB severity. However, ISR in MB with and without covered with DES had no significant difference among the 4 groups (p > 0.05). OCT could evaluate MB characteristics accurately compared to IVUS and had a higher rate of detecting MB than CAG. Moreover, it is safe and effective to guide DES covering the mild MB segment in patients with severe coronary lesions detected by the OCT.

Influence of Myocardial Bridge On Atherosclerotic Plaque Distribution and Characteristics Evaluated By Near-Infrared Spectroscopy Intravascular Ultrasound

Purpose This study aims to clarify whether myocardial bridge (MB) could influence atherosclerotic plaque characteristics assessed by using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) imaging. Methods One hundred and sixteen patients who underwent percutaneous coronary intervention (PCI) using NIRS-IVUS imaging were included. MB was defined as an echo-lucent band surrounding left anterior descending artery (LAD). In MB patients, LAD was divided into 3 segments: proximal, MB, and distal segments. In non-MB patients, corresponding 3 segments were defined based on the average length of the above segments. Segmental maximum plaque burden and lipid content derived from NIRS-IVUS imaging in the section of maximum plaque burden were evaluated in each segment. Lipid content of atherosclerotic plaque was evaluated as lipid core burden index (LCBI) and maxLCBI4mm. LCBI is the fraction of pixels indicating lipid within a region multiplied by 1000, and the maximum LCBI in any 4-mm region was defined as maxLCBI4mm. Results MB was identified in 42 patients. MB was not associated with maximum plaque burden in proximal segment. LCBI and maxLCBI4mm were significantly lower in patients with MB than those without in proximal segment. Multivariable analysis demonstrated both MB and maximum plaque burden in proximal segment to be independent predictors of LCBI in proximal segment. Conclusion Lipid content of atherosclerotic plaque assessed by NIRS-IVUS imaging was significantly smaller in patients with MB than those without. MB could be considered as a predictor of lipid content of atherosclerotic plaque when assessed by NIRS-IVUS imaging.

762 Myocardial bridge evaluation towards personalized medicine (the rialto registry): preliminary findings

Aims Myocardial bridge (MB) is the most common inborn coronary artery variant in which a segment of an epicardial coronary artery takes a tunneled course under a bridge of myocardium. MB has been documented from 1.5% to 16% of invasive angiographic series thus the true prevalence of MB is uncertain. The clinical relevance of MB is heterogeneous, being usually an asymptomatic bystander. However, a growing body of evidence suggests its association with myocardial ischaemia. In the present work, by setting up a database of patients affected by MB, we sought to assess their clinical characteristics and risk of major adverse cardiac events (MACE). Methods and results This is a prospective/retrospective study and observational study in which we included 17 681 patients referred to undergo invasive coronary angiography (ICA) for suspected coronary artery disease. During the screening phase, we found that 338 cases (26 non-recruitable) were reported to have MB (1.9%). In-hospital clinical-instrumental data was acquired after ICA. The data obtained in the follow-up (FUP) visit is also included in the study. In particular, we recorded MACE and Seattle Angina Questionnaire (SAQ). The most frequent location of MB was the LAD coronary artery (96.8%). Other locations were the circumflex artery (1.3%), the right coronary artery (1%), the posterior interventricular artery (0.6%), and the first diagonal artery (0.3%). Chronic coronary syndrome (CCS) was the most frequent clinical presentation (47.5%). A big proportion (34.6%) of our patients were found to have MB during the occurrence of an acute coronary syndrome (ACS). In acute setting, unstable angina was the most frequent clinical presentation (17.6%). 47 patients (15%) underwent coronary angiography with provocative test (intracoronary acetylcholine) in order to search vasomotor disorders: according to COVADIS criteria, 17 procedures (5.5%) resulted positive for vasospastic angina (VSA). Invasive functional assessment with FFR/iFR was accomplished to assess the haemodynamic significance both of MBs and atherosclerotic plaques proximal to the MB segment in 35 patients (11.2%): in nine procedures (2.9%), functional tests resulted positive. β-Blockers (BBs) are suggested as first-line drugs as they increase diastolic filling time, by decreasing heart rate. Calcium channel blockers (CCBs) are useful, in VSA setting, to reduce epicardial spasm. In our court, 40% of patients toke BBs and 20% of patients toke CCBs at admission. The primary endpoint of the study is the incidence of MACE, defined as the composite of cardiac death, myocardial infarction and cardiac hospitalization. Considering patients who have already undergone FUP (114; 36.5%), we recorded 19 MACE (16.7% of patients with FUP). The secondary endpoint is the rate of patients with SAQ Angina Summary Score &lt; 70: the rate of patients with SAQ &lt; 70 is 23.7% at 6 months, 23.8% at 12 months and 23.2% at 24 months. Conclusions MB has been typically considered benign and asymptomatic, but its clinical relevance is still matter of debate. A remarkable proportion of our patients were found to have a MB during the occurrence of ACS or CCS, highlighting that different mechanisms of ischaemia may coexist. Furthermore, invasive functional assessment shows a plausible correlation between MB and vasomotor disorders. Our study is still ongoing, and we hope to maximize the data in order to have a solid comprehension of MB and to propose the assessment that may indicate a tailored therapy.

CABG versus myotomy in symptomatic myocardial bridge patients : A systematic Review and Meta-analysis protocol

Review question / Objective: The aim of this study is to find which surgical intervention in myocardial bridge ( myotomy or CABG) is more effective in reducing adverse outcomes in symptomatic patients resistant to optimal medical therapy ? Condition being studied: Myocardial bridge : A myocardial bridge (MB) is a congenital heart defect in which a bridge of muscle fibers (myocardium) overlying a section of a coronary artery and the artery is squeezed and normal blood flow is disrupted. Most bridges don't seem to cause symptoms. However, some people can experience angina, or chest pain. In patients with symptoms, first line treatment is medication and if they have symptoms despite optimal medical treatment , invasive measures like CABG or myotomy should be taken.

Is myocardial bridge more frequently detected on radial access coronary angiography?

Background Although the incidence of myocardial bridge (MB) has been defined in different femoral access conventional coronary angiography (FACCA) studies, the frequency of MB on radial access coronary angiography (RACA) is unknown. The aim of this study was to determine the difference in the incidence of MB between patients undergoing RACA and FACCA. Method A total of 2500 consecutive patients who underwent RACA and a total of 1455 consecutive patients who underwent FACCA were retrospectively investigated to detect the presence of MB. The incidences of the groups were calculated separately and compared. The clinical and angiographic features of the patients with MB were analyzed. Results MB was detected at an incidence of 10.2%, in 255/2500 patients who underwent RACA, and 1.8% in 27/1455 patients who underwent FACCA (p < 0.001). In both RACA and FACCA patients, the most involved coronary artery was the left anterior descending artery (LAD) (86.9% and 93.1%) and the mid-segment (84.9% and 88.9%) was the most affected section. Co-involvement of multiple coronary arteries by MB was 7.8% in patients who underwent RACA and 7.4% in patients who underwent FACCA. Coronary artery disease (CAD) was determined in 111 (35.7%) of the coronary arteries with MB, of which 81.9% were proximal to the MB. No significant CAD was detected in any of the vessels of 69.8% (178/255) of the patients who underwent RACA for different clinical indications. Conclusion These data demonstrated that the incidence of myocardial bridge able to be detected on RACA was much higher than FACCA.

Flow reserve fraction: the optimal choice in lesion assessing and interventional guiding for patient with unstable angina pectoris and intermediate lesion wrapped with myocardial bridge: a case report

Background It is difficult to choose correctly interventional strategy for coronary intermediate lesions combined with myocardial bridge. Endovascular imaging is advocated to guide treatment, but flow reserve fraction (FFR) is not recommended to guide the interventional treatment of myocardial bridge disease because of the inaccurate judgment misled by myocardial bridge. Case presentation In this study, we reported a case of a 56-year-old male patient with unstable angina pectoris (UAP). From his coronary angiography, we found diffuse stenosis near the midsection of the left anterior descending (LAD) branch and the presence of a severe myocardial bridge in the lesion area. We were sure that the LAD was culprit vessel and this lesion was culprit lesion. Both FFR and intravenous ultrasound (IVUS) were performed and the conclusions of them are different. Although stent implantation is not usually recommended in the myocardial bridge area. However, after careful examination, a stent was finally implanted under the precise guidance of FFR. And the patient recovered well up-to now. Conclusions This case illustrates that FFR functional test was complimentary to intravascular imaging test for the coronary intermediate lesion, especially the lesion wrapped with myocardial bridges, both in assessing the lesion and in guiding treatment.

Relationship Between Coronary Atheroma, Epicardial Adipose Tissue Inflammation, and Adipocyte Differentiation Across the Human Myocardial Bridge

Background Inflammation in epicardial adipose tissue (EAT) may contribute to coronary atherosclerosis. Myocardial bridge is a congenital anomaly in which the left anterior descending coronary artery takes a “tunneled” course under a bridge of myocardium: while atherosclerosis develops in the proximal left anterior descending coronary artery, the bridged portion is spared, highlighting the possibility that geographic separation from inflamed EAT is protective. We tested the hypothesis that inflammation in EAT was related to atherosclerosis by comparing EAT from proximal and bridge depots in individuals with myocardial bridge and varying degrees of atherosclerotic plaque. Methods and Results Maximal plaque burden was quantified by intravascular ultrasound, and inflammation was quantified by pericoronary EAT signal attenuation (pericoronary adipose tissue attenuation) from cardiac computed tomography scans. EAT overlying the proximal left anterior descending coronary artery and myocardial bridge was harvested for measurement of mRNA and microRNA (miRNA) using custom chips by Nanostring; inflammatory cytokines were measured in tissue culture supernatants. Pericoronary adipose tissue attenuation was increased, indicating inflammation, in proximal versus bridge EAT, in proportion to atherosclerotic plaque. Individuals with moderate‐high versus low plaque burden exhibited greater expression of inflammation and hypoxia genes, and lower expression of adipogenesis genes. Comparison of gene expression in proximal versus bridge depots revealed differences only in participants with moderate‐high plaque: inflammation was higher in proximal and adipogenesis lower in bridge EAT. Secreted inflammatory cytokines tended to be higher in proximal EAT. Hypoxia‐inducible factor 1a was highly associated with inflammatory gene expression. Seven miRNAs were differentially expressed by depot: 3192‐5P, 518D‐3P, and 532‐5P were upregulated in proximal EAT, whereas miR 630, 575, 16‐5P, and 320E were upregulated in bridge EAT. miR 630 correlated directly with plaque burden and inversely with adipogenesis genes. miR 3192‐5P, 518D‐3P, and 532‐5P correlated inversely with hypoxia/oxidative stress, peroxisome proliferator‐activated receptor gamma coactivator 1‐alpha (PCG1a), adipogenesis, and angiogenesis genes. Conclusions Inflammation is specifically elevated in EAT overlying atherosclerotic plaque, suggesting that EAT inflammation is caused by atherogenic molecular signals, including hypoxia‐inducible factor 1a and/or miRNAs in an “inside‐to‐out” relationship. Adipogenesis was suppressed in the bridge EAT, but only in the presence of atherosclerotic plaque, supporting cross talk between the vasculature and EAT. miR 630 in EAT, expressed differentially according to burden of atherosclerotic plaque, and 3 other miRNAs appear to inhibit key genes related to adipogenesis, angiogenesis, hypoxia/oxidative stress, and thermogenesis in EAT, highlighting a role for miRNA in mediating cross talk between the coronary vasculature and EAT.

Relationship between Different Degrees of Compression and Clinical Symptoms in Patients with Myocardial Bridge and the Risk Factors of Proximal Atherosclerosis

Objective. To explore the relationship between different degrees of compression and clinical symptoms in patients with the myocardial bridge and the risk factors of proximal atherosclerosis. Methods. The clinical data of 156 patients with the myocardial bridge who underwent selective coronary angiography in our hospital from December 2010 to December 2015 were collected. The patients were divided into Noble grade I group (102 cases) and Noble grades II-III group (54 cases) according to the degree of mural coronary artery systolic stenosis. According to the results of coronary angiography, 156 patients with the myocardial bridge were divided into an atherosclerosis group (the myocardial bridge combined with atherosclerosis at the proximal end of the myocardial bridge of simple wall coronary artery), 91 cases, and a control group (isolated myocardial bridge), 65 cases. The relationship between different degrees of compression and clinical symptoms in patients with the myocardial bridge was observed, and the logistic regression model was used to analyze the risk factors of proximal atherosclerosis in patients with the myocardial bridge. Results. The incidence of atherosclerotic stenosis, angina pectoris, and myocardial infarction in the proximal part of the myocardial bridge in the Noble grades II-III group was higher than that in the Noble grade I group ( P < 0.05 ). The differences in age, hypertension, and Noble classification between the two groups were statistically significant ( P < 0.05 ). The differences of total cholesterol (TC) and C-reactive protein (CRP) between the two groups were statistically significant ( P < 0.05 ). Multivariate analysis showed that age, hypertension, Noble grade, and CRP were all risk factors for proximal atherosclerosis in patients with the myocardial bridge ( P < 0.05 ). Conclusion. The more severe the compression of the myocardial bridge, the greater the risk of cardiovascular events for patients and the higher the incidence of atherosclerotic stenosis in the proximal part of the myocardial bridge. In addition, the occurrence of atherosclerosis in the proximal coronary artery of the myocardial bridge may be affected by age, hypertension, Noble grade, and CRP level.