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Purpose of Review: This review investigates the relationship between myocardial bridges (MBs), intimal thickening in coronary arteries, and Atherosclerotic cardiovascular disease. It focuses on the role of mechanical forces, such as circumferential strain, in arterial wall remodeling and aims to clarify how MBs affect coronary artery pathology. Review Findings: MBs have been identified as influential in modulating coronary artery intimal thickness, demonstrating a protective effect against thickening within the MB segment and an increase in thickness proximal to the MB. This is attributed to changes in mechanical stress and hemodynamics. Research involving arterial hypertension models and vein graft disease has underscored the importance of circumferential strain in vascular remodeling and intimal hyperplasia. Summary: Understanding the complex dynamics between MBs, mechanical strain, and vascular remodeling is crucial for advancing our knowledge of coronary artery disease mechanisms. This could lead to improved management strategies for cardiovascular diseases, highlighting the need for further research into MB-related vascular changes. [ABSTRACT FROM AUTHOR]

Introduction: Wellens’ syndrome represents an important, at times overlooked, spectrum of left anterior descending (LAD) coronary artery occlusion, spontaneous reperfusion, and impending reocclusion. Once considered pathognomonic for a thromboembolic coronary event, an increasing number of clinical scenarios have been demonstrated to result in pseudo-Wellens’ syndrome, each requiring unique forms of assessment and management. Case Report: We describe two clinical presentations in which myocardial bridging (MB) of the LAD led to clinical and electrophysiologic presentations of a pseudo-Wellens’ syndrome. Conclusion: These reports represent a rare cause of pseudo-Wellens’ syndrome attributed to MB of the LAD. Transient ischemia secondary to myocardial compression of the traversing LAD leads to intermittent angina and electrocardiogram changes that are typical in patients presenting with Wellens’ syndrome secondary to an occlusive coronary event. As with other previously reported pathophysiologic mechanisms that have been shown to mimic Wellens’ syndrome, myocardial bridging should be considered in patients presenting with a pseudo-Wellens’ syndrome.

A 56-year-old female diagnosed with hypertrophic obstructive cardiomyopathy and myocardial bridge (MB) of the left anterior descending (LAD) coronary artery underwent septal myectomy with resolution of her left ventricular outflow tract gradient. She had ongoing refractory symptoms of exertional angina and fatigue for over a decade and finally presented to our clinic to be re-evaluated for treatment. Provocative angiographic testing confirmed significant ischemia secondary to LAD MB. She underwent robotic totally endoscopic off pump unroofing of the LAD MB with complete relief of her symptoms and return to full activity. We conclude that patients undergoing septal myectomy for hypertrophic obstructive cardiomyopathy should be evaluated for MB and undergo unroofing of the bridge at the time of surgery. A myocardial bridge (MB) is a condition in which a coronary artery, most often the left anterior descending, takes an intramuscular route and is covered by the myocardium leading to compression and potential ischemia. This case report adds to the growing body of evidence supporting the significance of considering MB in the overall management of hypertrophic obstructive cardiomyopathy, and the symptomatic relief that a patient can obtain from an unroofing procedure. [ABSTRACT FROM AUTHOR]

Aim. To evaluate the effectiveness of left ventricular (LV) peak global longitudinal strain and potential of computed tomography myocardial perfusion (CT perfusion) for the early diagnosis of asymptomatic patients with myocardial bridges (MBs).Material and methods. Forty patients were examined (20 with asymptomatic MBs in the area of the left anterior descending (LAD) artery and 20 without MBs) at the S. M. Kirov Military Medical Academy in the period from 2021 to 2023. The patients were divided into 2 equal groups consisting of 20 people (10 with MBs — the main group; 10 without MBs — the comparison group), one of which underwent speckle tracking echocardiography (STE), and the other — stress CT perfusion performed (adenosine triphosphate 160 mg/kg). The results were assessed in accordance with the 17-segment classification of LV proposed by the American Heart Association (2002).Results. When performing STE, 5 (50%) patients with MBs showed a decrease in LV local strain in the segments, the blood supply of which comes from the LAD artery and its branches, while in the comparison group — 1 (10%) (x2=5; p=0,025). When assessing the global longitudinal peak strain (GLPS), a significant difference was revealed among the study groups, amounting to -20,9±1,5% in patients with MBs and -22,1±0,9% in those without MBs (p=0,04). Using ROC analysis, the effectiveness of GLPS in prediction of asymptomatic MBs was calculated as follows: AUC=0,93 (95% confidence interval: 0,819-1,0; p=0,001), the cut-off point — -20,55% (sensitivity 80%, specificity 100%). According to CT perfusion data, impaired myocardial blood supply in the group of asymptomatic patients with MBs was noted in 6 (60%) cases, and in the comparison group — 2 (20%) (x2=9,8; p=0,002).Conclusion. Imaging of initial LV changes according to two-dimensional STE and detection of coronary circulatory disorders according to CT myocardial perfusion in asymptomatic patients with MBs makes it possible to timely suspect intramyocardial course of the coronary artery, as well as to consider further management tactics and carry out early prevention of possible cardiovascular events.

Intravascular ultrasound (IVUS) studies show that one-quarter of left anterior descending (LAD) arteries have a myocardial bridge. An MB may be associated with stent failure when the stent extends into the MB. The aim of this study was to investigate: 1) the association between an MB and chronic total occlusion (CTO) in any LAD lesions; and 2) the association between an MB and subsequent clinical outcomes after percutaneous coronary intervention in LAD CTOs. A total of 3,342 LAD lesions with IVUS-guided percutaneous coronary intervention (280 CTO and 3,062 non-CTO lesions) were included. The primary outcome was target lesion failure (cardiac death, target vessel myocardial infarction, definite stent thrombosis, and ischemic-driven target lesion revascularization). An MB by IVUS was significantly more prevalent in LAD CTOs than LAD non-CTOs (40.4% [113/280] vs 25.8% [789/3,062]; P < 0.0001). The discrepancy in CTO length between angiography and IVUS was greater in 113 LAD CTOs with an MB than 167 LAD CTOs without an MB (6.0 [Q1, Q3: 0.1, 12.2] mm vs 0.2 [Q1, Q3: −1.4, 8.4] mm; P < 0.0001). Overall, 48.7% (55/113) of LAD CTOs had a stent that extended into an MB after which target lesion failure was significantly higher compared to a stent that did not extend into an MB (26.3% vs 0%; P = 0.0004) or compared to an LAD CTO without an MB (26.3% vs 9.6%; P = 0.02). An MB was more common in LAD CTO than non-CTO LAD lesions. If present, approximately one-half of LAD CTOs had a stent extending into an MB that, in turn, was associated with worse outcomes. [Display omitted] [ABSTRACT FROM AUTHOR]

Background Cardiac computed tomography angiography derived fractional flow reserve (FFRCT) is a diastolic measurement and has emerged as a valuable non-invasive alternative to FFR in patients with stable coronary artery disease. It has, unlike FFR during coronary angiography, not been validated for the physiological evaluation of an isolated myocardial bridge (MB) so far. Case summary Our patient, previously known with a long myocardial bridge of the mid-segment of the left anterior descending artery, presented with a non-ST-segment elevation myocardial infarction that was treated by surgical unroofing of the MB. FFRCT after surgery confirms a major amelioration of coronary blood flow. Discussion Myocardial bridge may rarely present as a non-ST-segment elevation myocardial infarction. FFRCT has thus far been accepted as a useful diagnostic tool in stable coronary artery disease. Our case report suggests that cardiac computed tomography angiography may be considered a useful technique for anatomical and physiological evaluation of MBs. [ABSTRACT FROM AUTHOR]

AIM: The main objective is to investigate the value of the treadmill exercise test (TET) in relation to myocardial bridge through various clinical characteristic and risk factor for guiding the clinical therapy of myocardial bridging (MB) patients. METHOD: This was cross-sectional, single centre, observational prospective study conducted from January 2022 to June 2023. Total coronary angiography was performed on 4,321 cases of angina pectoris and suspected myocardial infarction at our hospital, 104 cases were confirmed as myocardial bridges, and exercise stress test was performed on 44 cases among them was investigated and evaluated the relationship between the TET results and the patients clinical characteristics, including sex, age, bridge length, reference diameter in systole and diastole and the degree of systolic stenosis. RESULTS: No Statistical differences were found between baseline clinical characteristic (age, sex, clinical features, ECG findings) between the Nobel I with less than 50% of systolic stenosis and the Nobel II with more than 50% of systolic stenosis. Quantitative coronary data in study population mean ref. vessel diameter was 2.41±0.33 mm, and the diastolic vessel diameter was 2.16±0.44 mm, 85% of the ref. vessel diameter, and the systolic vessel diameter was 1.16±0.43 mm, 46% of the ref. vessel diameter. The average systolic stenosis rate was 45±18% on average. The average myocardial bridge length was 11.86 ±4.92 mm, which did not match the degree of systolic compression. 44 patients performed the Treadmill exercise test in which 34 cases (77%) positive and 10 cases (23%) negative. No relationships were found between the quantitative coronary data, bridge length, lesion location, bridge compression, and Treadmill exercise test results and between the positive and negative groups. CONCLUSION: Our study found that patients with MB had high positive rate of treadmill exercise test. it is judged that various mechanisms other than simple mechanical compression may be involved as the cause of myocardial ischemic symptoms. The treadmill exercise test can improve our understanding of the characteristics of blood supply to them yo cardium,clarify whether MB can cause myocardial ischemia and help develop appropriate treatment strategies for MB patients [ABSTRACT FROM AUTHOR]

Introduction: Myocardial bridges (MB) are congenital anomalies of hearts observed as muscle fibers covering epicardial branches of the coronary artery. The left anterior descending artery (LAD) was found to be commonly showing myocardial bridges (MBs). Clinically, MBs were claimed to cause varied symptomatology. The data on the morphology and prevalence of MBs in fetuses was limited, despite the commonly accepted congenital origin. Material and methods: Fetal hearts obtained from 37 fetuses from the donation program were used. The hearts were dissected out from the thorax by standard dissection procedure. The pericardium and epicardium were dissected. The coronary arteries were delineated, and MBs were observed and noted. The coronary artery segment having MBs, its distance from the ostium as well as the direction and length of the MBs were studied. Results: The MBs were observed in 20 out of 37 fetal hearts studied over the left anterior descending, right coronary, posterior interventricular and circumflex arteries. The mid or distal part of the coronary arteries frequently exhibited MBs. The mean length of the MB was 4.2 mm, with MBs being situated about 1.5 cm away from the coronary ostium. The oblique pattern of MB was more frequently noted. Conclusion: The morphology and prevalence of fetal MBs showed common occurrence in the LAD artery, with a predominant oblique morphological pattern. [ABSTRACT FROM AUTHOR]

Abstract Background The treatment of coronary artery disease combined with severe atherosclerotic stenosis proximal to a left anterior descending artery myocardial bridge (LAD-MB) is still controversial. This study aimed to analyze the outcomes of surgical intervention in patients with severe atherosclerotic stenosis proximal to a LAD-MB. Methods We retrospectively reviewed all patients with coronary artery disease combined with severe atherosclerotic stenosis proximal to the LAD-MB. The enrolled criteria were systolic compression of LAD more than or equal to 50% and atherosclerotic stenosis proximal to the LAD-MB more than or equal to 70%. All patients suffered from anginal symptoms refractory to medical therapy. All patients received supra-arterial myotomy and coronary artery bypass grafting (CABG) procedures. Clinical characteristics, intraoperative findings, and postoperative outcomes were evaluated. Results Between 2004 and 2021, sixteen patients underwent supra-arterial myotomy and CABG procedure. The compression and length of LAD-MB were 63 ± 17.9% and 25.9 ± 16.3 mm, respectively. Of the 16 patients, one patient had a LAD-MB and proximal coronary stenosis, and 15 patients had LAD-MBs and multivessel lesions. All patients survived and recovered uneventfully without in-hospital mortality or severe complications. The median transfusion amount of red blood cells in the operation was 2 units, and no patients required unplanned reoperation for bleeding. The average length of intensive care unit stay was 2.74 days. Fifteen patients were followed up for 6–146.1 months (mean 45.3 ± 42.9 months). One patient had a recurrence of angina pectoris one year after surgery, and 14 patients had no symptoms of myocardial ischemia during the follow-up period. Significant improvement in symptoms and quality of life using the Seattle Angina Questionnaire assessment was observed in all five categories after surgery (p

Background: The aim of this multicenter study was to evaluate the prevalence and features of dual left anterior descending artery (LAD) subtypes using coronary CT angiography (CCTA). Methods: A retrospective multicenter analysis of 2083 CCTA from December 2020 to November 2022 was conducted to search for the presence and morphological features of dual LAD. The two classifications used were the updated classification of Spindola-Franco and the Jariwala classification. Statistical tests were conducted to evaluate the prevalence of dual LADs among sexes and its association with angina in patients without significant coronary stenoses and/or associated cardiac anomalies. Results: Dual LAD was observed in 124 (5.96%) patients analyzed. According to the Spindola-Franco revisited classification, type I dual LAD was the most common (71/124, 57.26%). According to the Jariwala classification, all cases were group I. In the general population, there was a higher prevalence of dual LAD among females (7.3% females vs. 5.1% males; p value: 0.04). No statistically significant difference was found in the prevalence of angina in the dual LAD population compared to the no dual LAD population (2.1% vs. 1.5%; p value: 0.10). Conclusions: The acknowledgment and reporting of LAD duplication is helpful for an optimal management of coronary patients with this condition. Dual LAD was more frequent in the female population, mainly not related with angina. Myocardial bridge was more frequent in the dual LAD population than in the no dual LAD population. [ABSTRACT FROM AUTHOR]

To assess the effect of beta-blocker treatment on left ventricular global longitudinal strain (LV Gls) as measured by echocardiography in patients with MB (Myocardial Bridge). Between January 2019 and February 2022, a prospective, single-center study was undertaken in which myocardial bridging was identified in individuals who had coronary angiography. One hundred patients with myocardial bridging were systematically recruited and strain echocardiography was performed. Patient data were analysed in two groups – those who weren't using beta-blockers in the last six months (Group I: n = 50) vs. those who were (Group II: n = 50). One hundred patients participated in the study (38 females, 62 males; average age: 57.4 years). There was a statistically significant difference in the mean heart rate between groups I and II (p < 0.001). LV Gls was found to be statistically significantly improved in favour of group II when compared to group I [Group I: (–12.57)±3 vs. Group II: (–15.92)±2.9, p < 0.001]. The negative chronotropic effect of beta-blocker medication in individuals with MB identified by coronary angiography has a beneficial effect on LV Gls as measured by echocardiography. [ABSTRACT FROM AUTHOR]

Myocardial bridging (MB) is the most frequent congenital coronary anomaly characterized by a segment of an epicardial coronary artery that passes through the myocardium. MB is an important cause of myocardial ischemia and is also emerging as a possible cause of myocardial infarction with non-obstructed coronary arteries (MINOCA). There are multiple mechanisms underlying MINOCA in patients with MB (i.e., MB-mediated increased risk of epicardial or microvascular coronary spasm, atherosclerotic plaque disruption and spontaneous coronary artery dissection). The identification of the exact pathogenetic mechanism is crucial in order to establish a patient-tailored therapy. This review provides the most up-to-date evidence regarding the pathophysiology of MINOCA in patients with MB. Moreover, it focuses on the available diagnostic tools that could be implemented at the time of coronary angiography to achieve a pathophysiologic diagnosis. Finally, it focuses on the therapeutic implications associated with the different pathogenetic mechanisms of MINOCA in patients with MB. [ABSTRACT FROM AUTHOR]

• Surgical unroofing via standard median sternotomy or minimally invasive approaches stands as an effective treatment for symptomatic and hemodynamically significant myocardial bridges. Myocardial bridges (MB) are a congenital variant in which an epicardial coronary artery—most commonly the left anterior descending (LAD)—is contained within an intramyocardial segment. The clinical significance of this lesion varies from no symptoms to debilitating angina, ventricular arrhythmia, and even sudden cardiac arrest. Traditionally difficult to diagnose, symptomatic myocardial bridges remain an elusive entity with a lack of clarity regarding medical treatment and surgical indications. Importantly, studies have shown that with appropriate patient selection, MB unroofing is an effective treatment for symptomatic lesions, in both the adult and pediatric populations. This article describes the preoperative evaluation and the surgical approach for myocardial bridges. Myocardial bridges (MB) are a congenital variant in which an epicardial coronary artery—most commonly the left anterior descending (LAD)—is contained within an intramyocardial segment. The clinical significance of this lesion varies from no symptoms to debilitating angina, ventricular arrhythmia, and even sudden cardiac arrest Traditionally difficult to diagnose, symptomatic myocardial bridges remain an elusive entity with a lack of clarity regarding medical treatment and surgical indications. Importantly, studies have shown that with appropriate patient selection, MB unroofing is an effective treatment for symptomatic lesions, in both the adult and pediatric populations. This article describes the pre-operative evaluation and the surgical approach for myocardial bridges. [ABSTRACT FROM AUTHOR]

Introduction: Myocardial bridge (MB) is usually defined as the segment of the coronary artery (epicardial) which passes intramurally. In the early days, it was not having any clinical importance, but later studies showed the presence of it in the left anterior descending (LAD) artery can be associated with myocardial infarction and cardiac death suddenly. Material and Methods: The aim of this study was mostly to assess the profile of patients with the MB on coronary angiography and to evaluate its association with atherosclerotic disease in the coronary artery at a tertiary care hospital in Rajasthan. In this study, evaluation was done (retrospectively) of the angiographic reports of the patients, and the prevalence of MB was seen totally, individually, or in combination with LAD, left circumflex, and right coronary artery. Results: Out of all 140 patients, 125 (89%) were males, and 15 (11%) were females. Among 140, the mean age of the patients having MB was 55.51 years. Out of 140 patients, 46% (65 patients) had diabetes, 41% (58 patients) had hypertension, and 42% (59 patients) were found to be smoker. Conclusion: The prevalence of MB in our study is similar to what is reported in the literature. The most common location of the MB was the mid-LAD segment.

We reviewed previously reported imaging features of coronary air embolism. We also reported an unusual image ‘rebound sign’ of proximal coronary artery air embolism for the first time, that is, with the regular contraction and relaxation of the heart, the contrast medium near the embolus rebounds regularly, and the smooth gas-liquid boundary is alternately clear and blurred. We conclude that myocardial bridge plays a role in the formation of ‘rebound sign.’ Abbreviations: CAE: Coronary Air Embolism; CAG: Coronary Angiography; RCA: Right Coronary Artery; LCA: Left Coronary Artery; LAD: Left Anterior Descending Coronary Artery; LCX: Left Circumflex Artery; MB: Myocardial Bridge; STEMI: ST Segment Elevation Myocardial Infarction; TOE: Transesophageal Echocardiography

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Background: The treatment of coronary artery disease combined with severe atherosclerotic stenosis proximal to a left anterior descending artery myocardial bridge (LAD-MB) is still controversial. This study aimed to analyze the outcomes of surgical intervention in patients with severe atherosclerotic stenosis proximal to a LAD-MB. Methods: We retrospectively reviewed all patients with coronary artery disease combined with severe atherosclerotic stenosis proximal to the LAD-MB. The enrolled criteria were systolic compression of LAD more than or equal to 50% and atherosclerotic stenosis proximal to the LAD-MB more than or equal to 70%. All patients suffered from anginal symptoms refractory to medical therapy. All patients received supra-arterial myotomy and coronary artery bypass grafting (CABG) procedures. Clinical characteristics, intraoperative findings, and postoperative outcomes were evaluated. Results: Between 2004 and 2021, sixteen patients underwent supra-arterial myotomy and CABG procedure. The compression and length of LAD-MB were 63 ± 17.9% and 25.9 ± 16.3 mm, respectively. Of the 16 patients, one patient had a LAD-MB and proximal coronary stenosis, and 15 patients had LAD-MBs and multivessel lesions. All patients survived and recovered uneventfully without in-hospital mortality or severe complications. The median transfusion amount of red blood cells in the operation was 2 units, and no patients required unplanned reoperation for bleeding. The average length of intensive care unit stay was 2.74 days. Fifteen patients were followed up for 6–146.1 months (mean 45.3 ± 42.9 months). One patient had a recurrence of angina pectoris one year after surgery, and 14 patients had no symptoms of myocardial ischemia during the follow-up period. Significant improvement in symptoms and quality of life using the Seattle Angina Questionnaire assessment was observed in all five categories after surgery (p < 0.01). Conclusions: Based on the results, supra-arterial myotomy and concomitant bypass surgery may be a better option for the treatment of LAD-MB combined with severe proximal stenosis. [ABSTRACT FROM AUTHOR]

Myocardial bridging (MB) was historically considered a benign structure as most people with MB are clinically asymptomatic. Recently, however, mounting evidence indicates that MB can cause adverse cardiac events owing to arterial systolic compression/diastolic restriction, atherosclerotic plaque progression upstream from MB, and/or vasospastic angina. In MB patients with refractory angina, the optimal treatment strategy should be determined individually based on versatile anatomic and hemodynamical assessments that often require multidisciplinary diagnostic approaches. The present review summarizes the clinical implication and management of MB, highlighting the role of imaging modalities currently available in this arena. [ABSTRACT FROM AUTHOR]

Background Percutaneous transluminal septal myocardial ablation (PTSMA) is an effective means for symptomatic patients with hypertrophic cardiomyopathy (HCM). We present a rare case in which myocardial bridge (MB) was exacerbated in a patient with HCM treated with PTSMA. Case summary Here, we present a case of HCM with palpitations and exertional dyspnoea for 2 years. There was no obvious epicardial coronary artery compression before PTSMA. Typical angina occurred 2 months after PTSMA. Coronary angiography showed no obvious stenosis of the coronary arteries, but an exacerbated MB in the middle part of the left anterior descending artery. Discussion This patient with HCM presented with typical angina, which might be caused by the rare exacerbation of the MB after PTSMA. Thus, patients with MB should carefully choose PTSMA. Future research is needed for HCM patients complicated with MB treated with PTSMA. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the prognostic impact of nitrate therapy in patients with myocardial bridge (MB) and coexisting coronary artery spasm (CAS). MB often accompanies CAS. Nitrates have been widely used as anti-ischemic drugs in CAS patients, while it is not recommended in MB patients. Thus, we investigated the long-term impact of nitrate on clinical outcomes in patients with both CAS and MB. A retrospective observational study was performed using propensity score matching (PSM) in a total of 757 consecutive MB patients with positive acetylcholine (Ach) provocation test. Patients were divided into two groups according to the regular administration of nitrates (nitrate group: n = 504, No nitrate group; n = 253). The PSM was used to adjust for selection bias and potential confounding factors, and major clinical outcomes were compared between the two groups up to 5 years. Baseline characteristics were well-matched between the two groups following PSM (n = 211 for both groups). There was no significant difference in the incidence of death, myocardial infarction, and major adverse cardiovascular events (MACEs) between the two groups. However, the nitrate group showed a significantly higher rate of recurrent angina which subsequently needed re-evaluation of coronary arteries by follow-up angiography (15.7 vs. 5.7%, Log-rank p = 0.012) compared to the non-nitrate group. Long-term nitrate administration in patients with MB and coexisting CAS did not show benefit in reducing MACE, rather it was associated with a higher incidence of recurrent angina requiring follow-up angiography. [ABSTRACT FROM AUTHOR]

Positive ischemia by noninvasive imaging studies often results in nonobstructive disease in cardiac catheterization. In this case, we observed ischemia by nuclear stress test in only the anteroseptal area, and the apex is free of ischemia. Coronary angiogram findings were unremarkable, but intravascular ultrasound confirmed the long length of the myocardial bridge. Further testing with spasm provocation and microvascular testing showed diffuse epicardial spasm in this area of myocardial bridge without microvascular dysfunction. We observed the myocardial bridge but no microvascular dysfunction. This case illustrates the coexistence of spasm in the area of a myocardial bridge and the challenges in the medical management of these patients. (Level of Difficulty: Advanced.)

Introduction: Myocardial bridge is a morphological anomaly of the heart characterised by the presence of a myocardial segment above a coronary artery, which results in a higher risk of cardiovascular events. In patients with prostate cancer treated with androgen receptor-targeted agents, a higher risk of cardiotoxicity was observed. Case report: An 88 years old man with metastatic castration-resistant prostate cancer in treatment with enzalutamide, denosumab, and triptorelin presented to our attention complaining dyspnoea and angina pectoris. Management and outcome: Blood examinations revealed normal Troponin I levels. Transthoracic echocardiography revealed no signs of acute myocardial ischaemia. The treadmill stress test revealed S-T tract under levelling in V4–V6 with a very slow resolution. Coronary angiography identified a myocardial bridge in the medium tract of the interventricular anterior artery. Due to these findings, ranolazine and simvastatin were started and, after multidisciplinary assessment, we decided to continue the treatment with enzalutamide. At the first follow-up visit echocardiography found out the cardiological reports stability and no therapy changes were performed. During follow-up visit cardiological revaluation showed reports stability and no therapy changes were performed. Discussion: Due to the high prevalence of prostate cancer in elderly patients at high cardiovascular risk and the increasing use of androgen receptor-targeted agent, a multidisciplinary approach is highly recommended to weigh survival benefits on toxicities. This case report may support the use of androgen receptor-targeted agent in elderly patients with controlled cardiovascular diseases, a population that is often excluded from randomised trials. [ABSTRACT FROM AUTHOR]

This study aims to clarify the impact of myocardial bridge (MB) on the presence and progression of atherosclerosis in left descending coronary artery (LAD) in patients with acute coronary syndrome (ACS). Ninety-eight patients who underwent percutaneous coronary intervention with the diagnosis of ACS and follow-up coronary angiography but had no significant stenosis in the LAD were included. MB was defined based on coronary angiography. Quantitative coronary angiography was performed to determine the segments where MB was present and proximal to the MB (proximal segment) in patients with MB. In patients without MB, a corresponding region was quantitatively analyzed. The primary endpoint was changes in minimum lumen diameter (MLD) and percentage of diameter stenosis (%DS) in the proximal segment from baseline to follow-up angiography, namely ΔMLD and Δ%DS. MB was identified in 29 (29.6%) patients. Patients with MB had larger MLD and smaller %DS in the proximal segment than their counterpart. During the mean follow-up period of 12.9 ± 5.7 months, MLD and %DS in the proximal segment did not change significantly from baseline to follow-up in patients with and without MB. No significant between-group differences were observed in ΔMLD and Δ%DS. Baseline MLD was identified as the only factor associated with ΔMLD in the proximal segment. ACS patients who had MB but no significant stenosis in the LAD had larger MLD and smaller %DS at the segment proximal to MB compared to those without. In this selected population, serial lumen changes assessed by ΔMLD were not associated with the presence of MB in the LAD. [ABSTRACT FROM AUTHOR]

Objective To investigate the CT flow reserve fraction (FFRCT) in evaluating myocardial ischemia induced by left anterior descending branch (LAD) myocardial bridge (MB) and the risk factors of FFRCT abnormality in the LAD mural coronary artery (MCA) segment with MB and calcified plaque. Methods A total of 124 patients diagnosed as LAD MB (60) or middle LAD MB with proximal MCA calcified plaque (64) by CT coronary angiography were selected. The Kappa test was used to compare the consistency between the criteria for diagnosing myocardial ischemia with the FFRCT of MCA segment ≤0.8 and the clinical criteria for myocardial ischemia. 64 patients with MB and calcified plaque were divided into abnormal FFRCT group (FFRCT≤0.8) or normal FFRCT group (FFRCT>0.8). Logistic regression was used to analyze the risk factors of abnormal FFRCT of MCA segment in MB with calcified plaque. Results The Kappa consistency test between the criteria for diagnosing myocardial ischemia and the criteria for clinically diagnosing myocardial ischemia was better (Kappa value=0.773, P<0.001) when FFRCT of MCA segment was ≤0.8. MB combined with calcified plaque was significantly (P=0.005) more likely to have myocardial ischemia symptoms (43.75%) than MB without plaque (20.00%). When MB was combined with calcified plaque, logistic regression analysis showed that the degree of coronary artery stenosis at the calcified plaque (OR=3.428, P=0.040), the plaque calcification score (OR=1.022, P=0.027), and the degree of MCA constriction and stenosis (OR=1.171, P=0.012) were risk factors for abnormal FFRCT values in the MCA segment. Conclusion Myocardial ischemia induced by LAD MB can be assessed by monitoring the FFRCT of the MCA segment of the LAD. In middle LAD MB combined with proximal MCA calcified plaque, the degree of coronary artery stenosis at the calcified plaque, plaque calcification score, and the degree of MCA stenosis are risk factors for abnormal FFRCT value in the MCA segment. [ABSTRACT FROM AUTHOR]

Arash Nemat,1– 3 Atiqullah Majeedi,2 Abdul Wahed Sediqi,2,4 Qingchun Zeng1 1Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, People’s Republic of China; 2Department of Cardiology, Ariana Medical Complex, Kabul, Afghanistan; 3Department of Microbiology, Kabul University of Medical Sciences, Kabul, Afghanistan; 4Department of Cardiology, Ali Abad Teaching Hospital, Kabul University of Medical Sciences, Kabul, AfghanistanCorrespondence: Qingchun Zeng, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, People’s Republic of China, Email qingchunzeng@smu.edu.cn Arash Nemat, Department of Cardiology, Ariana Medical Complex, Kabul, Afghanistan, Email dr.arashnemat@yahoo.comAbstract: Myocardial bridge (MB) is a congenital coronary anomaly in which a portion of the coronary artery courses intramyocardium instead of the normal trajectory on the epicardial surface. We report a case study with a 44-year-old man from Faryab Province in Afghanistan who presented chest pain and dizziness while suffering a common cold. After full investigation, the patient underwent coronary angiography which showed a myocardial bridge at the middle portion of the left anterior descending artery (LAD) with a significant stenosis causing ischemia. We treated the patient with a calcium channel blocker as initial treatment. The patient tolerated the medication well and remained asymptomatic during two years follow-up.Keywords: myocardial bridge, coronary angiography, case report

The adenosine stress test and exercise stress test have been widely used in the diagnosis of coronary heart disease, which has high sensitivity and specificity for diagnosis of coronary heart disease. The myocardial bridge is a congenital dysplasia of the coronary artery which may cause severe myocardial ischemia, acute myocardial infarction, arrhythmia, and sudden death. Although drug therapy for this disease is clear and widely used, indication for open-chest surgery is still vague. This case shows a patient with long-term chest pain undergoing the coronary computed tomographic angiography in our hospital 1 month ago, which showed the mild myocardial bridge in the left anterior descending (LAD) branch. Then, she did the mental stress-induced myocardial ischemia and cardiopulmonary exercise test which the results were negative. After the informed consent, the patient took the adenosine stress test and severe angina occurred during the test. Later, coronary angiography showed that the myocardial bridge caused 70% contraction of the middle segment of the LAD branch. In the case of long-term ineffective drug treatment, the patient underwent a open-chest surgery called coronary artery myotomy and her chest discomfort eventually recovered. To a degree, adenosine stress test may be more sensitive than exercise stress test in predicting the severity of coronary artery stenosis. Moreover, we may provide a unique direction of indication for surgeons to operate open-chest surgery on the myocardial bridge.

IntroductionAlthough the vast majority of patients with a myocardial bridge (MB) are asymptomatic, the anomaly was found to be associated with stable or unstable angina, vasospastic angina, acute coronary syndrome, and even malignant arrhythmias and sudden cardiac death in some cases.MethodsBy retrieving the relevant literature on MB from 1 January 1980 to 31 July 2022 from the Web of Science Core Collection (WoSCC) database, we used the bibliometric tools, including CiteSpace, VOS viewer, and alluvial generator, to visualize the scientific achievements on MB.ResultsA total of 630 articles were included. The number of published articles was in a fluctuating growth trend. These publications came from 37 contries, led by the USA and China. The leading country on MB was the United States, the leading position among institutions was Stanford University, and the most productive researcher on MB was Jennifer A. Tremmel. After analysis, the most common keywords were myocardial bridge, mortality, coronary angiography, descending coronary artery, and sudden death.ConclusionOur findings can aid researchers in understanding the current state of MB research and in choosing fresh lines of inquiry for forthcoming investigations. Prevalence and prognosis, mechanism atherosclerosis, hemodynamic significance, and molecular autops will likely become the focus of future research. In addition, more studies and cooperations are still needed worldwide.

Myocardial bridges are inborn anomalies frequently found in authopsies. Although tipically clinically silent, they are occasionally associated with severe clinical manifestations, e.g. myocardial ischemia or even sudden death. The pathophysiology and risk factors for these manifestations have not yet been completely elucidated. The connective tissue underneath the bridge has been considered as one of the factors the symptoms depend on. Thus, the aim of this research was to determine the histological characteristics of the connective tissue lying underneath the myocardial bridge and to contribute to a better understanding of the protective effects this passive compartment might have in prevention of severe clinical manifestations of myocardial bridging. The study was carried out on twenty hearts with myocardial bridges. Length of the bridge was determined using a precise electronic caliper. Sections of the myocardial bridges with the underlying connective tissue were obtained and prepared for qualitative and quantitative analysis. The connective tissue underneath the bridges was composed of adipose tissue and loose connective tissue in different ratios. The tissue underneath thin bridges was predominantly composed of adipose tissue, while loose connective tissue was the dominant component under thick bridges. The myocardial bridges had an average thickness of 0,98 ± 0.44 mm and an average length of 15,25±5,65 mm. We found a strong positive correlation between the myocardial bridge thickness and length (r = 0,860, p = 0,0001). The thickness of the passive connective tissue compartment under the myocardial bridges was 0,58±0,22 mm, and there was no correlation between this parameter and the myocardial bridge thickness (r = -0,011; p = 0,963). In the clinical evaluation of patients with these anomalies it is necessary to take into account independently the myocardial bridge thickness and length on one side and the thickness of the connective tissue lying underneath it on the other. [ABSTRACT FROM AUTHOR]

Background: This study aims to clarify whether myocardial bridge (MB) could influence atherosclerotic plaque characteristics assessed 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 three segments: proximal, MB, and distal segments. In non-MB patients, corresponding three 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. Conclusions: 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. [ABSTRACT FROM AUTHOR]

We reviewed previously reported imaging features of coronary air embolism. We also reported an unusual image 'rebound sign' of proximal coronary artery air embolism for the first time, that is, with the regular contraction and relaxation of the heart, the contrast medium near the embolus rebounds regularly, and the smooth gas-liquid boundary is alternately clear and blurred. We conclude that myocardial bridge plays a role in the formation of 'rebound sign.' Abbreviations: CAE: Coronary Air Embolism; CAG: Coronary Angiography; RCA: Right Coronary Artery; LCA: Left Coronary Artery; LAD: Left Anterior Descending Coronary Artery; LCX: Left Circumflex Artery; MB: Myocardial Bridge; STEMI: ST Segment Elevation Myocardial Infarction; TOE: Transesophageal Echocardiography [ABSTRACT FROM AUTHOR]

Background: The possibility of myocardial bridging (MB) causing chest pain has been widely reported; however, the effect of MB on coronary microvessels has not been thoroughly investigated. Therefore, this study evaluated the effects of MB on epicardial coronary artery and coronary microvascular function during coronary angiography (CAG) and coronary function test (CFT) in patients with ischaemia with non-obstructive coronary artery disease (INOCA). Methods: This study included 62 patients with INOCA who underwent CAG and CFT for the left anterior descending coronary artery (LAD) to evaluate chest pain. In the CFT, acetylcholine was first administered intracoronarily in a stepwise manner, followed by chest symptoms, electrocardiographic ST-T changes and CAG. Positive coronary spasm was defined as coronary vasoconstriction of >90% on CAG accompanied by chest symptoms or electrocardiographic ST-T changes. After nitroglycerin administration, CAG was performed to assess MB, which was defined as systolic narrowing of the coronary artery diameter by >20% compared with that in diastole. Coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) were subsequently obtained via transvenous adenosine triphosphate infusion using a pressure wire. Coronary microvascular vasodilatory dysfunction (CMD) was defined as a CFR of <2.0 or an IMR of ≥25 units. Results: Of the 62 patients, 15 (24%) had MB. The patients' characteristics did not differ between the two groups. Regarding the CAG and CFT results, the presence of coronary spasm in the LAD was higher in the MB (+) group (87%) than in the MB (−) group (53%, p = 0.02), whereas the values of CFR (MB (+): 2.7 ± 1.4, MB (−): 2.8 ± 1.1) and IMR (MB (+): 26.9 ± 1.0, MB (−): 30.0 ± 17.3) and the presence of CMD (MB (+): 53%, MB (−): 60%) were similar in the two groups. Conclusions: The findings suggest that MB predisposes patients with INOCA to coronary spasms. Conversely, MBs may have a limited effect on microvessels, particularly in such patients. [ABSTRACT FROM AUTHOR]

In this letter, we comment on a recent case report by Sun et al in the World Journal of Cardiology . The report describes the successful management of a rare complication: The unloading or detachment of a bioresorbable stent (BRS) during percutaneous coronary intervention (PCI) in a male patient. The unloading of BRS was detected via angiography and intravascular ultrasound (IVUS) imaging of the left coronary artery and left anterior descending artery. Although this case is interesting, the authors' report lacked crucial details. Specifically, insufficient information about the type of BRS used, potential causes of BRS unloading, or whether optical coherence tomography (OCT) imaging for coronary arteries was performed before, during, or after PCI. The OCT imaging of coronary arteries before PCI can potentially prevent BRS unloading due to its higher resolution compared to IVUS. In addition, despite detecting myocardial bridging during the PCI, the authors did not provide any details regarding this variation. Here we discuss the various types of BRS, the importance of OCT in PCI, and the clinical relevance of myocardial bridging., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background: Myocardial bridge (MB) is a common coronary anomaly characterized by a tunneled course through the myocardium. Coronary computed tomography angiography (CCTA) can identify MB. The impact of MB detected by CCTA on coronary physiological parameters before and after percutaneous coronary intervention (PCI) is unknown., Methods and Results: We investigated 141 consecutive patients who underwent pre-PCI CCTA and fractional flow reserve (FFR)-guided elective PCI for de novo single proximal lesions in the left anterior descending artery (LAD). We compared clinical demographics and physiological parameters between patients with and without CCTA-defined MB. MB was identified in 46 (32.6%) patients using pre-PCI CCTA. The prevalence of diabetes was higher among patients with MB. Median post-PCI FFR values were significantly lower among patients with than without MB (0.82 [interquartile range 0.79-0.85] vs. 0.85 [interquartile range 0.82-0.89]; P=0.003), whereas pre-PCI FFR values were similar between the 2 groups. Multivariable linear regression analysis revealed that the presence of MB and greater left ventricular mass volume in the LAD territory were independently associated with lower post-PCI FFR values. Multivariable logistic regression analysis also revealed that the presence of MB and lower pre-PCI FFR values were independent predictors of post-PCI FFR values ≤0.80., Conclusions: CCTA-defined MB independently predicted both lower post-PCI FFR as a continuous variable and ischemic FFR as a categorical variable in patients undergoing elective PCI for LAD.

Abstract 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.

Background: Of particular interest are the studies researching the correlations of myocardial bridges with hypertrophic cardiomyopathy and correlations of thick myocardial bridges with the development of coronary atherosclerosis in the proximal to the bridge arterial part. Material and methods: Assessment of the correlation between myocardial bridges, coronary atherosclerosis, and the degree of hypertrophy of the left ventricle was performed by retrospective analysis of 6168 coronary angiography protocols (2012-2019) and echocardiographic data from patients’ clinical records. Results: Moderate systolic compression predominated, and the number of patients detected with severe under the bridge systolic coronary stenosis was double as in patients with nonsignificant coronary atherosclerosis. From the total number, patients with myocardial hypertrophy and myocardial bridges were twice less when compared with the patients with the normal myocardial thickness. The comparative research did not show any interdependence between the degree of vascular compression and the degree of left ventricular myocardial hypertrophy. Proximal to the bridges atherosclerosis was detected in 32% of cases without correlation with the force of the myocardial bridge. Conclusions: The study showed the absence of the correlation between the degree of arterial stenosis caused by the bridge and the degree of hypertrophy of the ventricular myocardium as well as the degree of proximal to the bridge atherosclerosis. Important finding was that the degree of coronary systolic compression is higher in patients with moderate and severe proximal to the bridge atherosclerosis.

Background Cardiac amyloidosis (CA) is a rapidly progressive infiltrative cardiomyopathy, whose role is emerging as a not-so-rare disorder leading to heart failure (HF). Myocardial bridge (MB) is the most common inborn coronary artery variant, and its clinical relevance is still matter of debate. The exceptional coexistence of these two conditions could accelerate disease progression and worsen the already compromised clinical conditions. Case summary We present the case of a 76-year-old female patient experiencing relapsing HF decompensation and presenting to our centre with dyspnoea at rest and severe peripheral congestion. Echocardiogram showed severe concentric hypertrophy, severe biventricular contractile dysfunction, and third-degree diastolic dysfunction. Coronary angiography excluded epicardial atherosclerotic disease, though displaying a long intramyocardial course of left anterior descending artery. Physiological invasive test was achieved in terms of instantaneous wave-free ratio (iFR), both at baseline and after inotropic and chronotropic stimuli, and attested haemodynamic significance. Concurrently, the diagnostic flow chart for CA was accomplished, by means of both invasive (periumbilical fat biopsy, bone marrow aspiration) and non-invasive tests (99mTc-diphosphonate scintigraphy, serum-urine immunofixation) that confirmed the suspect of primary amyloidosis. Acute HF therapy was personalized according to the singularity of the case, avoiding both nitrates and beta-blockers, then first cycle of chemotherapy was started. Discussion Our clinical case shows a unique interaction between infiltrative cardiomyopathy and coronary artery abnormality. Amyloidosis can contribute to the ischaemic burden of the MB and this may, in turn, abbreviate the path to HF decompensation. [ABSTRACT FROM AUTHOR]

Myocardial bridge (MB) is generally considered as a benign condition, but it may trigger atherosclerosis, especially in the adjacent proximal coronary artery segment. In this study, we aimed to investigate whether the Framingham risk score (FRS) or atherogenic indices are risk factors for coronary atherosclerosis in patients with MB in the left anterior descending coronary artery (LAD). We performed a retrospective study evaluating 155 patients who have MB in LAD. The patients were evaluated in two groups according to the presence of atherosclerosis (74 patients in atherosclerotic group vs. 81 patients in non-atherosclerotic group). Baseline characteristics, FRS and atherogenic indices were reviewed between groups. Significant independent risk factors for coronary atherosclerosis were investigated by logistic regression analysis. Patients in atherosclerotic group were significantly older (58.15 ± 10.04 vs. 50.22 ± 9.27 years, p <.001) and 74.3% of the patients were male. While the mean FRS in the atherosclerotic group was 21.20 ± 8.81, it was 12.79 ± 8.61 in the non-atherosclerotic group (p <.001). Among the atherogenic indices, only LDL-c/HDL-c ratio was significantly higher in the atherosclerotic group (3.49 ± 1.2 vs. 3.11 ± 0.98, p:.033). Multivariable analysis showed that age (OR: 1.08, 95% CI 1.03–1.13, p <.001) and FRS (OR: 1.06, 95% CI 1.01–1.11, p:.012) were independently associated with the presence of atherosclerotic lesion. FRS is an easily applicable predictor in clinical practice that indicates the presence of coronary atherosclerosis in patients with MB in LAD. [ABSTRACT FROM AUTHOR]

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Objective: Left anterior descending Myocardial Bridge (LADMB) is considered a benign condition and actually becomes a forgotten cause of serious cardiac events. This study was conducted to estimate the prevalence of LADMB and its association to atherosclerosis. Methods: An observational retrospective study was conducted on patients referred for coronary angiography between June 2012 and June 2020. Coronary angiography database was revisedand studied population was divided into 2 groups: LADMB group versus Non-LADMB group. Results: LADMB was detected in 510 patients out of 35813 included in the study resulting in a prevalence at 1.42%. The mean age was 66.5 years. Male gender was more common than female (70vs30%). The prevalence of significant atherosclerotic LAD disease was more than two times higher in the non-LADMB group compared to the LADMB group. Statistical analysis revealed a significant negative association between LADMB and atherosclerosis (p

Background: Myocardial bridges are variants of the intramyocardial position of the coronary arteries. In the specialty literature, hot topics in cardiovascular field are myocardial infarction and non-obstructive coronary artery disease with frequent connection with myocardial bridges. Material and methods: The morphological study was based on the analysis of 200 human hearts and fragments of coronary arteries. The retrospective study was focused on the analysis of 6168 coronary angiography reports, to identify patients with myocardial bridges, their preferred location, the degree of systolic stenosis, the association between myocardial bridges and proximal to bridge and under the bridge coronary atherosclerosis. Results: The complete myocardial bridges were described in 62% of the analyzed hearts and only in 5.3% of the total number of studied coronarographies. In the majority of cases, the complete myocardial bridges covered the anterior interventricular branch. The degree of subpontine arterial systolic stenosis varied within 10-95%. The comparative study did not determine any correlations between the degree of subpontine vascular compression and the degree of the left ventricular myocardial hypertrophy. In 32% of cases were described proximal to bridge atherosclerotic plaques and only in one case (0.5%) – distal to bridge atherosclerotic plaques, located immediately under the bridge. Conclusions: The research findings underline the differences in anatomical and angiographic incidence of myocardial bridges, and the inability of all bridges to reduce the lumen of under bridged artery. Current study emphasizes attention to the topography of bridges, the correlation with ventricular hypertrophy and coronary atherosclerosis.

Vascular structure segmentation in intravascular ultrasound (IVUS) images plays an important role in pre-procedural evaluation of percutaneous coronary intervention (PCI). However, vascular structure segmentation in IVUS images has the challenge of structure-dependent distractions. Structure-dependent distractions are categorized into two cases, structural intrinsic distractions and inter-structural distractions. Traditional machine learning methods often rely solely on low-level features, overlooking high-level features. This way limits the generalization of these methods. The existing semantic segmentation methods integrate low-level and high-level features to enhance generalization performance. But these methods also introduce additional interference, which is harmful to solving structural intrinsic distractions. Distraction cue methods attempt to address structural intrinsic distractions by removing interference from the features through a unique decoder. However, they tend to overlook the problem of inter-structural distractions. In this paper, we propose distraction-aware hierarchical learning (DHL) for vascular structure segmentation in IVUS images. Inspired by distraction cue methods for removing interference in a decoder, the DHL is designed as a hierarchical decoder that gradually removes structure-dependent distractions. The DHL includes global perception process, distraction perception process and structural perception process. The global perception process and distraction perception process remove structural intrinsic distractions then the structural perception process removes inter-structural distractions. In the global perception process, the DHL searches for the coarse structural region of the vascular structures on the slice of IVUS sequence. In the distraction perception process, the DHL progressively refines the coarse structural region of the vascular structures to remove structural distractions. In the structural perception process, the DHL detects regions of inter-structural distractions in fused structure features then separates them. Extensive experiments on 361 subjects show that the DHL is effective (e.g., the average Dice is greater than 0.95), and superior to ten state-of-the-art IVUS vascular structure segmentation methods. • We propose the distraction-aware hierarchical learning (DHL) for vascular structure segmentation in IVUS images. • We propose new structural perception module to detect inconspicuous regions from fused structure features. • We explore a strategy of structural grouping to improve the efficiency of the refinement of structures. • We use new trajectory attention to solve global morphological variability. • The DHL explores for the first time the segmentation of IVUS myocardial bridges. [ABSTRACT FROM AUTHOR]

Myocardial bridge (MB) is less commonly documented by angiography than autopsy. Optical coherence tomography (OCT) may be useful to detect angiographically undetectable MB. To investigate OCT characteristics of MB, 86 LAD vessels were imaged by OCT. MB was defined as presence of intermediate optical intensity, "fine" layer surrounding coronary artery by OCT. Frequency and characteristics of the angio-detectable and angio-undetectable but OCT-detectable MB were investigated. In a subset of patients with angio-detectable MB, cyclic changes in coronary arterial dimensions were analyzed. OCT detected MB in 44 of 86 (51%). Arc of the MB was significantly larger (334.8 ± 58.5° vs. 268.4 ± 92.1°, P = 0.008) and length was significantly longer (22.6 ± 11.7 mm vs. 14.5 ± 8.1 mm, P = 0.014) in angio-detectable MB than OCT-detectable but angio-undetectable MB. Both vessel (6.8 ± 1.5 to 5.3 ± 1.0 mm2, P = 0.035) and lumen area (4.4 ± 1.5 to 3.1 ± 0.7 mm2, P = 0.040) decreased significantly from diastole to systole. Adventitial (0.08 ± 0.03 to 0.08 ± 0.02 mm, P = 0.828) and intima + plaque thickness (0.12 ± 0.05 to 0.10 ± 0.03 mm, P = 0.398) did not change significantly during cardiac cycle. On the other hand, medial thickness increased significantly from diastole to systole (0.08 ± 0.03 to 0.12 ± 0.03 mm, P = 0.022). In conclusion, MB is frequently detected as intermediate intensity, fine layer by OCT. During systole, vessel and lumen size decrease with increased medial thickness. Therefore, we should be careful for OCT interpretation of the coronary arteries with MB. [ABSTRACT FROM AUTHOR]