Quantitative analysis of the relationship between the myocardial bridge and the FAI of pericoronal fat on computed tomography.

We performed this cohort study to investigate whether the myocardial bridge (MB) affects the fat attenuation index (FAI) and to determine the optimal cardiac phase to measure the volume and the FAI of pericoronary adipose tissue (PCAT). The data of 300 patients who were diagnosed with MB of the left anterior descending (LAD) coronary artery were retrospectively analyzed. All of patients were divided into the MB group and the MB with atherosclerosis group. In addition, 104 patients with negative CCTA results were enrolled as the control group. There was no significant difference between FAI values measured in systole and diastole (P > 0.05). There was no significant difference in FAI among the MB group, the MB with atherosclerosis group, and the control group (P > 0.05). In MB with atherosclerosis group, LAD stenosis degree (< 50%) (OR = 0.186, 95% CI 0.036-0.960; P = 0.045) and MB located in the distal part of LAD opening (OR = 0.880, 95% CI 0.789-0.980; P = 0.020) were protective factors of FAI value. A distance (from the LAD opening to the proximal point of the MB) of 29.85 mm had the highest predictive value for abnormal FAI [area under the curve (AUC), 0.798], with a sensitivity of 81.1% and a specificity of 74.6%.

Quantitative computed tomography angiography evaluation of the coronary fractional flow reserve in patients with left anterior descending artery myocardial bridging.

PURPOSE: To quantitatively investigate the effect of myocardial bridge (MB) in the left anterior descending artery (LAD) on the fractional flow reserve (FFR). MATERIALS AND METHODS: Three-hundred patients with LAD MB who had undergone coronary artery CT angiography (CCTA) were retrospectively enroled, and 104 normal patients were enroled as the control. The CCTA-derived fractional flow reserve (FFRCT) was measured at the LAD 10 mm proximal (FFR1) and 20-40 mm distal (FFR3) to the MB and at the MB location (FFR2). RESULTS: FFR2 and FFR3 of the MB (with BM only) and MBLA (with both MB and atherosclerosis) groups were significantly (p < 0.01) lower than those of the control. The FFR3 distal to the MB was significantly lower (p < 0.01) than that of the control. The FFRCT of the whole LAD in the MBLA group was significantly (p < 0.05) lower than that of the MB and control group (p < 0.05). MB length (OR 1.061) and MB muscle index (odds ratio or OR 1.007) were two risk factors for abnormal FFRCT, and MB length was a significant independent risk factor for abnormal FFRCT (OR = 1.077). LAD stenosis degree was a risk factor for abnormal FFRCT values (OR 3.301, 95% confidence interval [CI] 1.441-7.562, p = 0.005) and was also a significant independent risk factor (OR = 3.369, 95% CI: 1.392-8.152; p = 0.007) for abnormal FFRCT. CONCLUSION: MB significantly affects the FFRCT of distal coronary artery. For patients with MB without atherosclerosis, the MB length is a risk factor significantly affecting FFRCT, and for patients with MB accompanied by atherosclerosis, LAD stenotic severity is an independent risk factor for FFRCT.

Myocardial bridging in obstructive hypertrophic cardiomyopathy: a risk factor for myocardial fibrosis.

BACKGROUND: Myocardial bridging (MB) is common in patients with hypertrophic cardiomyopathy (HCM). There are sparse data on the impact of MB on myocardial fibrosis in HCM. This study was designed to evaluate the relationship between MB and myocardial fibrosis in patients with obstructive HCM. METHODS: In this cohort study, retrospective data were collected from a high-volume HCM center. Patients with obstructive HCM who underwent septal myectomy and preoperative cardiac magnetic resonance (CMR) were screened from 2011 to 2018. RESULTS: Finally, 492 patients were included in this study, with an average age of 45.7 years. Of these patients, 76 patients had MB. MB occurred mostly in the left anterior descending artery (73/76). The global extent of late gadolinium enhancement (LGE) was correlated with the degree of systolic compression (r = 0.33, p = 0.003). Multivariable linear regression analysis revealed that the degree of systolic compression was an independent risk factor for LGE (ß = 0.292, p = 0.007). The LGE fraction of basal and mid anteroseptal segments in patients with severe MB (compression ratio ≥ 80%) was significantly greater than that in patients with mild to moderate MB (compression ratio < 80%). During a median follow-up of 28 (IQR: 15-52) months, 15 patients died. Kaplan-Meier analysis did not identify differences in all-cause death (log-rank p = 0.63) or cardiovascular death (log-rank p = 0.72) between patients undergoing MB-related surgery and those without MB. CONCLUSIONS: MB with severe systolic compression was significantly associated with a high extent of fibrosis in patients with obstructive HCM. Concomitant myotomy or coronary artery bypass grafting might provide excellent survival similar to that of patients without MB. Identification of patients with severe MB and providing comprehensive management might help improve the prognosis of patients with HCM.

The Association Between Myocardial Bridging and Hypertrophic Cardiomyopathy and Their Implications on Percutaneous Coronary Intervention Outcomes: A Retrospective Study.

Hypertrophic cardiomyopathy (HCM) is a complex cardiac disorder, often associated with adverse outcomes, including sudden cardiac death. Myocardial bridging (MB), where a coronary artery segment traverses intramurally within the myocardium, complicates coronary blood flow dynamics. This retrospective study investigates the relationship between MB and HCM and their impact on percutaneous coronary intervention (PCI) outcomes. Data from the 2019 National Inpatient Sample (NIS), representing 20% of U.S. hospitalizations, was utilized. Patients with both HCM and MB undergoing PCI were identified and analyzed. The study assessed inpatient outcomes, including mortality, length of stay, hospital cost, and post-PCI complications (atrial fibrillation, acute kidney injury, bleeding, coronary dissection). Patients with HCM and MB exhibited distinct demographics. The study did not find significant associations between HCM/MB and inpatient mortality, length of stay, or hospital cost. However, HCM patients had a higher incidence of atrial fibrillation and acute kidney injury post-PCI (aOR 2.33, 95% CI 1.46 to 3.71, p ≤ 0.001). MB was linked to increased occurrences of acute heart failure (aOR 0.62, 95% CI 0.42-0.92, p = 0.02) and post-PCI bleeding (aOR 4.88, 95% CI 1.17-20.2, p = 0.03). This nationwide study reveals unique demographic profiles for HCM and MB patients. Notably, HCM patients face higher risks of post-PCI complications, including atrial fibrillation and acute kidney injury. These findings provide fresh insights into the MB-HCM relationship and its implications for PCI outcomes. They emphasize the need for tailored interventions and improved patient management in cases involving both HCM and MB.

Acute Myocardial Infarction Due to Myocardial Bridge Treated With Surgery: a Case Report.

Myocardial bridging is congenital anomaly characterized by segment of epicardial coronary arteries passing through the myocardium. Various ischemic conditions are related with this pathology. We report a case of myocardial bridging that was complicated with acute anterior myocardial infarction and a review of the literature. The patient was treated successfully with coronary bypass graft surgery after unsuccessful percutaneous intervention.

A Contemporary Review of the Genomic Associations of Coronary Artery Myocardial Bridging.

BACKGROUND: Myocardial bridging (MB) is a congenital coronary artery anomaly that has limited molecular disease state characterization. Though a large portion of individuals may be asymptomatic, the myocardial ischemia caused by this anomaly can lead to angina, acute coronary syndrome, coronary artery disease, and sudden cardiac death in patients. OBJECTIVE: This study aims to summarize and consolidate the current literature regarding the genomic associations of myocardial bridge development and, in doing so, prompt further investigation into the molecular basis of myocardial bridge development. METHODS: We performed a systematic literature review of myocardial bridging using the key search terms "Myocardial Bridging" AND ("Gene" OR "Allelic Variants" OR "Genomic") in the databases of PubMed, CINAHL, EMBASE, and Cochran. We then performed a detailed review of the resulting abstracts and a full-text screening, summarizing these findings in this report. RESULTS: In total, we identified eight articles discussing the associated genomics behind MB development. Studies included review articles, case reports and genomic studies that led to the discussion of several genes: DES (E434K), FBN1 (I1175M), and COMMD10; MACROD2, SLMAP, MYH7 (A1157G), and DPP6 (A714T); MYH7 (A862V); SCN2B (E31D); and NOTCH1 (R2313Q), and to the discussion of miRNAs (miR-29b, miR-151-3p, miR-126, miR-503-3p, and miR-645). CONCLUSIONS: Our study is the first to summarize the genes and molecular regulators related to myocardial bridges as they exist in the current literature. This work concludes that definitive evidence is lacking, warranting much broader genetic and genomic studies.

Case report: hunting the hidden: surgical treatment of chronic silent thrombus in the left ventricle in a young alcoholic patient with myocardial bridging.

BACKGROUND: A silent left ventricular thrombus is dangerous. The current standard anticoagulation therapy was ineffective in our case or similar, and the outcome was poor. CASE PRESENTATION: A 33-year-old man with a silent left ventricular thrombus was detected incidentally by transthoracic echocardiography. After admission, anti-coagulation with low-molecular-weight heparin therapy was carried out. The CAG revealed 70% systolic stenosis in the middle of the right coronary artery along with myocardial bridging. Unfortunately, an acute left temporal embolism emerged 5 days later, then the patient was transferred to the neurology department for further treatment. One month later, the patient underwent left ventricular thrombectomy, ventricular aneurysm resection, and coronary artery bypass grafting (CABG) and was discharged uneventfully after surgery. CONCLUSIONS: Surgical treatment should be a priority for patients with giant or hypermobile left ventricular thrombus or recurrent systemic emboli.

Unlocking Promising Therapies: Drug-Eluting Stents in Medically Refractory Angina Patients With Myocardial Bridging.

Myocardial bridging (MB) is a congenital variation in which a coronary artery segment tunnels through the myocardium instead of following its usual epicardial route. Although MB is usually diagnosed incidentally and has a good long-term prognosis, it can lead to complications such as angina, myocardial infarction, arrhythmias, and sudden death. This study aimed to evaluate the outcomes of drug-eluting stent (DES) implantation in patients with MB and medically refractory angina. The study included 12 patients with significant MB who did not respond to maximal medical therapy and underwent DES implantation. The patients were followed up for a mean duration of 33 months. The procedural success rate was 92%, with only 1 patient experiencing acute coronary artery rupture during the procedure. During the follow-up period, none of the patients reported angina symptoms, required additional percutaneous coronary intervention, or developed stent thrombosis. One patient (8.3%) died from a non-cardiac cause. The procedure demonstrates a high procedural success rate and leads to favorable long-term outcomes, including the absence of angina symptoms and the avoidance of stent-related complications. In conclusion, this study suggests that DES implantation can serve as an effective treatment option for selected patients with medically refractory angina and significant MB.

Comprehensive Management of ANOCA, Part 1-Definition, Patient Population, and Diagnosis: JACC State-of-the-Art Review.

Angina with nonobstructive coronary arteries (ANOCA) is increasingly recognized and may affect nearly one-half of patients undergoing invasive coronary angiography for suspected ischemic heart disease. This working diagnosis encompasses coronary microvascular dysfunction, microvascular and epicardial spasm, myocardial bridging, and other occult coronary abnormalities. Patients with ANOCA often face a high burden of symptoms and may experience repeated presentations to multiple medical providers before receiving a diagnosis. Given the challenges of establishing a diagnosis, patients with ANOCA frequently experience invalidation and recidivism, possibly leading to anxiety and depression. Advances in scientific knowledge and diagnostic testing now allow for routine evaluation of ANOCA noninvasively and in the cardiac catheterization laboratory with coronary function testing (CFT). CFT includes diagnostic coronary angiography, assessment of coronary flow reserve and microcirculatory resistance, provocative testing for endothelial dysfunction and coronary vasospasm, and intravascular imaging for identification of myocardial bridging, with hemodynamic assessment as needed.

Combined Computed Tomography Angiography-Computed Tomography Perfusion in the Identification and Prognostic Assessment of Myocardial Bridging from the CORE320 Study: 5-Year Follow-Up.

Our objective is to use computed tomography angiography (CTA) and computed tomography perfusion (CTP) to identify the ischemic significance of myocardial bridging (MB). We also seek to determine the long-term prognostication of MB in the presence or absence of obstructive coronary artery disease (CAD). The CORE320, a prospective, multicenter study including 381 patients with known or suspected CAD clinically referred for invasive coronary angiography who underwent combined (CTA-CTP) and single-photon emission computed tomography before conventional coronary angiography. The incidence of MB was identified in 135 patients (35.4%) with 93.9% identified in the left anterior descending artery. MB were divided as partially encased versus fully encased. There was no difference in ischemia identified between partially encased MB and fully encased MB (37 [40%] vs 25 [35%], p = 0.54]. Ischemia was identified at similar rates in partially versus fully encased MB by single-photon emission computed tomography at (8 [9%] vs 8 [11%], p = 0.57] and CTP (34 [37%] vs 21 [30%], p = 0.33]. There was no difference in the primary outcome of 5-year outcome of combined incidence of myocardial infarction or death. The restricted mean survival time in patients with CTA with <50% stenosis with or without a MB was 4.906 years (95% confidence interval 4.759 to 5.000) and 4.891 years (95% confidence interval 4.718 to 5.000), respectively (p = 0.824). Cardiac computed tomography perfusion imaging can assess both anatomic and functional significance of myocardial bridging with diagnostic accuracy similar to current standard imaging. Furthermore, 5-year cardiovascular events were not different with the presence of MB in both obstructive and non-obstructive CAD.

Diagnostic Ability of Perivascular Fat Attenuation Index in Predicting Atherosclerotic Plaque Formation Proximal to Myocardial Bridging of the Left Anterior Descending Artery within 3 Years.

RATIONALE AND OBJECTIVES: This study was designed to investigate the association between the perivascular fat attenuation index (FAI) and atherosclerotic plaque formation proximal to myocardial bridging (MB) of the left anterior descending artery (LAD) within 3 years. MATERIALS AND METHODS: LAD-MB patients who underwent coronary computed tomography angiography at least twice between January 2016 and December 2022 were retrospectively included in this study. In total, 99 LAD-MB patients were included in the study. Based on the formation of atherosclerotic plaques proximal to LAD-MB during follow-up, the patients were classified into two groups: LAD-MB with plaque formation and LAD-MB without plaque formation within 3 years. The anatomical features, clinical factors, and proximal perivascular FAI of LAD-MB were measured and recorded. The association of the previously mentioned factors with the presence of atherosclerotic plaque proximal to LAD-MB was determined. RESULTS: The results showed that MB length, MB stenosis, and the perivascular FAI were significant predictors of the formation of atherosclerotic plaques proximal to LAD-MB. The area under the curve of the combined predictive model incorporating MB length, MB stenosis, and the perivascular FAI was 0.901(95% confidence interval: 0.824-0.952), with higher diagnostic performance than any other single parameter (all P < 0.05). Moreover, dynamic changes in the perivascular FAI of the vascular segments proximal to LAD-MB were higher in high-risk plaques than in non-high-risk plaques (P = 0.003). CONCLUSION: The combined use of the perivascular FAI, MB length, and MB stenosis may enable prediction of the probability of atherosclerotic plaque formation proximal to LAD-MB within 3 years. Dynamic changes in perivascular FAI were associated with the vulnerability of plaques proximal to LAD-MB.

Clinically significant myocardial bridging.

Myocardial bridging is a common anatomical variant in which a major epicardial coronary artery takes an intramyocardial course, leading to dynamic systolic compression. Because coronary perfusion occurs primarily during diastole, most patients with this anatomical variant have no associated perfusion abnormalities or symptoms. Despite this, there is a subset of patients with myocardial bridging who experience ischaemic symptoms. Determining which anatomical variants are benign and which are clinically relevant remains a challenge. Further complicating the picture, functional factors such as diastolic dysfunction and coronary vasospasm may exacerbate myocardial bridging-related ischaemia. In patients with ischaemic symptoms in the absence of alternative explanations, a detailed assessment of myocardial bridging with invasive physiology should be performed to define the significance of the lesion and guide tailored medical therapy. Patients with refractory symptoms despite maximally tolerated medical therapy should be considered for surgical coronary unroofing.

Contrast Stress Echocardiography Findings in Myocardial Bridging Compared to Normal Coronary Course, With and Without Coronary Artery Disease.

BACKGROUND: Myocardial bridging (MB) correlation with ischemia remains a diagnostic challenge. There is a lack of studies that have assessed MB using contrast stress echo and compared the findings with those in patients demonstrating a normal coronary course, with or without obstructive coronary artery disease (CAD). METHODS: We evaluated all consecutive patients who underwent contrast stress echocardiography and coronary computed tomography angiography (CCTA) due to suspected symptoms of CAD within 3 months in Parma Hospital. Coronary computed tomography angiography served as the reference standard for detecting MB and obstructive CAD. The patients were divided into 3 groups: (1) MB and no evidence of obstructive CAD (MB group, N = 64), (2) no evidence of obstructive CAD or MB (NoCAD group, N = 135), (3) obstructive CAD without MB (CAD group, N = 68). RESULTS: The coronary flow velocity reserve in the LAD (CFVR-LAD) was reduced in the MB and CAD groups, measuring 1.91 ± 0.21 and 1.82 ± 0.28, respectively, whereas it was 2.27 ± 0.34 in the NoCAD group (P < .001). The MB and CAD groups exhibited a higher prevalence of reversible myocardial perfusion defects (rMPDs) compared to the NoCAD group (57.8% vs 64.7% vs 3.7%, P < .001). Reversible wall motion abnormalities were frequently observed in the CAD group and rarely found in the MB and NoCAD groups (47.1% vs 18.8% vs 4.4%, P < .001). In multivariable analyses, the presence of MB was independently associated with reduced CFVR-LAD (odds ratio = 14.55; 95% CI, 6.84-30.93; P < .001) and the presence of rMPD (odds ratio = 37.96; 95% CI, 13.49-106.84; P < .001). Patients with deep MB (>2 mm depth) and very deep MB (≥5 mm depth) exhibited significantly greater CFVR-LAD reduction and rMPD than those with superficial MB. CONCLUSIONS: Myocardial bridging is capable of inducing rMPD and reducing CFVR-LAD similar to obstructive CAD. The depth of the MB correlates with the abnormalities found in the stress echo evaluation. Contrast stress echo may serve as a valuable noninvasive tool for evaluating patients with MB.