Predictors of adverse cardiac events of coronary myocardial bridging diagnosed with computed tomography angiography

AIMS

Myocardial bridging (MB) is a frequent congenital anomaly of the epicardial coronary arteries commonly considered a benign condition. However, in some cases a complex interplay between anatomical, clinical and physiology factors may lead to adverse events, including sudden cardiac death. Coronary CT angiography (CCTA) emerged as the gold standard noninvasive imaging technique for the evaluation of MB. Aim of the study was to evaluate MB prevalence and anatomical features in a large population of patients who underwent CCTA for suspected CAD and to identify potential anatomical and clinical predictors of adverse cardiac events at long-term follow-up.

METHODS AND RESULTS

Two-hundred and six patients (mean age 60.3 ± 11.8 years, 128 male) with MB diagnosed at CCTA were considered. A long MB was defined as ≥25 mm of overlying myocardium, whereas a deep MB as ≥2 mm of overlying myocardium. The study endpoint was the sum of the following adverse events: cardiac death, bridge-related acute coronary syndrome, hospitalization for angina or bridge-related ventricular arrhythmias and MB surgical treatment. Of the 206 patients enrolled in the study, 9 were lost to follow-up, whereas 197 (95.6%) had complete follow-up (mean 7.01 ± 3.0 years) and formed the analytic population. Nineteen bridge-related events occurred in 18 patients (acute coronary syndrome in 7, MB surgical treatment in 2 and hospitalization for bridge-related events in 10). Typical angina at the time of diagnosis and long MB resulted as significant independent predictors of adverse outcome.

CONCLUSIONS

Typical angina and MB length ≥ 25 mm were independent predictors of cardiac events.

High Prevalence of Myocardial Bridging Detected in an Indonesian Population Using Multi-Detector Computed Tomography

Background and Objectives: Myocardial bridging (MB) is still not yet considered a significant finding in Indonesia both radiographically and clinically. Hence, this article aims to assess the prevalence of MB using multi-detector computed tomography (MDCT) and look at factors contributing to stenosis amongst patients with MB. Materials and Methods: This study is cross-sectional in a single centre, with consecutive sampling, looking at all patients who underwent a multi-detector computed tomography (MDCT) scan from February 2021 until February 2023. GraphPad Prism version 9.0.0 for Windows (GraphPad Software, Boston, MA, USA) was used to analyse the results. Results: There are 1029 patients with an MB, yielding a prevalence of 44.3% (95%CI 42.3-46.4). The left anterior descending vessel is the most commonly implicated, with 99.6%. Among those with stenosis, the middle portion of the bridging vessel is the most common site of stenosis (n = 269), followed by the proximal portion (n = 237). The severity of stenosis is more often moderate, with 30-50% (n = 238). Females (odds ratio [OR] of 1.8, 95%CI 1.4-2.3; p-value < 0.0001), older age (t-value 5.6, p-value < 0.0001), symptomatic patients (OR 1.4, 95% CI 1.1-1.9; p-value = 0.013), and higher mean coronary artery calcium score (t-value 11.3, p-value < 0.0001) are more likely to have stenosis. The degree of stenosis is significantly higher in the proximal stenosis group than in the middle stenosis group (t-value 27, p-value < 0.0001). Conclusions: Our research demonstrates that MB may prevent atheromatosis of the coronary segment distal to the MB and predispose the development of atherosclerosis in the section proximal to the bridge.

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.

Relationship between myocardial bridging and fatal ventricular arrhythmias in patients with hypertrophic cardiomyopathy: the HCM-MB study

BACKGROUND

Myocardial bridging (MB) and hypertrophic cardiomyopathy (HCM) are associated with the risk of fatal ventricular arrhythmias (VAs). The goal of the study was to determine the relationship between MB and fatal VAs in HCM patients with implantable cardiac defibrillators (ICD).

METHODS

A total of 108 HCM patients (mean age: 46.6 ± 13.6 years; male: 73) were enrolled in this retrospective study. All patients underwent transthoracic echocardiography and coronary computed tomography angiography. Fatal VAs including sustained ventricular tachycardia and ventricular fibrillation were documented in ICD records.

RESULTS

There were documented fatal VAs in 29 (26.8%) patients during a mean follow-up time of 71.3 ± 30.9 months. Compared with the other groups, the fatal VA group had a higher incidence of the following: presence of MB (82.8 vs. 38%, p < 0.001), deep MB (62.1 vs. 6.3%, p < 0.001), very deep MB (24.1 vs. 0%, p < 0.001), long MB (65.5 vs. 11.4%, p < 0.001), presence of > 1 MB (17.2 vs. 0%, p = 0.001), and MB of the left anterior descending artery (79.3 vs. 17.7%, p < 0.001) . Sudden cardiac death (SCD) risk score (hazard ratio: 1.194; 95% CI: 1.071-1.330; p = 0.001) and presence of MB (hazard ratio: 3.815; 95% CI: 1.41-10.284; p = 0.008) were found to be independent predictors of fatal VAs in HCM patients.

CONCLUSIONS

The current data suggest that the SCD risk score and presence of MB were independent risk factors for fatal VAs in patients with HCM. In addition to conventional risk factors, the coronary anatomical course can provide clinicians with valuable information when assessing the risk of fatal VAs in HCM patients.

Prevalence of Myocardial Bridging in Angiography Study

BACKGROUND

Myocardial bridging is a congenital anomaly in which a segment of epicardial coronary artery takes an intramyocardial course, the systolic compression of which could be asymptomatic or may lead to major hemodynamic changes such as myocardial ischemia, arrhythmias or sudden cardiac death. The prevalence is highly variable depending upon different investigational modalities to diagnose it. Here we have aimed to study the prevalence through invasive coronary angiography.

METHODS

This retrospective study was carried out at Manmohan Cardiothoracic Vascular and Transplant center, Kathmandu, Nepal. The invasive coronary angiography of 5096 patients were studied from March 2018 to April 2021 done for various indications.

RESULTS

Among all the patients, the myocardial bridging was identified in 257 (5.04%) patients. About 177 (68.9%) were males and 80 (31.1%) were females. The mean age of the patients having myocardial bridging was 54.52 ± 10.31years. Diabetes mellitus was found in 33(12.8%) and hypertension was found in 77(29.9%) patients with myocardial bridging. Stable angina (29.2%) was the most common clinical presentation. Treadmill test was positive in about 70 (27.2%) patients. Majority of patients had myocardial bridge in left anterior descending artery alone (89.9%) and located mostly in mid-part (74.9%).

CONCLUSIONS

The myocardial bridging is not an uncommon finding on invasive coronary angiography in middle aged people who present with typical angina.

Interplay Between Myocardial Bridging and Coronary Spasm in Patients With Myocardial Ischemia and Non-Obstructive Coronary Arteries: Pathogenic and Prognostic Implications

Background

Myocardial bridging (MB) may represent a cause of myocardial ischemia in patients with non‐obstructive coronary artery disease (NOCAD). Herein, we assessed the interplay between MB and coronary vasomotor disorders, also evaluating their prognostic relevance in patients with myocardial infarction and non‐obstructive coronary arteries (MINOCA) or stable NOCAD.

Methods and Results

We prospectively enrolled patients with NOCAD undergoing intracoronary acetylcholine provocative test. The incidence of major adverse cardiac events, defined as the composite of cardiac death, non‐fatal myocardial infarction, and rehospitalization for unstable angina, was assessed at follow‐up. We also assessed angina status using Seattle Angina Questionnaires summary score. We enrolled 310 patients (mean age, 60.6±11.9; 136 [43.9%] men; 169 [54.5%] stable NOCAD and 141 [45.5%] MINOCA). MB was found in 53 (17.1%) patients. MB and a positive acetylcholine test coexisted more frequently in patients with MINOCA versus stable NOCAD. MB was an independent predictor of positive acetylcholine test and MINOCA. At follow‐up (median, 22 months; interquartile range, 13–32), patients with MB had a higher rate of major adverse cardiac events, mainly driven by a higher rate of hospitalization attributable to angina, and a lower Seattle Angina Questionnaires summary score (all P<0.001) compared with patients without MB. In particular, the group of patients with MB and a positive acetylcholine test had the worst prognosis.

Conclusions

Among patients with NOCAD, coronary spasm associated with MB may predict a worse clinical presentation with MINOCA and a higher rate of hospitalization attributable to angina at long‐term follow‐up with a low rate of hard events.

Frequency and Significance of Coronary Artery Disease and Myocardial Bridging in Patients With Hypertrophic Cardiomyopathy

The etiology of chest pain in hypertrophic cardiomyopathy (HC) is diverse and includes coronary artery disease (CAD) as well as HC-specific causes. Myocardial bridging (MB) has been associated with HC, chest pain, and accelerated atherosclerosis. We compared HC patients with age-, gender- and CAD pre-test probability-matched outpatients presenting with chest pain to investigate differences in the presence of MB and CAD using coronary computed tomography angiography (CCTA). We studied 84 HC patients who underwent CCTA and compared these with 168 matched controls (age 54 ± 11 years, 70% men, pre-test probability 12% [5% to 32%]). MB, calcium score, plaque morphology and presence and extent of CAD were assessed for each patient. Linear mixed models were used to assess differences between cases and controls. MB was more often seen in HC patients (50% vs 25%, p <0.001). Calcium score and the presence of obstructive CAD were similar in both groups (9 [0 to 225] vs 4 [0 to 82] and 18% vs 19%; p = 0.22 and p = 0.82). In the HC group, MB was associated with pathogenic DNA variants (p = 0.04), but not with the presence of chest pain (74% vs 76%, p = 0.8), nor with worse outcome (log-rank p = 0.30). In conclusion, the prevalence and extent of CAD was equal among patients with and without HC, demonstrating that pre-test risk prediction using the CAD Consortium clinical risk score performs well in HC patients. MB was twice as prevalent in the HC group compared with matched controls, but was not associated with chest pain or decreased event-free survival in these patients.

High Prevalence and Clinical Implication of Myocardial Bridging in Patients with Early Repolarization

PURPOSE

Recent evidence suggests that early repolarization (ER) is related with myocardial ischemia. Compression of coronary artery by a myocardial bridging (MB) can be associated with clinical manifestations of myocardial ischemia. This study aimed to evaluate the associations of MB in patients with ER.

MATERIALS AND METHODS

In consecutive patients (n=1303, age, 61±12 years) who had undergone coronary angiography, we assessed the prevalence and prognostic implication of MB in those with ER (n=142) and those without ER (n=1161).

RESULTS

MB was observed in 54 (38%) and 196 (17%) patients in ER and no-ER groups (p<0.001). In multivariate analysis, MB was independently associated with ER (odd ratio: 2.9, 95% confidence interval: 1.98-4.24, p<0.001). Notched type ER was more frequently observed in MB involving the mid portion of left anterior descending coronary artery (LAD) (69.8% vs. 30.2%, p=0.03). Cardiac event was observed in nine (6.3%) and 22 (1.9%) subjects with and without ER, respectively. MB was more frequently observed in sudden death patients with ER (2 out of 9, 22%) than in those without ER (0 out of 22).

CONCLUSION

MB was independently associated with ER in patients without out structural heart disease who underwent coronary angiography. Notched type ER was closely related with MB involving the mid portion of the LAD. Among patients who had experienced cardiac events, a higher prevalence of MB was observed in patients with ER than those without ER. Further prospective studies on the prognosis of MB in ER patients are required.

Prevalence of Myocardial Bridging in Patients With Myocardial Infarction and Nonobstructed Coronary Arteries

Mechanisms of acute myocardial infarction and nonobstructed coronary arteries (MINOCA) are incompletely understood. Myocardial bridging (MB) is usually considered a benign congenital variant, but serious complications have been reported. MB has also been proposed as a cause of takotsubo syndrome (TS). We aimed to examine whether MB was more frequent in patients with MINOCA or TS than in age- and gender-matched controls and to compare the MB detection rates of coronary computed tomography angiography (CTA) and invasive coronary angiography (ICA). Patients with MINOCA (n = 57) and age- and gender-matched controls (n = 58), aged 45 to 70 were enrolled. Myocarditis was excluded by cardiovascular magnetic resonance imaging. Patients with TS (n = 15) were considered as a subgroup and therefore not excluded. Patients with MINOCA underwent ICA and all study participants underwent coronary CTA. All examinations were reviewed with focus on MB. Among 57 MINOCA patients, 15 MINOCA patients with TS and 58 controls, MB was demonstrated in 28 patients (49%), 8 patients (53%), and 26 patients (45%), respectively. There were no statistically significant differences regarding the prevalence of MB or the type, location, length, or thickness of MB. There was a statistically significant difference (p <0.01) between the detection rates of coronary CTA and ICA that demonstrated MB in 54 subjects (47%) and 13 subjects (23%), respectively. In conclusion, MB was frequent with a similar prevalence in patients with MINOCA, patients with TS and controls. This suggests that there is no causal link between MB and MINOCA or TS. Furthermore, coronary CTA detects MB at a significantly higher rate than ICA.

Myocardial Bridging: An Up-to-Date Review

Myocardial bridging is a congenital anomaly in which a segment of a coronary artery takes a "tunneled" intramuscular course under a "bridge" of overlying myocardium. This causes vessel compression in systole, resulting in hemodynamic changes that may be associated with angina, myocardial ischemia, acute coronary syndrome, left ventricular dysfunction, arrhythmias, and even sudden cardiac death. While described on autopsy for centuries, technological advances such as coronary computed tomography angiography and intravascular ultrasound have contributed greatly to our understanding of the anatomic, hemodynamic, and pathophysiological consequences of systolic compression. Atherosclerosis preferentially develops immediately proximal to the bridged segment, likely due to alterations in shear stress, while the compressed segment itself is often spared. First-line therapy of symptomatic bridging remains medical treatment with beta-blockers and non-dihydropyridine calcium-channel blockers, and nitrates are contraindicated. Surgical myotomy, intracoronary stenting, and coronary artery bypass graft surgery have been used for refractory symptoms, but long-term outcomes remain uncertain. Further research is required to better define the patient population that would derive the greatest benefit from surgical and percutaneous intervention.

Prevalence of coronary artery anomalies in patients undergoing coronary artery angiography: a review of 16768 patients. A retrospective, single-center study

AIM

Coronary artery anomalies (CAAs) most of the time are detected at birth. The aim of this study was to report the prevalence of CAAs by investigating coronary artery angiography (CAG) images of patients admitted to the authors' hospital, a tertiary healthcare provider.

METHODS

Images of 16,768 patients who underwent CAG in our hospital were evaluated regarding CAAs.

RESULTS

CAAs were detected in 120 (0.7%) cases. Anomalous origin and course of arteries were observed in 86 (0.51%) cases. Seven of these cases were diagnosed with acute coronary syndrome and 5 of them were treated with angioplasty without any complication. Absence of LMCA was revealed as the most frequent anomaly in the subgroup analysis of origin and course anomalies by being spotted in 59 (49.9 %) cases of total 120. Myocardial bridge, which constituted all intrinsic coronary anomalies in our study, was determined in 18 (0.1%) patients. All of the anomalies of coronary termination were coronary artery fistulas which were seen in 16 (0.09%) of patients and 2 of them were occluded with coil.

CONCLUSION

Absence of LMCA was the most frequently encountered anomaly. Although CAAs are rare cases, they can cause difficulties in CAG interventions and surgical operations. This study presents CAA frequencies of patients who performed CAG.

The intramyocardial left anterior descending artery: prevalence and surgical considerations in coronary artery bypass grafting

BACKGROUND

Major coronary arteries usually have a subepicardial course and only dip into the myocardium near or at their termination. However, occasionally a segment of the epicardial artery may have an intramural course, and it is often referred to as a myocardial bridge. The left anterior descending (LAD) artery is the most commonly bridged vessel. Its prevalence has been evaluated at both autopsy and angiography. However, in the literature reviewed it is apparent that there are no reports of the prevalence of the intramyocardial LAD (IMLAD) artery in coronary artery bypass graft (CABG) series.

OBJECTIVES

To document the prevalence of the IMLAD artery in a series of CABGs and to describe the surgical techniques used in these cases.

METHODS

A retrospective analysis of 1349 surgical reports of consecutive CABGs performed over a period of 23 years was conducted.

RESULTS

An IMLAD artery was present in 293 patients (21.7%). The prevalence was 20.2% (51/253) in females and 22.1% (242/1096) in males. The IMLAD arteries extended into the interventricular septum in 3.8% (11/293) of the patients.

CONCLUSION

An intramyocardial course of the LAD artery is relatively common in patients undergoing CABG and poses a challenge in bypass grafting. Techniques are described to address this anatomical variation when it is encountered at surgery.

Relation of myocardial bridge to myocardial infarction: a meta-analysis

BACKGROUND

Small case series have suggested an association of coronary myocardial bridge (MB) with myocardial infarction (MI). However, the relationship between MB and major adverse cardiac events (MACE) remains largely unknown. The aim of this study was to assess the relationship between MB and MACE involving MI.

METHODS

We performed a systematic search of MEDLINE, PreMEDLINE, and all EMB Reviews as well as a reference list of relevant articles according to the SPICO (Study design, Patient, Intervention, Control-intervention, and Outcome) criteria using the following keywords: myocardial bridging, myocardial bridge, intramural coronary artery, mural coronary artery, tunneled coronary artery, coronary artery overbridging, etc. Bibliographies of the retrieved publications were additionally hand searched. Studies were included for the meta-analysis if they satisfied the following criteria: (1) they evaluate the association of MB with cardiovascular endpoint event; (2) they included individuals with MB and those without MB; 3) they excluded individuals with obstructive coronary artery disease (CAD). Studies were reviewed by a predetermined protocol including quality assessment. Dates were pooled using a random effect model.

RESULTS

Seven observational studies that followed 5 486 patients eligible for the enrolled criteria were included from 7 136 initially identified articles. The prevalence of MB was 24.8% (1 363/5 486). During 0.5-7.0 years of follow-up of this cohort of population, crude outcome rates were 8.0% in the MB group and 7.7% in the non-MB group. The odds ratio of overall MACE and MI were 1.34 (95% confidence interval (CI): 0.57-3.17, P = 0.51, n = 7 studies) and 2.75 (95% CI: 1.08-7.02, P < 0.03, n = 5 studies) respectively for subjects of MB compared to non-MB.

CONCLUSION

Relationship between MB and MI appears to be a real one, although the study did not reveal a connection of MB to MACE, suggesting whether the necessity of antiplatelet therapy needs to be further studied in a larger cohort of patients with MB prospectively.

Assessment of myocardial bridge and mural coronary artery using ECG-gated 256-slice CT angiography: a retrospective study

Recent clinical reports have indicated that myocardial bridge and mural coronary artery complex (MB-MCA) might cause major adverse cardiac events. 256-slice CT angiography (256-slice CTA) is a newly developed CT system with faster scanning and lower radiation dose compared with other CT systems. The objective of this study is to evaluate the morphological features of MB-MCA and determine its changes from diastole to systole phase using 256-slice CTA. The imaging data of 2462 patients were collected retrospectively. Two independent radiologists reviewed the collected images and the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter, and thickness of MB-MCA in diastole and systole phases were recorded, and changes of MB-MCA were calculated. Our results showed that among the 2462 patients examined, 336 have one or multiple MB-MCA (13.6%). Out of 389 MB-MCA segments, 235 sites were located in LAD2 (60.41%). The average diameter change of MCA in LAD2 from systole phase to diastole phase was 1.1 ± 0.4 mm, and 34.9% of MCA have more than 50% diameter stenosis in systole phase. This study suggested that 256-slice CTA multiple-phase reconstruction technique is a reliable method to determine the changes of MB-MCA from diastole to systole phase.

Myocardial perfusion GSPECT imaging in patients with myocardial bridging

BACKGROUND

The aim of this study was to investigate the incidence, reversibility, and severity of LV perfusion abnormalities in patients with isolated myocardial bridges using a gated myocardial perfusion SPECT study (GSPECT).

METHODS

A retrospective study involved 42 patients without history of myocardial infarction, with isolated myocardial bridges detected in coronary angiography and no substantial evidence of atherosclerotic changes in coronary arteries. In all patients a gated SPECT study was performed at both rest and stress, after intravenous administration of (99m)Tc MIBI. Reconstructed slices were analyzed using a 20-segment model of the left ventricle.

RESULTS

Incidence and severity of stress-induced ischemia were related to degree of artery constriction (P = .002 and .00014, respectively). Perfusion abnormalities were detected only in patients with critical narrowing (≥ 50%) of artery (in 12 out of 28, i.e., 43% of patients). Summed stress scores (SSS) ranged from 4 to 11 (mean 7), indicating slight or moderate defect intensity. Only 1 patient presented with a SSS value of 31 (severe defect). Perfusion defects were stress induced in 70 out of 72 (97%) segments with abnormal perfusion.

CONCLUSION

Perfusion abnormalities were observed in ab. 40% of patients with critical (≥ 50%) narrowing of artery affected by bridging and were mild, stress induced.

Myocardial bridging and coronary artery anomalies detected by ECG-gated 64-row multidetector computed tomography angiography in symptomatic patients

Advances in 64-row multidetector computed tomography have provided noninvasive imaging of coronary arteries. The aim of this study was to evaluate the prevalence of coronary artery anomalies in Iranian symptomatic patients and to determine the presence of anomalies resulting in myocardial ischaemia without atherosclerotic plaque. This study was carried out in Tabriz University of medical sciences on 534 patients with suggestive symptoms for coronary artery diseases. Original slices were reconstructed from data achieved by using a ECG-gated multidetector computed tomography scanner, and reconstructed 3-dimentional images of the heart were reviewed. Congenital angiography was performed in 36.3% of patients. The prevalence of myocardial bridging in symptomatic patients was 6.0% by multidetector computed tomography while conventional angiography could detect 20% of them. The most prevalent site was the middle portion of the left anterior descending artery. Anomalous origin or course of coronary arteries and AV fistula was detected by multidetector computed tomography coronary angiography in 2.6% of cases while conventional angiography could detect 44.4% of these anomalies. The prevalence of atherosclerotic plaques in patients with myocardial bridging was 53.1%. In 46.9% of these patients, myocardial bridging was held responsible for signs and symptoms of myocardial ischaemia as no atherosclerotic plaque was evident. This rate was 64.3% in symptomatic patients with other anomalies in origin or course of coronary arteries. This study gives the prevalence of coronary artery anomalies and myocardial bridging in the Iranian population. The results suggest multidetector computed tomography coronary angiography as the preferred utility for diagnosing such anomalies.

Myocardial bridging in Taiwan: depiction by multidetector computed tomography coronary angiography

BACKGROUND/PURPOSE

Myocardial bridging (MB) is a condition in which a segment of the major epicardial coronary artery is tunneled within and surrounded by the myocardium. This condition has been linked to severe complications. The aim of this study was to evaluate the incidence of MB in Taiwanese subjects examined with electrocardiogram-gated, 16-slice, multidetector computed tomography (MDCT) coronary angiography, as well as to determine the location, depth, and length of the bridged segments and the concomitant atherosclerosis of MB.

METHODS

From August 2004 to May 2005, 276 consecutive subjects referred to our department for MDCT coronary angiography were enrolled in the study after written informed consent was obtained from each participant.

RESULTS

Twenty-four subjects (8.7%) had at least one coronary segment that was completely surrounded by myocardium. Patients ranged in age from 27 to 76 years, with an average of 54 +/- 12 years. Thirty coronary segments were found to have MB. The most common location of MB was in segment 7, which accounted for 14 coronary segments (46.7%) of the total number of bridged segments; left anterior descending artery (LAD) segments accounted for 23 (76.7%); and right coronary artery and left circumflex artery segments accounted for three (10%) and two (6.7%), respectively. The length of bridged segments ranged from 5.2 to 50.6 mm, with an average length of 24.6 +/- 11.8 mm, and the depth of the bridged segments ranged from 0.5 to 9.1 mm, with an average depth of 3.65 +/- 1.89 mm. Two bridged segments (6.7%) had concomitant atherosclerosis; these were located in segment 7 (24.0 mm long and 6.10 mm deep) and segment 8 (27.1 mm long and 7.0 mm deep). Bridged segments with concomitant atherosclerosis were deeper, but not longer, compared with bridged segments without concomitant atherosclerosis (p < 0.05).

CONCLUSION

Electrocardiogram-gated MDCT is an effective noninvasive tool for evaluating MB in a clinical setting. The most common location of MB was in the LAD, especially in segment 7. Bridged segments with concomitant atherosclerosis were deeper, but not longer, compared with bridged segments without concomitant atherosclerosis.

Prevalence of myocardial bridging and correlation with coronary atherosclerosis studied with 64-slice CT coronary angiography

PURPOSE

This study aimed to assess the prevalence and characteristics of myocardial bridging in patients who underwent multislice computed tomography coronary angiography (MSCT-CA) and to evaluate the correlation between bridged coronary segments and atherosclerosis.

MATERIALS AND METHODS

A total of 277 patients (mean age 60+/-11 years) we consecutively examined with 64-slice MSCT-CA for suspected or known coronary atherosclerosis were retrospectively reviewed for myocardial bridging. Segments proximal and distal to the bridging were evaluated for atherosclerotic plaque, as were the remaining coronary segments.

RESULTS

Myocardial bridging was present in 82 patients (30%, mean age 59+/-12). Bridges were of variable length (<1 cm 58%; 1-2 cm 32%; >2 cm 10%) and depth (superficial 69%, intramyocardial 31%) and frequently localised in the mid-distal segment of the left anterior descending artery (95%). Myocardial bridging cannot be considered a significant risk factor for coronary atherosclerosis (odds ratio 0.49) compared with traditional cardiovascular risk factors. Coronary segments proximal to the bridge showed no atherosclerotic disease (33%), positive remodelling (27%), <50% stenosis (20%) or >50% stenosis (20%). We identified 12 noncalcified, 32 mixed and 17 calcified plaques. The distal segments were significantly less affected (p<0.0001).

CONCLUSIONS

MSCT-CA is a reliable, noninvasive method that is able to depict myocardial bridging and associated atherosclerotic plaque in the proximal segments.

Evaluation of myocardial bridges with 64-slice computed tomography coronary angiography

OBJECTIVE

The aim of this study is to report the characteristics of myocardial bridging (MB) using 64-slice computed tomography and to demonstrate the association between atherosclerotic coronary artery disease (CAD) and MB.

METHODS AND RESULTS

In 990 consecutive patients who underwent multi-slice computed tomography (MSCT) coronary angiography for suspected or known coronary artery disease, myocardial bridge evaluation was performed with axial, curved multiplanar reconstruction and three-dimensional volume-rendered images. 265 bridged segments were identified in 223 (22.5%) patients. Multiple MBs on left coronary arteries were found in 41 patients. Most of the MBs were in the LAD (62.6%), followed by the obtuse marginal artery (14.7%) and diagonal artery (14.3%). The average length of MBs was 14 +/- 7 mm, and the average depth was 1.6 +/- 11 mm. No significant difference was observed between patients with and without MB on the middle LAD in respect of age, gender, prevalence of diabetes, hyperlipidaemia, hypertension, current smoking and prevalence of atherosclerotic plaques at the proximal LAD. On the other hand, prevalence of atherosclerotic plaques at the distal LAD were significantly lower in patients with MB on the middle LAD (3.5% vs. 19.7%, P: 0.0001).

CONCLUSIONS

The presence and morphological characteristics of MB and its relation with atherosclerotic plaques in the involved coronary artery can be comprehensively analysed with 64-slice computed tomography coronary angiography. Atherosclerosis is a common finding in segments proximal to MB, but the prevalence of plaques in equivalent segments (proximal LAD in our study) is not higher than in patients under similar coronary artery disease risk and without MB. On the other hand, prevalence of atherosclerotic plaques at the distal LAD was significantly lower in our patients with MB on the middle LAD. Finally, we suggest that rather than causing proximal atherosclerosis, MB might have a more important role in the protection of distal segments of the bridged arteries from atherosclerosis.

[Detection and its clinical value of myocardial bridging with 64-slice spiral CT coronary angiography]

To evaluate the detection rate of myocardial bridging by 64-slice spiral CT coronary angiography.

METHODS

The data of 3011 patients with suspected coronary artery disease undergoing 64-slice spiral CT coronary angiography were collected and analyzed retrospectively.

RESULTS

A total of 174 cases (5.8%) with myocardial bridging were detected by 64-slice spiral CT coronary angiography, among which 168 (96.6%) had single foci of involvement and 6 (3.4%) had were multiple foci. Involvement of the left anterior descending coronary artery (LAD) was detected in 167 out of the 174 cases (96.0%). The length of the myocardial bridge varied between 5 and 120 mm (mean of 30.5 mm), and the depth of the tunneled artery ranged between 1.3 and 2.8 mm (mean 2.3 mm). Seventy-nine of the cases (45.4%) had uncomplicated myocardial bridging and 95 (54.6%) had myocardial bridging complicated by coronary atherosclerosis.

CONCLUSION

Multi-slice spiral CT coronary angiography is a reliable and noninvasive modality for diagnosis of myocardial bridging to allow direct measurement of the length and depth of the myocardial bridge and detection of concurrent coronary and cardiac lesions.

The angiographic aspects of myocardial bridges in Turkish patients who have undergone coronary angiography

INTRODUCTION

Little is known of the clinical significance of myocardial bridges, which may be recognised as the narrowing of the systolic coronary artery as seen in an angiography. In this study, our goal was to review the literature information about the anatomic aspects, the clinical manifestations and implications, and the angiographic characteristics.

MATERIALS AND METHODS

The angiographic data of 7200 adult patients undergoing coronary angiography were retrospectively analysed for the diagnosis of myocardial bridge. The main angiographic evidence of a myocardial bridge that we required was the narrowing of a systolic coronary artery resulting in at least 50% reduction of lumen diameter in comparison with the diastolic phase. All coronary angiograms were reviewed independently by at least 2 of the authors and the case was included only if there was a consensus that the myocardial bridge resulted in 50% narrowing or more.

RESULTS

Myocardial bridge was present in 29 (0.4%) of the 7200 coronary angiographies. The location of the myocardial bridge was in the left anterior descending coronary artery in 28 cases (96.5%), and the left circumflex coronary artery in 1 case (3.4%). Myocardial bridge was most common in the middle segment of the left anterior descending coronary artery (78.5 %). Each of these patients with myocardial bridge was referred for angiography because of symptom of chest pain alone or symptom of chest pain, palpitations and dyspnoea. Of the 29 patients with myocardial bridge, 2 patients without any symptom, demonstrated ischaemia as assessed by Tc- 99m MIBI myocardial perfusion scintigraphy.

CONCLUSION

Chest pain was the common reason for angiography in patients with myocardial bridge. The incidence of myocardial bridge may vary according to population. Myocardial bridge is more frequently found in the middle segment of the left anterior descending coronary artery.