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.

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.

Prevalence of myocardial bridges in the Mexican population: A morphometric and histological analysis.

BACKGROUND: Myocardial bridge (MB) is described as an abnormal band of myocardium covering a variable portion of any coronary artery. METHODS: The current study explores the presence of MB throughout the coronary arterial system and provides a morphometric description through instrumented dissection of a sample of 100 human hearts. The study shows a higher prevalence of MB in the Mexican population than in previous reports. RESULTS: In the total sample (n=100), MB was identified in 96% of it. A total of 421 MBs were observed, with a mean of 4.38mm (±0.28) per dissected heart. The most frequently affected vessel is the anterior interventricular artery where a total of 52 MBs were found, of the total sample studied. DISCUSSION: The high prevalence of MB among Mexican patients could be the result of a genetic association for this population or the neoformation of MB after birth due to lifestyle-associated factors. Further studies are required to better understand the high prevalence of MB among Mexican subjects.

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.

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

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

Abnormal shear stress and residence time are associated with proximal coronary atheroma in the presence of myocardial bridging.

BACKGROUND: Atheromatous plaques tend to form in the coronary segments proximal to a myocardial bridge (MB), but the mechanism of this occurrence remains unclear. This study evaluates the relationship between blood flow perturbations and plaque formation in patients with an MB. METHODS AND RESULTS: A total of 92 patients with an MB in the mid left anterior descending artery (LAD) and 20 patients without an MB were included. Coronary angiography, intravascular ultrasound, and coronary physiology measurements were performed. A moving-boundary computational fluid dynamics algorithm was used to derive wall shear stress (WSS) and peak residence time (PRT). Patients with an MB had lower WSS (0.46 ± 0.21 vs. 0.96 ± 0.33 Pa, p < 0.001) and higher maximal plaque burden (33.6 ± 15.0 vs. 14.2 ± 5.8%, p < 0.001) within the proximal LAD compared to those without. Plaque burden in the proximal LAD correlated significantly with proximal WSS (r = -0.51, p < 0.001) and PRT (r = 0.60, p < 0.001). In patients with an MB, the site of maximal plaque burden occurred 23.4 ± 13.3 mm proximal to the entrance of the MB, corresponding to the site of PRT. CONCLUSIONS: Regions of low WSS and high PRT occur in arterial segments proximal to an MB, and this is associated with the degree and location of coronary atheroma formation.

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.

Coronary plaque burden of the left anterior descending artery in patients with or without myocardial bridge: A case-control study based on coronary CT-angiography.

BACKGROUND: The clinical significance of myocardial bridging (MB) on the left anterior descending artery (LAD) is debated. We aimed to assess the association between MB and LAD plaque volumes/compositions in a case-control set up. METHODS: In our retrospective analysis we investigated 50 cases with incidentally recognized LAD MB and 50 matched controls without LAD MB on coronary computed tomography angiography. We quantified plaque volumes proximal to the MB and beneath it in patients with MB and in the corresponding coronary segments in patients without MB. RESULTS: In total, we have included 100 patients (mean age 60.6 ± 10.8 years, males: 80%). Plaque volume was similar in the LAD segments proximal to the MB in cases vs. controls (150.0 mm3 [IQR: 90.7-194.5 mm3] vs. 132.8 mm3 [IQR: 94.2-184.3 mm3], respectively; p = 0.95) while the plaque volume was smaller beneath LAD MB vs. control segment (16.2 mm3 [IQR: 12.6-25.8 mm3] vs. 21.1 mm3 [IQR: 14.0-42.4 mm3], respectively; p = 0.002). No significant differences were found regarding different plaque components in segments proximal to the MB while fatty plaque and necrotic core volumes were smaller or negligible in coronary segment beneath MB than in controls (0.07 mm3 [IQR: 0.005-0.27 mm3] vs. 12.7 mm3 [IQR: 7.4-24.4 mm3] and 0.00 mm3 [IQR: 0.00-0.04 mm3] vs. 0.06 mm3 [IQR: 0.03-2.8 mm3], respectively (p < 0.001). CONCLUSION: Comparing patients with MB vs. matched controls without it, MB was not associated with increased plaque volumes in LAD segment proximal to MB and plaque quantity was smaller in the MB segment. Our data are supportive of benign nature of incidentally recognized LAD MB.

Myocardial bridges: A meta-analysis.

Myocardial bridges are anatomical entities characterized by myocardium covering segments of coronary arteries. In some patients, the presence of a myocardial bridge is benign and is only incidentally found on autopsy. In other patients, however, myocardial bridges can lead to compression of the coronary artery during systolic contraction and delayed diastolic relaxation, resulting in myocardial ischemia. This ischemia in turn can lead to myocardial infarction, ventricular arrhythmias and sudden cardiac death. Myocardial bridges have also been linked to an increased incidence of atherosclerosis, which has been attributed to increased shear stress and the presence of vasoactive factors. Other studies however, demonstrated the protective roles of myocardial bridges. In this study, using systematic review and a meta-analytical approach we investigate the prevalence and morphology of myocardial bridges in both clinical imaging and cadaveric dissections. We also discuss the pathophysiology, clinical significance, and management of these anatomical entities.

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.

Accuracy of a novel stress echocardiography pattern for myocardial bridging in patients with angina and no obstructive coronary artery disease - A retrospective and prospective cohort study.

BACKGROUND: Myocardial bridge (MB) may cause angina in patients with no obstructive coronary artery disease (CAD). We previously reported a novel stress echocardiography (SE) pattern of focal septal buckling with apical sparing in the end-systolic to early-diastolic phase that is associated with the presence of an MB. We evaluated the diagnostic accuracy of this pattern, and prospectively validated our results. METHODS: The retrospective cohort included 158 patients with angina who underwent both SE and coronary CT angiography (CCTA). The validation cohort included 37 patients who underwent CCTA in the emergency department for angina, and prospectively underwent SE. CCTA was used as a reference standard for the presence/absence of an MB, and also confirmed no obstructive CAD. RESULTS: In the retrospective cohort, an MB was present in 107 (67.7%). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 91.6%, 70.6%, 86.7% and 80%, respectively. On logistic regression, focal septal buckling and Duke treadmill score were associated with an MB. In the validation cohort, an MB was present in 31 (84%). The sensitivity, specificity PPV and NPV were 90.3%, 83.3%, 96.5% and 62.5%, respectively. On logistic regression, focal septal buckling was associated with an MB. CONCLUSION: Presence of focal septal buckling with apical sparing on SE is an accurate predictor of an MB in patients with angina and no obstructive CAD. This pattern can reliably be used to screen patients who may benefit from advanced non-invasive/invasive testing for an MB as a cause of their angina.

Prevalence of myocardial bridging associated with coronary endothelial dysfunction in patients with chest pain and non-obstructive coronary artery disease.

AIMS: Myocardial bridging (MB), characterised by the epicardial coronary vessel diving into the myocardium, is present in up to one third of adults and is associated with angina and acute coronary syndromes. MB is accompanied by altered blood flow mechanics and regional changes in wall sheer stress. The purpose of this study was to determine the association between myocardial bridging and coronary endothelial dysfunction. METHODS AND RESULTS: Patients presenting with chest pain and found to have non-obstructive CAD (stenosis <40%) on angiography underwent an invasive assessment of epicardial and microvascular endothelial function. Epicardial endothelial function was assessed by measuring the percent change in coronary artery diameter in response to intracoronary infusions of acetylcholine (%ΔCADAch). Epicardial endothelial dysfunction was defined as a %ΔCADAch of <-20%. Microvascular endothelial function was assessed by the percent change in coronary blood flow in response to intracoronary infusions of acetylcholine (%ΔCBFAch), and microvascular endothelial dysfunction was defined as a %ΔCBFAch of <50%. MB was diagnosed angiographically by identifying the characteristic reduction in minimal luminal diameter during systole. Patients were divided into those with and those without MB, and the frequency of epicardial endothelial dysfunction and microvascular endothelial dysfunction was compared between patients with versus those without MB. Between 1993 and 2012, 1,469 patients (mean age 50.4 years, 35% male) underwent coronary angiography and invasive testing of endothelial function. Two hundred and eight (14.2%) patients were found to have MB in the LAD. Patients with any MB had a significantly higher frequency of endothelial dysfunction within the mid and/or distal vessel segment compared to patients without MB (60.1% vs 50.4%, p=0.012). In multivariate analyses, mid and/or distal vessel MB was a significant predictor of mid and/or distal vessel epicardial endothelial dysfunction (OR 1.44, 95% CI: 1.04-2.00, p=0.029) and of microvascular endothelial dysfunction (OR 1.34, 95% CI: 1.00-1.82, p=0.050). CONCLUSIONS: MB co-localises with epicardial endothelial dysfunction and is significantly associated with microvascular endothelial dysfunction in symptomatic patients with non-obstructive CAD, supporting its potential role as a mechanism for angina in symptomatic patients with MB.

A potential protective element of myocardial bridge against severe obstructive atherosclerosis in the whole coronary system.

BACKGROUND: Myocardial bridge (MB) is generally described as a congenital benign variation. Previous studies have suggested that MB prevents atherosclerotic plaques from accumulating within the bridge segment but promotes coronary stenosis in the proximal segment adjacent to MB. However, it is still not clear whether MB has positive or negative effects on severe obstructive atherosclerosis in the whole coronary artery system. METHODS: In this study, 6774 patients with symptoms of angina who were clinically diagnosed coronary artery disease (CAD) or suspected CAD underwent coronary angiography (CAG) in our center. The presence of MB was diagnosed, and a retrospective analysis was performed between MB and severe obstructive CAD requiring percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in the whole coronary system. RESULTS: Among 6774 patients, 3583 (52.89%) were diagnosed with severe obstructive CAD (SOCAD) requiring a treatment of PCI or CABG and enrolled into the SOCAD group; and 3191 (47.11%) without SOCAD into the non-SOCAD group. Non-SOCAD and SOCAD groups had 512(16.05%) and 66(1.84%) patients with MB, respectively (P <  0.0001). The rate of SOCAD requiring PCI or CABG in patients with MB was much lower than that in patients without MB (11.42% vs. 56.76%, P <  0.0001). After adjusting for sex, age, diabetes mellitus, hypertension, and other risk factors, MB still had some positive role in preventing severe obstructive CAD (log-OR = - 2.134, p-value < 0.0001) through logistic regression. CONCLUSIONS: Our results provided a clue that MB might act as a potential protective element against severe obstructive atherosclerosis in the whole coronary artery system.

The impact of myocardial bridge on coronary artery spasm and long-term clinical outcomes in patients without significant atherosclerotic stenosis.

BACKGROUND AND AIMS: Myocardial bridge (MB) and coronary artery spasm (CAS) can induce a sustained chest pain, acute coronary syndrome (ACS) and even sudden cardiac death. The aim of this study is to evaluate the relationship between MB and CAS and its impact on long-term clinical outcomes. METHODS: A total of 812 patients with MB without significant coronary artery disease (CAD), who underwent acetylcholine (ACH) provocation test, were enrolled. Significant CAS was defined as ≥70% temporary narrowing by ACH test, and MB was defined as the characteristic phasic systolic compression of the coronary artery with a decrease of more than 30% in diameter on the angiogram after intracoronary nitroglycerin infusion. To adjust baseline confounders, logistic regression analysis was performed. The primary endpoint was incidence of CAS, and secondary endpoints were major adverse cardiac events (MACE) and recurrent angina requiring repeat coronary angiography (CAG) at 5 years. RESULTS: MB is closely implicated in a high incidence of CAS, spontaneous spasm, ischemic ECG change and chest pain during ACH provocation test. In addition, MB of various severity and reference vessel size was substantially implicated in CAS incidence, and severe MB was a strong risk factor of CAS. MB patients with CAS were shown to have a higher rate of recurrent angina compared with MB patients without CAS, up to a 5-year follow-up. However, there were no differences regarding the incidence of MACE. CONCLUSIONS: Severe MB was associated with high incidence of CAS, and MB patients with CAS were likely to have a higher incidence of recurrent angina. Intensive medical therapy and close clinical follow-up are needed for better clinical outcomes in MB patients with CAS.

Impact of myocardial bridging on in-hospital outcome in patients with takotsubo syndrome.

BACKGROUND: Prevalence of myocardial bridging of the left anterior descending coronary artery (LAD) in patients with takotsubo syndrome (TTS) has been demonstrated. However, the impact of myocardial bridging on in-hospital outcome has not been fully evaluated. METHODS: A total of 144 consecutive patients with TTS were enrolled. Coronary angiography and left ventriculography were performed in all patients and absence of obstructive coronary disease explaining the left ventricular contraction abnormality was confirmed. Myocardial bridging was diagnosed when a dynamic compression in systole, so-called "milking effect", was observed in the LAD. We evaluated differences in the clinical characteristics and in-hospital outcome between patients with and without myocardial bridging. Furthermore, multiple logistic regression analysis was performed to predict in-hospital death. RESULTS: Myocardial bridging was observed in 33 patients (23%). In-hospital death was more frequent in patients with myocardial bridging (21% vs. 6%, p=0.02), which was due mainly to a higher non-cardiac death in those patients (15% vs. 5%, p=0.049). Multiple logistic regression analysis demonstrated myocardial bridging (odds ratio=12.0, 95% CI=2.52-78.5, p<0.01) as one of the independent predictors of in-hospital death. CONCLUSION: Myocardial bridging is an independent predictor of in-hospital death in patients with TTS.

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.

Tortuosity, Recurrent Segments, and Bridging of the Epicardial Coronary Arteries in Patients With the Takotsubo Syndrome.

Myocardial bridging (MB) and a long recurrent wraparound left anterior descending artery (wrap-LAD) are coronary anatomic variants that have been recently suggested to be associated with takotsubo syndrome (TS). Until now, coronary artery tortuosity (CAT) has never been investigated in this setting. Our study sought to evaluate the prevalence of the aforementioned anatomic variants in a large population with TS. In this retrospective angiographic study, 109 patients with TS were compared with 109 age- and gender-matched subjects without coronary artery disease, valve heart disease, or cardiomyopathy. CAT was identified by ≥3 consecutive curvatures ≥90° (criteria 1) or by ≥2 consecutive curvatures ≥180° (criteria 2). Wrap-LAD was defined if any part of the vessel outreached the apex of the left ventricle and MB as the presence of a milking effect or a step-up and step-down phenomenon. An anatomic variant was found in 79 patients with TS (72%) and in 48 controls (44%) (p <0.001). CAT in at least 1 vessel (criteria 1: 49% vs 20%, p <0.001; criteria 2: 38% vs 13%, p <0.001), ≥2 vessels (criteria 2: 14% vs 3%, p = 0.005), and wrap-LAD (41% vs 27%, p = 0.02) were significantly more frequent in patients with TS than in controls. The prevalence of MB (9% vs 5%, p = 0.18) did not differ between groups. In conclusion, CAT and wrap-LAD have higher prevalence in patients with TS than in matched controls. These findings could support the hypothesis that anatomic variants might act as potential pathogenic substrates in TS.

Prevalence and three-year follow-up of patients with isolated myocardial bridge in the mid-Black Sea region: a retrospective single-center study.

OBJECTIVE: Myocardial bridge (MB), also known as muscular bridge, is a rare congenital disease with relatively good prognosis. However, it has been associated with unstable angina, myocardial infarction, and sudden cardiac death. Incidence and prognosis of patients diagnosed with isolated MB after having undergone coronary angiography are evaluated in the present retrospective study. METHODS: Coronary angiograms of 18,250 patients, obtained between 2008 and 2011, were reexamined for presence of MB at the cardiology clinic. Of these patients, 241 (0.95%) had MB, and 181 (0.99%) had it as an isolated finding. Patients with isolated MB were divided into 2 groups according to severity of the lesion in the cardiac systole. Group 1 was comprised of patients with non-critical (<70%) stenosis; group 2 was comprised of patients with critical (≥70%) stenosis. Demographic characteristics, symptoms at initial diagnosis, and coronary angiographic findings regarding localization and severity of stenosis were noted. Follow-up was performed by phone, with outpatient clinic visits, and by reviewing hospital records. RESULTS: Twenty-five patients (13%) had critical stenosis (group 2), and 146 (87%) had non-critical stenosis (group 1). Mean follow-up duration was 38±7 months. Recurrent angina and repeated coronary angiography were reported in 15 group 1 patients (10.2%) and in 2 group 2 patients (8.0%) (p=non-significant). No instance of myocardial infarction was reported. CONCLUSION: Isolated MB seems to be a relatively benign disease, a conclusion made in accordance with those of previous studies. Symptoms and prognosis are not determined by degree of stenosis generated by the muscular bridge.