Surgical treatment of symptomatic left anterior descending myocardial bridges: myotomy vs. bypass surgery

Myocardial ischemia caused by the synergistic effect of myocardial bridge and moderate stenosis: case report

BACKGROUND

Clinical events such as angina pectoris, acute coronary syndrome, and sudden death caused by myocardial bridge (MB) have attracted increasing attention. It is still a challenge to diagnose whether MB can cause the symptoms of patients with MB. For most MB patients, medication remains the primary treatment.

CASE PRESENTATION

This article reports a case of chest pain in a patient with MB in the middle segment of the left anterior descending artery (LADm) with moderate stenosis in the proximal segment (LADp). Through functional assessment, we found that neither MB nor fixed stenosis had sufficient effect on coronary blood flow to cause myocardial ischemia, but their synergistic effect resulted in myocardial ischemia. Finally, a stent was implanted in LADp and good clinical results were achieved.

CONCLUSIONS

For symptomatic patients with MB combined with fixed stenosis, functional evaluation may be necessary, which has significant guiding significance for treatment strategy selection. For asymptomatic patients, early detection of myocardial ischemia may also improve the prognosis of patients.

Update review on myocardial bridging: New insights

Myocardial bridging (MB) is a common congenital abnormality that remains asymptomatic in a large proportion of patients. The peak of clinical manifestation occurs during the third and fourth decades of life. MB provokes myocardial ischemia through different mechanisms including supply-demand mismatch, endothelial dysfunction, coronary microvascular dysfunction and external mechanical compression. The association between MB and atherosclerotic disease is controversial. Recent studies established a significant association of MB with myocardial infarction and non-obstructive coronary artery disease. The first line medical treatment is based on beta-blockers and calcium channel blockers. Ivabradine is used in second line therapy. Invasive approaches involving percutaneous coronary intervention, coronary artery bypass graft and myotomy are performed in patients with symptoms refractory to maximally tolerated medical treatment. The choice of revascularization technique depends on anatomical characteristics, clinical condition and physician experience. Available data derived from anecdotal evidence view the lack of randomized clinical trials.

Surgical strategies and outcomes for myocardial bridges coexisting with other cardiac conditions

BACKGROUND

Myocardial bridges are congenital coronary artery anomalies. There are still many controversies surrounding surgical treatment strategies for myocardial bridges combined with other heart disorders. The purpose of this study was to evaluate the surgical treatment strategies and outcomes in patients with these conditions.

METHODS

Between March 2004 and October 2021, our institution witnessed 77 patients diagnosed with myocardial bridging who underwent surgical intervention. According to the myocardial bridge and combined heart disorder, four groups were identified: 1. isolated LAD supra-arterial myotomy group, 2. LAD CABG and(or not) myotomy  group, 3. LAD supra-arterial myotomy and grafting of other branches group, and 4. LAD supra-arterial myotomy and other cardiac surgery group. The perioperative outcomes, symptoms, life quality, mortality, and major adverse cardiac events (MACEs) were analyzed.

RESULTS

There were no deaths during hospitalization and no rethoractomy for postoperative bleeding or major adverse cardiac events (MACEs). The follow-up period ranged from 2 months to 199.2 months (55.61 ± 10.21) months, the 10-year cumulative survival rates for the four groups of patients were 95.0%, 100%, 100% and 74.1%, and the 10-year freedom rates from the MACEs were 83.9%, 92.0%, 87.5% and 76.2%, respectively.

CONCLUSIONS

Supra-arterial myotomy is preferred in patients with isolated myocardial bridge, and acceptable results can be achieved by choosing supra-arterial myotomy in combination with CABG or other cardiac surgery simultaneously for patients with myocardial bridges and other heart disorders.

MINOCA Associated with a Myocardial Bridge: Pathogenesis, Diagnosis and Treatment

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.

A bibliometric analysis on the progress of myocardial bridge from 1980 to 2022

Introduction

Although 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.

Methods

By 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.

Results

A 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.

Conclusion

Our 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.

The myocardial bridge: incidence, diagnosis, and prognosis of a pathology of uncertain clinical significance

The myocardial bridge (MB) is a common anomaly of the coronary tree, very often clinically silent. The artery typically involved is the left anterior descending in its proximal and/or middle portion. MB can cause ischaemia with various mechanisms, directly proportional to the degree of compression of the intra-myocardial tract, which impairs the coronary flow. It is a dynamic phenomenon that is affected by the adrenergic tone and is therefore often brought by physical exercise. MB, when symptomatic, often begins with angina from exertion; some patients have more severe conditions such as unstable angina or myocardial infarction. Coronary vasospasm related to MB-induced endothelial dysfunction can explain a number of cases that come to observation even with catastrophic pictures such as ventricular fibrillation caused by ischaemia. The diagnostic workup includes the non-invasive study using computed tomography angiography and the invasive study of the haemodynamic impact using pressure and Doppler guides. In symptomatic cases, drug therapy with a beta-blocker is enough to manage angina. When it fails, there is the option of coronary angioplasty or surgical treatment techniques.

Comprehensive functional and anatomic assessment of myocardial bridging: Unlocking the Gordian Knot

Myocardial bridging (MB) is the most frequent congenital coronary anomaly in which a segment of an epicardial coronary artery takes a tunneled course under a bridge of the myocardium. This segment is compressed during systole, resulting in the so-called "milking effect" at coronary angiography. As coronary blood flow occurs primarily during diastole, the clinical relevance of MB is heterogeneous, being usually considered an asymptomatic bystander. However, many studies have suggested its association with myocardial ischemia, anginal symptoms, and adverse cardiac events. The advent of contemporary non-invasive and invasive imaging modalities and the standardization of intracoronary functional assessment tools have remarkably improved our understanding of MB-related ischemia, suggesting the role of atherosclerotic lesions proximal to MB, vasomotor disorders and microvascular dysfunction as possible pathophysiological substrates. The aim of this review is to provide a contemporary overview of the pathophysiology and of the non-invasive and invasive assessment of MB, in the attempt to implement a case-by-case therapeutic approach according to the specific endotype of MB-related ischemia.

Myocardial Bridging: Diagnosis, Functional Assessment, and Management: JACC State-of-the-Art Review

Myocardial bridging (MB) is a congenital coronary anomaly in which a segment of the epicardial coronary artery traverses through the myocardium for a portion of its length. The muscle overlying the artery is termed a myocardial bridge, and the intramyocardial segment is referred to as a tunneled artery. MB can occur in any coronary artery, although is most commonly seen in the left anterior descending artery. Although traditionally considered benign in nature, increasing attention is being given to specific subsets of MB associated with ischemic symptomatology. The advent of contemporary functional and anatomic imaging modalities, both invasive and noninvasive, have dramatically improved our understanding of dynamic pathophysiology associated with MBs. This review provides a contemporary overview of epidemiology, pathobiology, diagnosis, functional assessment, and management of MBs.

Surgical intervention and outcome for treatment of myocardial bridging refractory to medication

INTRODUCTION

Myocardial bridging (MB) is a common and usually benign inborn coronary abnormality that may lead to anginal symptoms, acute coronary syndrome, arrhythmias, and rarely sudden cardiac death. MB are most commonly localized in the middle segment of the left anterior descending coronary artery (LAD). The treatment of LAD-MB is still challenging. Our objective was to assess the short- and long-term results of surgical procedures in patients with LAD-MB who had chest pain refractory to medical therapy.

METHODS

Between March 2005 and January 2020, 26 patients (19 males and 7 females; mean 55.8 ± 12.4 years) with MB underwent surgery. All MB was located in the mid-segment of the LAD with a mean length of 4.2 ± 1.7 cm. Coronary angiography before surgery demonstrated LAD-MB with systolic compression more than or equal to 70% in all patients.

RESULTS

Twenty-five patients underwent myotomy and one patient underwent coronary artery bypass grafting (CABG). All patients survived and recovered uneventfully. Neither hospital or late death nor major complications occurred. Follow-up time was 3-173 months (mean 55.7 months). Follow-up of coronary angiography or computed tomography scan performed in 16 patients demonstrated restoration of coronary blood flow and myocardial perfusion without significant residual compression of the artery. All patients were symptom-free and are currently in NYHA Class I.

CONCLUSION

The symptomatic LAD-MB patients who are refractory to medication should actively undergo the surgical intervention such as myotomy and CABG to eliminate the clinical symptoms and achieve satisfactory results by follow-up findings. Myotomy is a preferred procedure because of its safety and satisfactory results.