Clinical Outcomes of Surgical Unroofing of Myocardial Bridging in Symptomatic Patients

Coronary Artery Anomalies: Diagnosis & Management

Coronary artery anomalies encompass a spectrum of congenital abnormalities affecting the origin, course, or termination of the major epicardial coronary arteries. Despite their rarity, coronary artery anomalies represent a significant burden on cardiovascular health due to their potential to disrupt myocardial blood flow and precipitate adverse cardiac events. While historically diagnosed postmortem, the widespread availability of imaging modalities has led to an increased recognition of coronary artery anomalies, particularly in adults. This review synthesizes current knowledge on the classification, mechanisms, and clinical implications of coronary anomalies, focusing on prevalent variants with significant clinical impact. We discuss strategies for medical and surgical management, as well as contemporary screening recommendations, acknowledging the evolving understanding of these anomalies. Given the breadth of possible variants and the limited data on some presentations, this review provides a framework to aid clinicians in the recognition and management of coronary anomalies, with a particular emphasis on their stratification by anatomical location. By consolidating existing knowledge and highlighting areas of uncertainty, this review aims to enhance clinical decision-making and improve outcomes for individuals with coronary anomalies.

Robotic Totally Endoscopic Off-Pump Unroofing of Myocardial Bridge: Early Experience and Midterm Outcomes

OBJECTIVE

Myocardial bridging (MB) occurs when a coronary artery, commonly the left anterior descending (LAD), has an intramyocardial course. In symptomatic patients who fail medical therapy, surgical unroofing can provide symptomatic relief by improving coronary blood flow. We present a series of patients undergoing robotic totally endoscopic beating-heart MB unroofing.

METHODS

There were 34 patients with an LAD-MB who failed medical therapy and underwent robotic totally endoscopic, off-pump unroofing between January 2017 and October 2023. Patients were evaluated by a multidisciplinary team and underwent provocative coronary angiography to confirm hemodynamic significance. We reviewed perioperative outcomes and contacted patients for midterm follow-up, including completion of a modified Seattle Angina Questionnaire (SAQ).

RESULTS

The mean age was 48 ± 8 years, and 56% were female patients. One patient had prior septal myectomy via sternotomy. All patients had significant dobutamine Pd/Pa reduction on preoperative coronary angiography. One patient had atrial fibrillation and underwent concomitant ablation with left atrial appendage ligation. The mean procedure time was 140 ± 69 min. All were completed totally endoscopically off-pump without intraoperative conversions. The mean MB length was 4.5 ± 1.4 cm, and the mean depth was 1.6 ± 0.9 cm. Of the patients, 76% were extubated in the operating room. The mean intensive care unit and hospital length of stay were 0.97 ± 0.58 and 1.73 ± 1.1 days, respectively. There were no mortalities or strokes. There was 1 postoperative take-back for bleeding. At midterm follow-up (19 ± 14 months), 28 patients completed the SAQ; 86% reported "much less angina" during activity compared with before surgery, and 93% reported taking no antianginal medication since surgery.

CONCLUSIONS

In appropriate patients with hemodynamically significant LAD-MB who fail medical therapy, robotic beating-heart unroofing is possible with good outcomes. Further studies are warranted.

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.

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.

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.

Use of Intravascular Ultrasound and Coronary Angiography to Measure the Prevalence of Myocardial Bridge in Heart Transplant Patients

Myocardial bridge (MB) detection rates vary across methods and most studies that have assessed MB include symptomatic patients. Intravascular ultrasound (IVUS) is a sensitive tool for MB detection and donor hearts may serve as a surrogate measure of asymptomatic patients. We used IVUS and coronary angiography to measure MB prevalence in heart transplant patients during routine follow-up invasive coronary assessments. This was a retrospective, single-center study of heart transplant patients who received follow-up coronary assessments at the University of Chicago Heart and Vascular Center between December 2014 and December 2021. A single experienced interventional cardiologist assessed incidental findings of MB in IVUS and coronary angiography. Detection rates were compared with meta-analysis-reported prevalence. Of 129 patients, IVUS-detected MB in 87 patients (67.4%), whereas coronary angiography detected 41 (31.8%). All MB found by coronary angiography were detected by IVUS. Some level of cardiac allograft vasculopathy was found in 92 patients (71.3%). Our IVUS-detected MB prevalence was greater than meta-analysis-reported pooled prevalence across all methods: autopsy, computed tomography angiography, and coronary angiography (67.4% [95% confidence interval [CI] 59.4 to 75.5] vs 42% [95% CI 30 to 55]; 22% [95% CI 18 to 25]; 6% [95% CI 5 to 8], p ≤0.005). The difference between our observed IVUS-detected MB prevalence and meta-analysis autopsy reported MB prevalence was 1.25 (95% CI 1.11 to 1.40). In conclusion, the high prevalence of MB recorded in donor hearts emphasizes the need to further investigate the causes of chest pain in patients who are found to have MB.

A Comprehensive Review of Myocardial Bridging: Exploring Diagnostic and Treatment Modalities

Myocardial bridging (MB) is a congenital coronary artery anomaly involving an overlying myocardium's partial or complete encasement of a coronary artery segment. The obstruction can lead to significant cardiac symptoms, resulting in myocardial ischemia, arrhythmia, and sudden cardiac death. Several approaches, including invasive and non-invasive methods, have been proposed to diagnose and manage MB. Invasive modalities, such as intravascular ultrasound (IVUS) and coronary angiography, offer high specificity and sensitivity. In contrast, non-invasive methods like Doppler ultrasound, multislice computed tomography (MSCT), and magnetic resonance imaging (MRI) are advantageous due to their non-invasive nature, high sensitivity and specificity, and cost-effectiveness. Treatment options for MB mainly focus on relieving symptoms and preventing adverse outcomes. The use of pharmacological agents and surgical and percutaneous interventions has been documented in numerous studies. Studies conclude that MB is a treatable cardiac anomaly, and a combined approach of diagnosis, treatment, and follow-up is necessary to reduce the morbidity and mortality associated with this condition.

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 chart review on surgical myocardial debridging in symptomatic patients: a safe procedure with good long-term clinical outcome and coronary computed tomographic angiography results

OBJECTIVES

Myocardial bridging is mostly diagnosed as an incidental imaging finding but can result in severe vessel compression and significant clinical adverse complications. Since there is still an ongoing debate when to propose surgical unroofing, we studied a group of patients where this was performed as an isolated procedure.

METHODS

In 16 patients (38.9 ± 15.7 years, 75% men) who had surgical unroofing for symptomatic isolated myocardial bridges of the left anterior descending artery, we retrospectively analysed symptomatology, medication, imaging modalities used, operative techniques, complications and long-term outcome. Computed tomographic fractional flow reserve was calculated to understand its potential value for decision-making.

RESULTS

Most procedures were performed on-pump (75%, mean cardiopulmonary bypass 56.5 ± 27.9 min, mean aortic cross-clamping 36.4 ± 19.7 min). Three patients needed a left internal mammary artery bypass since the artery dived inside the ventricle. There were no major complications or deaths. The mean follow-up was 5.5 years. Although there was a dramatic improvement in symptoms, still 31% experienced atypical chest pain at various moments during follow-up. Postoperative radiological control was performed in 88%, showing no residual compression or recurrent myocardial bridge and patent bypass if performed. All postoperative computed tomographic flow calculations (7) showed a normalization of coronary flow.

CONCLUSIONS

Surgical unroofing for symptomatic isolated myocardial bridging is a safe procedure. Patient selection remains difficult but introducing standard coronary computed tomographic angiography with flow calculations could be helpful in preoperative decision-making and during follow-up.

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.

Myocardial Bridging Leading to Cardiac Collapse in a Marathon Runner

Myocardial bridging (MB) is a congenital coronary anomaly, which is defined as cardiac muscle overlying a portion of a coronary artery. Although traditionally considered benign in nature, increasing attention is being given to specific subsets of MB. Sports medicine recognizes MB as a cause of sudden death among young athletes. We present a case of a 30-year-old man who suddenly collapsed during a marathon running. Diagnostic workup with coronary computed tomography angiography revealed the presence of three simultaneous myocardial bridges in this patient, possibly explaining the exercise-induced syncope. The other diagnostic tests excluded seizures, cranioencephalic lesions, ionic or metabolic disturbances, acute coronary syndromes, cardiomyopathies, myocarditis, or conduction disturbances. Exertional syncope is a high-risk complaint in the marathon runner. In the context of intense physical activity, the increased sympathetic tone leading to tachycardia and increased myocardial contractility facilitates MB ischemia. In this illustrative case, the patient’s syncope might probably be associated with an ischemia-induced arrhythmia secondary to MB and potentiated by dehydration in the context of prolonged stress (marathon running). In conclusion, this case highlights that MB may be associated with dangerous complications (myocardial ischemia and life-threatening ventricular arrhythmias), particularly during intense physical activity and in the presence of a long myocardial bridge.

[Surgical treatment of obstructive hypertrophic cardiomyopathy combined with muscle bridging of the left anterior descending artery]

Myocardial bridging is often detected during diagnostic coronary angiography in patients with congenital and acquired heart defects. In most cases, muscle bridging does not require surgical treatment. Myocardial bridging and tunnels causing compression of one or more major coronary arteries is a potential cause of myocardial ischemia in patients with hypertrophic cardiomyopathy. The authors report surgical treatment of a patient with obstructive hypertrophic cardiomyopathy and myocardial bridging of the left anterior descending artery.

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.

Impact of Diastolic Vessel Restriction on Quality of Life in Symptomatic Myocardial Bridging Patients Treated With Surgical Unroofing: Preoperative Assessments With Intravascular Ultrasound and Coronary Computed Tomography Angiography

[Figure: see text].

Minimally invasive coronary artery bypass grafting via a lower ministernotomy for left anterior descending artery myocardial bridging: mid-term results

OBJECTIVES

Coronary artery bypass grafting or supra-arterial myotomy is now suggested as a better therapeutic option in myocardial bridging (MB) when medical treatment fails to control symptoms. For left anterior descending (LAD) MB, minimally invasive coronary artery bypass via a lower ministernotomy can be offered.

METHODS

Forty-four consecutive patients who underwent elective minimally invasive coronary artery bypass surgery from 2005 to 2014 via an inferior sternotomy using the left internal mammary artery as a bypass graft for LAD MB were evaluated retrospectively.

RESULTS

The mean age was 59.1 ± 13.1 years with 26 (59%) men and 18 (41%) women. The mean body mass index was 27.2 ± 3.9 and the mean EuroSCORE II was 1.6 ± 1.8. Routine coronary multislice computed tomography angiography on the 6th postoperative day revealed 97.7% graft patency. During the initial hospital stay, 1 patient (2.3%) underwent a reoperation for early graft failure. Forty patients (91%) could be followed up for a mean period of 64.4 ± 24.5 months after the procedure, during which 2 patients (4.5%) died of non-cardiac causes and 9 patients (20.5%) underwent postoperative coronary angiography with confirmed graft occlusion in only 1 case (2.3%). The improvement in the distribution of patients in the Canadian Cardiovascular Society class 0 was from 4 patients (9%) preoperatively to 37 patients (84%) at the end of the follow-up period (P-value 0.001).

CONCLUSIONS

Minimally invasive coronary artery bypass surgery via a lower ministernotomy may be safe and efficient for treating LAD artery MB with acceptable complication rates, cosmetic benefits and patency rates.

Off-Pump Minithoracotomy Versus Sternotomy for Left Anterior Descending Myocardial Bridge Unroofing

BACKGROUND

Myocardial bridge (MB) of the left anterior descending (LAD) coronary artery occurs in approximately 25% of the population. When medical therapy fails in patients with a symptomatic, hemodynamically significant MB, MB unroofing represents the optimal surgical management. Here, we evaluated minimally invasive MB unroofing in selected patients compared with sternotomy.

METHODS

MB unroofing was performed in 141 adult patients by sternotomy on-pump (ST-on, n = 40), sternotomy off-pump (ST-off, n = 62), or minithoracotomy off-pump (MT, n = 39). Angina symptoms were assessed preoperatively and 6 months postoperatively using the Seattle Angina Questionnaire. Matching included all MT patients and 31 ST-off patients with similar MB characteristics, no previous cardiac operations or coronary interventions, and no concomitant procedures.

RESULTS

MT patients tended to have a shorter MB length than ST-on and ST-off patients (2.57 vs 2.93 vs 3.09 cm, P = .166). ST-on patients had a longer hospital stay than ST-off and MT patients (5.0 vs 4.0 vs 3.0 days, P < .001), and more blood transfusions (15.2% vs 0.0% vs 2.6%, P = .002). After matching, MT patients had a shorter hospital stay than ST-off patients (3.0 vs 4.0 days, P = .005). No deaths or major complications occurred in any group. In all groups, MB unroofing yielded significant symptomatic improvement regarding physical limitation, angina stability, angina frequency, treatment satisfaction, and quality of life.

CONCLUSIONS

We report our single-center experience of off-pump minimally invasive MB unroofing, which may be safely performed in carefully selected patients, yielding dramatic improvements in angina symptoms at 6 months after the operation.

Midterm results of different treatment methods for myocardial bridging in patients after septal myectomy

BACKGROUND

Myocardial bridging (MB) is commonly treated in patients with hypertrophic cardiomyopathy. However, whether and how MB should be treated in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent septal myectomy remain unclear.

METHODS

A total of 823 adults with HOCM who underwent septal myectomy at the Fuwai Hospital from 2011 to 2017 were retrospectively studied.

RESULTS

Overall, 31 events occurred: 24 patients died and 7 had nonfatal myocardial infarction (MI). The 3-year cumulative event-free survival of all-cause death (97.9% vs. 100% vs. 100% vs. 98.4%, p = .89) and cardiovascular death (98.3% vs. 100% vs. 100% vs. 98.4%, p = .63) were similar among the four groups (non-MB, coronary artery bypass grafting [CABG], unroofing, untreated, respectively). However, the 3-year cumulative event-free survival of nonfatal MI (100% vs. 97.5% vs. 98.0% vs. 89.9%, p < .001) and combined endpoints (97.9% vs. 97.5% vs. 98.0% vs. 88.4%, p = .02) were significantly lowest in untreated MB (non-MB, CABG, unroofing, untreated, respectively). Cox regression analysis indicated that untreated MB was a significant independent predictor of combined endpoints (hazard ratio: 4.06, 95% confidence interval: 1.60-10.32, p < .001). Moreover, 49 patients underwent coronary artery computed tomography 1 year after surgery. The patency rate of the saphenous vein graft was significantly higher than that of the left internal mammary artery (13.3% vs. 84.2%, p < .001). No MB was detected in the unroofing group.

CONCLUSIONS

Surgical MB treatment could be beneficial and performed safely during septal myectomy. Myocardial unroofing is the recommended treatment for MB, and unroofing when technically possible may be preferable for long-term outcomes.