Long‐Term Prognosis of Non‐Interventionally Followed Patients with Isolated Myocardial Bridge and Severe Systolic Compression of the Left Anterior Descending Coronary Artery

Abstract

Purpose: The aim of this study was to investigate the long-term prognosis of non-interventionally followed patients with myocardial bridge and angiographic milking of the left anterior descending (LAD) coronary artery. Methods: All of the coronary angiography records from May 2000 to November 2007 were reevaluated and patients who had more than 70% narrowing during systole on LAD were eligible for the present study. Follow-up was carried out by physical examination, echocardiography, and treadmill exercise testing. The clinical situations of the patients, medical treatment at the time of follow-up, and experienced events (death, myocardial infarction, or revascularization) were recorded. Results: There were 59 eligible patients (44 male, 74.6%). The mean age of the patients was 54 ± 11 years. The bridges were located in the proximal, mid, and distal portion of the LAD in 17 (28.8%), 20 (33.9%), and 22 (37.3%) patients, respectively. Distributions of the narrowing degree were as follows: between 70% to 89% in 33 (56%) patients and 90% to 100% in 26 (44%) patients. Mean follow-up duration of the group was 37 ± 13 months (range 15-65 mo). The clinical presentation during follow-up was stable angina in 9 (15.3%) cases, atypical angina in 12 (20.3%), atypical chest pain in 13 (22%), dyspnea in 3 (5.1%), and syncope in 3 (5.1%) cases. There were no experienced events and/or hospitalizations related to cardiac disease. Echocardiographic examination revealed normal systolic ventricular function. Only 17 (28.8%) patients continued to use medication. Most of them were on β-blocker therapy. Conclusion: Patients with myocardial bridges and angiographic milking of the LAD coronary artery have a good long-term prognosis. IntroductionMyocardial bridging is anatomically defined as the muscle overlying the intramural segment of a major epicardial coronary artery. A myocardial bridge is the most common congenital coronary anomaly, with an incidence of between 1.5% and 16% as assessed on coronary angiography and up to 80% as assessed at necroscopy. 1 -3 It is usually considered an innocent anomaly. 4 -6 Although it is rare, myocardial infarction, left ventricular dysfunction, paroxysmal atrioventricular block, as well as exercise-induced ventricular tachycardia and sudden cardiac death are accused sequela of this pathology. 4 -12 The aim of this study was to investigate the prognosis of non-interventionally followed patients with myocardial bridge and angiographic milking of the left anterior descending (LAD) coronary artery.

Intramural Coronary Arterial Course Is Associated With Coronary Arterial Stenosis and Prognosis of Major Cardiac Events

“…Previous prospective studies mainly focused on the significance of isolated ICA in the absence of atherosclerosis in the nonbridging arteries [8][9][10] or with small sample sizes. 2,3,11 The results were quite discordant; some showed that ICA is a benign anatomic variation, 2,3,10,11 and others showed it as an anatomic risk factor for CAD. 8,9 Recently, multidetector computed tomography (MDCT) has been used noninvasively to examine coronary arteries directly, and surprisingly, the wide use of MDCT also increased the detection rate for ICA.…”

Significance of the Anatomical Properties of a Myocardial Bridge in Coronary Heart Disease

“…9 The magnitude of the compressive force exerted by the MB on the coronary artery is closely related to the contractile force of the MB muscle, which is distinctly associated with the anatomical properties of the MB, namely, its length, 20 thickness, 29,57 and location. 58 In fact, coronary angiography combined with IVUS reveals that a longer MB has a significant association with more severe systolic compression, 20 and MDCT shows that the thickness of MB correlates with the severity of systolic compression. 29, 57 In hypertrophic hearts, a long MB also leads to significant LAD compression, 14 and a deeply situated intramyocardial LAD with a thick MB is associated with sudden cardiac death.…”

Attenuation Drop of Intra-Mural Coronary Segment Observed at Diastolic Phase of Coronary CT Angiography Predicts Significant Systolic Compression of Myocardial Bridge

“…Although MB is generally considered a benign anomaly, it may be associated with clinical manifestations that have been linked to dynamic compression [5][6][7][8][9][10][11]. The treatment strategy is guided by the presence of reduced myocardial perfusion, which is closely related to extent of dynamic compression [18,19].…”