Impact of Myocardial Bridge on Life‐Threatening Ventricular Arrhythmia in Patients With Implantable Cardioverter Defibrillator

Abstract

Background Myocardial bridge (MB), common anatomic variant, is generally considered benign, while previous studies have shown associations between MB and various cardiovascular pathologies. This study aimed to investigate for the first time possible impact of MB on long‐term outcomes in patients with implantable cardioverter defibrillator, focusing on life‐threatening ventricular arrhythmia (LTVA). Methods and Results This retrospective analysis included 140 patients with implantable cardioverter defibrillator implantation for primary (n=23) or secondary (n=117) prevention of sudden cardiac death. Angiographically apparent MB was identified on coronary angiography as systolic milking appearance with significant arterial compression. The primary end point was the first episode(s) of LTVA defined as appropriate implantable cardioverter defibrillator treatments (antitachyarrhythmia pacing and/or shock) or sudden cardiac death, assessed for a median of 4.5 (2.2–7.1) years. During the follow‐up period, LTVA occurred in 37.9% of patients. Angiographically apparent MB was present in 22.1% of patients; this group showed younger age, lower rates of coronary risk factors and ischemic cardiomyopathy, higher prevalence of vasospastic angina and greater left ventricular ejection fraction compared with those without. Despite its lower risk profiles above, Kaplan–Meier analysis revealed significantly lower event‐free rates in patients with versus without angiographically apparent MB. In multivariate analysis, presence of angiographically apparent MB was independently associated with LTVA (hazard ratio, 4.24; 95% CI, 2.39–7.55; P <0.0001). Conclusions Angiographically apparent MB was the independent determinant of LTVA in patients with implantable cardioverter defibrillator. Although further studies will need to confirm our findings, assessment of MB appears to enhance identification of high‐risk patients who may benefit from closer follow‐up and targeted therapies.

The Impact of Myocardial Bridging on the Coronary Functional Test in Patients with Ischaemia with Non-Obstructive Coronary Artery Disease

“…The results of the cited study must be discounted because the patients in this study were a group of patients who underwent CFT for suspected coronary spasm and were actually diagnosed with VSA in 63% of the studied patients. Nevertheless, 87% of patients with MB had provoked coronary spasms, which fully confirms the results of previous studies showing an increased susceptibility to coronary spasms in patients with MB [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Regarding the relationship between coronary spasms and MB, Im et al [ 13 ] showed that coronary spasms in patients with MB was provoked at a low ACh dose, and the spasms were severe, diffuse and long.…”

“…Because of the combination of the presence of atherosclerosis beneath the MB and systolic compression of the coronary artery by MB, it has been reported that FFR is reduced in patients with MB [ 1 ]. Third, MB may increase the susceptibility to coronary spasms [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”

“…However, in some cases, acute myocardial infarction, vasospastic angina (VSA), exertional angina and sudden cardiac death have been reported to be caused by MB [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. Additionally, an increase in reports regarding the relationship between the presence of MB and coronary spasm [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ] has recently occurred.…”

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

“…They revealed that patients with MB had significantly higher rates of LTVA and a higher prevalence of vasospastic angina than patients without MB. It may account for some potential mechanisms for bad prognosis in patients with myocardial infarction/ischemia with non-obstructive coronary arteries (MINOCAs) (41). MB may be the major etiology of angina in MINOCA, given the high proportion (58%) of patients with MB detected by IVUS in patients suffering from angina but without the absence of obstructive CAD (42).…”

“…MB may be the major etiology of angina in MINOCA, given the high proportion (58%) of patients with MB detected by IVUS in patients suffering from angina but without the absence of obstructive CAD (42). Although most MBs were considered a benign cardiovascular anomaly, the potential poor prognosis of some symptomatic patients should be paid more attention, and the evaluation of MB seems to improve the identification of high-risk individuals in case of the occurrence of LTVA or sudden death (41).…”