Prevalence of Myocardial Bridge and Possible Associated Variables with Coexisting Coronary Atherosclerosis and Acute Coronary Syndrome

INTRODUCTION: The present study aims to evaluate the prevalence of myocardial bridging (MB) and investigate patient and bridge-related factors that may be associated with an increased tendency for atherosclerosis and acute coronary syndrome.

METHODS: Consecutive coronary angiography recordings that were recorded between 01/01/2013 and 01/01/2016 were retrospectively evaluated in this study. Data of consecutive patients with MB were obtained from patient files. Patients with MB were grouped according to the presence of significant atherosclerosis in any coronary artery and the presence of significant atherosclerosis proximal to bridge. Patients with isolated MB were also sub-grouped according to their presentation with the acute coronary syndrome. Demographic, clinical and angiographic parameters were compared between groups.
RESULTS: There were a total of 75 patients with MB, with an overall prevalence rate of 1.07%. MB patients without coexisting significant atherosclerotic lesion had longer bridge length and more severe stenosis rate (21.4±9.9 mm vs. 17.2±7.6 mm, p=0.045; 73.0±12.5% vs. 65.6±13.0%, p=0.015, respectively). Diabetes mellitus was the only risk factor that was more prevalent in MB patients with significant coexisting atherosclerotic lesions. MB segment of patients with proximal significant atherosclerosis was significantly shorter compared with the length of patients without significant proximal atherosclerosis (16.0±7.4 mm vs 20.7±9.5 mm, p=0.05). The presentation as an acute coronary syndrome was more prevalent in patients with significant atherosclerosis compared to patients with isolated MB (68.8% vs. 46.5%, p=0.045). There was no significant discriminative variable for presentation as acute coronary syndrome in patients with isolated MB.
DISCUSSION AND CONCLUSION: The prevalence rate of MB in our study is in agreement with the previous angiographic studies reported from Turkey. Coexisting atherosclerotic lesions seem to be primarily involved in the pathogenesis of acute coronary syndrome and ischemic symptoms that had necessitated coronary angiography.