Impact of Clinical and Morphological Factors on Long-Term Mortality in Patients with Myocardial Bridge

Although myocardial bridging (MB) has been intensively investigated using different methods, the effect of bridge morphology on long-term outcome is still doubtful. We aimed at describing the anatomical differences in coronary angiography between symptomatic and non-symptomatic LAD myocardial bridges and to investigate the influence of clinical and morphological factors on long-term mortality. In our retrospective, long-term, single center study we found relevant MB on the left anterior descendent (LAD) coronary artery in 146 cases during a two-year period, when 11,385 patients underwent coronary angiography due to angina pectoris. Patients were divided into two groups: those with myocardial bridge only (LAD-MB(neg), n = 78) and those with associated obstructive coronary artery disease (LAD-MB(pos), n = 68). Clinical factors, morphology of bridge by quantitative coronary analysis and ten-year long mortality data were collected. The LAD-MB(neg) group was associated with younger age and decreased incidence of diabetes mellitus, as well as with increased minimal diameter to reference diameter ratio (LAD-MB(neg) 54.5 (13.1)% vs. LAD-MB(pos) 46.5 (16.4)%, p = 0.016), while there was a tendency towards longer lesions and higher vessel diameter values compared to the LAD-MB(pos) group. The LAD-MB(pos) group was associated with increased mortality compared to the LAD-MB(neg) group. The analysis of our data showed that morphological parameters of LAD bridge did not influence long-term mortality, either in the overall population or in the LAD-MB(neg) patients. Morphological parameters of LAD bridge did not influence long-term mortality outcomes; therefore, it suggests that anatomical differences might not predict long-term outcomes and should not influence therapy.