Impact of Myocardial Bridging on the Long-term Clinical Outcomes of Patients with Left Anterior Descending Coronary Artery Disease Treated with a Drug-Eluting Stent

Myocardial bridging (MB) is mostly confined to the left anterior descending coronary artery (LAD) and has been reported to be correlated with increased atherosclerotic plaques in the segment proximal to the bridging. This study aimed to assess the impact of MB on the clinical outcomes of patients with DES implantation in the LAD.A total of 551 consecutive patients with DES implantation on LAD from January 2008 to December 2009 were included. Patients were divided into an MB group (n=94, 17.1%) and a non-MB group (n=457, 82.9%) based on angiographic findings. They were followed up for three years to evaluate major adverse cardiac events (MACE), which were defined as all-cause death, myocardial infarction (MI), target lesion revascularisation (TLR) or ischaemic driven target vessel revascularisation (Id-TVR).During three years of follow-up, the rate of MACE was significantly higher in the MB group than in the non-MB group (18.1% vs. 9.8%, p=0.024), especially rates of TLR (8.5% vs. 2.4%; p=0.003) and Id-TVR (13.8% vs. 4.2%; p0.001). However, no difference was observed for MI (3.2 vs. 2.6%; p=0.692) and all-cause death rates (3.2 vs. 4.6%; p=0.575). Multivariate regression analysis showed that the presence of MB was an independent predictor for MACE (Hazard ratio 2.897, 95% CI 1.536 - 5.464, p=0.001).MB appears to be associated with adverse effects in patients with DES implantation in the LAD.