A Study of the Proximal Left Anterior Descending Coronary Artery Motion

Abstract

Objective: The purpose of this study is to elucidate deformation of each compression and torsion exerted to the proximal left anterior descending (LAD) artery during the cardiac cycle. Background: We hypothesised that mechanical stress exerted on the proximal LAD artery by cardiac contractions is a determinant of the need for repeat revascularization after stenting, though the proximal LAD motion has not been thoroughly studied. Methods: We prospectively analysed the electrocardiogram-gated, 64-slice multi detector row computed tomography (CT) images obtained in 297 consecutive patients suspected of suffering from coronary artery disease for having major risk factors, an abnormal electrocardiogram, or angina pectoris. Results: Using multi-planar reconstruction and enhanced cross-sectional CT images, the compression and torsion of the proximal LAD artery between end-systole and end-diastole were 15.6 ± 26.4% and 0.5 ± 0.6°/mm, respectively. The compression ratio was significantly smaller in diabetic (12.3 ± 33.8%) than in non-diabetic (16.5 ± 24.1%) patients (P<0.05). The torsion was also smaller in patients with versus without 3-vessel coronary disease (0.3 ± 0.3°/mm versus 0.5 ± 0.6°/mm; P<0.05) and in patients with versus without histories of previous valve surgery (0.2 ± 0.1°/mm versus 0.5 ± 0.6°/mm; P<0.05). Conclusions: We measured the amount of compression and torsion to the proximal LAD artery associated with the cardiac contractions. These mechanical stimuli may promote plaque rupture and progression, and in-segment restenosis after stent implantations.