Correlation Analysis Of The Morphological Diversity Of The Left Coronary Artery And The Formation Of Atherosclerotic Plaques

Purpose: The aim of our study was to determine the length of the left maincoronary (LM), the dimensions and areas at different points including ostium,midvessel and distal, the bifurcation angles and the types of the LM on320-slicespiral computed tomography, and research the differences between men and womenwithout atherosclerotic plaques. We also studied the relationship between the anatomyvariations in LM and the localization and formation of the atherosclerotic plaques incoronary artery.Materials and Methods: A total of199consecutive patients who underwent320-row spiral CT coronary angiography in our hospital between September2014andMarch2015were selected, including98females and101males, age55to65yearsold. According to the presence and severity of the plaques in the left coronary artery,the patients were divided into three groups, including69cases of the normal group,74cases of the mild stenosis group, and56cases of the moderate-severe stenosisgroup. On the basis of the plaque positions, the coronary lesion group was furtherdivided into proximal and distal lesions. If multiple lesions were coexist in any of themajor branches, the most severe one was taken into consideration. According to the3D volume rendering technology, the LM can be divided into four types: type I(biconcave-shaped pattern), type II (tapering pattern), type III (combined pattern,cone-shaped at the ostium and then tubular-shaped in the other parts of the vessel),and type IV (funnel-shaped pattern) We adopted the Japan Toshiba320-row spiral CTscanner, the retrospective ECG gating and the75%R-R intervals reconstruction.Using Vitrea Workstation software and reconstruction technologies such as thevolume rendering, the maximum intensity projection, the multi-planar reformattingand the curved multi-planar reformation, the length of the LM, the dimensions andareas (at the ostium, midvessel and distal of the LM), angle1, angle2, angle3, theangles between LAD and LCX, LM and LAD, LM and LCX were measured,. Thediameter stenosis rate of the vessel was measured, and the locations of plaques wererecorded. The statistics analyses were performed using SPSS19.0softwareResults: In the normal group, the range of the LM length was3~22mm, themean length was9.73mm. The largest and smallest mean cross-sectional diameters of the LM measured at the ostium were3.98and5.31mm, respectively; at themidportion,3.63and4.4mm, respectively; and the distal portions,3.71and4.67mm,respectively. The mean cross-sectional area measured at ostium, midportion and distalLM were17.71mm2,12.77mm2and14.14mm2, respectively. The angles between LMand LAD, LM and LCX, LAD and LCX were145.15°,123.1°and73.39°respectively. The angle1, angle2and angle3were93.59°,111.64°and70.57°respectively. The angles between LAD and LCX in women were smaller than those inmen in the normal group (P=0.01). Forty out of69participants (58%) in normalgroup showed biconcave-shaped appearance of the LM (type I),13/69participants(18.8%) showed tapering morphology (type II),7/69participants (10.2%) hadcombined pattern (type III) and9/69participants (13%) had funnel-shaped appearance.In the comparison of the normal group, the proximal lesions group and the distallesions group, the mean angle between LAD and LCX in the normal group wassmaller than that in proximal lesions group (P=0.018) and that in the distal lesionsgroup (P=0.026). In the comparison of the normal group, the mild stenosis group andthe moderate-severe stenosis group, the overall distributions of LM types weredifferent (P=0.026), the mean angle between LAD and LCX in the normal group wassmaller than that in the mild stenosis group (P=0.013) and that in themoderate-severe stenosis group (P=0.037). In the comparison of the normal group,the proximal mild stenosis group and the proximal moderate-severe stenosis group,the overall distributions of LM types were different (P=0.04), the mean anglebetween LAD and LCX in the normal group were smaller than that in the proximalmoderate-severe stenosis group (P=0.021), and the mean length of the LM in thenormal group was larger than that in the moderate-severe stenosis group (P=0.026).Conclusion:320-row CT can objectively evaluate the anatomical morphology ofthe left coronary artery and the relationship with the distribution and degree of thecoronary atherosclerotic plaques, thus providing references for the diagnosis andtreatment of coronary artery diseases.The left coronary artery is not a simple straighttube, but usually has various anatomical configurations, variable length, dimensions,areas and bifurcation angles. The overall distributions of LM types were different among individuals without atherosclerosis and with atherosclerosis in left coronaryartery. The shorter LM and the wider angle between left anterior descending branchand circumflex branch will promote the formation of the left coronary atheroscleroticplaque.