| Objective: Using intravascular ultrasound(IVUS),the present study was underwent to determine plaque morphology of culprit artery in patients with coronary artery disease and to analysis the pathological mechanism of acute coronary syndrome.meanwhile,we also investigated the relationship between lesion morphology and no-reflow phenomenon of post-PCI for patients with AMI,and evaluated the predictive factors for no-reflow.Methods:(1)135 patients (UAP group,40;AMI group,45;SAP group,50) were underwent coronary angiography(CAG) and IVUS.63 target lesions by CAG was in left anterior descending artery(LAD),23 in left circumflex artery(LCX),and 49 in right coronary artery(RCA).Angiographic no-reflow was defined as TIMI flow grade 0,1, or 2 without any mechanical obstruction or stenosis by IVUS.Patients with AMI were divided into 2 subgroup according to post-PCI angiogram:normal flow(group R,n=36) and no-reflow(group NR,n=9).The coronary artery and lesion underlying the atherosclerotic event(ie.culprit) were identified of precrisis and intercrisis ECGs,left ventricle wall motion abnormalities,UCG,and angiographic lesion appearance. (2) After completion of CAG, All patients received a bolus injection of heparin(100 ~ 120u/Kg),and an intracoronary isosorbide dinitrate(200ug),a 0.014-inch guide wire was passed over the target lesion and IVUS catheter advanced over the guide wire was located at least 10mm distal to the target lesion.Continuous IVUS imaging was recorded using a 2.9-3.0Fr monorail system with 30-MHz mechanical transducer-tipped catheter (Boston Scientific Corporation).All images were obtained with a automatic pullback system at 0.5mm/s.Pullback was started from a position about 10mm distal to target lesion to aorto-coronary junction.On-line quantitative measurements were made during diastole stage and off-line measurements were performed from a 1/2-inch high resolution super VHS videotape(Sony,Tokyo,Japan)which recorded the images simultaneously.Three ideal segments were identified and analyzed: the proximal reference segment,target lesion,the distal reference segment. Results:(1 )There was no significant difference in plaque eccentricity ,calcification and remodeling index among three groups(P>0.05). Incidences of high echoic plaque and mixed plaque were more frequent in SAP group than in AMI group and UAP group(30% vs 10% ,11.1%;30% vs 12.5%,8.9%; P<0.05, respectively).However UAP group and AMI group have higher incidences ofthrombus(10.0%,28.9%),dissection/rupture(20.0%,42.2%),low echoic plaque(60.0%,64.4%),lipid core(27.5%,40.0%) than SAP group(0%, 4%, 20.0%, 0%,respectively P<0.05 or 0.01). dissection/rupture and thrombus were more frequent in AMI group than in UAP group(P<0.05).(2) EEM CSA,Lumen CSA,P&M CSA of proximal and distal reference segments have no significant difference among three groups.EEM CSA(UAP group 15.3 6.0,AMI 15.1 6.2, mm2),Lumen CSA(3.5 2.0, 3.1+2.2,mm2),P&M CSA(12.0 + 5.2,12.4 + 5.9,mm2),plaque length(16.9 9.0,17.5 10.1,mm),and plaque burden(78 8%,80 8%) of plaque site were significantly different in ACS group than in SAP group(12.9 + 5.7, 6.3 + 2.4, 9.1+4.3, 10.3 + 5.7, 69+10%, respectively PO.05 or 0.01).(3) Incidences of soft plaque and calcification was not statistically different between NR group and R group.However lipid core and rupture/dissection were more frequent in group NR than in group R(90% vs28% P<0.01,78% vs33% PO.05, respectively); plaque EEM-CSA was not significantly different between two groups (15.2 + 5.3 vs 14.7 + 4.9, P>0.05); positive vessel remodeling was also more frequently found in group NR than in group R(90 % vs 47 %, P<0.05).Multivariate logistic regression analysis showed that lipid core(OR97,P<0.05,95 % CI, 1.34-1078) and positive remodeling(OR1.33 P<0.05,95%CI, 1.15-3.21) are independent predictive factors of no-reflow phenomenon after PCI for AMI.Concusions:( 1 )thrombus,dissection/rupture, longer lesion,larger plaque burden,and low echoic plaque a... |
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