| PARTIReproducibility of multi-detector CT measurements of aortic annulus of severe aortic stenosis patients for transcatheter aortic valve implantationObjectives This study sought to determine the reproducibility of multideterctor computed tomography (MDCT) measurements of aortic annulus and compare the difference between MDCT and transthoracic echocardiography in measurement of aortic annulus.Methods The study population comprised severe aortic valve stenosis patients from May2011to November2013. All the patients were assessed by institutional heart team, including experienced clinical and interventional cardiologist and cardiovascular surgeons and anesthesilologists, for an increased surgical risk and not able to undergo a surgery. All selected patients underwent dual-source contrast-enhanced computed tomography and transthoracic echocardiography between2weeks. Annulus measurements were performed in those patients planned for transcathether aortic valve implantation in TTE and MDCT. The images in end-systole were chosen to post-processe and measure in short-axis and double oblique view in CT work station. At the short-axis view connecting the nadirs of all3aortic cusps, minimum and maximum inner lumen diameters were measured, and lumen perimeter and area were obtained by manual polygonal border tracing in post-processing software. The analyses were performed independently by2experienced observers who were blinded to clinical and echocardiographic data.Results The measurement reproducibilities of the three methods were comparable, the inter-reader intraclass correlation coefficient (ICC) in mean diameter, perimeter-derived diameter, area-derived diameter were:0.86,[95%confidence interval:0.82-0.93];0.77,[95%confidence interval:0.63-0.85];0.81,95%confidence interval:0.69-0.89], respectively; intrareader ICC were:0.94,[95%confidence interval:0.90-0.96];0.89,[95%confidence interval:0.79-0.94];0.81,[95%confidence interval:0.88-0.95], respectively. The pearson’s correlations coefficients between three methods of measurement of cardiac CT with TTE were:0.482.0.481.0.493. all p<0.05. respectively. There were no significant differences between those methods of measurement in cardiac CT with paired samples t test (24.18±4.27mm,24.25±2.63mm,23.66±2.62mm p>0.05). While, the diameter of aortic annulus in MDCT were2.29±2.52mm larger than that in TTE, p<0.001.Conclusions MDCT can measure the diameter of aortic annulus by the methods of mean diameter of maximum and minimum diameter, perimeter and area derived diameter with comparable reproducibility. There is no significant difference in those methods. The values obtained from MDCT were generally larger than those obtained in TTE. PART ⅡComparison of dimension of aortic root by multidetector computed tomography in severe aortic valve stenosis patient with Bicuspid versus Tricuspid aortic valveObjectives The aim of this study was to characterize the diference in the anatomy of aortic valve stenosis patients with BAV vs.TAV, and definite the probability of the suitability of prosthetic valves for two kinds of valves.Methods The study population comprised consecutive elderly patients with severe aortic valve stenosis from September2009to November2013in our hospital. All the patients underwent a dual-source contrast-enhanced computed tomography and echocardiography between4weeks. The diagnosis was made by transthoracic echocardiography, and cardiac CT confirmed the definite diagnosis. Multiplanar reconstruction and measurements were used to measure the dimension of aortic valve annulus, sinus of aortic valve, sino-tubular junction and coronary ostia in the end-systole and left ventricular in the end-diastole. Aortic valve cacificaltion were quantified by CT scored with the Agatston scoring method.Results There were72patients with BAV in all163patients with severe aortic valve stenosis (107male, age:65.43±11.58years, from31to89years). The age of paitents with TAV was elder than those of BAV (68.82±11.24years vs.61.24±10.60years, p<0.01). There were no significant difference of AVC load between BAVs and TAVs (3323.14±2377.45HU vs.3618.90±2441.09HU,1915.64±1358.41HU/m2vs.2088.57±1401.09HU/m2,701.48±428.75HU/cm2vs.725.63±426.15HU/cm2, p all<0.05). Mean diameter of aortic annular and ascending aorta measured by CT were larger in BAVs than TAVs (24.56±3.26mm vs.24.20±2.72mm,32.65±5.30mm vs.30.80±4.85mm,44.74±6.48mm vs.39.11±7.59mm; all p<0.05).The percentage of the ellipse aortic annulus in TAVs was larger than in BAVs (64.8%vs.44.4%, p<0.05), while the diameters of aortic sinus in the BAVs was larger than in TAVs (72.2%vs.11.0%, p<0.05). The heights of left and right coronary artery ostia and cusp were larger in BAVs than TAVs (13.99±2.73mm vs.15.33±2.93mm;15.33±2.35mm vs.16.64±3.42mm; p all<0.05;17.98±3.32mm vs.19.54±3.79mm;19.98±3.01mm vs.21.39±3.23mm, p all <0.05). Controlling for the impact of the age, gender and number of valves, the mean diameter of aortic annulus showed largest associations with the mean diameter of LVOT(r=0.856,P<0.01) and the transverse diameter of LV (r=0.609,P<0.01).According the dimensions of aortic root, there was no difference of the probability of the suitability of prosthetic valves in TAVs and BAVs(94.5%vs.91.7%, p>0.05).Conclusions CT can demonstrate the anatomy differences in aortic root between severe aortic valve stenosis elderly patients in BAVs and in TAVs. There was no difference of the probability of size suitability of prosthetic valves in TAVs and in BAVs(94.5%vs.91.7%, p>0.05). PART IIIComparison of the quantification of aortic valve calcification by multidetector computed tomography in male and female aortic valve stenosis patientsObjectives To characterize aortic valve calcification of aortic valve stenosis patients in male and female. And to analysis the role of different influence factors of aortic valve calcification (AVC).Methods The study population comprised consecutive patients with aortic valve stenosis from September2009to November2013. All the patients underwent a dual-source contrast-enhanced computed tomography and echocardiography between4weeks. Aortic valve calcification were quantified by CT scored with the Agatston scoring method. Multiplanar reconstruction and measurements were used to measure the aortic annulus.Results362consecutive patients with aortic valve stenosis (239male, age:63.37+11.54years, from31to89years) were included. The age of female AS paitents was elder than those of male patients (65.88±11.16years vs.62.08±11.55years, p<0.01). The height, weight and body surface area (BSA) in female patients were significantly bigger than male patients(1.69±0.06m vs.1.58±0.05m, p<0.001;70.77±10.35Kg vs.61.23±9.88Kg, p<0.001;1.82±0.15m2vs.1.63±0.14m2, p<0.001), the other clinical characteristics were all comparable. AVC score was higher in male patients than in female patients (p<0.001), even after adjustment for their smaller body surface area or aortic valve area. The AVCi and AVCd were both higher in male patients than in female patients (p=0.003, p=0.018, respectively). AVC load both in two groups showed good associations with hemodynamic AS severity measured by peak aortic jet velocity or mean transvalvular gradient in men and women(all r>0.62, p<0.001). For all level of AS severity, the AVC load was higher in men than in women. In three levels of AS severity in patients, the aortic valve calcification score showed the mild positive correlation to the age(r1=0.283, r2=0.311, r3=0.151, all p<0.001). Assessing the various influence factors of aortic valve calcification (age, coronary artery calcification, body mass index, peak aortic jet velocity, LVEF, mean aortic valve annulus diameter, male, hypertention, Diabetes Mellitus, coronary artery disease, hyperlipemia, bicuspid aortic valve) in multiple linear regression analysis, according to the standardized regression coefficient the correlation of different factor with aortic valve calcification were peak aortic jet velocity, gender, age. LVEF. mean aortic annularConclusions cardiac CT can demonstrate several differences between male and female aortic valve stenosis patients. The male sex is associated with more AVC load. The aortic valve calcification score in patients showed the mild positive correlation to the age of patients. In turn, the AVC load is associated with peak aortic jet velocity, gender, age, LVEF, mean diameter of aortic annulus. PART IVComparison of the differences of aortic root dimension and left ventricular geometry by multi-detector computed tomography in moderate and severe aortic stenosis patientsObjectives To evaluate changes in aortic root dimensions and left ventricule in relation to the degree of aortic valve stenosis in patients with morderate and severe aortic valve stenosis. And to analyse different influence factors of aortic root dimension and left ventricle.Methods The study population comprised consecutive patients with aortic valve stenosis from September2009to November2013. All the patients underwent a dual-source contrast-enhanced computed tomography and echocardiography between4weeks. Transthoracic echocardiography (TTE) evaluated the hemodynamic severity in diagnosis of aortic stenosis. Patients with rheumatic valvular heart disease, bicuspid aortic valve, underwent surgical aortic valve replacement or old myocardial infarction had been excluded. Multiplanar reconstruction and measurements were used to measure the aortic root and ascending aorta in end-systole. Left ventricle diameter was measured in transverse section in end-diastole.Results154patientswith moderate and severe aortic valve stenosis (101male, age:66±12years, from31to87years) were included. The age of paitents with severe AS was elder than those of moderate AS patients (68.51±11.94years vs.63.38±10.88years, p<0.01). There was no other significant differences in clinical characteristics between two groups patients except for the hemodynamic degree of aortic valve stenosis(4.87±0.54m/s vs.3.54±0.35m/s, p<0.001;58.22±13.89mm Hg vs.28.03±6.25mm Hg, p<0.001). Mean diameter of aortic annular, sinus of valsalva, sinotubular junction (STJ), left ventricular outflow tract (LVOT) and left/right coronary ostia measured by CT were larger in severe AS group than moderate AS group. When the age was analysed as covariate, after correcting the main action of gender, stenosis level and interaction of gender and stenosis level, the influence of age on the different plane average diameter was statistically significant. There was no significant difference in the ellipticity index of the level of aortic annulus, sinus of valsalva, STJ, LVOT between the both genders of two groups, respectively. The ellipticity indexs in every level of aortic root were significantly different. El of LVOT was the biggest, that of aortic annulus was next, and that of STJ was the smallest. The thickness of interventricular septum and left ventricular lateral wall of two groups patients with different gender had significant differences within the group and between groups. To determine the independent associations between aortic valve stenosis the bigger aortic annulus, multiple linear regression analysis was performed. The presence of male gender, less LV ejection fraction, elder age and larger BSA were independent determinants of a larger aortic annulus on MDCT(standardized β were0.429,-0.343,-0.213,0.155, all p<0.05), and height, Vmax, left ventricle diameter, male gender (standardized β were0.844,0.623,-0.322,-0.178, all p<0.001) were independent determinants of thickness of left ventricular lateral wall.Conclusions Cardiac CT can demonstrate several differences in aortic root dimensions and left ventricule between moderate and severe aortic valve stenosis patients. Male gender, less LV ejection fraction, elder age and larger BSA were independent determinants of dimention of aortic annulus, while height, Vmax, left ventricle diameter, male gender were independent determinants of thickness of left ventricular lateral wall.
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