不同主动脉瓣瓣叶分型中国拟行经导管主动脉瓣置换术患者的血管入路特征研究

目的 本研究旨在探究不同主动脉瓣叶分型的中国拟行经导管主动脉瓣置换术（TAVR）患者，在主动脉-髂动脉-股动脉血管入路方面的特征性差异。

方法 本研究回顾性纳入215例行计算机断层扫描（CT）的拟行TAVR治疗的重度主动脉瓣狭窄患者。基于CT图像，完成二叶式主动脉瓣（BAV）与三叶式主动脉瓣（TAV）判定及分组。完成主动脉-髂动脉-股动脉血管入路13个截面水平（主动脉瓣环平面、Valsalva窦平面、窦管交界平面、升主动脉最大内径平面、主动脉弓近端平面、主动脉弓远端平面、主动脉峡平面、降主动脉平面、肾上部分腹主动脉平面、肾下部分腹主动脉平面、髂动脉平面、髂外动脉平面、股动脉平面）的管径、钙化程度、迂曲程度及血管并发症（动脉粥样硬化、壁内血肿、贯穿型溃疡）的综合评估。钙化程度参考横截面钙化分级，迂曲程度参考迂曲指数。进行两分组间的上述各参数的比较。

结果 本研究中，44%（94例）患者为BAV患者，年龄低于TAV患者 (74.4±7.3 岁 vs 76.6±6.7 岁, p = 0.02)。BAV组主动脉瓣环、Valsalva窦、升主动脉及主动脉弓的内径均高于TAV组。 BAV组升主动脉扩张发生率较TAV组高（p = 0.03）。TAV组主动脉弓部钙化发生率较高(45% vs 27%, p = 0.01; 23% vs 9%, p = 0.01)。校正年龄、性别、高血压、高脂血症、冠心病、糖尿病等动脉粥样硬化相关混杂因素后，TAV组发生I级、II级以上主动脉弓钙化危险性均高于BAV组。BAV患者发生I级以上腹主动脉钙化危险性则为TAV组的2.02倍（95%CI 1.60-5.31, p < 0.001)。BAV组伴轻度髂动脉迂曲（迂曲指数 = 1）患者仅占比15%，但在TAV组，轻度髂动脉迂曲占比高达29%（p = 0.01）。在部分血管层面，BAV组动脉粥样硬化、壁内血肿及贯穿型溃疡发生率高于TAV组。

结论 中国拟行TAVR的重度主动脉瓣狭窄患者中，二叶式主动脉瓣患者占比高。不同瓣叶类型间主动脉-髂动脉-股动脉入路在管径、钙化程度、迂曲程度等方面存在显著特征性差异。该差异对于BAV相关技术操作提出更多挑战，并提示建立针对不同瓣叶类型的纳入解剖结构学方面的TAVR风险评分体系的重要性于必要性。

拟行经导管主动脉瓣置换术的二叶式主动脉瓣狭窄患者最佳瓣环测量策略的研究

目的 探究拟行经导管主动脉瓣置换术治疗的二叶式主动脉（BAV）患者的最佳瓣环测量方式方法。

方法 回顾性入选104例重度主动脉瓣狭窄拟定行TAVR治疗，但经多学科团队评估后行外科主动脉瓣置换治疗的BAV患者。患者均伴外科中危及以上风险，并完成术前二维经胸超声心动图（2DTTE）和计算机断层扫描（CT）的评估。2DTTE在左室长轴切面获取瓣环内径值。CT图像获取后，导入3 mensio分析软件，获得CT面积导出内径值 (CTarea), CT周长导出内径值 (CTperi) 和CT平均内径值 (CTmean)。三维经食道超声（3DTEE）测量与示瓣器测量在术中完成。我们分别将五种由影像方法得到的瓣环内径测量值 (2DTTE, 3DTEE, CTarea，CTperi， CTmean)与术中值进行比较，分析五种方法与术中法的一致性与差异性。根据主动脉根部钙化主要分布位置将患者分为三组，即钙化主要分布于瓣环组、钙化主要分布于瓣叶组、钙化于瓣环瓣叶均有分布组，各组分别以术中值为参考标准，比较各影像学方法的准确性。分别将参考3DTEE值, CTmean值, CTperi值，CTarea值选择假设的外科瓣膜型号与实际植入型号对比；分别将参考3DTEE值, CTmean值, CTperi值，CTarea值选择假设的TAVR瓣膜型号与参考术中值选择的TAVR瓣膜型号对比。根据CTperi选择的外科瓣膜型号较实际植入瓣膜型号的差异，将患者分为较大组、较小组、相同组三组比较。

结果 研究共纳入104例BAV患者，平均年龄69.1±6.2岁，其中55.7%为男性，平均STS评分6.8±3.2%。患者瓣环平均离心率为0.21±0.07，提示瓣环椭圆形形态显著。五种影像学方法的内径测量值与校正值均与示瓣器方法数据存在统计学差异，但CT面积导出内径值及校正值仅略高于术中值及校正术中值（25.6±2.1 mm vs 25.3±2.0 mm, p < 0.001; 15.5±0.6 mm/m² vs 15.3±0.6 mm/m², p < 0.001）。CT周长导出内径值显著高于术中值（26.2±2.2 mm vs 25.3±2.0 mm, p < 0.001）。CTarea值与术中值表现极好相关性（r = 0.932, p < 0.001）。CTarea法与CTperi法具有良好的测量者间一致性（ICC 0.90, 95%CI 0.81 - 0.95; ICC 0.89, 95%CI 0.79 - 0.95）。3DTEE法测的的内径较术中值小（差值均值, 0.53 mm; LOA, -0.72 mm - 1.78 mm）。参考CTarea值选择外科瓣膜型号或TAVR瓣膜型号结果与实际植入型号或参考术中值选择TAVR瓣膜型号相近（κ = 0.791, p < 0.001; κ = 0.585, p < 0.001）。但参考CTperi值会导致26.9%患者得到高估的外科瓣膜型号，36.5%患者得到高估的TAVR瓣膜型号。根据钙化主要分布位置分组后，各分组中，CT测量法与示瓣器法相关性较好（r = 0.860 - 0.953）。

结论 对于瓣环椭圆形态显著的BAV患者，基于CT图像的面积导出内径方法为具备高精准度及良好观察者间一致性的最佳测量方法。该方法应当考虑纳入BAV患者的标准化测量推荐。基于CT图像的周长导出内径方法容易导致测量值高估及瓣膜型号高估情况。3DTEE也表现较好一致性，为CT检查禁忌患者的替代选择，但该方法在伴主动脉瓣瓣环钙化患者中慎用。

瓣叶接合钙化对经导管主动脉瓣置换术后新发传导阻滞预测价值的研究

目的 应用一种合理评估钙化量、钙化分布、钙化对称性的新分区方法，探讨不同分层、不同分区钙化对经导管主动脉瓣置换术（TAVR）后新发传导阻滞（NOCD）的预测作用。

方法 纳入136例行计算机断层扫描（CT）及TAVR治疗的三叶式主动脉瓣狭窄患者，根据是否发生术后新发传导阻滞分成两组。采用HU850为钙化分析截断值，分别评估主动脉根部复合结构（AVC）区域与左室流出道（LVOT）区域钙化。在AVC区域及LVOT区域分别根据冠瓣三分区法（左冠瓣，LCC；右冠瓣，RCC；无冠瓣，NCC）和与传导束相对位置关系的二分区法（近传导束区[AVCadj/LVOTadj]，远传导束区 [AVCrem/LVOTrem]）进行分区，后完成各区的钙化定量分析。钙化非对称性分析参考各区域近传导束区与远传导束区的钙化量差值。同时完成瓣膜植入深度及瓣架膨胀率的测量。采用Mann-Whiteny U检验完成两组不同分区钙化量的比较，采用ROC曲线分析不同分区钙化量对NOCD的诊断特异性和敏感性，应用多因素分析探讨NOCD独立危险因素。

结果 研究纳入136例三叶式主动脉瓣狭窄患者，平均年龄79.6 ± 6.2岁，81.6%为男性，24.2%（33例）患者可见术后新发传导阻滞。NOCD组患者AVC区域的总钙化量（578.4 mm³ vs. 474.7 mm³, p = 0.038）、左冠瓣区钙化量（247.8 mm³ vs. 149.2 mm³, p = 0.001）、远传导束区（AVC_rem）钙化量（403.1 mm³ vs. 259.5 mm³, p < 0.001）及非对称（△AVC）钙化量（ΔAVC 238.4 mm³ vs. 31.4 mm³, p<0.001）显著高于非NOCD组。对于LVOT区域，LVOT_NCC（2.7 mm³ vs 2.3 mm³, p = 0.021）, LVOT_adj（3.3 mm³ vs 2.8 mm³, p = 0.028）and LVOT_total（4.9 mm³ vs 3.9 mm³, p = 0.004）钙化量与NOCD的发生相关。ROC曲线分析显示，△AVC与AVCrem曲线下面积较大，较其他指标诊断精度更佳。多因素分析结果显示AVC_rem > 374.1 mm³（OR: 5.55; 95%CI: 1.03 - 29.87; p = 0.046）, △AVC > 103.3 mm³（OR: 9.57; 95%CI: 9.44 - 26.65; p < 0.001）及瓣架植入深度> 6.0 mm（OR: 3.34; 95%CI: 1.22 - 8.63; p = 0.013）为NOCD发生的独立危险因素。有三项危险因素组的NOCD发生率远高于仅有△AVC > 103.3 mm³与植入深度> 6.0 mm的两项组（94.4% vs 50.0%）。

结论AVC区域钙化非对称分布、AVCrem钙化量增加、低瓣架植入为TAVR术后NOCD发生的独立危险因素。采用与传导束相对解剖学位置关系的钙化分区方法可有效检出NOCD高危患者，该分区法尤其适用于瓣叶结合处钙化多见的中国患者。

characteristics of aorto-iliofemoral arterial tree

according to aortic valve morphology

in chinese patients considered for tavr

abstract

ive to characterize the anatomy of aorto-iliofemoral arterial tree according to aortic valve phenotype by computed tomography (ct) in patients referred for transcatheter aortic valve replacement (tavr).

methods we retrospectively enrolled 215 patients with severe symptomatic (as) screened for tavr who underwent ct. dimensions, calcification, vascular tortuosity index score and other putative risk features of thirteen different regions (the iliac artery, external iliac artery, femoral artery and following sections of entire aorta: aortic annulus, sinus of valsalva, sinotubular junction, maximal ascending aorta, proximal arch, distal arch, aortic isthmus, descending aorta, suprarenal aorta and infra-renal aorta) were evaluated for bicuspid aortic valve (bav) and tricuspid aortic valve (tav) morphology.

results the study consisted of 44% (n = 94) bavs with younger age than tavs (74.4 ± 7.3 years vs 76.6 ± 6.7 years, p = 0.02). the dimensions of the annulus, sinus of valsalva, ascending aorta and aortic arch were consistently larger in bavs. there is a significantly higher prevalence of ascending aortic dilation in the bav group compared with the tav group (p = 0.03). univariate analysis indicated that the prevalence of calcification of aortic arch was significantly higher in tav cohort (45% vs 27%, p = 0.01; 23% vs 9%, p = 0.01). rates of both over grade ⅰ and grade ⅱ aortic arch calcification remained significantly higher in tav group (p = 0.047, p = 0.04, respectively) even after adjustment. bavs was associated with two-fold higher odds of having over ⅰ degree aa calcification (odds ratio, 2.02; 95%ci 1.60 - 5.31; p < 0.001). the prevalence of slight iliac tortuosity (tortuosity index = 1) is only 15% for bavs, but for persons with tav, the prevalence increases to 29% (p = 0.01). bavs had a trend to more atheroma, intramural hematoma and penetrating ulcers than tavs in 5 segments of aorta.

conclusions bav anatomy is common in chinese as patients screened for tavr. aorto-iliofemoral pathology varies according to aortic valve phenotype, which may contribute to technical challenges in bav vs tav anatomy and support the need for specific anatomical tavr risk scores for each valve phenotype.

study on the optimal annulus sizing approach for patients assigned for transcatheter aortic valve replacement with bicuspid aortic valve

abstract

ive to clarify the optimal measurements for patients with bicuspid aortic valve (bav) preferred to transcatheter aortic valve replacement (tavr), our study compared intraoperative sizing with five different approaches by transthoracic echocardiography (tte), 3-dimensional transesophageal echocardiography (3dtee) and computed tomography (ct).

methods we enrolled 104 bavs suffering from severe aortic stenosis who were prescreened for tavr but underwent surgery. all patients had at least intermediate surgical risk and underwent preoperative 2dtte, 3dtee, ct and intraoperative measurement of the aortic annulus with metric sizers. all five approaches (2dtte, 3dtee, area-derived perimeter (ctarea), perimeter-derived diameter (ctperi) and mean diameter (ctmean)) were compared with intraoperative sizing respectively. all patients were divided into three subgroups according to the predominant localization of aortic valve calcifications. agreements of theoretical valve selections by five methods with those by intraoperative sizing were analyzed. the surgical valve and tavr valve were theoretically selected according to 3dtee measurements, ctmean measurements, ctperi measurements, ctarea measurements, and intraoperative measurements, respectively. patients were stratified according to the suggested surgical valve size by ctperi relative to the implanted surgical valve size.

results one hundred and four patients with bav (mean age, 69.1 ± 6.2 years; 55.7% male) constituted the study population, and the sts score was 6.8 ± 3.2%. the eccentricity index of 0.21 ± 0.07 indicated a pronounced oval shape of the annulus in bavs. significant differences in the mean values and those indexed to bsa, were both observed in all five calculations, while area-derived diameter and indexed area-derived diameter were only slightly higher than those obtained by intraoperative measurements (25.6±2.1 mm vs 25.3 ± 2.0 mm, p < 0.001; 15.5 ± 0.6 mm/m² vs 15.3 ± 0.6 mm/m², p < 0.001). the perimeter-derived diameter was markedly larger than that assessed in surgery by approximately one millimeter (26.2 ± 2.2 mm vs 25.3 ± 2.0 mm, p < 0.001). ctarea showed the highest correlation (r = 0.932, p < 0.001) and the best agreement with intraoperative sizing. ctarea and ctperi were found to be more reproducible than other measurements (icc 0.90, 95%ci 0.81 to 0.95; icc 0.89, 95%ci 0.79 to 0.95). the diameters measured by 3dtee were systematically smaller than those by intraoperative sizing (mean difference, 0.53 mm; limits of agreement, -0.72 mm to 1.78 mm). agreement for theoretical surgical and tavr prosthesis selection was found in 84.6% and 74.0% bavs by ctarea (κ = 0.791, p <0.001; κ = 0.585, p < 0.001). ctperi-based prosthesis selection led to overestimation of 26.9% for surgical valves (κ = 0.589, p < 0.001) and 36.5% for tavr valves (κ = 0.425, p < 0.001). good correlations were observed between ct measurements and intraoperative sizing regardless of the predominant site of aortic valve calcification (r = 0.860-0.953).

conclusion the ctarea, which demonstrated the optimal approach for annulus sizing and prosthesis choice of bavs with high eccentricity, should be included into the bav-specific annulus sizing recommendation. the insufficiency of ctperi lied in overestimation of surgical or tavr valve selections. good agreement of 3dtee sizing proved its superiority in annulus sizing for bavs unsuitable for ct, but with caution for patients with calcified annulus.

commissural-based calcification assessment by ct

to aid post-tavr nocd predictions

abstract

ive the predictive value of the quantification, distribution and asymmetry of the calcification on new onset conduction disturbance (nocd), particularly regarding its anatomic proximity to the conduction pathway is poorly characterized. we aim to identify the predictors of nocd following transcatheter aortic valve replacement (tavr), with a particular emphasis on sector calcification quantified by a new dividing method.

methods a total of 136 patients who underwent tavr and computed tomography (ct) were analyzed and divided into two groups according to the appearance of nocd. calcification was quantitatively measured by using the 850-hounsfield unit threshold in the aortic valve complex (avc) region and the left ventricular outflow tract (lvot) region. calcium load was then quantified precisely by coronary cusps (left coronary cusp [lcc], right coronary cusp [rcc], non-coronary cusp [ncc]) and sectors according to its positional relationship with the conduction pathway (the adjacent sector [avcadj/lvotadj] and the remote sector [avcrem/lvotrem]). the asymmetry was assessed by the maximum absolute difference of calcium volume. implantation depth of the prosthesis and oversizing rate were also measured. mann-whitney u test was used to analyze the calcification data in different regions or sectors. receiver-operating characteristic (roc) curves were generated using the new onset conduction disturbance and the area under the curve (auc) was calculated. the best discriminatory thresholds of calcium volume were calculated by determining the youden index separately for each area of interest. preoperative and perioperative variables with a p-value of <0.05 at univariate analysis were included into the multivariate analysis to test for independence.

results of the 136 patients (mean age, 76.9 ± 6.2 years; 81.6% male), 24.2% (n=33) presented with pre-existing conduction disturbance. patients with nocd exhibited higher median calcium volumes of total calcium volume (578.4 mm³ vs. 474.7 mm³, p = 0.038), calcium volume of lcc (247.8 mm³ vs. 149.2 mm³, p = 0.001), remote sector (avc_rem) (403.1 mm³ vs. 259.5 mm³, p < 0.001) and higher asymmetry (△avc) (δavc 238.4 mm³ vs. 31.4 mm³, p < 0.001). for the lvot region, calcium volumes in the lvot_ncc (2.7 mm³ vs 2.3 mm³, p = 0.021), lvot_adj (3.3 mm³ vs 2.8 mm³, p = 0.028) and lvot_total (4.9 mm³ vs 3.9 mm³, p = 0.004) was associated with nocd. the greatest discriminatory value for nocd was numerically highest in △avc, followed by avcrem. multivariate analysis revealed avc_rem calcium volume> 374.1 mm³ (or: 5.55; 95%ci: 1.03 to 29.87; p = 0.046), △avc calcium volume> 103.3 mm³ (or: 9.57; 95%ci: 9.44 to 26.65; p < 0.001) and prosthesis implantation depth> 6.0 mm (or: 3.34; 95%ci: 1.22 to 8.63; p = 0.013) as independent predictors of nocd. the elevated nocd rate, driven largely by the presence of △avc calcium volume> 103.3 mm³, was observed predominantly in patients with all 3 risk factors when compared with patients of co-existing implantation depth> 6.0 mm and avc_rem > 374.1 mm³ (94.4% vs 50.0%).

conclusion calcification asymmetry in the avc region, elevated avcrem calcification and deeper prosthesis implantation were identified as independent predictors of post-tavr nocd, with an emphasis on the calcium asymmetry of avc. our proposed division methodology could help the pre-tavr calcification assessment by ct that may effectively help identity nocd risk-groups, especially for chinese tavr patients with frequent calcification in the borderline area.