Shahgaldi Kambiz, da Silva Cristina, Bäck Magnus, Rück Andreas, Manouras Aristomenis, Sahlén Anders
Karolinska Institutet, Department of Cardiology, Karolinska University Hospital, Huddinge, 141 86, Stockholm, Sweden.
Cardiovasc Ultrasound. 2013 Jan 30;11:5. doi: 10.1186/1476-7120-11-5.
Aortic stenosis (AS) is a relevant common valve disorder. Severe AS and symptoms and/or left ventricular dysfunction (EF <50%) have the indication for aortic valve replacement (AVR). Majority of the patients with AS are elderly often with co-morbidities and generally have high preoperative risk. Transcatheter aortic valve implantation (TAVI) is offered in this group. Four different sizes of Corevalve prosthesis are available. Correct measurement of aortic size prior to TAVI is of great important to choose the right prosthesis size to avoid among others paravalvular leak or prosthesis patient mismatch.Aim of the study is to assess the aortic annulus diameter in patients undergoing TAVI by biplane (BP) mode using transesophageal echocardiography (TEE) and compare it to two-dimensional (2D) transthoracic echocardiography (TTE) and 2DTEE using three-dimensional (3D) TEE as reference method.
The study population consisted of 50 patients retrospectively (24 men and 26 women, mean age 85±8 years of age) who all had undergone echocardiography examination prior to TAVI.
The mean aortic annulus diameter was 20.4±2.2 mm with TTE, 22.3±2.5 mm with 2DTEE, 22.9±1.9 mm with BP-mode and 23.1±1.9 mm with 3DTEE. TTE underestimated the mean aortic annulus diameter in comparison to transesophageal imaging modalities (p<0.001). Using 3DTEE, 2% of patients were unsuitable for TAVI due to a too-small AoA (n=1). This figure was similar with BP (4%, n=2; p=1.00) but considerably larger with 2DTTE (36%, n=18; p < 0.001) and 2DTEE (12%, n=6; p=0.06). There was a strong correlation between BP-mode and 3DTEE for assessment of aortic annulus diameter (r-value 0.88) with small mean difference (-0.2±0.9 mm) whereas the other modalities showed larger 95% confidence interval and modest correlation (2DTTE vs. 3DTEE, -6.3 to 0.9 mm, r=0.64 and 2DTEE vs. 3DTEE, -4.8 to 3.2 mm, r=0.61).
A multi-dimensional method is preferred to assess aortic annulus diameter in TAVI patients since there is risk of underestimation using single plane. Biplane mode is the method of choice in view of speedy post-processing with no need for expensive dedicated software. Lastly, single plane methods lead to misclassification of patients as unsuitable for TAVI. This may be of major clinical importance.
主动脉瓣狭窄（AS）是一种常见的重要瓣膜疾病。重度AS以及症状和/或左心室功能障碍（射血分数<50%）有主动脉瓣置换术（AVR）的指征。大多数AS患者为老年人，常伴有合并症，术前风险一般较高。该类患者可采用经导管主动脉瓣植入术（TAVI）。有四种不同尺寸的Corevalve人工瓣膜可供使用。在TAVI术前正确测量主动脉大小对于选择合适的人工瓣膜尺寸非常重要，以避免出现瓣周漏或人工瓣膜与患者不匹配等问题。本研究的目的是通过经食管超声心动图（TEE）的双平面（BP）模式评估接受TAVI治疗患者的主动脉瓣环直径，并将其与二维（2D）经胸超声心动图（TTE）以及以三维（3D）TEE作为参考方法的2DTEE进行比较。
研究人群包括50例患者（回顾性研究）（24例男性和26例女性，平均年龄85±8岁），他们均在TAVI术前接受了超声心动图检查。
TTE测得的主动脉瓣环平均直径为20.4±2.2mm，2DTEE为22.3±2.5mm，BP模式为22.9±1.9mm，3DTEE为23.1±1.9mm。与经食管成像方式相比，TTE低估了主动脉瓣环平均直径（p<0.001）。使用3DTEE时，2%的患者因主动脉瓣环过小（n=1）不适合TAVI。BP模式下该比例与之相似（4%，n=2；p=1.00），但2DTTE（36%，n=18；p<0.001）和2DTEE（12%，n=6；p=0.06）时该比例则显著更高。在评估主动脉瓣环直径方面，BP模式与3DTEE之间存在强相关性（r值为0.88），平均差异较小（-0.2±0.9mm），而其他方式显示出更大的95%置信区间和适度相关性（2DTTE与3DTEE相比，-6.3至0.9mm，r=0.64；2DTEE与3DTEE相比，-4.8至3.2mm，r=0.61）。
由于使用单平面有低估风险，因此在评估TAVI患者的主动脉瓣环直径时，首选多维方法。鉴于后处理速度快且无需昂贵的专用软件，双平面模式是首选方法。最后，单平面方法会将患者错误分类为不适合TAVI。这可能具有重要的临床意义。
