Centro Cardiologico Monzino, IRCCS, Milan, Italy.
JACC Cardiovasc Imaging. 2013 Feb;6(2):196-205. doi: 10.1016/j.jcmg.2012.09.011.
The authors sought to investigate the accuracy of transthoracic echocardiography (TTE)-derived parameters in the identification of bileaflet aortic prosthesis dysfunction, compared with fluoroscopy (FL).
Identification of bileaflet aortic prosthesis dysfunction is challenging, because high mean pressure gradient (MPG >20 mm Hg) is not proof of prosthetic obstruction (AVPO), and may be due to prosthesis-patient mismatch (PPM). Conversely, high gradients may not be manifest in AVPO and low cardiac output.
TTE and FL were prospectively performed in 100 nonconsecutive patients with bileaflet aortic prosthesis. TTE included the estimation of MPG, indexed effective orifice area (EOAi), Doppler velocity index (DVI), intraprosthetic regurgitation, acceleration time (AT), ejection time (ET), AT/ET, and the difference (dA) between the expected prosthetic orifice area and EOA. FL allowed the calculation of opening and closing angles, and the discrimination of AVPO from normal (NL) and PPM.
On the basis of FL examination and MPG and EOAi at TTE, patients were classified as NL (42%), PPM (32%), and AVPO (26%). High MPG (>20 mm Hg) was present in 65% of the patients, with higher values in PPM (36 ± 8 mm Hg) and AVPO (43 ± 16 mm Hg) than in NL (16 ± 6 mm Hg). DVI was reduced in PPM (0.30 ± 0.05) and AVPO (0.25 ± 0.04) compared with NL (0.42 ± 0.09). In AVPO, dA (0.59 ± 0.32 cm(2)), AT (108 ± 20 ms), and AT/ET (0.35 ± 0.05) significantly differed from NL (dA = -0.12 ± 0.43 cm(2), AT = 74 ± 15 ms, AT/ET = 0.25 ± 0.05) and PPM (dA = 0.15 ± 0.24 cm(2), AT = 78 ± 13 ms, AT/ET = 0.26 ± 0.04). Moderate or severe intraprosthetic regurgitation was observed only in AVPO. All considered TTE-derived parameters were found related to obstruction, and dA (accuracy = 87%), AT (94%), and AT/ET (89%) showed the highest accuracy in discriminating normofunctioning prostheses from AVPO.
In the presence of high MPG, TTE parameters play a key role in aortic prosthesis examination. Especially time indices and dA add to the functional assessment of prosthetic aortic valves. However, the TTE discrimination between AVPO and PPM may be suboptimal, and fluoroscopy is a complementary and essential diagnostic step.
本研究旨在比较经胸超声心动图（TTE）与透视（FL）检测双叶主动脉瓣假体功能障碍的准确性。
双叶主动脉瓣假体功能障碍的识别具有挑战性，因为平均压力梯度高（MPG >20mmHg）并不能证明瓣膜假体梗阻（AVPO），并且可能是由于瓣膜假体不匹配（PPM）。相反，高梯度可能在 AVPO 和低心输出量中并不明显。
前瞻性地对 100 例双叶主动脉瓣假体患者进行 TTE 和 FL 检查。TTE 包括 MPG、有效瓣口面积指数（EOAi）、多普勒速度指数（DVI）、瓣周漏、加速度时间（AT）、射血时间（ET）、AT/ET 和预期瓣口面积与 EOAi 之间的差值（dA）的评估。FL 允许计算开口和关闭角度，并区分 AVPO 与正常（NL）和 PPM。
根据 FL 检查和 TTE 时的 MPG 和 EOAi，患者被分为 NL（42%）、PPM（32%）和 AVPO（26%）。65%的患者存在高 MPG（>20mmHg），PPM（36±8mmHg）和 AVPO（43±16mmHg）的 MPG 高于 NL（16±6mmHg）。PPM（0.30±0.05）和 AVPO（0.25±0.04）的 DVI 均低于 NL（0.42±0.09）。在 AVPO 中，dA（0.59±0.32cm2）、AT（108±20ms）和 AT/ET（0.35±0.05）与 NL（dA=-0.12±0.43cm2、AT=74±15ms、AT/ET=0.25±0.05）和 PPM（dA=0.15±0.24cm2、AT=78±13ms、AT/ET=0.26±0.04）明显不同。仅在 AVPO 中观察到中度或重度瓣周漏。所有考虑的 TTE 衍生参数均与梗阻相关，dA（准确性=87%）、AT（94%）和 AT/ET（89%）在区分功能正常的假体与 AVPO 方面具有最高的准确性。
在存在高 MPG 的情况下，TTE 参数在主动脉瓣假体检查中起着关键作用。特别是时间指数和 dA 增加了对人造主动脉瓣功能的评估。然而，TTE 区分 AVPO 和 PPM 的能力可能并不理想，FL 是一种补充和必要的诊断步骤。
