Kamperidis Vasileios, van Rosendael Philippe J, Katsanos Spyridon, van der Kley Frank, Regeer Madelien, Al Amri Ibtihal, Sianos Georgios, Marsan Nina Ajmone, Delgado Victoria, Bax Jeroen J
Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, PO Box 9600, 2300 RC Leiden, The Netherlands Department of Cardiology, AHEPA University Hospital, Thessaloniki, Greece.
Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, PO Box 9600, 2300 RC Leiden, The Netherlands.
Eur Heart J. 2015 Aug 14;36(31):2087-2096. doi: 10.1093/eurheartj/ehv188. Epub 2015 Jun 1.
Low gradient severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) may be attributed to aortic valve area index (AVAi) underestimation due to the assumption of a circular shape of the left ventricular outflow tract (LVOT) with 2-dimensional echocardiography. The current study evaluated whether fusing Doppler and multidetector computed tomography (MDCT) data to calculate AVAi results in significant reclassification of inconsistently graded severe AS.
In total, 191 patients with AVAi < 0.6 cm/m and LVEF ≥ 50% (mean age 80 ± 7 years, 48% male) were included in the current analysis. Patients were classified according to flow (stroke volume index <35 or ≥35 mL/m) and gradient (mean transaortic pressure gradient ≤40 or >40 mmHg) into four groups: normal flow-high gradient (n = 72), low flow-high gradient (n = 31), normal flow-low gradient (n = 46), and low flow-low gradient (n = 42). Left ventricular outflow tract area was measured by planimetry on MDCT and combined with Doppler haemodynamics on continuity equation to obtain the fusion AVAi. The group of patients with normal flow-low gradient had significantly larger AVAi and LVOT area index compared with the other groups. Although MDCT-derived LVOT area index was comparable among the four groups, the fusion AVAi was significantly larger in the normal flow-low gradient group. By using the fusion AVAi, 52% (n = 24) of patients with normal flow-low gradient and 12% (n = 5) of patients with low flow-low gradient would have been reclassified into moderate AS due to AVAi ≥ 0.6 cm/m.
The fusion AVAi reclassifies 52% of normal flow-low gradient and 12% of low flow-low gradient severe AS into true moderate AS, by providing true cross-sectional LVOT area.
左心室射血分数（LVEF）保留的低梯度重度主动脉瓣狭窄（AS）可能归因于二维超声心动图对左心室流出道（LVOT）采用圆形假设而导致主动脉瓣面积指数（AVAi）低估。本研究评估融合多普勒和多排螺旋计算机断层扫描（MDCT）数据来计算AVAi是否会导致对分级不一致的重度AS进行显著的重新分类。
本分析共纳入191例AVAi<0.6 cm/m²且LVEF≥50%的患者（平均年龄80±7岁，48%为男性）。根据流量（每搏量指数<35或≥35 mL/m²）和梯度（平均跨主动脉压力梯度≤40或>40 mmHg）将患者分为四组：正常流量-高梯度（n = 72）、低流量-高梯度（n = 31）、正常流量-低梯度（n = 46）和低流量-低梯度（n = 42）。通过MDCT上的面积测量法测量左心室流出道面积，并结合连续性方程上的多普勒血流动力学来获得融合AVAi。正常流量-低梯度患者组与其他组相比，AVAi和LVOT面积指数显著更大。尽管四组之间MDCT得出的LVOT面积指数相当，但正常流量-低梯度组的融合AVAi显著更大。使用融合AVAi时，正常流量-低梯度组中52%（n = 24）的患者和低流量-低梯度组中12%（n = 5）的患者会因AVAi≥0.6 cm/m²而被重新分类为中度AS。
融合AVAi通过提供真实的LVOT横截面积，将52%的正常流量-低梯度重度AS和12%的低流量-低梯度重度AS重新分类为真正的中度AS。
