Brener S J, Duffy C I, Thomas J D, Stewart W J
Department of Cardiology, Cleveland Clinic Foundation, Ohio 44195.
J Am Coll Cardiol. 1995 Feb;25(2):305-10. doi: 10.1016/0735-1097(94)00406-g.
This study reports the results of echocardiographic follow-up in a large cohort of patients with aortic stenosis and correlates the progression of aortic stenosis with changes in the degree of mitral regurgitation and left ventricular hypertrophy and systolic dysfunction.
Progressive aortic stenosis often causes left ventricular dysfunction and mitral regurgitation. Doppler echocardiography has greatly assisted in the noninvasive evaluation and follow-up of aortic stenosis. Nevertheless, the longitudinal follow-up of patients with Doppler echocardiography for the progression of aortic stenosis and the significance of progressive ventricular hypertrophy and mitral regurgitation have not been reported.
Serial Doppler echocardiography was performed in 394 consecutive patients with valvular aortic stenosis at baseline and after a mean follow-up period of 37 +/- 16 months. Mean and peak aortic gradients, aortic valve area, left ventricular systolic and diastolic diameters and percent area change (shortening fraction) were expressed as continuous variables, and systolic dysfunction, mitral regurgitation, ventricular hypertrophy and filling properties were tabulated as categoric variables using a semiquantitative grading system.
Peak and mean gradients increased by an average of 8.3 and 6.3 mm Hg/year, respectively; end-systolic and end-diastolic diameters increased by 1.9 and 1.6 mm/year, respectively; and aortic valve area decreased by 0.14 cm2/year during the follow-up interval (p < 0.001 for all), indicating progression of aortic stenosis and ventricular dilation. Patients in the lowest quartile of aortic valve area and highest quartiles of mean and peak gradients had the least change compared with those in the highest quartile of aortic valve area and lowest quartile of mean and peak gradients (p < 0.01 for all). Patients with more mitral regurgitation at follow-up than at baseline had higher mean percent increase in mean and peak gradients as well as more progression of ventricular dilation and worsening systolic function compared with those with stable or improving mitral regurgitation (p < 0.05 for all). Similarly, subjects with worsening left ventricular hypertrophy had larger mean percent increase in mean and peak gradients than those with stable left ventricular hypertrophy (p < 0.01) but maintained stable ventricular volumes and systolic function. There was no correlation between the amount of change in mean or peak gradients and degree of deterioration in systolic function.
Aortic stenosis progresses predictably over time; however, systolic dysfunction is an inconsistent marker of the hemodynamic consequences of severe aortic stenosis. As an adaptive response to pressure overload, progressive hypertrophy appears to prevent ventricular dilation and development or worsening of mitral regurgitation. Conversely, progressive mitral regurgitation may be seen as a maladaptive consequence of increasing aortic stenosis.
本研究报告了一大群主动脉瓣狭窄患者的超声心动图随访结果，并将主动脉瓣狭窄的进展与二尖瓣反流程度、左心室肥厚及收缩功能障碍的变化相关联。
进行性主动脉瓣狭窄常导致左心室功能障碍和二尖瓣反流。多普勒超声心动图极大地有助于主动脉瓣狭窄的无创评估和随访。然而，尚未有关于对主动脉瓣狭窄进展以及进行性心室肥厚和二尖瓣反流的意义进行多普勒超声心动图纵向随访患者的报道。
对394例连续性瓣膜性主动脉瓣狭窄患者在基线时及平均随访37±16个月后进行系列多普勒超声心动图检查。平均和峰值主动脉压力阶差、主动脉瓣面积、左心室收缩和舒张直径以及面积变化百分比（缩短分数）以连续变量表示，收缩功能障碍、二尖瓣反流、心室肥厚和充盈特性使用半定量分级系统以分类变量列表。
随访期间，峰值和平均压力阶差分别平均每年增加8.3和6.3 mmHg；收缩末期和舒张末期直径分别平均每年增加1.9和1.6 mm；主动脉瓣面积平均每年减少0.14 cm²（所有均p<0.001），表明主动脉瓣狭窄进展和心室扩张。与主动脉瓣面积最高四分位数且平均和峰值压力阶差最低四分位数的患者相比，主动脉瓣面积最低四分位数且平均和峰值压力阶差最高四分位数的患者变化最小（所有均p<0.01）。随访时二尖瓣反流较基线时增多的患者，其平均和峰值压力阶差的平均百分比增加更高，心室扩张进展和收缩功能恶化程度也高于二尖瓣反流稳定或改善的患者（所有均p<0.05）。同样，左心室肥厚加重的受试者，其平均和峰值压力阶差的平均百分比增加大于左心室肥厚稳定的受试者（p<0.01），但心室容积和收缩功能保持稳定。平均或峰值压力阶差的变化量与收缩功能恶化程度之间无相关性。
主动脉瓣狭窄随时间推移进展具有可预测性；然而，收缩功能障碍并非严重主动脉瓣狭窄血流动力学后果的一致标志物。作为对压力超负荷的适应性反应，进行性肥厚似乎可防止心室扩张以及二尖瓣反流的发生或加重。相反，进行性二尖瓣反流可能被视为主动脉瓣狭窄加重的不良后果。
