Objectives Aortic valve calcifications (AVC), mostly observed in the ageing population, can progress to become severe enough to induce aortic stenosis and may result in a postoperative relevant paravalvular leak in the patients undergoing Transcatheter aortic valve implantation (TAVI). Techniques for echocardiographic assessment of the AVC in human beings is scarcely reported. The purpose of this study was to evaluate the quantification of the AVC using non-ionising, feasible echocardiographic integrated backscatter (IB) in the degenerative aortic valve stenosis patients pre-TAVI, compared to the multi-slice spiral computed tomography (MSCT).
Methods Thirty-two consecutive patients aged 72.4 ± 7.2 years, 68.8% male were included. The optimal images of the aortic valve in short-axis and long-axis views by two-dimensional echocardiography were saved with S5-1 transducer (Philips IE33). The distributions of the calcification were recorded and the calibrated integrated backscatter (cIB) values and the areas of the calcification of each aortic semilunar valve were measured in the short-axis view using QLAB software. The echocardiographic AVC score was noted as the sum of products of the calcified area and the cIB value of the AVC. At the meantime, the Agatston AVC score and the volumetric AVC score were analysed off-line using MSCT software.
Results: All patients were severe aortic stenosis (tricuspid valve 72%,bicuspid valve 28%) with the maximum velocity 5.2 ± 0.8 m/s and the mean pressure of gradient 67.3 ± 27.8 mmHg. The average cIB value and echocardiographic AVC sore were 31.60 ± 3.12 dB, and 4123.3 ± 2073.5, respectively. The echocardiographic AVC score showed good agreement with the Agatston AVC score and the volumetric AVC score of MSCT (r = 0.72, p<0.05, and r = 0.71, p<0.005, respectively ). High inter- and intra-observer correlations were observed for the echocardiographic calcified score (intraclass correlation coefficient = 0.87 and = 0.82, respectively).
Conclusions: Echocardiographic integrated backscatter is a feasible, non-invasive, non-ionising, and reproducible method to quantify aortic valve calcifications in the aortic stenosis patients. This technique might play an important role in the prognosis of aortic valve disease and evaluation of treatment efficacy.