A novel synchronised diastolic injection method to reduce contrast volume during aortography for aortic regurgitation assessment: in vitro experiment of a transcatheter heart valve model

Aims: In the minimalist transcatheter aortic valve implantation (TAVI) era, the usage of transoesophageal echocardiography has become restricted.Conversely, aortography has gained clinical ground in quantifying prosthetic valve regurgitation (PVR) during the procedure.In a mock circulation system, we sought to compare the contrast volume required and the accuracy of aortographic videodensitometric PVR assessment using a synchronised diastolic and standard (non-synchronised) injection aortography.Methods and results: Synchronised diastolic injection triggered by the signal stemming from the mock circulation was compared with standard non-synchronised injection.A transcatheter heart valve was implanted and was deformed step by step by advancing a screw perpendicularly to the cage of the valve in order to create increasing PVR.Quantitative measurement of PVR was derived from time-density curves of both a reference area (aortic root) and a region of interest (left ventricle) developed by a videodensitometric software.The volume of contrast required for the synchronised diastolic injection was significantly less than in the non-synchronised injection (8.1 [7.9-8.5]ml vs. 19.4[19.2-19.9]ml, p<0.001).The correlation between the two methods was substantial (Spearman's coefficient rho ranging from 0.991 to 0.968).Intraobserver intra-class correlation coefficient for both methods of injection was 0.999 (95% CI: 0.996-1.000)for the synchronised diastolic and 0.999 (95% CI: 0.996-1.000)for the non-synchronised injection group.The mean difference in the rating was 0.17% and limits of agreement were ±1.64% for both groups.Conclusions: A short synchronised diastolic injection enables contrast volume reduction during aortography without compromising the accuracy of the quantitative assessment of PVR using videodensitometry.