A granular approach to improve reproducibility of the echocardiographic assessment of paravalvular regurgitation after TAVI

Distinct pressure half-time values by transthoracic echocardiography for grading of paravalvular regurgitation after transcatheter aortic valve replacement

Postprocedural aortic regurgitation (AR) has negative impact on patient outcome after transcatheter aortic valve replacement (TAVR). Standard assessment of AR severity by echocardiography is hampered after TAVR. Measurement of pressure half-time (PHT) by echocardiography is not limited in these patients but it may be affected by concomitant left ventricular hypertrophy (LVH). This study sought to evaluate distinct cut-off values of PHT differentiating between patients without and with more than mild LVH for grading of AR after TAVR with cardiac magnetic resonance (CMR) as the reference method for comparison. 71 patients (age 81 ± 6 years) with severe aortic stenosis undergoing TAVR were included into the study. Transthoracic echocardiography (TTE) and CMR were performed after TAVR. Left ventricular mass index was calculated by TTE. PHT was measured by continuous-wave Doppler echocardiography of aortic regurgitation jet. In 18 patients (25%) PHT could not be obtained due to no or very faint Doppler signal. Aortic regurgitant volume and regurgitant fraction were calculated by CMR by flow analysis of the ascending aorta. In 14 of 53 patients (26%) AR after TAVR was moderate or severe as categorized by CMR analysis. More than mild LVH was present in 27 of 53 patients (51%). PHT correlated inversely less to regurgitant fraction by CMR analysis in patients with LVH (r = −0.293; p = 0.138) than in patients without LVH (r = −0.455; p = 0.020). In patients without relevant LVH accuracy of PHT to predict moderate or severe paravalvular regurgitation AUC was 0.813 using a cut-off value of 347 ms and AUC was 0.729 in patients with more than mild LVH using a cut-off value of 420 ms. Analysis of PHT by TTE with distinct cut-off values for patients without and with more than mild LVH allows detection of moderate or severe AR after TAVR as defined by CMR. In none of the patients in which PHT could not be measured AR was categorized as more than trace by CMR analysis.

Inter-Technique Consistency and Prognostic Value of Intra-Procedural Angiographic and Echocardiographic Assessment of Aortic Regurgitation After Transcatheter Aortic Valve Implantation

BACKGROUND

We investigated the relationship between intraprocedural angiographic and echocardiographic AR severity after TAVI, and the clinical robustness of angiographic assessment.

METHODS AND RESULTS

In 74 consecutive patients, the echocardiographic circumferential extent (CE) of the paravalvular regurgitant jet was retrospectively measured and graded based on the VARC-2 cut-points; and angiographic post-TAVI AR was retrospectively quantified using contrast videodensitometry (VD) software that calculates the ratio of the contrast time-density integral in the LV outflow tract to that in the ascending aorta (LVOT-AR). Seventy-four echocardiograms immediately after TAVI were analyzable, while 51 aortograms were analyzable for VD. These 51 echocardiograms and VD were evaluated. Median LVOT-AR across the echocardiographic AR grades was as follows: none-trace, 0.07 (IQR, 0.05-0.11); mild, 0.12 (IQR, 0.09-0.15); and moderate, 0.17 (IQR, 0.15-0.22; P<0.05 for none-trace vs. mild, and mild vs. moderate). LVOT-AR strongly correlated with %CE (r=0.72, P<0.0001). At 1 year, the rate of the composite end-point of all-cause death or HF re-hospitalization was significantly higher in >mild AR patients compared with no-mild AR on intra-procedural echocardiography (41.5% vs. 12.4%, P=0.03) as well as in patients with LVOT-AR >0.17 compared with LVOT-AR ≤0.17 (59.5% vs. 16.6%, P=0.03).

CONCLUSIONS

VD (LVOT-AR) has good intra-procedural inter-technique consistency and clinical robustness. Greater than mild post-TAVI AR, but not mild post-TAVI AR, is associated with late mortality.