Post-TAVR Aortic Regurgitation
Which measurements on periprocedural transesophageal echocardiography (TEE) are clinically useful in grading paravalvular aortic regurgitation (PAR)?
This study examined 388 patients treated with a balloon-expandable Edwards transcatheter heart valve, and compared the ability of TEE measurements to identify significant PAR. The reference standard was the vena contracta, and a value ≥10 mm2 was considered significant (≥ moderate) PAR. The color Doppler circumferential extent, longitudinal jet length, and jet extent as well as presence of holodiastolic flow reversal (HDFR) in the descending aorta were evaluated.
Patients with significant PAR were observed to have higher frequency of HDFR, longer jet length, greater jet extent, greater circumferential extent, greater circumferential length, and greater radial length (p < 0.001 for each). On multivariable analysis, only consistent HDFR (odds ratio [OR], 21.5; 95% confidence interval [CI], 4.5-102.3; p < 0.001) and extent of PAR jet beyond the tip of the anterior mitral valve leaflet (OR, 6.4; 95% CI, 2.0-21.1; p = 0.002) were independently associated with significant PAR. Vena contracta, jet extent, and HDFR could be assessed in 74%, 80%, and 100% of individuals with PAR. To identify significant PAR, consistent HDFR had a sensitivity and specificity of 58% and 100%, while extent of PAR beyond the anterior mitral leaflet had a sensitivity and specificity of 44% and 97%, respectively. In a subgroup analysis of patients with available data and PAR (n = 33), short-axis Doppler measurements of PAR correlated with invasive AR index when Doppler measurements were made at the annulus level, but not at the bottom of the prosthesis.
The authors concluded that the presence of consistent HDFR and PAR extending below the anterior mitral valve leaflet are suggestive of significant PAR.
Assessment of PAR remains challenging on TEE during transcatheter aortic valve replacement (TAVR), as these jets are often complex and highly eccentric, and patterns of PAR may vary between different TAVR devices. Further, existing criteria for grading PAR have not been validated for TAVR devices, and the optimal method for grading PAR remains unclear. There are several key findings in this study. First, it observes that many measurement parameters cannot be obtained in all patients, reinforcing the need for combined assessment using multiple methods to grade PAR. Second, it finds that consistent HDFR or extent of the jet beyond the anterior mitral leaflet is independently associated with significant PAR, with a high specificity and moderate sensitivity. Identification of these two findings can be helpful to identify patients with PAR, although the low sensitivity suggests that these should not be used in isolation. Third, the optimal site for measurement of short-axis Doppler on TEE has been unclear, and a substudy in this manuscript provides supporting evidence that measurement of short-axis Doppler at the annulus level may be preferable over measurement at the bottom of the prosthesis. This manuscript may improve our ability to grade PAR with the balloon-expandable Edwards valve, although whether these findings apply to other TAVR devices is not clear.
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