Echocardiographic Versus Invasive Aortic Valve Gradients In Different Clinical Scenarios.
Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography
BACKGROUND: The role of echocardiography in deriving transvalvular mean-gradients from transaortic velocities in aortic stenosis (AS) and in degenerated surgical bioprosthetic valves (SVD) is well established. However, reports following surgical aortic valve replacement (SAVR), post-transcatheter aortic valve replacement (TAVR), and valve-in-valve-TAVR (ViV-TAVR) have cautioned against the use of echocardiography-derived mean-gradients to assess normal functioning bioprosthesis due to discrepancy compared to invasive measures in a phenomenon called discordance.
METHODS: In a multicenter study, intra-procedural echocardiographic and invasive mean-gradients in AS, SVD, post-native-TAVR, and post-ViV-TAVR were compared, when obtained concomitantly, and discharge echocardiographic gradients were recorded. Absolute discordance (intra-procedural echocardiographic - invasive mean-gradient) and percent discordance (intra-procedural echocardiographic - invasive mean-gradient/echocardiographic mean-gradient) were calculated. Multivariable regression analysis to determine variables independently associated with elevated post-procedure invasive gradients ≥20mmHg, absolute discordance >10mmHg, and discharge echocardiographic mean-gradient ≥20mmHg RESULTS: 5027 patients were included in the registry; 4725 native-TAVR and 302 ViV-TAVR. Intra-procedural concomitant echocardiographic and invasive mean-gradients were obtained pre-TAVR in AS (N=2418), pre-ViV-TAVR in SVD (N=101), in 77 post-ViV-TAVR, and in 823 post-TAVR. Echocardiographic and invasive mean-gradients demonstrated strong correlation (r=0.69) and agreement (bias: 0.11, 95% confidence interval (CI) -0.4-0.62) in AS, moderate correlation (r=0.56) and agreement (bias:1.08, 95% CI -2.53-4.59) in SVD, moderate correlation (r=0.61) and weak agreement (bias:6.47, 95% CI 5.08-7.85) post-ViV-TAVR, and weak correlation (r=0.18) and agreement (bias:3.41, 95% CI 3.16-3.65) post-TAVR. Absolute discordance occurs primarily in ViV-TVR, is not explained by STJ size, and increases with increasing echocardiographic mean gradient. Percent discordance in AS and SVD (1.3% and 4%, respectively) was lower compared to post-TAVR/ViV-TAVR (66.7% and 100%, respectively). Compared to self-expanding valves, balloon-expandable valves were independently associated with elevated discharge echocardiographic but lower invasive mean-gradient (odds ratio=3.411, 95% CI:1.482-7.852, p= 0.004 vs. OR=0.308, 95% CI:0.130-0.731, p=0.008, respectively).
CONCLUSIONS: Post TAVR/ViV-TAVR, echocardiography is discordant from invasive mean-gradients and absolute discordance increases with increasing echocardiographic mean-gradient and is not explained by STJ size. Percent discordance is significantly higher post-TAVR/ViV-TAVR than in AS and SVD. Post-TAVR/ViV-TAVR, poor correlation and wide limits of agreement suggest echocardiographic and invasive mean-gradients may not be used interchangeably and a high residual echocardiographic mean-gradient should be confirmed invasively before considering any additional procedure to "correct" the gradient. TAVR valve types have variable impact on echocardiographic and invasive mean-gradients.
Abbas AE, Khalili H, Madanat L, Elmariah S, Shannon F, Al-Azizi K, et al Echocardiographic versus invasive aortic valve gradients in different clinical scenarios. J Am Soc Echocardiogr. 2023 Jul 26:S0894-7317(23)00381-4. doi: 10.1016/j.echo.2023.06.016. Epub ahead of print. PMID: 37507058.