Standardized Invasive Hemodynamics for Elevated Gradients Post TAVR (DISCORDANCE TAVR)

Study Overview
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Brief Summary
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The DISCORDANCE TAVR study will determine the discordance between echocardiography-derived and invasive transaortic gradients, as determined by a consistent and reproducible technique (Standardized Invasive Hemodynamics) post-TAVR.

Detailed Description
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Since the introduction of Doppler echocardiography, non-invasive estimation of aortic valve gradients through modification and simplification of the Bernoulli equation and derivation of the AVA, via the continuity equation, have become the primary method to assess the severity of AS. The utility of echocardiography to successfully determine aortic valve gradients and AVA has been established in the presence of AS, and such observations have been extrapolated to prosthetic valves. However, several reports following SAVR and TAVR for both native and valve-in-valve have demonstrated significant discordance between echocardiography-derived and direct invasive measurements of aortic valve mean gradients. The indexed AVA (iAVA) is derived from the stroke volume indexed to the BSA. The stroke volume index (SVI) divided by the Doppler velocity time integral of the continuous wave aortic valve spectral profile, is used to determine the presence of severe PPM. As such, a low iAVA may occur due to a low flow state defined by a reduced SVI (<35 ml/m2) or a reduced stroke flow rate (< 200 ml/second) and calculated by dividing the SV by the ejection time spuriously increasing the incidence of severe PPM. A low indexed effective orifice area due to a low SVI, in the absence of intrinsic PPM, has been referred to as pseudo-severe PPM, but the impact of flow state on PPM has not been described. Nonetheless, echocardiographic thresholds for the evaluation of prosthetic valve performance after TAVR have been widely adopted: mean-gradient > 20mmHg, severe PPM as defined by an iAVA < 0.65 cm2/m2, and AR, including paravalvular and transvalvular AR of moderate or greater severity. These criteria are suggested to indicate procedural success and predict long-term clinical outcomes (12). Practically many centers utilize an echocardiography-derived mean gradient for the follow-up of transcatheter heart valves. While the association of at least moderate paravalvular AR with mortality has been consistently demonstrated, there remains uncertainty regarding the clinical impact of severe PPM as determined by index echocardiography. Furthermore, the magnitude of discordance between echocardiography-derived and invasive aortic valve mean-gradients post TAVR is unknown and it remains unclear how to reconcile measurement discordances in clinical practice. These potential differences may have an important impact on patient management post TAVR. The DISCORDANCE TAVR study will determine the discordance between echocardiography-derived and invasive transaortic gradients, as determined by a consistent and reproducible technique (Standardized Invasive Hemodynamics) post-TAVR.

Official Title
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Standardized Invasive Hemodynamics for Monitoring Acute and Long Term Valve Performance in Patients With Elevated Gradients Post Transcatheter Aortic Valve Replacement

Conditions
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Aortic Stenosis, Aortic Valve Stenosis

Intervention / Treatment
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* Diagnostic Test: Standardized Invasive Hemodynamics


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Echocardiographic transaortic mean gradient ≥ 20mmHg OR VARC-3 criteria for ≥ moderate hemodynamic valve deterioration post TAVR on any TTE > 1 month post-TAVR Consensus by the Heart Team that the patient is suitable for Standardized Invasive Hemodynamics (SIH). Exclusion Criteria: CT demonstrating leaflet thrombosis or hypoattenuated leaflet thickening (HALT)
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with Elevated Gradients Post Transcatheter Aortic Valve Replacement<br>Patients who have an echocardiographic transaortic mean gradient ≥ 20mmHg OR VARC-3 criteria for ≥ moderate hemodynamic valve deterioration post TAVR on any TTE > 1 month post-TAVR | Diagnostic Test: Standardized Invasive Hemodynamics<br>* The SIH technique is a standardized, reproducible and efficient way of obtaining hemodynamic measurements.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Transaortic valve gradients | Transaortic valve gradients measured by echocardiography and direct invasive methods | 30 days | 
| Transaortic mean gradient reclassification | Proportion of patients reclassified to a transaortic mean gradient < 20mmHg using direct invasive methods | 30 days | 
| VARC-3 hemodynamic valve deterioration reclassification | Proportion of patients reclassified to ≤ moderate VARC-3 hemodynamic valve deterioration using direct invasive methods, including mean gradient and valve area, compared to echocardiography | 30 days | 
| Patient-Prosthesis Mismatch (PPM) reclassification | Proportion of patients with echocardiographic severe PPM reclassified as non-severe PPM using direct invasive methods | 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total procedure time | Total procedure time (mins) to complete standardized invasive hemodynamics | 30 days | 
| Risks of procedural complications | Evaluate risks of procedural complications associated with direct-invasive hemodynamics | 30 days |