TAVI in Young Patients and Prosthetic Valve Echocardiography

KEY LEARNING POINTS

Part 1

• TAVI volumes in the US now exceed isolated surgical aortic valve replacement, but increasing use in patients under 65 has been linked to a first-ever population-level rise in aortic stenosis-related mortality, likely driven by premature valve failure requiring complex re-intervention.

• Guidelines recommend heart team-based shared decision-making for TAVI in patients aged ≥65 (ACC/AHA 2020) or ≥70 (ESC 2024), but the key determinant is not age - it is life expectancy, quality of life, and whether a future redo procedure will be feasible.

• When a TAVI valve fails, surgical explant carries significant risk (13–30% 30-day mortality in registry data), making redo-TAVI an attractive but technically demanding alternative that requires detailed pre-procedural CT workup.

• CT planning for redo-TAVI must assess the coronary risk plane, functional neoskirt height, valve-to-coronary distance (VTC), and anticipated neo-sinus geometry to determine whether safe coronary access is achievable with a second valve.

• Up to 50% of patients may face coronary access challenges at redo-TAVI, particularly if a tall-frame self-expanding valve was used as the index procedure, where 70–90% may require leaflet modification before a second valve can be safely deployed.

• TAVI valve under-expansion - often undetectable on fluoroscopy but visible on post-procedural CT, contributes to leaflet pinwheeling, hypoattenuating leaflet thickening (HALT), and accelerated structural valve deterioration.

• Redo-TAVI requires a true multidisciplinary approach: interventional cardiologist, cardiac surgeon, and imaging specialist must review CT together. Dedicated planning apps can assist but do not replace expert judgment.

Part 2

• TOE assessment of prosthetic valves in the perioperative setting is complicated by rapidly changing haemodynamics post-bypass (low output, vasoplegia, haemodilution), acoustic shadowing, and the competing demands of anaesthetic management.

• Prosthetic valve failure encompasses five categories: structural deterioration, non-structural dysfunction (including PPM and paravalvular leak), thrombus, infective endocarditis (with near-universal paravalvular abscess), and leaflet entrapment - each with distinct TOE appearances.

• Any central regurgitation beyond a trace is abnormal in a tissue valve. Mechanical bileaflet valves normally display up to four physiological intra-stent jets - a normal finding that should not be misidentified as pathological.

• The simplified Bernoulli equation has critical limitations for prosthetic valves - high gradients must be interpreted in the context of cardiac output, pressure recovery, haemodilution, and clinical haemodynamics before concluding obstruction.

• The dimensionless velocity index (DVI) and continuity equation EOA are more reliable and less flow-dependent metrics than peak gradient for assessing prosthetic aortic valve function.

• A systematic approach to high gradients post-AVR should first exclude high-flow states, then assess the valve structurally, then consider subvalvular causes including SAM (systolic anterior motion), which produces LVOT obstruction with a posteriorly directed MR jet.

• 3D TOE with the surgeon’s anatomical view orientation is the most reliable method for localising paravalvular leaks - essential for repair planning. These jets are always wall-hugging and carry more energy than their vena contracta size suggests.

• Anomalous intra-annular jets seen with early-generation Inspiris valves (circa 2021) relate to a sewing ring design feature that has since been revised; this finding is now uncommon with current-generation valves.