Why Murmurs Persist After TAVR
The murmur often does not improve after TAVR because paravalvular regurgitation (PVR) is extremely common, occurring in 85% of patients immediately post-procedure, with 75% still having mild or greater PVR at one year. 1
Primary Mechanisms of Persistent Murmurs
Paravalvular Regurgitation (Most Common)
Paravalvular leaks are the predominant cause of persistent murmurs post-TAVR, arising from:
- Inadequate prosthesis inflation or expansion - The valve fails to fully deploy against the annulus
- Calcific deposits preventing proper sealing - Heavy, irregular, or eccentric calcification creates gaps between the valve stent and native annulus where the prosthesis cannot conform 1, 2
- Incorrect valve sizing - Undersized valves relative to the annulus leave gaps
- Suboptimal positioning - Increased LVOT angulation or valves seated less deeply in the annulus predispose to leaks 1
The incidence of mild-to-moderate PVR is significantly higher in TAVR compared to surgical AVR, though severe regurgitation (+3 or +4) remains rare 1.
Central (Intravalvular) Regurgitation
Central regurgitation produces murmurs from:
- Improper valve deployment or sizing
- Leaflet damage during crimping of the prosthesis
- Overhanging leaflet material altering diastolic flow patterns
- Heavy guidewires holding leaflets open during assessment (resolves once wires removed) 1, 2
Critical Anatomic Risk Factors
Specific anatomic features predict persistent regurgitation and murmurs:
- Eccentric or bulky calcification in the annular area
- Heavy irregular calcific deposits preventing valve seating
- Small annular size relative to valve chosen
- Increased LVOT-to-aorta angulation
- Shallow valve implantation depth 1
Dynamic Nature of Post-TAVR Regurgitation
Regurgitation severity can change in the days following TAVR, requiring continued surveillance 1:
- Self-expanding valves (CoreValve) may reduce PVR grade as the nitinol frame expands over time
- Conversely, recoil from compressive forces of heavy calcification can worsen regurgitation
- Small paravalvular jets may spontaneously regress over 10-15 minutes post-deployment 3
Clinical Significance
The persistence of paravalvular regurgitation after TAVR carries clinical concern because moderate-to-severe AR after any AVR can lead to:
- Chronic volume overload
- Left ventricular remodeling and dysfunction
- Increased risk of hemolysis (though not yet reported with TAVR specifically) 1, 4
At one year post-TAVR, one-third of patients have more than mild regurgitation 1, though long-term clinical significance remains under investigation.
Assessment Approach
Post-deployment evaluation must characterize regurgitation by location (central vs. paravalvular), severity, and cause 1, 2:
- Use multiwindow, multiparametric echocardiography including both long-axis and short-axis views
- Image the entire annular and subannular region as jets can occur anywhere around the valve perimeter
- Assess total circumferential extent, jet width at origin, number of jets, and proximal flow convergence 3
- 3D echocardiography may overcome 2D limitations for quantifying regurgitation 3
Management Considerations
Acute paravalvular leaks may respond to repeat balloon dilation to achieve better seal and expansion 1, 2. Newer valve designs specifically target PVR reduction:
- Outer skirts (Sapien S3) for improved sealing
- Recapture/repositioning capability (CoreValve Evolut R) before full deployment 2
Moderate-to-severe paravalvular regurgitation typically requires intervention before leaving the procedure room 2.
Common Pitfall
Do not confuse jets entering the LVOT through the incomplete skirt (lower 4mm of self-expanding valves) with true paravalvular regurgitation. These eccentric jets are directed into the center of the LVOT, are difficult to quantify, and many spontaneously regress as the frame expands 3.