Impact of simulated MitraClip on forward flow obstruction in the setting of mitral leaflet tethering: An in vitro investigation.
Catheter Cardiovasc Interv
; 92(4): 797-807, 2018 10 01.
Article
in En
| MEDLINE
| ID: mdl-30091509
ABSTRACT
OBJECTIVES:
We aimed to evaluate diastolic leaflet tethering as a factor that may cause mitral stenosis (MS) after simulated MitraClip implantation, using an in vitro left heart simulator.BACKGROUND:
Leaflet tethering commonly seen in functional mitral regurgitation may be a significant factor affecting the severity of MS after MitraClip implantation.METHODS:
A left heart simulator with excised ovine mitral valves (N = 6), and custom edge-to-edge clip devices (GTclip) was used to mimic implantation of MitraClip in a variety of positions. Anterior mitral leaflet (AML) tethering severity was varied for each case (leaflet excursion of 75°, 60°, and 45°, consistent with mild, moderate and severe tethering), and the baseline mitral annular area (MAA) was varied across samples (3.6-4.8 cm2 ). The resulting mitral valve area (MVA), and peak/mean mitral valve gradient (MVG) were measured in each case.RESULTS:
AML tethering severity was a highly significant factor increasing MVG and decreasing MVA (P < 0.001). When GTclip placement was simulated with severe AML tethering, mean MVG >5 mmHg resulted more frequently than with GTclip placement alone (46% vs. 4%, respectively). However, severe AML tethering alone significantly reduced baseline MVA to 3.6 ± 0.2 cm2 , and increased baseline MVG to 3.0 ± 0.4 mmHg. At MAA above 4.7 cm2 , severe AML tethering did not cause moderate MS, even with placement of two GTclips (95% confidence).CONCLUSIONS:
Our results show that diastolic AML tethering may predispose to MS after clip placement, however, MS was not observed when baseline MVA was above 4.0 cm2 . Severity of AML tethering may be an important criterion in selecting patients for edge-to-edge repair.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Heart Valve Prosthesis
/
Heart Valve Prosthesis Implantation
/
Mitral Valve Annuloplasty
/
Hemodynamics
/
Mitral Valve
/
Mitral Valve Stenosis
Type of study:
Etiology_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Catheter Cardiovasc Interv
Journal subject:
CARDIOLOGIA
Year:
2018
Document type:
Article
Affiliation country:
Georgia