Survival with Aortic Stenosis (AS) is Determined by Progression of Calcification (1)
Calcium Grows in Typical Patterns
Bridge Pattern- Calcification grows as two arcs from two sides of the leaflet base, and then connects at the center of the leaflet. (2)
Half-Bridge Pattern - Calcification grows as two arcs from one or two sides of the leaflet base and do not connect at the center of the leaflet. (2)
Two 'Half Bridges'
Calcium Limits Valve Opening
Leaflets open along natural folding lines. The leaflets’ mobility is significantly compromised when calcium grows across these defined lines.
Leaflet's natural folding lines (A, dashed lines)
Calcium patterns cross leaflet's folding lines (B)
Scoring May Potentially Regain Leaflets Mobility
Finite Elements Analysis
The aortic valve was modeled using Finite Elements Analysis.
Typical calcification patterns were modeled on a hyperelastic valve tissue model, representing the mechanical behaviour of calcified leaflet.
The analyses guided the Leaflex™ design to define optimal scoring location and maximal treatment efficacy.
Bridge Calcium Pattern Without Scoring
Scoring Calcium Pattern in Bridge
Bases and Centerline
Engineered Valve Model
The hemodynamic effect of creating and adding scoring lines was tested in a setup using a pulsatile flow loop in an engineered valve model, - showing a dramatic increase in Aortic Valve Area (AVA) and decrease in pressure gradient. (3)
1 Scoring line
3 Scoring lines
6 Scoring lines
9 Scoring lines
7 Scoring lines
AVA - 0.65 cm²
AVA - 0.83 cm²
AVA - 1.12 cm²
AVA - 1.32 cm²
AVA - 1.49 cm²
AVA - 1.64 cm²
The Leaflex™ Performer
The Leaflex Procedure
Scoring Appears to Improve Valve Function
Bench tests, using ex-vivo reconstructed human valves, further indicates that creating scoring lines within the natural folding lines of the leaflet is potentially effective for increasing leaflets' pliability, and thus may increase and improve the valve opening area. (3)
The Leaflex™ is Potentially Superior to
Balloon Aortic Valvuloplasty (BAV)
Bench tests, using the ex-vivo reconstructed valves in a pulse-duplicator, showed an increase in valve opening area and a decrease in pressure gradients post-treatment with the Leaflex™, while BAV showed only moderate improvement.(3)
AVA - 0.56 cm²
PG - 80 mmHg
AVA -0.63 cm²
PG - 63 mmHg
AVA - 1.32 cm²
PG - 12 mmHg
Designed to Mitigate Risks of Structural Damage and Embolization
Bench testing and first in human feasibility studies show that the ventricular tissue of the valve is preserved during scoring, as further confirmed by histopathology and micro CT (Histopathology images, front and back images of leaflet shown). (3)
Quantitative bench testing shows similar emboli following Leaflex™ as compared to TAVR. (3)
Micro CT analysis of scored leaflet (Dr. R. Virmani, cvpath institute). Ventricular aspect of leaflet undamaged (left); leaflet cross-section showing scored calcium deposits and undamaged ventricular tissue (right). (3)
(1) Bhattacharyya et al. Controversies in cardiovascular medicine, Risk stratification in asymptomatic severe aortic stenosis: a critical appraisal. European Heart Journal, July 5, 2012.
(2) Jonas et al. The Leaflex™ Catheter System – a viable treatment option alongside valve replacement? Preclinical feasibility of a novel device designed for fracturing aortic valve Calcification. EuroIntervention 2014;10-online Nov 14.
(3) Data available on file at Pi-Cardia.