The Tricuspid Valve Maladapts in a Pulmonary Hypertension Rat Model

Area of Science:

• Cardiovascular research
• Valve disease mechanisms
• Animal models in cardiology

Background:

• Tricuspid valve regurgitation is a common heart valve issue linked to mortality.
• The tricuspid valve, often presumed intact, may undergo significant remodeling.
• Previous studies in sheep demonstrated tricuspid valve thickening and stiffening.

Purpose of the Study:

• To investigate tricuspid valve remodeling in a rodent model.
• To establish a scalable model for studying tricuspid valve disease.
• To determine if tricuspid valve remodeling occurs in rats under pressure overload.

Main Methods:

• Pulmonary artery banding (PAB) was used in male rats to induce right ventricular pressure overload.
• Tricuspid valves were excised and analyzed for anterior leaflet morphology.
• Optical coherence tomography mapped leaflet thickness, and bulge testing assessed mechanics.

Main Results:

• Pulmonary artery banding increased tricuspid valve anterior leaflet area in rats.
• Leaflets showed region-specific thickening, particularly near the annulus.
• Tricuspid valve leaflets became less compliant due to structural thickening.

Conclusions:

• Rats exhibit tricuspid valve remodeling, similar to sheep, involving thickening and stiffening.
• This study validates rats as a scalable model for investigating tricuspid valve disease.
• Tricuspid valves are active participants in regurgitation, not passive bystanders.