Heart failure after long-term supravalvular aortic constriction in rats

Area of Science:

• Cardiovascular Research
• Animal Models of Disease
• Heart Failure Pathophysiology

Background:

• Human pressure overload heart failure is chronic and progressive, often leading to mortality.
• Existing animal models often fail to replicate the long-term temporal features of human heart failure.
• Understanding chronic pressure overload is crucial for developing effective treatments.

Purpose of the Study:

• To determine if gradual chronic pressure overload in young rats predictably induces heart failure.
• To characterize the specific phenotype features of heart failure in this model.
• To compare findings with established heart failure models.

Main Methods:

• Young normotensive rats underwent gradual aortic banding at 7 weeks of age.
• Hemodynamic load increased progressively with growth.
• Hearts from banded rats (with and without failure) were compared to controls at 11 months.

Main Results:

• Aortic-banded rat hearts transitioned from compensated hypertrophy to heart failure.
• Failure was marked by increased hypertrophy, depressed function, fibrosis, and stiffness.
• Significant alterations in gene expression for contractile and extracellular matrix proteins were observed.

Conclusions:

• Gradual aortic constriction reliably induced heart failure in rats over 3-18 months.
• The resulting phenotype closely resembles that of aged spontaneously hypertensive rats.
• A common heart failure phenotype emerges from long-term pressure overload, irrespective of the initial cause.