Effects of spironolactone treatment on an experimental model of chronic aortic valve regurgitation.

BACKGROUND AND AIM OF THE STUDY: Aortic regurgitation (AR) is a disease for which there is currently no effective medical treatment. It has been shown previously in an experimental model of AR that the renin-angiotensin-aldosterone system (RAAS) plays a major role, and that medications blocking the RAAS are effective to protect against left ventricular (LV) hypertrophy and also help to maintain a normal systolic function. The role of aldosterone receptor blockers in this disease has never been evaluated. Thus, the effects were studied of the aldosterone receptor blocking agent spironolactone in a model of chronic AR in rats.

METHODS

The effects of a six-month treatment with spironolactone were evaluated in adult Wistar rats with severe AR, compared to sham-operated and untreated AR animals.

RESULTS

Spironolactone treatment decreased the total heart weight. In addition, the LV expression of atrial natriuretic peptide mRNA was decreased by spironolactone treatment, as was the expression of collagen 1 and LOX1 mRNAs. Left ventricular fibrosis was decreased by spironolactone treatment.

CONCLUSION

Spironolactone protected against volume-overload cardiomyopathy in this model of aortic valve regurgitation. The predominant protective effect was a decrease in myocardial fibrosis.