Aldosterone receptor antagonists – how cardiovascular actions may explain their
beneficial effects in heart failure
Ovaert, P., Elliott, J., Bernay, F., Guillot, E., Bardon, T.
Journal of Veterinary Pharmacology and Therapeutics, 2010, 33:109-117
Les antagonistes de l’aldostérone ont été considérés longtemps comme diurétiques épargnant du potassium.
Toutefois, vu que l’aldostérone joue un rôle important dans des processus impliqués dans la progression de l’insuf-
fisance cardiaque chez l’homme et l’animal, on a fait récemment beaucoup de progrès en recherches sur d’autres
applications de ces molécules. Cet article résume la littérature disponible concernant l’influence de l’aldostérone sur
le myocarde, les vaisseaux sanguins et le système nerveux autonome en cas d’insuffisance cardiaque.
Il existe de nombreuses études démontrant le rôle
que joue l’aldostérone dans l’apparition de la fibrose
myocardique et la prévention de celle-ci par des an-
tagonistes de l’aldostérone. Il a été démontré que le
développement de la fibrose du myocarde entraîne
une rigidité anormale du myocarde, conduisant à une
dysfonction ventriculaire diastolique et systolique, abou-
tissant à la progression de l’insuffisance cardiaque
chez l’homme.
Les antagonistes de l’aldostérone, comme la spiro-
nolactone, aident à prévenir la fibrose myocardique.
Ceci permet d’expliquer leur effet bénéfique clair sur la réduction du risque de mortalité chez le chien et l’homme
souffrant d’insuffisance cardiaque. La fibrose myocardique a été démontrée chez les animaux de laboratoire, les
chiens et l’homme souffrant d’insuffisance cardiaque. Dans une publication récente de Falk et al. (2006, 2007)
les chiens souffrant d’insuffisance cardiaque avaient significativement plus de fibrose myocardique que les chiens
sains et plus le degré de fibrose était élevé, plus la durée de survie était courte. Yang et al. (2008) ont conclu que
la spironolactone aidait à prévenir la fibrillation atriale chez le chien souffrant d’insuffisance cardiaque induite grâce
à une réduction de la fibrose dans l’atrium.
L’aldostérone induit une élasticité réduite des vaisseaux sanguins, conduisant à une augmentation de la résistance
périphérique. On a observé une amélioration de la fonction endothéliale après l’utilisation de la spironolactone chez
l’homme. L’aldostérone a également un effet délétère sur l’activité du système parasympathique. Grâce au traite-
ment aux antagonistes de l’aldostérone, on a réussi à ralentir le rythme cardiaque et à en améliorer la variabilité.
Chez le chien, un réflexe barorécepteur altéré et une réaction réduite du rythme cardiaque aux changements dans
la pression sanguine ont également été constatés.
Les antagonistes de l’aldostérone, comme la spironolactone, aident à prévenir la fibrose du
myocarde et ils ont un effet bénéfique sur la mortalité chez l’homme et l’animal souffrant d’insuffi-
sance cardiaque.
Falk, T., Jönsson, L., Olsen, L.H., Pedersen, H.D. (2006) Arteriosclerotic changes in myocardium, lung and kidney in dogs with chronic
congestive heart failure and myxomatous valve disease. Cardiovascular Pathology, 15, 185-193.
Falk, T., Jönsson, L., Olsen, L.H., Tarnow, I., Pedersen, H.D. (2007) Correlation of cardiac pathology and clinical findings in dogs with naturally
occurring congestive heart failure. Abstract. Proceedings of the 17th annual ECVIM congress. Budapest Hungary, Sept. 13th-15th.
Yang, S., Han., W., Zhou, H., Dong, G., Wang, B., Huo, H., Wei, N., Cao, Y., Zhou, G., Xiu, C. & Li, W. (2008) Effects of spironolactone on
electrical and structural remodelling of atrium in congestive heart failure dogs.Chinese Medical Journal, 121, 38-42.
ACTION
ANTIFIBROTIQUE…
ADVERTORIAL
Two New Publications Discuss the Use and Benefi ts
of Spironolactone in Dogs
Fraser Broadfoot BVetMed GPCert(SAP) MRCVS
This article summarises two new publications that discuss the clinical benefi ts of giving spironolactone
(Prilactone®, CEVA Animal Health) as part of fi rst-line therapy to dogs with congestive heart failure caused
by mitral valve disease.
The aim of this study was to determine the clinical effi cacy of spironolactone
for dogs with mitral valve disease when added as part of fi rst-line congestive
heart failure therapy. 212 dogs were enrolled onto the study and were
randomised, under double blind conditions, to receive either spironolactone
or placebo. All dogs also received an ACE inhibitor and other authorised
treatments included furosemide, digoxin and L-carnitine. The study was
continued for 15 months and the following end-points were recorded:
• death or euthanasia due to heart failure (mortality)
• severe worsening of heart failure (morbidity), defi ned as the need to
introduce an unauthorised cardiac therapy or to increase the dose of
furosemide over 10mg/kg/day to prevent life-threatening oedema
By the end of this period, 10.8% of dogs in the spironolactone group reached
the end-point (death, euthanasia and severe worsening) versus 25.5% of
dogs in the placebo group. This represents a 55% reduction in the risk of
cardiac morbidity-mortality (p = 0.017), see fi gure 1, and an even greater
69% reduction in the risk of mortality (p = 0.0071).
These results were highly statistically signifi cant and support the use of
Prilactone® as part of fi rst-line therapy for the treatment of dogs with
congestive heart failure caused by mitral valve disease.
This paper summarises the mode of action of spironolactone which, as an
aldosterone antagonist, has traditionally been classifi ed only as a potassium-
sparing diuretic. However it has now been discovered that aldosterone plays
a pivotal role in many other pathogenic processes involved in the progression
of heart failure, including myocardial fi brosis, see fi gure 2.
In human patients, the development of myocardial fi brosis has been shown
to cause abnormal myocardial stiffness, leading to ventricular diastolic and
systolic dysfunction and ultimately to progression of heart failure. In recent
studies, Falk
et al
. (2006/2007) showed that dogs with congestive heart
failure had signifi cantly more myocardial fi brosis than control dogs and the
higher the degree of fi brosis then the shorter the survival time.
Aldosterone antagonists, such as spironolactone, help to prevent
myocardial fi brosis and this helps to explain their marked benefi cial
effects on reducing the risk of mortality in dogs and people with heart
failure.
Effi cacy of Spironolactone on Survival in Dogs with Naturally-occurring
Mitral Regurgitation Caused by Myxomatous Mitral Valve Disease.
Bernay, F., Bland, J.M., Häggström, J., Baduel, L., Combes, B., Lopez, A., Kaltsatos,
V. (2010),
Journal of Veterinary Internal Medicine
. In Press.
Aldosterone receptor antagonists – how cardiovascular actions may
explain their benefi cial effects in heart failure.
Ovaert P., Elliott J., Bernay F., Guillot E., Bardon T. (2010),
Journal of Veterinary
Pharmacology and Therapeutic.
In Press.
Figure 1: Survival curve for dogs receiving spironolactone (Prilactone®) versus those receiving
placebo (end point = death/euthanasia and severe worsening due to cardiac disease)
Figure 2: Myocardial subendocardial and interstitial fi brosis; areas of fi brosis (collagen) are coloured
in blue. Photo. I. Raymond-Letron National Veterinary School of Toulouse, France.
For further information about how Prilactone® can be incorporated into your
heart failure treatment regimes, please contact Fraser Broadfoot MRCVS by
telephone on 01494 781510 or by email at fraser.broadfoot@ceva.com.
Other references
Falk, T., Jönsson, L., Olsen, L.H., Pedersen, H.D. (2006), Arteriosclerotic changes in myocardium, lung and kidney in dogs with chronic congestive heart failure and myxomatous valve disease, Cardiovascular Pathology, 15, p185-
193. Falk, T., Jönsson, L., Olsen, L.H., Tarnow, I., Pedersen, H.D. (2007), Correlation of cardiac pathology and clinical fi ndings in dogs with naturally occurring congestive heart failure. Abstract. Proceedings of the 17th annual ECVIM
congress. Budapest Hungary, September 13th -15th. Abstract 23.
Prilactone® contains spironolactone POM-V Further information is available from CEVA Animal Health Ltd, 90 The Broadway, Chesham, Bucks HP5 1EG
UK Vet A4 Prilactone Advertorial Feb 10.indd 1 11/02/2010 09:54
Fibrose myocardique et interstitielle; les zones de fibrose
(collagène) sont colorées en bleu.