Neurohormonal and circulatory effects of short-term treatment with enalapril and quinapril in dogs with asymptomatic mitral regurgitation: abstract no. 9

TY - ABST

T1 - Neurohormonal and circulatory effects of short-term treatment with enalapril and quinapril in dogs with asymptomatic mitral regurgitation

T2 - ECVIM-CA Congress

AU - Moesgaard, Sophia Gry

AU - Pedersen, Lotte Gam

AU - Teerlink, Tom

AU - Häggström, Jens

AU - Pedersen, Henrik Duelund

N1 - Conference code: 15

PY - 2005

Y1 - 2005

N2 - Mitral regurgitation (MR) is a common cause of heart failure in dogs. Cavalier King Charles Spaniels (CKCS) are predisposed to the disease and often develop asymptomatic MR at a young age, which seems to be associated with a decreased production of nitric oxide (NO) (measured as the stable metabolites nitrate and nitrite in plasma (NOx)). Activation of angiotensin-converting enzyme (ACE) in heart failure might lead to reduced endothelial NO release. Accordingly, ACE inhibition has been shown to improve endothelial function in humans, most likely by increasing the availability of NO. In that context, quinapril has been shown to have a superior effect on endothelial function compared to enalapril. In CKCS with MR enalapril does not prolong the asymptomatic period where endothelial dysfunction seems to be present. Quinapril, however, might be ab le to prolong the asymptomatic period of MR - provided that the results seen in humans regarding improved endothelial dysfunction can be reproduced in dogs. The aim of the study was to compare the effect enalapril and quinapril on neurohormonal and circulatory parameters in CKCS with asymptomatic MR. Ten CKCS with mild to severe untreated MR completed a protocol were they were treated with quinapril and enalapril (0.-5 mg/kg PO SID for 7 days), in a double-blind coss-over study with a wash out period of 7 days between treatments. Blood samples were drawn and echocardiography was performed on days 0, 7, 14 and 21. B oth treatments reduced ACE activity (P<.001) and increased renin activity (P<.001) and atrial natriuretic peptide concentration (P<.005). The ACE inhibitors had no effect on the plasma concentration of NOx or asymmetric dimethylarginine (ADMA). On day 0, a lower NOx concentration (P = .02) was found in samples taken in the clinic as compared to samples taken in the home of the dogs. Quinapril caused a significant reduction in a greater number of variables reflecting the severity of MR (e.g. jet size and left centricular end diastolic diameter) than was found with enalapril. Howev er, in terms of specific parameters, there was no significant difference between the effects of the two treatments on MR. These results suggest that ACE inhibitors do not affect NOx and ADMA concentrations in asymptomatic dogs with MR, however, stress in connection with clinical examination may influence NOx concentrations in these dogs.

AB - Mitral regurgitation (MR) is a common cause of heart failure in dogs. Cavalier King Charles Spaniels (CKCS) are predisposed to the disease and often develop asymptomatic MR at a young age, which seems to be associated with a decreased production of nitric oxide (NO) (measured as the stable metabolites nitrate and nitrite in plasma (NOx)). Activation of angiotensin-converting enzyme (ACE) in heart failure might lead to reduced endothelial NO release. Accordingly, ACE inhibition has been shown to improve endothelial function in humans, most likely by increasing the availability of NO. In that context, quinapril has been shown to have a superior effect on endothelial function compared to enalapril. In CKCS with MR enalapril does not prolong the asymptomatic period where endothelial dysfunction seems to be present. Quinapril, however, might be ab le to prolong the asymptomatic period of MR - provided that the results seen in humans regarding improved endothelial dysfunction can be reproduced in dogs. The aim of the study was to compare the effect enalapril and quinapril on neurohormonal and circulatory parameters in CKCS with asymptomatic MR. Ten CKCS with mild to severe untreated MR completed a protocol were they were treated with quinapril and enalapril (0.-5 mg/kg PO SID for 7 days), in a double-blind coss-over study with a wash out period of 7 days between treatments. Blood samples were drawn and echocardiography was performed on days 0, 7, 14 and 21. B oth treatments reduced ACE activity (P<.001) and increased renin activity (P<.001) and atrial natriuretic peptide concentration (P<.005). The ACE inhibitors had no effect on the plasma concentration of NOx or asymmetric dimethylarginine (ADMA). On day 0, a lower NOx concentration (P = .02) was found in samples taken in the clinic as compared to samples taken in the home of the dogs. Quinapril caused a significant reduction in a greater number of variables reflecting the severity of MR (e.g. jet size and left centricular end diastolic diameter) than was found with enalapril. Howev er, in terms of specific parameters, there was no significant difference between the effects of the two treatments on MR. These results suggest that ACE inhibitors do not affect NOx and ADMA concentrations in asymptomatic dogs with MR, however, stress in connection with clinical examination may influence NOx concentrations in these dogs.

M3 - Conference abstract in proceedings

SP - 193

BT - Congress proceedings

PB - ECVIM

Y2 - 1 September 2005 through 3 September 2005

ER -