Evaluation of renal parameters during the treatment of congestive heart failure due to myxomatous mitral valve disease

Abstract

Myxomatous mitral valve disease (MMVD) is the most common cardiac disease in small animal practice, mainly affecting small dog breeds. The severity of MMVD is commonly classified by the American College of Veterinary Internal Medicine (ACVIM). Recently, the mitral insufficiency echocardiographic score (MINE score) related the severity of the ACVIM scale with the prognosis of dogs with MMVD, and the higher the value, the worse the prognosis. In addition, renal dysfunction secondary to the use of diuretics has shown to be a negative prognostic factor in dogs with MMVD. The objective of the study was to evaluate several clinical parameters before and after the initiation of diuretic treatment in a group of dogs affected by MMVD and evaluated by MINE score. In this study, 11 patients were specifically selected; 7 females and 4 males with an average weight of 6.33 kg and 13.10 years. All dogs were diagnosed with stage Ca (ACVIM) of MMVD and no animal had previously received cardiovascular medication. Subsequently, they were chronically administered Pimobendan (0.25mg/kg BID), Benazepril hydrochloride (0.3mg/kg BID), Spironolactone (1mg/kg BID) and Furosemide (1mg/kg BID). MINE echocardiographic score (4-14), various hematological parameters, several biochemical parameters, various urinary parameters and blood pressure measurements were determined and evaluated before the start of treatment and later (30-90 days). The results showed variation in the MINE score, finding lower values in the study after the start of treatment (Median; 12 vs 9). In the same way, different mean values were reported in several biochemical and urinary parameters analyzed, without reporting notable results in the blood count. Likewise, a consistent decrease in arterial pressures and beats per minute was observed. In general, the obtained changes can be attributed to the established medication. Most of the parameters were in the physiological range at the end of the evaluation of the patients, being an information that demonstrates the effectiveness of the drugs and the safety in their use in the patients evaluated. The results should be considered of interest for the greater knowledge of the alterations caused at the cadiorrenal level for the management and therapy of MMVD.