Efficacy of oral torasemide in dogs with degenerative mitral valve disease and new onset congestive heart failure: The CARPODIEM study

Self-Reported Utilization of International (ACVIM Consensus) Guidelines and the Latest Clinical Trial Results on the Treatment of Dogs with Various Stages of Myxomatous Mitral Valve Degeneration: A Survey among Veterinary Practitioners

BACKGROUND

Myxomatous mitral valve degeneration is the most common canine heart disease. Several clinical trials have investigated various treatments. The latest recommendations are published in the ACVIM consensus guidelines (2019). Our study aimed to investigate how closely veterinary practitioners apply the treatment recommendations of these guidelines and the latest clinical trials.

METHODS

An online survey was sent to Dutch and Belgian veterinary practices via digital channels.

RESULTS

The data from 363 fully completed surveys were analyzed. For stage B1 disease, 93% recommended, correctly, no treatment. For stage B2 disease, 67% of the respondents recommended starting pimobendan as monotherapy. For chronic treatment of stage C disease, 16 different drug combinations were mentioned, but nobody recommended surgery. Only 48% of the respondents recommended the only evidence-based drug combination: a loop diuretic with pimobendan. A concerning finding was the simultaneous prescription of two loop diuretics, by 19% of the respondents.

CONCLUSIONS

Treatment recommendations showed an increasing variation with more advanced disease stages from B1 through B2 to C. This reflects the increasing disagreement among the panelists who prepared the ACVIM consensus guidelines. Practitioners of our study seem to practice more evidence-based medicine than veterinary cardiologists, as it was reported in a recent survey-based study.

Effect of a specially formulated diet on progression of heart enlargement in dogs with subclinical degenerative mitral valve disease

BACKGROUND

Previous studies in dogs with degenerative mitral valve disease (DMVD) have identified altered myocardial energy metabolism and oxidation, which might contribute to cardiac hypertrophy. Diets rich in medium chain fatty acids and antioxidants are a potential means of treatment. A previous clinical study found significantly smaller left atrial diameter (LAD) and left atrium-to-aorta diameter ratio (LA : Ao) in dogs with subclinical DMVD fed a specially formulated diet vs control diet for 6 months.

HYPOTHESIS/OBJECTIVES

A specially formulated diet will slow or arrest left heart enlargement in dogs with subclinical DMVD over 365 days.

ANIMALS

One hundred twenty-seven dogs with unmedicated subclinical DMVD; 101 dogs in the per protocol cohort.

METHODS

Randomized double-blinded controlled multicenter clinical trial.

RESULTS

The study's primary composite outcome measure was the sum of percentage change in LAD and left ventricular internal dimension at end-diastole (LVIDd) at day 365. In the per protocol cohort, the outcome measure increased by 8.0% (95% confidence interval [CI], 2.9%-13.1%) in dogs receiving the test diet vs 8.8% (95% CI, 5.1%-12.5%) in dogs receiving control diet (P = .79). Neither component of the primary outcome measure was significantly different between groups (LAD, P = .65; LVIDd, P = .92). No difference was found in mitral valve E wave velocity (P = .36) or the proportion of dogs withdrawn from the study because of worsening DMVD and heart enlargement (P = .41).

CONCLUSIONS AND CLINICAL IMPORTANCE

Feeding a specially formulated diet for 365 days was not associated with a significantly different rate of change of left heart size in dogs with subclinical DMVD as compared to control.

Retrospective evaluation of risk factors for development of kidney injury after parenteral furosemide treatment of left-sided congestive heart failure in dogs

BACKGROUND

Kidney injury (KI) has been documented in dogs treated with furosemide for left-sided congestive heart failure (CHF).

HYPOTHESIS/OBJECTIVES

Determine risk factors for development of KI in furosemide-treated dogs and determine the effect of KI on survival.

ANIMALS

Seventy-nine client-owned dogs receiving parenteral furosemide for CHF.

METHODS

Serum creatinine (sCr) and electrolyte concentrations were determined during hospitalization and at first outpatient reevaluation to detect and stage KI (increase in sCr ≥0.3 mg/dL). Furosemide dosage administered between timepoints was calculated. Multivariable modeling was performed to identify predictors of KI and percent change in serum biochemistry results over time.

RESULTS

Kidney injury was identified in 38/79 (48%) dogs and mostly occurred during hospitalization. Kidney injury was Grade I in 25 dogs, Grade II in 9 dogs, and Grade III in 4 dogs. Higher blood pressure was associated with acute KI during hospitalization (odds ratio, 1.03; 95% confidence interval [95% CI] 1.01-1.07; P = .03) whereas PO furosemide dosage was associated with KI after hospital discharge (odds ratio, 7.77; 95% CI, 2.05-68.6; P = .02). Baseline sCr and use of a furosemide continuous rate infusion were not associated with increased risk of KI. Kidney injury was not associated with long-term outcome. Of 13 dogs with Grade II-III KI, azotemia was reversible in 9 dogs, and 6 dogs survived >1 year after KI.

CONCLUSIONS AND CLINICAL IMPORTANCE

In this cohort of dogs receiving parenteral furosemide for CHF, KI was common, mostly nonazotemic (Grade I), and did not impact survival.

Pharmacokinetic and pharmacodynamic properties of orally administered torasemide in healthy cats

BACKGROUND

In people and dogs, torasemide has higher bioavailability, longer half-life, and longer duration of action than equivalent doses of furosemide but data regarding pharmacological properties of torasemide in cats are limited.

OBJECTIVE

To assess pharmacokinetic and pharmacodynamic parameters of torasemide in healthy cats, and to investigate the effects of a single administration of torasemide on indicators of diuresis, plasma creatinine concentration, blood pressure, electrolyte concentrations and markers of the renin-angiotensin-aldosterone system (RAAS).

ANIMALS

Six clinically healthy adult European shorthair cats.

METHODS

Randomized 4-period crossover design with 3 groups and 4 treatments. Pharmacokinetic parameters were obtained using a noncompartmental analysis, and the clinically effective dose was assessed using a Hill model.

RESULTS

Mean absolute bioavailability was estimated at 88.1%. Mean total body clearance was 3.64 mL/h/kg and mean terminal half-life was 12.9 hours. Urine output significantly increased after torasemide administration (P < .001). The urine sodium : potassium ratio (uNa : uK) paralleled and was statistically correlated to urine output (P < .001). Administration of a single torasemide dose led to a significant dose-dependent increase in urine aldosterone : creatinine ratio (uAldo : C; P < .001) and a transient decrease in plasma potassium concentration (P < .001) but did not affect blood pressure or plasma creatinine concentration.

CONCLUSIONS AND CLINICAL IMPORTANCE

A single torasemide dose leads to a significant increase in diuresis and renin-angiotensin-aldosterone system (RAAS) activation in healthy cats, with high absolute bioavailability, and without clinically relevant adverse effects. Pharmacokinetic parameters indicate that once daily dosing of 0.27 mg/kg may be appropriate in a clinical setting.

DIAGNOSIS AND MANAGEMENT OF SUSPECTED CONGESTIVE HEART FAILURE SECONDARY TO DILATED CARDIOMYOPATHY IN A SAND TIGER SHARK (CARCHARIAS TAURUS) WITH ESTABLISHMENT OF PRELIMINARY NORMAL ECHOCARDIOGRAPHIC INDICES

Elasmobranch cardiac anatomy and physiology has been well described; however, there is a dearth of information regarding cardiac disease. In support of a clinical case of suspected congestive heart failure in a 22-yr-old male sand tiger shark (Carcharias taurus), a study was undertaken to identify feasible echocardiographic imaging planes and preliminary indices for this species. Eleven echocardiograms were performed on six apparently healthy sand tiger sharks. Echocardiographic parameters are presented using descriptive statistics, including mean, median, standard deviation (SD), minimum and maximum values. These data were utilized for the diagnosis and clinical management of the affected shark. The shark initially presented with increased respiratory effort, dependent, peripheral edema, and anemia. Echocardiography revealed atrial, ventricular, and sinus venosus dilation. As congestive heart failure secondary to dilated cardiomyopathy was strongly suspected, therapy was initiated with oral benazepril and torsemide, and later pimobendan. After a year of therapy, clinical signs resolved. Cardiac size and function improved on echocardiography with a reduction in sinus venosus dilation, maximum and minimum atrial and ventricular inner diameters, and an increase in atrial and ventricular fractional shortening. Cardiac disease in elasmobranchs may be underdiagnosed, so it may be necessary to develop standardized ultrasound techniques and cardiac measurements for each species of elasmobranch managed within zoos and aquaria.

Management of Chronic Congestive Heart Failure Caused by Myxomatous Mitral Valve Disease in Dogs: A Narrative Review from 1970 to 2020

Simple Summary

Myxomatous mitral valve disease (MMVD) is the most common acquired cardiovascular disease in dogs. The progression of the disease and the increasing severity of valvular regurgitation cause a volume overload of the left heart, leading to left atrial and ventricular remodeling and congestive heart failure (CHF). The treatment of chronic CHF secondary to MMVD in dogs has not always been the same over time. In the last fifty years, the drugs utilized have considerably changed, as well as the therapeutic protocols. Some drugs have also changed their intended use. An analysis of the literature concerning the therapy of chronic heart failure in dogs affected by this widespread degenerative disease is not available; a synthesis of the published literature on this topic and a description of its current state of art are needed. To the authors’ knowledge, a review of this topic has never been published in veterinary medicine; therefore, the aim of this study is to overview the treatments of chronic CHF secondary to MMVD in dogs from 1970 to 2020 using the general framework of narrative reviews.

Abstract

The treatment of chronic congestive heart failure (CHF), secondary to myxomatous mitral valve disease (MMVD) in dogs, has considerably changed in the last fifty years. An analysis of the literature concerning the therapy of chronic CHF in dogs affected by MMVD is not available, and it is needed. Narrative reviews (NRs) are aimed at identifying and summarizing what has been previously published, avoiding duplications, and seeking new study areas that have not yet been addressed. The most accessible open-access databases, PubMed, Embase, and Google Scholar, were chosen, and the searching time frame was set in five decades, from 1970 to 2020. The 384 selected studies were classified into categories depending on the aim of the study, the population target, the pathogenesis of MMVD (natural/induced), and the resulting CHF. Over the years, the types of studies have increased considerably in veterinary medicine. In particular, there have been 43 (24.29%) clinical trials, 41 (23.16%) randomized controlled trials, 10 (5.65%) cross-over trials, 40 (22.60%) reviews, 5 (2.82%) comparative studies, 17 (9.60%) case-control studies, 2 (1.13%) cohort studies, 2 (1.13%) experimental studies, 2 (1.13%) questionnaires, 6 (3.40%) case-reports, 7 (3.95%) retrospective studies, and 2 (1.13%) guidelines. The experimental studies on dogs with an induced form of the disease were less numerous (49–27.68%) than the studies on dogs affected by spontaneous MMVD (128–72.32%). The therapy of chronic CHF in dogs has considerably changed in the last fifty years: in the last century, some of the currently prescribed drugs did not exist yet, while others had different indications.

Analysis of canine cardiovascular therapeutic agent prescriptions using electronic health records in primary care veterinary practices in the United Kingdom

INTRODUCTION/OBJECTIVES

Canine cardiovascular (CV) diseases are often managed in primary care settings. The objectives were to describe CV therapeutic agent (CVTA) prescribing patterns in primary care practices in the United Kingdom (UK) and to evaluate recorded clinical signs, diagnostic tests and justifications for use of torasemide, a recently marketed and authorised loop-diuretic in the UK.

ANIMALS, MATERIALS AND METHODS

Electronic health records (EHRs) describing 3,579,420 consultations (1,043,042 unique dogs) were collated (1 April 2014 and 31 December 2018) by the Small Animal Veterinary Surveillance Network from 270 veterinary practices. Consultations prescribing at least one CVTA were identified. Annual variation in individual CVTA prescriptions was analysed using mixed-effects binomial regression models. Free-text clinical narratives were manually read to determine the first-prescribing event for torasemide.

RESULTS

Twenty-nine thousand and seven consultations (0.81% of all consultations, 95% confidence interval [CI], 0.76-0.86) prescribed CVTA in 14,148 (1.36%) dogs. Furosemide (52.8% of CV-prescribing consultations, 95% CI 50.7-54.9) and pimobendan (51.9%, 95% CI 50.1-53.7) were most prescribed. Longitudinal analysis (2014-2018) showed a significant negative temporal trend for angiotensin-converting enzyme inhibitors (p < 0.001), and furosemide (p = 0.003) and a positive temporal trend for pimobendan (p = 0.020) and torasemide (p < 0.001). First prescriptions of torasemide were identified in 16.5% of torasemide-prescribing consultations. Where justification for prescription of torasemide was identified (32.5%), furosemide resistance was the most common (92.0%).

CONCLUSIONS

EHRs can be used to temporally monitor prescribing habits, including responses to market authorisations. Despite authorisation in the UK for torasemide use as a first-line diuretic, it was most commonly prescribed after furosemide resistance.

Safety of torasemide in healthy adult dogs administered daily for 26 weeks

Thirty‐two (16 males and 16 females) healthy young beagles were randomly divided into four groups of eight. The control group remained untreated. Torasemide (ISEMID^®, Ceva Santé Animale) was orally administered, once daily, at 0.5 mg/kg from Days 1–5 then 0.25 mg/kg to Day 182, and at three times and five times this dosing regimen in two additional groups. Treated animals (predominantly at the higher dose levels) showed dryness of the oral mucosa, evidence of diuresis, decreased diet consumption, decreased bodyweight gain over the first 3 weeks, increased water consumption, increases in erythrocytes count, haemoglobin, calcium and magnesium, decrease in chloride, phosphorus, potassium and sodium, increases in urine pH, decreases in urine specific gravity and increases in serum aldosterone concentrations. Plasma concentrations of torasemide increased in a dose‐dependent manner and showed no evidence of accumulation. There were also changes to electrocardiogram patterns and the macroscopic and microscopic appearance of the kidney and adrenal glands, but these changes were almost exclusively confined to the over‐dosed groups. In conclusion, torasemide was found to be safe when administered to dogs at 0.25 mg/kg once daily for 26 weeks, and any changes were consistent with its known diuretic effects.

Efficacy of oral torasemide in dogs with degenerative mitral valve disease and new onset congestive heart failure: The CARPODIEM study

Background

Torasemide is a potent loop diuretic with potential to treat congestive heart failure (CHF) in dogs.

Objective

Evaluate the efficacy and safety of torasemide compared to furosemide in dogs with first occurrence of CHF caused by degenerative mitral valve disease (DMVD).

Animals

Three hundred and nineteen dogs with new onset CHF attributable to DMVD.

Methods

Double‐blinded randomized noninferiority study of PO torasemide vs furosemide in addition to standard CHF treatment. The primary efficacy criterion was decreased pulmonary edema and cough and no worsening of dyspnea or exercise tolerance at day 14. Secondary endpoints included clinical response at day 84 and time to death, euthanasia, or premature study withdrawal for cardiac reasons.

Results

Torasemide q24h (n = 161) was noninferior to furosemide q12h (n = 158); percentage of dogs meeting primary efficacy criterion at day 14 was similar between groups (torasemide, 74.4% [95% confidence interval (CI), 66.8%‐81.0%] vs. furosemide, 73.5% [95% CI, 65.7%‐80.4%]; risk ratio [RR], 1.01; 95% CI, 0.89‐1.15; P = .87). Efficacy at day 84 showed similar results (RR, 1.05; 95% CI, 0.88‐1.25; P = .6). Dogs receiving torasemide had a longer time to endpoint and were less than half as likely to experience death, euthanasia, or premature study withdrawal (hazard ratio, 0.36; 95% CI, 0.19‐0.65; P = .001) than dogs receiving furosemide at any time during the study.

Conclusion and Clinical importance

Torasemide was noninferior to furosemide as first line PO treatment for new onset CHF caused by DMVD. Torasemide significantly decreased risk of cardiac‐related death or premature study withdrawal for cardiac reasons compared to furosemide.