Finding a Consensus on Canine CVHD

Canine chronic valvular heart disease (CVHD) is the most important nonparasitic cardiovascular disease in veterinary medicine, but controversy remains about the best treatment.

THE PANELBruce Keene, DVM, MSc, Diplomate ACVIM, Panel ChairClarke Atkins, DVM, Diplomate ACVIM (Internal Medicine & Cardiology)John Bonagura, DVM, MS, Diplomate ACVIMStephen J. Ettinger, DVM, Diplomate ACVIM (Internal Medicine &Cardiology)Philip R. Fox, DVM, MS, Diplomate ACVIM/ECVIM (Cardiology) & ACVECCVirginia Luis-Fuentes, VetMB, PhD, CertVR, DVC, MRCVS, DiplomateACVIM & ECVIMSonya G. Gordon, DVM, DVSc, Diplomate ACVIM (Cardiology)Jens Häggström, DVM, PhD, Diplomate ECVIM (Cardiology)Robert Hamlin, DVM, PhD, Diplomate ACVIMRebecca Stepien, DVM, Diplomate ACVIM

THE PLAYERSCanine CVHD, also known as endocardiosis, myxomatous valve degeneration, and mitral regurgitation (MR), affects approximately 85% of dogs 13 years of age or older and accounts for 75% of heart disease in dogs.¹ For such a substantial disease, it may be surprising that there still is controversy and general lack of agreement about the appropriate medical management, both before and after the onset of heart failure.

To this end, the American College of Veterinary Internal Medicine’s (ACVIM) Board of Regents recently selected a group of European and American board-certified cardiologists to present a formal consensus for the diagnosis and treatment of CVHD.¹ The 10 panel members represented diverse points of view on cardiac therapeutics.

The consensus statements and recommendations of the panel are not to be taken as “cutting edge” but rather as a sampling of the “collective wisdom” that occurs when reasonable people reach a compromise after reviewing published data and their own experiences.

THE PROCESSBased on available evidence, the ACVIM panel determined whether the potential benefits of a given treatment option clearly outweighed the risk for adverse events and if the financial impact on the patient and client would be justifiable. Consensus was defined as all 10 panel members agreeing to a particular recommendation, but we also revealed when a majority of the panelists agreed on a recommendation even if the criteria for consensus were not met.

HEALTH CARE SCHEMEAlthough a number of classification schemes that grade cardiac disease in dogs are already in place, we created a novel scheme modeled after one used by the American Heart Association and the American College of Cardiology. Our system avoids the inclusion of progressive exercise intolerance when grading disease severity and adds a category for dogs that show no clinical signs but are at risk for the disease (eg, cavalier King Charles spaniels, dachshunds, miniature and toy poodles).

In this article, I describe some of the more important consensus and majority findings from the panel, as well as offer some insights into how these findings can translate into everyday patient care based on my own practice.

Note: Not all consensus recommendations would be appropriate for each patient. For example, it is unlikely that a dog on pimobendan would also receive dobutamine.

View recommendations for Stage A and Stage B₁

View recommendations for Stage B₂, C_, and C_c

View recommendations for Stage D_, and D_c

LATE-BREAKING DATAThe consensus statement was prepared before the publication of a placebo-controlled, double-blind study that demonstrated the positive impact of spironolactone when added to standard therapy in dogs with heart failure.¹⁸ The panel may have reached consensus on the use of spironolactone in dogs with stage C disease if this information had been available during our deliberations.

See what Clarke Atkins recommends

CANINE CVHD—IDEALLY A SURGICAL DISEASEIdeally, severe canine CVHD is a surgical disease, but valve repair or replacement efforts have not been met with adequate success. Recent case studies have shown that surgical mitral valve repair has resulted in high perioperative mortality¹⁹ and surgical valve replacement has resulted in postoperative thrombus formation, ²⁰ but there have been some individual successes. However, the cost, small number of participating hospitals, and limited success have rendered surgical correction of canine CVHD impractical, leaving it as a medically managed disease in veterinary medicine for the foreseeable future.

ACE = angiotensin-converting enzyme, CVHD = chronic valvular heart disease, IMPROVE = invasive multicenter prospective veterinary evaluation of enalapril study, MRB = mineralocorticoid receptor blocker

For related articles, please see the following:PimobendanStandard of Care in the Treatment of Mitral Valvular Heart Disease in the DogClinical Notes: Canine heart failure—early diagnosis, prompt treatment

CANINE CVHD • Clarke Atkins

References1. Guidelines for the diagnosis and treatment of canine chronic valvular heart disease. Atkins C, Bonagura J, Ettinger S, et al. J Vet Intern Med 23:1142-1150, 2009.

1. Efficacy of enalapril for prevention of congestive heart failure in dogs with myxomatous valve disease and asymptomatic mitral regurgitation. Kvart C, Haggstrom J, Pedersen HD, et al. J Vet Intern Med 16:80-88, 2002.3. Results of the veterinary enalapril trial to prove reduction in onset of heart failure in dogs chronically treated with enalapril alone for compensated, naturally occurring mitral valve insufficiency. Atkins CE, Keene BW, Brown WA, et al. JAVMA 231:1061-1069, 2007.

2. Effect of benazepril on survival and cardiac events in dogs with asymptomatic mitral valve disease: A retrospective study of 141 cases. Pouchelon JL, Jamet N, Gouni V, et al. J Vet Intern Med 22:905-914, 2008.5. Current Clinical Practices Survey. Bonagura J. ACVIM Heart Failure Symposium, Oral presentation, 2010.6. Aldosterone escape in furosemide-activated circulating renin-angiotensin-aldosterone system (RAAS) in normal dogs (abstr). Lantis AC, Atkins, CE, DeFrancesco TC, et al. J Vet Intern Med 24:xx-yy, 2010.

3. Intermittent bolus injection versus continuous infusion of furosemide in normal adult greyhound dogs. Adin DB, Taylor AW, Hill RC, et al. J Vet Intern Med 17:632-636, 2003.8. Furosemide continuous rate infusion in the horse: Evaluation of enhanced efficacy and reduced side effects. Johansson AM, Gardner SY, Levine JF, et al. J Vet Intern Med 17:887-895, 2003.9. Haemodynamic effects of enalaprilat and preload in acute severe heart failure complicating myocardial infarction. Tohmo H, Karanko M, Korpilahti K. Eur Heart J 15:523-527, 1994.10. Hemodynamic response of a canine model of chronic heart failure to intravenous dobutamine, nitroprusside, enalaprilat, and digoxin. Sabbah HN, Levine TB, Gheorghiade M, et al. Cardiovasc Drugs Ther 7:349-356, 1993.

4. The IMPROVE study group. Acute and shortterm hemodynamic, echocardiographic, and clinical effects of enalapril maleate in dogs with naturally acquired heart failure: Results of the invasive multicenter prospective veterinary evaluation of enalapril study. J Vet Intern Med 9:234-242, 1995.12. Effects of enalapril maleate on survival of dogs with naturally acquired heart failure. The longterm investigation of veterinary enalapril (LIVE) study group. Ettinger SJ, Benitz AM, Ericsson GF, et al. JAVMA 213:1573-1577, 1998.13. The BENCH study group. The effect of benazepril on survival times and clinical signs of dogs with congestive heart failure: Results of a multi center, prospective, randomized, double-blinded, placebo-controlled, long-term clinical trial. J Vet Cardiol 1:5-18, 1999.14. Clinical evaluation of imidapril in congestive heart failure in dogs: Results of the EFFIC study. Besche B, Chetboul V, Lachaud Lefay MP, et al. J Small Anim Pract 48:265-270, 2007.15. Comparison of the effects of imidapril and enalapril in a prospective, multicentric randomized trial in dogs with naturally acquired heart failure. Amberger C, Chetboul V, Bomassi E, et al. J Vet Cardiol 6:9-16, 2004.16. Controlled clinical evaluation of enalapril in dogs with heart failure: Results of the cooperative veterinary enalapril study group. The COVE Study Group. J Vet Intern Med 243-252, 1995.

5. Effect of pimobendan or benazepril hydrochloride on survival times in dogs with congestive heart failure caused by naturally occurring myxomatous mitral valve disease: The QUEST study. Haggstrom J, Boswood A, O’Grady M, et al. J Vet Intern Med 22:1124-1135, 2008.

6. Efficacy of spironolactone on survival in dogs with naturally occurring mitral regurgitation caused by myxomatous mitral valve disease. Bernay F, Bland JM, Haggstrom J, et al. J Vet Intern Med 24:331-341, 2010.19. Technique and outcome of mitral valve replacement in dogs. Orton EC, Hackett TB, Mama K, Boon JA. JAVMA 226:1508-1511, 2005.20. Evaluation of techniques and outcomes of mitral valve repair in dogs. Griffiths LG, Orton EC, Boon JA. JAVMA 224:1941-1945, 2004.