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

THE PANEL
Bruce Keene, DVM, MSc, Diplomate ACVIM, Panel Chair
Clarke Atkins, DVM, Diplomate ACVIM (Internal Medicine & Cardiology)
John Bonagura, DVM, MS, Diplomate ACVIM
Stephen J. Ettinger, DVM, Diplomate ACVIM (Internal Medicine &
Cardiology)
Philip R. Fox, DVM, MS, Diplomate ACVIM/ECVIM (Cardiology) & ACVECC
Virginia Luis-Fuentes, VetMB, PhD, CertVR, DVC, MRCVS, Diplomate
ACVIM & ECVIM
Sonya G. Gordon, DVM, DVSc, Diplomate ACVIM (Cardiology)
Jens Häggström, DVM, PhD, Diplomate ECVIM (Cardiology)
Robert Hamlin, DVM, PhD, Diplomate ACVIM
Rebecca Stepien, DVM, Diplomate ACVIM

THE PLAYERS
Canine 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 PROCESS
Based 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 SCHEME
Although 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_a and C_c

View recommendations for Stage D_a and D_c

LATE-BREAKING DATA
The 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 DISEASE
Ideally, 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:
Pimobendan
Standard of Care in the Treatment of Mitral Valvular Heart Disease in the Dog
Clinical Notes: Canine heart failure—early diagnosis, prompt treatment

CANINE CVHD • Clarke Atkins

References
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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.
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