Improving diagnosis and treatment of canine heart disease
Submitting Institution
Royal Veterinary CollegeUnit of Assessment
Agriculture, Veterinary and Food ScienceSummary Impact Type
TechnologicalResearch Subject Area(s)
Medical and Health Sciences: Cardiorespiratory Medicine and Haematology, Clinical Sciences
Summary of the impact
RVC research has helped transform differential diagnosis of canine heart
disease, in first opinion veterinary practice, by demonstrating the value
of peptide biomarkers and collaborating with diagnostics companies to
ensure the findings have been translated into commercial assay kits
available around the world. Contributions to major clinical trials have
complemented this through improvements in canine cardiac disease
treatment. This has benefitted dogs and their owners through improved and
prolonged canine health; and has additionally delivered new guidance for
professional practice, and economic value through increased therapeutic
product sales and novel diagnostic services.
Underpinning research
Research led by Adrian Boswood, (appointed as Lecturer in Internal
Medicine in 1996 and progressing to Professor of Veterinary Cardiology in
2008), has focused on improving management of small animal cardiac
conditions through enhanced differential diagnosis, increasing prognostic
accuracy and earlier identification of, and introduction of treatment for,
sub- clinical disease. Boswood has published work which clearly defined
risk factors for progression [1] in a heterogeneous population of dogs
presenting to primary care practices in the UK.
His research has focused particularly on the potential of natriuretic
peptides as biomarkers and their combination with other parameters, to
refine prognosis and management. Although increased concentration of
atrial natriuretic peptide (ANP) was known to be associated with heart
failure, its short plasma half-life and instability after collection made
it impractical to use as a biomarker, and Boswood proposed that a proANP
assay could have practical value. The RVC research team, collaborated with
the biotechnology business, Guildhay Ltd, demonstrating that an ELISA for
a proANP fragment could distinguish normal dogs from those with heart
failure [2]. After further discussion between Boswood and Guildhay it was
suggested that an assay for NTproBNP would be superior to a proANP assay.
Such an assay was developed and shown to discriminate between respiratory
and cardiac disease in dogs presenting with difficulty breathing [3], thus
offering a valuable diagnostic for first opinion practice. The Guildhay
assay acted as the prototype for the Idexx assay that is now marketed and
used internationally.
Prospective studies of dogs in primary care practice determined the
prognostic value — in predicting mortality — of measuring NT-proBNP in
dogs presenting with a heart murmur, indicative of degenerative mitral
valve disease (DMVD), in partnership with Idexx Laboratories and CEVA
Animal Health [4]. This work has been extended to show enhanced prognostic
value of combining NT-proBNP with high sensitivity cardiac troponin I in
serial blood samples to identify dogs progressing to cardiac death [1].
Boswood's recognition as a key opinion leader in cardiology clinical
trial design and analysis has positioned him to contribute in a major way
to international multicentre trials. The outcome of the QUEST trial [5] is
recognised as one of the most compelling pieces of evidence for the, then
unexpected (based on mode of action), beneficial effects of the calcium
sensitiser, pimobendan, on survival of dogs with DMVD when evaluated
relative to treatment which was considered at that time to be the gold
standard; benazepril. In 2002 Boswood was one of four members of the
clinical trial committee and one of two academics who led the design of
the study protocol. His input (with that of lead author Professor Jens
Haagstrom, of the Swedish University of Agricultural Sciences) meant this
study overcame shortcomings of previous trials addressing survival as an
end-point and produced compelling evidence for the benefit of pimobendan.
In particular, it had the highest event rate of any of the published
studies due to the care taken in defining three related endpoints a
priori; was appropriately powered to address the relative benefits
of the two drugs; and offered the most comprehensive consideration of
co-variates of any studies involving DMVD in the dog. As such it is
considered to provide the best current evidence for benefit of treatment
in slowing disease progression.
Boehringer Ingelheim invited Boswood to be involved in the subsequent
`PROTECT' trial: to contribute to study design, screen cases for
inclusion, undertake an interim analysis, advise on the continuation and
conclusion of the study, and participate in the publication committee, as
supervisor for the statistical analysis and corresponding author. PROTECT
examined the effect of pimobendan administration in the preclinical phase
of dilated cardiomyopathy in Doberman Pinschers. At its inception, the
value of inotropic drugs in asymptomatic dogs was considered highly
controversial. The study demonstrated a significant prolongation to the
time to onset of congestive heart failure or sudden death in the dogs
receiving pimobendan: the first cardiology study to demonstrate clear
benefit of therapy in a pre-clinical period [6]. It was also the first to
demonstrate a survival benefit in dogs identified through screening of an
apparently normal population.
Other quality indicators
Boswood, A. Elliott, J and Brodbelt, D. Identification of diagnostic tests
predictive of progression of mitral valve disease in the dog. £92,798.
2008-2011. Petplan Charitable Trust. References [2] and [3], won the BSAVA
Petsavers Award for the best clinical paper of their year in the Journal
of Small Animal Practice.
References to the research
1. Hezzell, MJ, Boswood, A, Chang, YM, Moonarmart, W, Souttar, K, Elliott
J. 2012 The combined prognostic potential of serum high-sensitivity
cardiac troponin I and N-terminal pro-B- type natriuretic peptide
concentrations in dogs with degenerative mitral valve disease. Journal of
Veterinary Internal Medicine; 26(2):302-11. DOI:
10.1111/j.1939-1676.2012.00894.x.
2. Boswood, A, Attree, S, Page, K. 2003 Clinical validation of a proANP
31-67 fragment ELISA in the diagnosis of heart failure in the dog. Journal
of Small Animal Practice; 44(3):104-108 DOI:
10.1111/j.1748-5827.2003.tb00128.x
3. Boswood, A, Dukes-McEwan, J, Loureiro, J, James, RA, Martin, M,
Stafford-Johnson, M, Smith, P, Little, C, Attree, S. 2008 The diagnostic
accuracy of different natriuretic peptides in the investigation of canine
cardiac disease. Journal of Small Animal Practice 49(1): 26-32 DOI:
10.1111/j.1748-5827.2007.00510.x
4. Moonarmart, W, Boswood, A, Fuentes, VL, Brodbelt, D, Souttar, K,
Elliott, J. 2010 N- terminal pro B-type natriuretic peptide and left
ventricular diameter independently predict mortality in dogs with mitral
valve disease. Journal of Small Animal Practice; 51(2): 84-96 DOI:
10.1111/j.1748-5827.2009.00889.x
5. Häggström, J, Boswood, A, O'Grady, M, Jöns, O, Smith, S, Swift, S,
Borgarelli, M, Gavaghan, B, Kresken, JG, Patteson, M, Ablad, B, Bussadori,
CM, Glaus, T, Kovacević, A, Rapp, M, Santilli, RA, Tidholm, A, Eriksson,
A, Belanger, MC, Deinert, M, Little, CJ, Kvart, C, French, A, Rønn-Landbo,
M, Wess, G, Eggertsdottir, AV, O'Sullivan, ML, Schneider, M, Lombard, CW,
Dukes-McEwan, J, Willis, R, Louvet, A, DiFruscia, R. 2008 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. Journal of Veterinary Internal Medicine;
22(5):1124-35 DOI: 10.1111/j.1939-1676.2008.0150.x
6. Summerfield, NJ, Boswood, A, O'Grady, MR, Gordon, SG, Dukes-McEwan, J,
Oyama, MA, Smith, S, Patteson, M, French, AT, Culshaw, GJ, Braz-Ruivo, L,
Estrada, A, O'Sullivan, ML, Loureiro, J, Willis, R, Watson, P. 2012
Efficacy of Pimobendan in the prevention of congestive heart failure or
sudden death in Doberman Pinschers with preclinical cilated cardiomyopathy
(The PROTECT Study). Journal of Veterinary Internal Medicine; 26:1337-1349
DOI: 10.1111/j.1939- 1676.2012.01026.x
Details of the impact
Cardiac disease is one of the most common conditions presented to the
veterinarian. It has been estimated that up to 15% of dogs presented to a
practice may show some signs of cardiac disease and this increases to over
40% in dogs older than 7 years of age. DMVD, which is progressive and
incurable, accounts for around 75% of all cases of canine congestive heart
failure. A number of breeds show a predisposition — such as Cavalier King
Charles Spaniels (most animals eventually affected and high proportion at
younger age), Chihuahuas, fox terriers, Boston terriers and miniature
poodles, pinschers and schnauzers. Dobermans and a number of other large
breeds have disproportionately high rates of dilated cardiomyopathy.
Diagnosis can be challenging: Clinical signs of cardiac disease may be
absent or indistinguishable from those of other conditions, particularly
respiratory disease. Indications from physical examination may be
inconclusive, especially in a distressed, anxious or uncooperative patient
and thoracic radiographs difficult to interpret. Detection of a heart
murmur is not conclusive. Cardiac ultrasound, which usually requires
referral to a specialist, is often necessary to fully characterise the
disease. However, a cardiac biomarker can be used in first opinion
practice as part of the diagnostic workup and guide decisions about
additional testing, the need for referral and treatment.
[text removed for publication]. The RVC team has continued to work in
partnership with Idexx to provide evidence for the clinical value of this
test and to identify ways of enhancing this.
Prior to 2008, ACE inhibitors were the primary drug class used in
treatment for canine DMVD. The QUEST trial demonstrated compelling
evidence (91% improvement) that pimobendan in conjunction with
conventional therapy could prolong life. Accompanying the publication of
the trial results, an editorial, by Mark Oyama of University of
Pennsylvania, commented: "I ... currently consider pimobendan the single
most important addition to the medical therapy of dogs with symptomatic
DMVD and dilated cardiomyopathy since becoming a veterinary cardiologist
more than a decade ago. ... the study by Haggstrom et al is to be
commended not only for its ambition and meticulous reporting but also for
its ultimately successful multicentered design"[d].
An American College of Veterinary Internal Medicine Consensus Statement,
which disseminates good practice via cardiology specialists in the USA and
Europe, to which RVC contributed, was rapidly issued reflecting these
findings [e].
The trial results have transformed sales of the drug (as Vetmedin) during
the REF impact period. In its 2009 Annual Report, Boehringer Ingelheim
(BI) reported for Vetmedin, double digit growth in Europe, compared with
the previous year; year on year growth in the USA exceeding 50%; and
market leader position in the cardiovascular segment in Japan, from launch
in 2008 [f]. [text removed for publication]
The QUEST trial also showed significant improvement in quality of life.
As dogs may be euthanized when their symptoms are perceived to be
overwhelmingly debilitating, rather than dying naturally of disease, this
was a critical factor in transforming the approach to management of this
condition and, of course, represents a hugely positive outcome for
affected dogs and their owners.
Boswood's contributions to the QUEST and PROTECT trials have led to BI's
requesting his assistance in designing and leading an even larger trial —
EPIC [h] - aiming at identifying if pre- symptomatic use can delay the
onset of signs of clinical disease in DMVD. He is principal investigator
on the study and was one of three international cardiologists involved in
writing the protocol. The study involves 36 centres in 11 countries, is
the largest prospective veterinary cardiology study to date and has
already successfully recruited its target of 360 patients. [text removed
for publication]
As an international opinion leader in veterinary cardiology, Boswood has
contributed to the dissemination of research findings thereby contributing
to changes in professional practice. In addition to invited conference
presentations, including those to the British Veterinary Association
Congress (2011) [j] and international CEVA cardio symposium (2011) [k]; he
is featured in CEVA's on-line CPD `cardio-academy e-learning programme
[l]. In the twenty month period from launch in March 2011, Boswood's first
cardio-academy presentation received 2,196 visits from a total of 4,200
veterinary cardiology specialists from 8 European countries, registered on
the site [m].
Sources to corroborate the impact
a. [text removed for publication]
b. [text removed for publication]
c. [text removed for publication]
d. http://onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2008.0157.x/full
[accessed 14 Aug 2013]
e. http://onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2009.0392.x/pdf
[accessed 14 Aug 2013]
f. http://www.boehringer-ingelheim.com/content/dam/internet/opu/com_EN/document/01_news/04_Annual_Report/AR_2009_english.pdf
Page 109 of 167. [accessed 14 Aug 2013]
g. [text removed for publication]
h. https://www.epictrial.com
[accessed 14 Aug 2013]
i. [text removed for publication]
j. http://www.bva.co.uk/news/2366.aspx
[accessed 14 Aug 2013]
k.http://cardiosymposium2011.ceva.com/
[accessed 14 Aug 2013]
l. http://www.cardioacademy.cevalearn.com/en/Programme/Sessions/1-Pathophysiology-of-Mitral-Valve-Disease
[accessed 14 Aug 2013]
m. Information supplied by Ceva Sante Animale, by email dated 9 November
2012. Held by RVC.