Specialist multidisciplinary hypertrophic cardiomyopathy clinics: should they be the standard of care?

The prevalence, complexity, clinical importance, heterogeneity and unpredictability of inherited cardiovascular diseases make the development of inherited cardiovascular disease centres an inevitability, with the ultimate goal of reducing the morbidity and mortality associated with these conditions. An inherited cardiovascular disease center may be seen as a subunit of a cardiology department, with health professionals specialising in these types of disorders, organised to provide excellence in all related areas, including diagnosis, treatment, follow-up, prevention, risk stratification and prognosis. Among its objectives are the development of action protocols and the creation of databases that enable patients to be included in national and international research networks. To achieve these objectives these centres should include functional units of clinical and basic sciences, research, training and education, acting in harmony in a holistic approach to patients and their families. Nuno Cardim, António Freitas and Dulce Brito Hypertrophic cardiomyopathy (HCM), the commonest cardiac monogenetic disorder, is defined by the presence of myocardial hypertrophy in absence of haemodynamic stresses sufficient to account for the degree of hypertrophy (e.g. arterial hypertension and aortic stenosis) and without systemic diseases that present HCM phenocopies (such as amyloidosis and glycogen storage disease). HCM is a diverse disease with variable phenotypic expression and with a substantial percentage of patients living a normal life without any significant limitation and minimal risk of sudden cardiac death. However, some patients with or without symptoms may die suddenly even without clinical features of severe left ventricular hypertrophy or outflow tract obstruction. Hence, the approaches to the evaluation, monitoring, risk stratification and management of HCM are as complex as its manifold phenotypic manifestations. It is on this background of intricate genetic underpinnings and pathophysiology, as well as pleiotropic phenotypic expression and rapidly evolving understanding of disease concepts and management, that the need for specialist multidisciplinary centres dedicated to the study and management of HCM has emerged. Moreover, HCM clinicians are faced with multiple challenges; including delay in making the diagnosis, lack of prospective evaluation of the effectiveness of different therapeutic interventions and limited access to specialised investigations and sophisticated management modalities, which can be overcome through management in a specialist clinic. The experience of general cardiologists in genetic cardiovascular diseases, including HCM, is relatively limited because these conditions represent a small percentage of the cases seen in general cardiology consultations. The ultimate goal of such specialised clinics, through the promotion of integrated and standardised management, should be the reduction in morbidity and mortality related to HCM. Further, specialised units for HCM are key in (i) gathering phenotypic information and the development of databases, (ii) providing opportunities to monitor prospectively the effectiveness of therapeutic interventions, directly impacting our ability to develop good practice guidelines and (iii) teaching and training of medical professionals from many different spheres, not only cardiology and genetics. It is noteworthy that the first specialist HCM clinic in the world was established 21 years ago by Dr David Richmond at the Royal Prince Alfred Hospital in Sydney (now under the direction of Dr Christopher Semsarian).1 Subsequently, the concept of specialist multidisciplinary clinics for HCM has been accepted, and the past 20 years have witnessed their proliferation throughout Europe and North America. More recently, both the European Society of Cardiology and the American Heart Association have strongly advocated for the management of HCM patients in specialised multidisciplinary centres. In this issue of the Journal, Beale et al.2 report on a retrospective review of care of HCM patients 2 years after the establishment of a specialist HCM clinic at the Alfred Hospital in Melbourne, Australia. Unsurprisingly, the authors demonstrate that attendance at the clinic was associated with improvement in guideline-mandated investigation and management of patients: 24-h Holter monitoring increased by 39%, stress echocardiography by 25%, cardiovascular magnetic resonance by 70%, and importantly 70 new first degree relatives were screened, yielding 10 extra cases of HCM. In this study, medical therapy was optimised in 47% of patients, 6% had implantable cardioverter-defibrillator implantation, and 13% underwent septal myomectomy. The authors rightly conclude ‘referral to a specialised clinic offering comprehensive management should be considered for all patients with HCM’. The study by Beale et al. suffers from the drawbacks of a retrospective design. Additionally, while their results are encouraging, the authors fail to show how increased uptake of investigations and altered management influences outcomes in their cohort of HCM patients. It is envisaged that in the future, there will be more reports on the impact of specialised clinics on morbidity and mortality in HCM. The utilisation of specialist units to improve outcomes in the management of acute coronary syndromes and cerebrovascular accidents is well established. The question is whether there is evidence that specialist units confer benefit for patients with other cardiovascular conditions. A systematic review of multidisciplinary interventions in heart failure, which included 74 heart failure trials, showed that when heart failure was treated in specialist centres, there was a reduction in all-cause mortality and in heart failure hospital admissions.3 Similarly, a population-based study conducted in Ontario, Canada of 14 468 patients with heart failure (of whom 1288 were seen in specialist heart failure clinics) showed a reduction in all-cause mortality, but an increase in the number of readmissions.4 A study conducted in the UK to assess the efficacy of a specialised valvular heart disease clinic demonstrated that a specialist clinic for valve disease (i) delivered higher quality care than in a general clinic as a result of greater volumes allied to specialisation of training, continuing education and clinical interest, (ii) guidelines are more consistently applied and (iii) the number of inappropriate echocardiograms reduced.5 Who should the members of the specialised multidisciplinary HCM clinical team be? Bearing in mind the need for thorough cardiologic and imaging investigations (electrocardiology, echocardiography, cardiovascular magnetic resonance imaging, cardiovascular computed tomography, cardiac electrophysiology, interventional cardiology), accurate genetic diagnosis, definitive management, including advanced cardiac surgery and counselling and advice for patients and their families, these specialised units require not only the integration of cardiology and genetics, but also the development of shared care between cardiological, surgical, radiological departments, and where appropriate, primary care services.6 Furthermore, it is critical that these specialised units are associated with a basic sciences unit, a research unit and a training unit. The importance of a family-based unit cannot be overestimated. International institutions have collaboratively defined centres of reference or expertise by eight criteria. These include the appropriate capacity to diagnose, follow up and manage patients, attractiveness (measured through volume of activity), the ability to provide expert advice on diagnosis and management, the ability to produce and adhere to good practice guidelines, demonstration of a multidisciplinary approach, a high level of expertise and experience demonstrated through publications, grants, honorary positions, teaching and training and a strong contribution to research.6 The complexity of HCM lends itself to all aspects mentioned above. We strongly believe that, in 2015, specialised multidisciplinary clinics associated with basic sciences, research and training units should be the standard of care for patients with HCM. The complexity and marked clinical heterogeneity of HCM demand management in such units that provide excellence in all aspects of care, including diagnosis, treatment, follow up, risk stratification and prognosis, with the ultimate goal being reduction in morbidity and mortality for both patients and their family members.