By Rachel Pugh
Drugs emerging onto the market are transforming cardiomyopathy from a clinical description with limited treatment options into a more ‘specific and nuanced diagnosis with targeted treatment’ across all forms of cardiomyopathy.
Professor Perry Elliott, Professor of Cardiovascular Medicine at University College London and consultant at Barts Heart Centre London, United Kingdom, charted the recent progress in what he described as the ‘complicated world’ of cardiomyopathy, which he ascribed both to the possibility of studying data from large cohorts and the emergence of a trials culture.
In particular he highlighted the following advances in Cardiomyopathy:
- Identification of the role of Iron channel function.
- Understanding of the importance of Sodium current - evident in patients with cardiomyopathy, causing calcium overload and interfering with systolic and diastolic function. Drugs to treat this include Disopyramide.
- Research into drugs affecting the contractility of the heart1.
- Amyloidosis - involved in different forms of cardiomyopathy, with a new drug called Tafamidis (being unveiled at the European Society of Cardiology Congress 2018 in Munich) which stabilises TTR cardiomyopathy and reduces mortality and heart failure symptoms.
- Phase 2 trial of a Mitogen-activated protein kinase inhibitor designed to help patients with Lamin A/C-related Dilated Cardiomyopathy.
Professor Elliott said: “Cardiomyopathy is not a diagnosis it is a description with many genetic and non-genetic causes.”
He pointed out that for 60 years clinicians had relied on a classification according to the morphology and physiology of the heart, for example dilated, hypertrophic or restrictive, which does not take account of genetic and acquired forms, variable phenotypes and incomplete age-related expression2.
Cardiomyopathy is defined as a thickening of the heart muscle in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease1. 1 in 200 members of the population are believed to be suffering from some form of the condition.
All the treatment to date has focused on treating symptoms, but without making any difference to the underlying heart muscle. Patients diagnosed with hypertrophic cardiomyopathy (HCM) in their 20s will have a cumulative burden of adverse events of 70-80% by the time they reach 60. He said this was “heart failure over decades” and that the drugs used for HCM treatment, beta blockers, had not changed in 30 years.
A comparison of 2 patients both presenting with HCM - beta blockers, indicates the complexity of condition. One patient turned out to have a mutation in PRKAG2, whilst in the second case the underlying condition was amyloidosis.
Professor Elliot said: “Through the elaboration of the cardiomyopathy paradigm we are starting to develop specific therapies. So diagnosis really does matter.”