Strength of patient cohorts and biobanks for cardiomyopathy research.

In 2011 the Netherlands Heart Foundation allocated funding (CVON, Cardiovasculair Onderzoek Nederland) to stimulate collaboration between clinical and preclinical researchers on specific areas of research. One of those areas involves genetic heart diseases, which are frequently caused by pathogenic variants in genes that encode sarcomere proteins. In 2014, the DOSIS (Determinants of susceptibility in inherited cardiomyopathy: towards novel therapeutic approaches) consortium was initiated, focusing their research on secondary disease hits involved in the onset and progression of cardiomyopathies. Here we highlight several recent observations from our consortium and collaborators which may ultimately be relevant for clinical practice.

Tachyarrhythmia in patients with congenital heart disease: inevitable destiny?

The prevalence of patients with congenital heart disease (CHD) has increased over the last century. As a result, the number of CHD patients presenting with late, postoperative tachyarrhythmias has increased as well. The aim of this review is to discuss the present knowledge on the mechanisms underlying both atrial and ventricular tachyarrhythmia in patients with CHD and the advantages and disadvantages of the currently available invasive treatment modalities.

The future of atrial fibrillation therapy: intervention on heat shock proteins influencing electropathology is the next in line.

Atrial fibrillation (AF) is the most common age-related cardiac arrhythmia accounting for one-third of hospitalisations. Treatment of AF is difficult, which is rooted in the progressive nature of electrical and structural remodelling, called electropathology, which makes the atria more vulnerable for AF. Importantly, structural damage of the myocardium is already present when AF is diagnosed for the first time. Currently, no effective therapy is known that can resolve this damage.Previously, we observed that exhaustion of cardioprotective heat shock proteins (HSPs) contributes to structural damage in AF patients. Also, boosting of HSPs, by the heat shock factor-1 activator geranylgeranylacetone, halted AF initiation and progression in experimental cardiomyocyte and dog models for AF. However, it is still unclear whether induction of HSPs also prolongs the arrhythmia-free interval after, for example, cardioversion of AF.In this review, we discuss the role of HSPs in the pathophysiology of AF and give an outline of the HALT&REVERSE project, initiated by the HALT&REVERSE Consortium and the AF Innovation Platform. This project will elucidate whether HSPs (1) reverse cardiomyocyte electropathology and thereby halt AF initiation and progression and (2) represent novel biomarkers that predict the outcome of AF conversion and/or occurrence of post-surgery AF.

Molecular adaptations in human atrial fibrillation: mechanisms of protein remodelling.

The chance that the treatment of atrial fibrillation (AF) is successful depends on the duration of the arrhythmia. The low efficacy of cardioversion therapy after long-term AF can be explained by the occurrence of cellular adaptation mechanisms. In this article we describe ion-channel protein remodelling and structural changes in the atria of patients with persistent and paroxysmal AF and its relation with electrical remodelling.