Personalized medicine and atrial fibrillation: will it ever happen?

The role of transcription factors in atrial fibrillation

Atrial fibrillation (AF) is a complex disease that results from genetic and environmental factors and their interactions. In recent years, genome-wide association studies (GWAS) and family-based linkage analysis have found amounts of genetic variants associated with AF. Some of them lie in coding sequences and thus mediate the encoded proteins, some in non-coding regions and influence the expression of adjacent genes. These variants exert influence on the development of cardiovascular system and normal cardiac electrical activity in different levels, and eventually contribute to the occurrence of AF. Among these affected genes, as a crucial means of transcriptional regulation, several transcription factors play important roles in the pathogenesis of AF. In this review, we will focus on the potential role of PITX2, PRRX1, ZHFX3, TBX5, and NKX2.5 in AF.

Lone atrial fibrillation - an overview

Atrial fibrillation (AF) sometimes develops in younger individuals without any evident cardiac or other disease. To refer to these patients who were considered to have a very favourable prognosis compared with other AF patients, the term 'lone' AF was introduced in 1953. However, there are numerous uncertainties associated with 'lone' AF, including inconsistent entity definitions, considerable variations in the reported prevalence and outcomes, etc. Indeed, increasing evidence suggests a number of often subtle cardiac alterations associated with apparently 'lone' AF, which may have relevant prognostic implications. Hence, 'lone' AF patients comprise a rather heterogeneous cohort, and may have largely variable risk profiles based on the presence (or absence) of overlooked subclinical cardiovascular risk factors or genetically determined subtle alterations at the cellular or molecular level. Whether the implementation of various cardiac imaging techniques, biomarkers and genetic information could improve the prediction of risk for incident AF and risk assessment of 'lone' AF patients, and influence the treatment decisions needs further research. In this review, we summarise the current knowledge on 'lone' AF, highlight the existing inconsistencies in the field and discuss the prognostic and treatment implications of recent insights in 'lone' AF pathophysiology.