Non-atrial fibrillation cardiac phenotypes associated with common atrial
fibrillation genotypic risk
Abstract
Background: Atrial fibrillation (AF) genetics studies have focused on a
linear genotype- phenotype relationship, i.e. genetic predisposition to
the arrhythmia. Genome wide association studies have implicated numerous
upstream mechanisms responsible for AF. Objective: We hypothesized that
the genetic predisposing factors for AF might be associated with non-AF
clinical phenotypes and sought to characterize electrophysiology
parameters as a function of AF genetic risk. Methods:. Biosamples were
obtained from 405 subjects for classification of carrier status at 12
single nucleotide polymorphisms with a known association to AF allowing
calculation of a validated AF genetic risk score. We then analyzed
subgroups within the total population; in order to understand the effect
on (a) sinus node function and cardiac conduction (b) primary atrial
flutter (c) left atrial appendage morphology. Results: We evaluated 405
patients consisting of a range of genetic risk scores from −1.016 to
+2.178. Within this, we identified 86 patients without prescribed
chronotropic pharmacotherapy with a 24-hour Holter recording to
investigate sinus node function; 181 patients with invasive H-V
measurement at the time of electrophysiologic study to investigate
cardiac conduction; 78 undergoing cavotricuspid isthmus ablation for
typical atrial flutter without prior diagnosis of AF; and 284 patients
with cardiac imaging of the left atrial appendage. Conclusions: A common
AF genetic risk score is associated with a number of non-AF
electrophysiologic relevant phenotypes. Sinus node function, AV node
physiology, post flutter ablation AF risk, atrial appendage morphology
all appear to be associated with the common genetic AF risk.