Conclusions from the analysis included: 1) Gencaro produced substantial prevention of atrial fibrillation in the entire BEST population, with a risk reduction of 41%; 2) the risk reduction for new onset atrial fibrillation was pharmacogenetically determined, with patients who were homozygous arginine at beta-1 389 having a 74% risk reduction and patients having any glycine at this position having no effect. This effect differentiation is greater than for heart failure mortality or hospitalization endpoints, where the homozygous arginine at beta-1 389 genotype is associated with risk reductions of 34-48% vs. 8-22% in the glycine at any position genotypes.Atrial Fibrillation Atrial fibrillation is a disorder in which the normally regular and coordinated contraction pattern of the heart's two small upper chambers (the atria) becomes irregular and uncoordinated. The irregular contraction pattern associated with atrial fibrillation causes blood to pool in the atria, predisposing the formation of clots. These clots may travel from the heart and become lodged in the arteries leading to the brain and other organs, thereby blocking necessary blood flow and potentially resulting in stroke. In addition, in patients with heart failure with reduced left ventricular ejection fraction (HFREF), new onset atrial fibrillation may also contribute to worsening heart failure and increased risk of death. Studies estimate atrial fibrillation affected between 2 and 3 million Americans in 2005. Those same studies estimate the prevalence of atrial fibrillation will likely increase to between 3.8 million and 4.8 million by 2025. Industry estimates expect the atrial fibrillation drug market in developed countries to increase more than eight-fold, from $843 million in 2009 to $6.8 billion in 2019. The Company believes there is an unmet medical need for new atrial fibrillation treatments that have fewer side effects than currently available therapies and are more effective, particularly in patients with HFREF, where most of the approved atrial fibrillation drugs are contra-indicated or have warnings in their prescribing information.