ADRB2 and heart failure: Persistent β-adrenoreceptor (β-AR) activation promotes progressive heart failure,1,2 and a cornerstone of therapy in heart failure is the use of blockers of β-ARs.3-10 There is substantial evidence to implicate the β1-AR subtype in the pathogenesis of progressive heart failure.11 The activity of β1-AR is nevertheless determined in part by functional variants within the gene encoding the receptor.