The present invention concerns the use of methods for evaluating β-adrenergic receptor targeting agent treatment for a patient, particularly one with a heart condition. In general, the disclosed methods entail determining the presence or absence of one or more polymorphisms in an endothelin gene system member. Based on the results of this determination, a β-adrenergic receptor targeting agent may be prescribed, administered or a treatment regimen altered, including the administration of a β-blocker. Accordingly, methods of treatment are also described.
