Effects of different degrees of sympathetic antagonism on cytokine network in patients with ischemic dilated cardiomyopathy

Background: The proinflammatory cytokines have been implicated in the pathogenesis of heart failure. Recent studies have shown that beta-adrenergic blockade can modulate cytokine production. This study investigates the different impact of different degrees of sympathetic antagonism on circulating levels of cytokines in patients with heart failure resulting from ischemic dilated cardiomyopathy (IDC). Methods and Results- Thirty-five patients with IDC were randomly assigned to receive metoprolol or carvedilol in an open-label study. Echocardiographic measurements and circulating levels of tumor necrosis (TNF)-alpha and interleukin (IL)-1 beta and IL-6 were obtained at baseline and after 3 months of treatment. The 2 beta-blockers significantly improved the left ventricular ejection fraction and reduced end-diastolic and end-systolic volume. The magnitude of these changes was greater with carvedilol than with metoprolol (respectively P <.001, P <.05, and P <.05). Both treatments induced a significant decrease in the levels of cytokines (for all P <.01), but the decrease in TNF-alpha and IL-1 beta was more consistent in the carvedilol group (P <.01). Conclusion: Our results Support the hypothesis that a more complete block of sympathetic activity by carvedilol induces a greater decrease in the circulating levels of proinflammatory cytokines that could explain, oil least in part, the better improvement in the left ventricular remodelling and systolic function in patients with IDC.