Long-Term Effects of Carvedilol or Metoprolol on Left Ventricular Function in Ischemic and Nonischemic Cardiomyopathy

Data regarding the effects of β blockers on left ventricular (LV) function after 12 months are scarce in ischemic and nonischemic cardiomyopathy. Echocardiograms of 72 patients with ischemic and nonischemic cardiomyopathy, who were free of clinical events susceptible to alter LV function while receiving carvedilol or metoprolol for at least 24 months, were prospectively reanalyzed. Twelve months after β-blocker initiation, LV ejection fraction (EF) increased by ≥5% in 75% of patients, whereas EF failed to increase by 5% or decreased in the remaining 25%. Over the subsequent 32 months, LVEF increased further in patients who had experienced an initial EF increase by ≥5%, whereas EF tended to further decrease in patients who had experienced an initial EF increase of <5% or a decrease. Thus, the benefits of carvedilol or metoprolol on LV function are long lasting in patients with ischemic or nonischemic cardiomyopathy who are free of events susceptible to alter LV function while receiving β blockade.