The Metoprolol CR/XL Randomized Intervention Trial in Heart Failure (MERIT-HF) randomized patients with NYHA class II to IV HF symptoms to receive metoprolol succinate ver- This trial was stopped prematurely because of a 34% reduction in mortality in the metoprolol arm. Four clinical trials of carvedilol in HF were stopped prematurely because of a highly significant 65% reduction in mortality in patients treated with carvedilol compared with placebo.265 The Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial assessed patients with severe HF symp- toms who were clinically not volume overloaded and who had an LV ejection fraction <25%. Compared with placebo, carvedilol reduced the mortality risk at 12 months by 38% and the risk of death or hospitalization for HF by 31%.266 The Multicenter Oral Carvedilol Heart Failure Assessment (MOCHA) trial demonstrated that this effect of carvedilol is dose related, with higher doses of 25 mg twice daily showing greater LV functional and clinical superiority than 6.25 mg twice daily, a dose that was superior to placebo.267 Another longer-acting -blocker, bisoprolol, showed similar long-term benefit on survival in patients with HF. The Cardiac Insufficiency Bisoprolol Study (CIBIS-II) showed a 32% reduc- tion in all-cause mortality in bisoprolol-treated patients with NYHA class III or IV HF caused by ischemic and nonischemic cardiomyopathy at a median follow-up of 1.3 years. In that trial, sudden deaths were reduced by 44% in the bisoprolol-treated group, whereas pump failure deaths were reduced by 26%.170 Nebivolol is a 1 -selective -blocker with vasodilating properties related to nitric oxide modulation. 