There is increasing evidence that activation of both the SNS and the RAAS contributes to disease progression in heart failure, thereby establishing a role for the use of both beta-blockers and ACE inhibitors in the management of these patients. With the amount of evidence (large number of trials including thousands of patients) demonstrating a benefit of reduced mortality and morbidity with the use of ACE inhibitors in patients with mild, moderate or severe heart failure , current guidelines for the management of heart failure recommend ACE inhibitors as first-line therapy . In patients who demonstrate heart failure progression despite the use of ACE inhibitor therapy, consideration can be given to the addition of a diuretic, digoxin or another vasodilator (ie, hydralazine or isosorbide dinitrate). At the time of publication of the Canadian Cardiovascular Society Consensus guidelines, the United States Carvedilol Heart Failure Study results were not available. In addition, the results of a large (6800 patients), randomized, controlled trial of digoxin in heart failure has recently been published , demonstrating no overall survival benefit ofdigoxin. However, there was a reduction in hospitalizations due to heart failure in patients receiving di-goxin. The greatest benefit with digoxin appeared to be in patients with the most severe heart failure, represented by the lowest EFs, enlarged hearts and those in NYHA functional class III or IV.
Based on these data, carvedilol should be considered in patients with mild to moderate heart failure (NYHA class II or III) who demonstrate progression of heart failure despite the use of diuretics, ACE inhibitors or other vasodilators. In patients with severe heart failure (NYHA class IV), carvedilol cannot be recommended until there is more experience in this particular population. These patients, however, may benefit more from the addition of digoxin rather than a beta-blocker.