This article provides information and a commentary on landmark trials presented at the American Heart Association meeting held in November 2004, relevant to the pathophysiology, prevention, and treatment of heart failure. An open trial of the ACORN Cardiac Support Device (CSD) showed encouraging preliminary results in patients with severe heart failure. The PEACE (Prevention of Events with Angiotensin-Converting Enzyme inhibition) study supports data from previous studies showing that ACE inhibitors reduce vascular events in patients at increased risk. The CREATE (clinical trial of metabolic modulation in acute MI treatment evaluation) study of patients with acute myocardial infarction (MI) showed no mortality benefit of a glucose/insulin/potassium regimen, but treatment with reviparin reduced the incidence of death, MI, or stroke. Azimilide was not associated with a significant reduction in shocks, but reduced the shocks or episodes of markedly symptomatic ventricular tachycardia terminated by pacing in the SHIELD (Shock Inhibition Evaluation with Azimilide) study. The addition of isosorbide dinitrate plus hydralazine to standard therapy improved survival in black heart failure patients in the A-HeFT (African-American Heart Failure Trial) study. In an investigation of hypertensive patients with diabetes, carvedilol had fewer adverse effects on diabetic control than metoprolol. A meta-analysis of high-dose vitamin E supplementation suggested an association with increased mortality. The ESCAPE (Evaluation Study of CHF and Pulmonary Artery Catheterisation Effectiveness) study showed no benefit of pulmonary artery catheterisation over clinical management in patients with severe heart failure. Routine prophylactic coronary revascularisation for stable coronary disease prior to major vascular surgery showed no benefit in the CARP (Coronary Artery Revascularization Prophylaxis) study. Analysis of data from SCD-HeFT supports the cost-effectiveness of ICDs in heart failure, although overall cost implications may be prohibitive.