This article provides information and a commentary on trials relevant to the pathophysiology, prevention and treatment of heart failure, presented at the American Heart Association 2007. These should be considered as preliminary data, as analyses may change in the final publication. Rosuvastatin did not reduce mortality compared to placebo in patients with heart failure and left ventricular systolic dysfunction due to ischaemic heart disease in the CORONA study. Results of RethinQ provide equivocal evidence of benefit from CRT in patients with heart failure, echocardiographic dyssynchrony and QRS interval <130 ms. In the MASCOT study, the addition of atrial overdrive pacing did not reduce the incidence of permanent atrial fibrillation in patients receiving CRT. The AF-CHF study failed to show a benefit of rhythm control over rate control in patients with heart failure and atrial fibrillation. Self-management skills training and education had no benefit on the combined outcome of death or heart failure hospitalisation, compared with education alone in heart failure patients in the HART study. Microvolt T-wave alternans testing failed to identify patients at increased risk of life-threatening ventricular arrhythmias in the MASTER study. POISE suggests that initiating metoprolol therapy shortly prior to non-cardiac surgery increases the risk of hypotension, stroke and death, despite reducing the risk of myocardial infarction. Three trials of stem cell therapy in post-MI patients gave conflicting results.