This article provides information and a commentary on key trials relevant to the pathophysiology, prevention, and treatment of heart failure presented at the European Society of Cardiology meeting held in Paris, France in August 2011. Unpublished reports should be considered as preliminary, since analyses may change in the final publication. Results from ARISTOTLE suggest that apixaban is more effective than warfarin for the prevention of stroke in patients with atrial fibrillation. Electrical dyssynchrony, measured by the time from onset of electrical activity on the surface ECG to activation of myocardium by intrinsic conduction at the pacing site (QLV), was a strong and independent predictor of improvement in ventricular function after cardiac resynchronization therapy (CRT) in an observational analysis of a subgroup of patients from the SMART-AV study. Subgroup analyses from SHIFT suggest that heart rate reduction with ivabradine causes favourable left ventricular remodelling and improves quality of life in patients with symptomatic systolic heart failure and an increased heart rate. The European CRT Survey reported outcome data.