AIMS: We analysed the contemporary incidence, outcomes, and predictors of heart failure (HF) and/or left ventricular systolic dysfunction (LVSD) before discharge in patients with acute myocardial infarction (MI). The baseline presence of HF or LVSD, or its development during hospitalisation, increases short- and long-term risk after MI, yet its incidence, predictors, and outcomes have not been well described in a large, international, general MI population. METHODS AND RESULTS: The VALIANT registry included 5573 consecutive MI patients at 84 hospitals in nine countries from 1999 to 2001. A multivariable logistic survival model was constructed using baseline variables to determine the adjusted mortality risk for those with in-hospital HF and/or LVSD. Baseline variables were also tested for associations with in-hospital HF and/or LVSD. Of the 5566 patients analysed, 42% had HF and/or LVSD during hospitalisation. Their in-hospital mortality rate was 13.0% compared with 2.3% for those without HF and/or without LVSD. After adjustment for other baseline risk factors, in-hospital HF and/or LVSD carried a hazard ratio for in-hospital mortality of 4.12 (95% confidence interval: 3.08-5.56). Patients with HF and/or LVSD also had disproportionately higher rates of other cardiovascular events. CONCLUSIONS: HF and/or LVSD is common in the general contemporary MI population and precedes 80.3% of all in-hospital deaths after MI. Survivors of early MI-associated HF and/or LVSD have more complications, longer hospitalisations, and are more likely to die during hospitalisation. Although baseline variables can identify MI patients at highest risk for HF and/or LVSD, such patients are less likely to receive indicated procedures and medical therapies.