[Arrhythmia risk stratification in patients with heart failure. Foreword]

The challenge of preventing arrhythmic sudden death is one of the major issues of today's treatment of heart failure. To pursue this aim, an accurate selection of candidates for sudden death has to be routinely carried out, while a maximized and individualized drug treatment has to be extensively administered in all high-risk selected patients. However, in clinical practice there is no agreement on the selection criteria of sudden death risk, particularly in patients with advanced heart failure. Furthermore, the real impact of each category of drugs in reducing the risk of sudden death in heart failure patients is still under debate. As far as non-pharmacological options are concerned, implantable cardioverter-defibrillators (ICD) have been demonstrated to be the most effective therapy in patients with prior cardiac arrest due to ventricular fibrillation or poorly tolerated ventricular tachycardia. Low left ventricular ejection fraction, unsustained ventricular tachycardia and inducibility at electrophysiological study also may identify high-risk patients requiring ICD implantation. However, such a stratification seems to be effective in ischemic more than in non-ischemic patients, while generally the primary prevention of sudden death is still restricted to a minority of patients. Biventricular pacing has been proven to be effective in optimizing left ventricular function in more than 50% of left bundle branch block and advanced heart failure patients, while further studies are needed to evaluate the real impact of cardiac resynchronization therapy on hard endpoints, such as survival and long-term clinical outcome. Therefore, the selection criteria of "responders" to this novel non-pharmacological therapy still have to be defined. There is convincing evidence in the literature that tailored drug therapy can be highly effective in preventing heart failure progression as well as in reducing total and sudden mortality. Nevertheless, prevention of sudden death is still a debated point in heart failure treatment. For this reason, we aimed to provide heart failure specialists with updated reviews on this topic, such as those published in this issue of the Italian Heart Journal Supplement. Therefore, we are proud to present all the authors who contributed with the high quality of their articles to this editorial effort. Obviously, we have to thank the authors, but we also have to address the readers, thanking them in advance for their interest in such an initiative.