Care-HF CArdiac Resynchronization in Heart Failure

Inclusion Criteria: * Heart failure for at least 6 weeks requiring loop diuretics * Currently in NYHA class III/IV * A high standard of pharmacological therapy * LV systolic dysfunction and dilation (EF \<=35%; EDD \>30mm/height in metres) * QRS \>=120 ms Dyssynchrony confirmed by echo if QRS 120-149 ms (Aortic pre-ejection delay \>140ms, Interventricular mechanical delay \>40 ms, Delayed activation of postero-lateral LV wall) Exclusion Criteria: * Age \< 18 years old or age \< legal age defined in the country in case different * Chronic atrial fibrillation within 6 weeks prior to randomization; * Impairment of left ventricular function not related to left ventricular systolic function * Potentially reversible forms of cardiomyopathy: * Cardiac surgery, percutaneous coronary intervention, cardiomyoplasty, myocardial infarction,unstable severe angina or stroke within 6 weeks before randomization * A conventional indication for bradyarrhythmia pacing exists; * A conventional indication for an ICD exists * A pacemaker or ICD has already been implanted; * In-Patients requiring continuous intravenous therapy for Heart Failure; * Life expectancy \< 1 year for disease unrelated to Heart Failure; * Pregnancy or childbearing potential and not on reliable contraceptive; * Mechanical tricuspid valve; * Anticipated compliance problem or participation in another trial;