2. To show that lenient rate control is not inferior to strict rate control in terms of all cause mortality, cardiovascular hospitalizations, NYHA class for exercise tolerance, left ventricular function and left atrial size, quality of life, neurohormonal activation as measured by NT-proBNP, hospitalization for heart failure, syncope, sustained ventricular tachycardia, appropriate shocks or anti-tachycardia pacing of ICD for ventricular arrhythmias, cardiac arrest, and pacemaker implantations, stroke, systemic emboli, and bleeding, unstable angina pectoris and myocardial infarction, costs and renal function