OptiLink HF Study: Optimization of Heart Failure Management Using Medtronic OptiVol Fluid Status Monitoring and CareLink Network

Inclusion Criteria * Subjects have a Medtronic Virtuoso™ ICD single- or dual-chamber or Concerto™ CRT-D or subsequently market released Medtronic device providing at least the same functionality) implanted, including device replacement. Subjects with CRT-D must fulfill CRT-indication as described in the ESC guidelines for cardiac pacing and cardiac resynchronization therapy 2007: EF ≤ 35% and NYHA III, and LVEDD ≥ 55 mm, and QRS ≥ 120 ms, and optimized therapy * Subjects with stable chronic heart failure (CHF) in New York Heart Association (NYHA) class II or III for at least 30 days and left ventricular ejection fraction of no more than 35% (most recent measurement within 6 months prior to randomization by echocardiography or contrast ventriculography, magnetic resonance or nuclear imaging, based on local practice), on optimal target or maximal tolerated dose of ACE-inhibitors or angiotensin receptor blockers, ß-blockers and diuretics if clinically indicated to reduce fluid retention and one of the following criteria: * At least one hospitalization due to the heart failure within the last 12 months before enrollment * Or one course of ambulatory IV-or oral diuretic treatment or a BNP value of \> 400 pg/ml or a NT-proBNP values \> 450 in subject \< 50 years, \> 900 (50-75 years) and \> 1800 subject of than 75 years old within 30 days of enrollment * Written informed consent by the subject for study participation prior to clinical investigation plan specific procedures, * The subject must be able and willing to comply with the clinical investigation plan and willing to remain available for follow-up visits to the study closure, * Subjects or the subject's caregiver must be willing and able to use the Medtronic CareLink® monitor as instructed and to perform the required duties, if subject is randomized to the access arm. Exclusion Criteria: * Subjects with chronic renal failure needing renal dialysis * Subjects with serum creatinine \> 2.5 mg/dl, measured within 14 days prior to enrollment, * Subjects with severe to very severe Chronic Obstructive Pulmonary Disease (COPD) as determined by physician and documented in medical records (Stage III and Stage IV), * Subjects with suspected or confirmed COPD require a current test of lung function (not more than 12 months before inclusion). If the "forced expiratory volume" is \<1.0 L/sec,the subject may not participate in the study, * Subjects on the heart transplantation list or subjects with transplanted hearts, * Subjects listed for valve replacement or interventional valve therapy, * Subjects with myocardial infarction within the last 40 days before implant. MI is defined by typical changes in biochemical markers including troponin levels \> 3 times the upper limits of normal and creatinine kinase \< 2 times of upper limit, or with CKMB greater than the upper limit of normal, combined (for all enzymes) with at least one of the following ischemic symptoms, ECG changes consistent of diagnostic ST-T wave changes or pathologic Q waves or new LBBB, * Subjects with stroke within 40 days prior randomization, * Subjects who have had a percutaneous coronary intervention within 3 months prior to randomization, * Subjects with cardiac surgery within 90 days of randomization, * Subjects with complex and uncorrected Congenital Heart Disease, * Subject's life expectancy is less than 18 months in the opinion of the physician, * Subjects in situations that would limit participation, not eligible to receive a CareLink® monitor (e.g. hearing or speech impaired with no family member or caregiver available to assist, or those who spend extended periods abroad, or those who intend to enroll in a study that would preclude use of the monitor), * Subject is participating in a concurrent intervention study, * Subject or the subject's caregiver is unwilling to give consent for the release of information for the evaluation or to give additional consent for the release of subject medical and privacy data for CareLink® subjects, * Subjects with exclusion criteria required by local law (age \< 18, women who are pregnant or breastfeeding)