Integrating device-based monitoring into clinical practice: insights from a large heart failure clinic

Heart failure is a difficult and costly disease to manage in part because the symptoms may be protean, the physical findings obscure, and the laboratory assessments unreliable. New implanted physiologic monitors may simplify the care of patients with heart failure, if they can be incorporated into routine clinical practice. Cardiac resynchronization therapy/defibrillators and implantable cardioverter defibrillators with continuous intrathoracic impedance monitoring capabilities (OptiVol fluid status monitoring; Medtronic, Inc., Minneapolis, MN) have recently been introduced and may provide an early warning of thoracic fluid retention. However, patients who have devices with this diagnostic capability must be identified, and the device-based information must be accessed systematically, if it is to be used in the disease management process. Ancillary information, such as the Heart Failure Management Report that is generated from data stored in Medtronic devices, may facilitate recognition of disease mechanisms associated with decompensation. The predictive value of continuous intrathoracic impedance monitoring with an implantable device is still unknown. Thus, therapeutic decisions should be made in conjunction with a clinical assessment. Physicians and other healthcare providers will need to become familiar with these devices so they can appreciate their advantages and limitations.