OptiVol fluid status monitoring with an implantable cardiac device: a heart failure management system.

Early intervention and prevention of hospitalizations would reduce the burden of heart failure on the healthcare system while improving the quality of life of affected patients. Traditional methods of patient assessment, including physical examination and patient report of symptoms, have a low sensitivity for detecting elevations in left ventricular filling pressure, a major precursor of pulmonary congestion and heart failure decompensation. Intrathoracic fluid accumulation during pulmonary congestion leads to decreased impedance across the lung. The OptiVol system in the InSync Sentrycardiac resynchronization therapy-defibrillator, Concerto cardiac resynchronization therapy-defibrillator and Virtuoso implantable cardioverter-defibrillator devices monitors intrathoracic impedance and is intended to recognize early signs of volume accumulation before physical symptoms appear. Through a recent clinical trial, the default setting for the OptiVol system functioned as a predictor of hospitalization with 76.9% sensitivity. Intrathoracic impedance monitoring is not intended to replace careful frequent clinical evaluation of the heart failure patient, but instead aims to complement traditional heart failure management practices.

Prediction of rehospitalization and death in severe heart failure by physicians and nurses of the ESCAPE trial.

BACKGROUND: The predictive accuracy of physician investigators and nurse coordinators in estimating the risk of rehospitalization and death was determined for 373 hospitalized patients with severe advanced heart failure enrolled in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial. METHODS AND RESULTS: Estimates were made at discharge, and patients were followed for 6 months after hospitalization. A statistical prognostic model was developed from clinical and laboratory data for the end points of rehospitalization and death. Both nurse and physician predictions of death were generally associated with the observed deaths (c-indices of 0.675 and 0.611), although the nurses' prediction was significantly better (chi-square = 4.75, P = .029). The prediction ability of the prognostic model was similar to the physicians' model (c-index = 0.603). The predictions of rehospitalization were much weaker for nurse, physician and prognostic models. CONCLUSIONS: Nurses' estimations of survival in discharged, advanced-stage heart failure patients were superior to either physicians' or model-based predictions. Not nurses, physicians, or the prognostic model provided useful predictions for rehospitalizations, but this may have resulted from the fact that the rehospitalization estimates did not include the death risk.