PREVENT-HF: Prevention of Heart Failure Events With Impedance Cardiography Testing

The purpose of this study is to determine whether outpatient therapeutic management guided by impedance cardiography (ICG), in addition to standard clinical assessment, will result in a longer time in days to the first heart failure hospitalization than therapy guided by clinical assessment alone.

The course of patients with chronic heart failure is marked by periodic episodes of clinical decompensation that not only impair the quality of life and may be fatal but also consume substantial health care resources, primarily due to the costs of hospitalization. Heart failure management programs have been developed to reduce the frequency and severity of these clinical events, but their effectiveness may be limited by physicians' difficulty in identifying patients at imminent risk. Reliable prediction of these events may afford physicians the opportunity to intervene aggressively and potentially minimize the need for hospitalization or the risk of a serious adverse outcome. Noninvasive impedance cardiography (ICG) is a simple test that utilizes changes in thoracic electrical impedance to measure thoracic fluid content, changes in the duration of cardiac ejection and the velocity of blood flow within the aorta. ICG has been used to estimate cardiac output and cardiac filling pressure in patients with or without heart failure (HF). PREVENT-HF is a randomized prospective study being conducted at up to 35 experienced investigative centers from the United States, Canada, and Europe. Subjects will be enrolled within 4-12 days of a discharge from a hospitalization for exacerbation of heart failure, with screening procedures to occur prior to the enrollment. Following enrollment, subjects will be randomized in a 1:1 ratio to outpatient management by either clinical assessment (Standard Care Arm) or ICG in addition to clinical assessment (ICG Arm) during the enrollment visit. ICG variables will be collected in all subjects but will be blinded in the Standard Care Arm. Each subject's study participation will last for a minimum of 24 weeks and a maximum of 52 weeks post-discharge. Four weeks after hospital discharge, subjects will visit the clinic. Remaining study visits will occur every four weeks thereafter until the subject has completed the 52-week visit or until the subject has experienced a hospitalization that has been adjudicated by the Clinical Events Committee as being a heart failure hospitalization. In the PREDICT study, a composite ICG score was the most powerful predictor of a short-term HF event when compared to standard clinical variables. This composite ICG score is provided for subjects in the PREVENT-HF ICG Arm. If the score indicates a subject is at a higher risk for a short-term HF event, clinicians will be required to intervene. Clinicians may intervene if indicated by the subject's clinical status for an intermediate-risk score, and intervention is not recommended based on the ICG score for lower-risk scores. Compliance to these guidelines will be tracked.