Evaluating the Effectiveness of the LifeVest Defibrillator and Improving Methods for Determining the Use of Implantable Cardioverter Defibrillators

An ICD is a device designed to quickly detect a life-threatening, rapid heartbeat. Through a process called defibrillation, the ICD tries to convert an abnormal heart rhythm back to normal by delivering an electrical shock to the heart. The ICD continuously monitors heartbeats to ensure that they are normal, and it only delivers a shock to the heart when it senses a life-threatening arrhythmia. The LifeVest is a new, non-invasive, wearable defibrillator vest that is an alternative to an ICD. It consists of a vest that is worn over the chest and a monitor that is worn around the waist or shoulder. The LifeVest is less expensive than an ICD and does not require surgery. Currently, the LifeVest is approved by the Food and Drug Administration (FDA) for detecting and treating arrhythmias, but it is not known how effective it is in people who have recently had a heart attack.

This study is composed of two parts: the Vest Prevention of Early Sudden Death Trial (VEST) and a follow-up study called Prediction of ICD Therapies Study (PREDICTS). The purpose of VEST is to evaluate the effectiveness of the LifeVest defibrillator at preventing death caused by an arrhythmia in the 3 months after a heart attack. In PREDICTS, participants will be followed for several years after receiving an ICD or a Reveal monitor, which is an implantable heart monitoring device that does not treat arrhythmias. The purpose of PREDICTS is to improve the methods that doctors use to determine which patients will benefit the most from receiving an ICD.

This study will enroll people who have recently had a heart attack. While participants are in the hospital or clinic, they will undergo a baseline medical history review, physical exam, electrocardiogram (EKG) to measure electrical activity of the heart, and blood collection. Participants will then be randomly assigned to either wear the LifeVest for 3 months or receive usual care for 3 months. The LifeVest will continually collect and store heart rhythm information, and participants will transmit this data over the phone to study researchers on a weekly basis. At Month 1, participants will receive a follow-up phone call. At Month 2, all participants will attend a study visit that will include repeat baseline testing, a signal-averaged electrocardiogram (SAECG) test to identify any scar tissue, a baroreflex sensitivity (BRS) test to measure heart rate changes in response to blood pressure changes, an echocardiogram (ECHO) of the heart, an exercise stress test, and quality of life questionnaires. Participants will wear a monitor for 24 hours after the study visit to record heart activity. A small amount of blood will be stored for future DNA analysis.

Participants whose heart function remains poor will receive an ICD implant, and all other participants will receive a Reveal monitoring device implant. The Reveal device will continuously monitor and record arrhythmias, but it will not provide any treatment. Every 1 to 3 months, participants will transmit their ICD or Reveal data by phone to researchers. For 1 to 8 years, depending on when study entry occurs, participants will attend follow-up visits once a year for repeat testing. Study researchers will call participants periodically to monitor medication changes and medical problems.

The VEST/PREDICTS study was originally introduced as a single study with two phases (VEST and PREDICTS), with all consenting participants required to participate in both phases consecutively. Beginning with Version 2.0 of the protocol, the two phases were uncoupled resulting in three possible avenues for participant enrollment:

1. VEST/PREDICTS combined (V/P): Participants who meet inclusion criteria for VEST/PREDICTS combined enroll in both phases using one consent form (same as the original). This is the preferred enrollment strategy.

2. VEST only (V): Participants who meet inclusion criteria for VEST/PREDICTS combined but may not want to be in the three to five-year Predicts PREDICTS study, may opt to enroll in the 3-month VEST only study using the VEST consent

3. PREDICTS only (P): Participants who meet inclusion criteria for PREDICTS only may be enrolled while in the hospital for the qualifying MI, within the 7-day post discharge window, and up to 6 months post MI.