Jons C, et al. Trials. 2019;20(1):563.
Over recent decades, prognosis of myocardial infarction (MI) has improved drastically due to improved and faster revascularization, platelet inhibition, and device therapy. But, post-acute MI (AMI) patients with additional risk factors still remains at high risk, with 5-year mortality ranging from 15% to 45% depending on the population. Implantable cardiac monitors (ICMs) permits early documentation of asymptomatic cardiac arrhythmias that would previously have gone unnoticed. Remote monitoring (RM) addition to cardiac devices allows physicians to receive an early warning in cases of new-onset arrhythmias. To increase HF survival, RM is recommended for patients with HF with implantable defibrillators; patients who experienced cardiac arrhythmias such as atrial fibrillation, bradycardia, and ventricular tachyarrhythmia have an increased risk of major adverse cardiac events. Cardiac arrhythmias frequently start as asymptomatic, shorter lasting, and nightly events.
The Biomonitoring in patients with preserved left ventricular function after diagnosed myocardial infarction (BIO-GUARD-MI) study, a multicenter, open, prospective, randomized controlled international study with an event-driven design aims to investigate and clarify whether the incidence of major adverse cardiac events can be decreased by early detection and treatment of cardiac arrhythmias using an ICM in patients after myocardial infarction. The study describes the interplay between baseline characteristics, arrhythmias, and clinical events to improve the treatment of this high-risk patient population. The patients enrolled in the study were high-risk postmyocardial infarction patients with CHA2DS2-VASc score ≥ 4 and left ventricular ejection fraction > 35% randomly assigned to an ICM or conventional treatment. Around 1400 patients were enrolled in the study and followed until 372 primary endpoints have occurred. The primary endpoint was the time from randomization to the first MACE during the clinical investigation. The major adverse cardiac events (MACEs) comprise the following events: 1) cardiovascular death; 2) worsening of the status of the patient due to heart failure, requiring acute unscheduled hospitalization or urgent visit; or 3) unscheduled cardiovascular hospitalization due to arrhythmia, acute coronary syndrome, stroke, major bleeding, or systemic embolism (Figure 1).
Figure 1: BIO-GUARD-MI flow diagram. AV atrioventricular, CEMB central electrocardiogram monitoring board, ICD implantable cardioverter-defibrillator, ICM implantable cardiac monitor, TIA transient ischemic attack, VF ventricular fibrillation, VT ventricular tachycardia.
Thus, the BIO-GUARD-MI trial represents the first attempt to simplify the response to the rather complex nature of heart arrhythmias. RM may improve clinical outcome if it uncovers conditions with low symptom burden, which cause or indicate an increased risk.
