AUTHOR=Jøns Christian , Bloch Thomsen Poul Erik , Riahi Sam , Smilde Tom , Bach Ulrich , Jacobsen Peter Karl , Táborský Miloš , Faluközy Jozsef , Wiemer Marcus , Christensen Per Dahl , Kónyi Attila , Schelfaut Dan , Bulava Alan , Grabowski Marcin , Merkely Béla , Nuyens Dieter , Mahajan Rajiv , Nagel Patrick , Tilz Roland , Malczynski Jerzy , Steinwender Clemens , Brachmann Johannes , Serota Harvey , Schrader Jürgen , Behrens Steffen , Søgaard Peter 

TITLE=Arrhythmia monitoring and outcome after myocardial infarction (BIO|GUARD-MI): a randomized trial

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 11 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2024.1300074

DOI=10.3389/fcvm.2024.1300074

ISSN=2297-055X

ABSTRACT=Objectives: Cardiac arrhythmias predict poor outcome after myocardial infarction (MI). We studied if arrhythmia monitoring with an insertable cardiac monitor (ICM) can improve treatment and outcome.Design: BIO|GUARD-MI was a randomized, international open-label study with blinded outcome assessment.Setting: Tertiary care facilities monitored the arrhythmias, while the follow-up remained with primary care physicians.Participants: Patients after ST-elevation (STEMI) or non-ST-elevation MI with an ejection fraction >35% and a CHA2DS2-VASc score ≥4 (men) or ≥5 (women).Interventions: Patients were randomly assigned to receive or not receive an ICM in addition to standard post-MI treatment. Device-detected arrhythmias triggered immediate guideline recommended therapy changes via remote monitoring.Main outcome measures: MACE, defined as a composite of cardiovascular death or acute unscheduled hospitalization for cardiovascular causes.Results: 790 patients (mean age 71 years, 72% male, 51% non-STEMI) of planned 1400 pts were enrolled and followed for a median of 31.6 months. At 2 years, 39.4% of the device group and 6.7% of the control group had their therapy adapted for an arrhythmia (hazard ratio [HR]=5.9, P<0.0001). Most frequent arrhythmias were atrial fibrillation, pauses and bradycardia. The use of an ICM did not improve outcome in the entire cohort (HR=0.84, 95%-CI: 0.65-1.10; P=0.21). In secondary analysis, a statistically significant interaction of the type of infarction suggests a benefit in the prespecified non-STEMI subgroup. Risk factor analysis indicates that this may be connected to the higher incidence of MACE in patients with non-STEMI.The burden of asymptomatic but actionable arrhythmias is large in postinfarction patients. However, arrhythmia monitoring with an ICM did not improve outcome in the entire cohort. Post-hoc analysis suggests that it may be beneficial in non-STEMI patients or other high-risk subgroups.