New-onset atrial fibrillation predicts malignant arrhythmias in post-myocardial infarction patients--a Cardiac Arrhythmias and RIsk Stratification after acute Myocardial infarction (CARISMA) substudy

Am Heart J. 2013 Nov;166(5):855-63.e3. doi: 10.1016/j.ahj.2013.08.017. Epub 2013 Sep 26.

Abstract

Background: After myocardial infarction (MI) the risk of sudden cardiac death due to arrhythmias is substantial.

Objective: The purpose of this study was to investigate if new-onset atrial fibrillation (AF) is associated with development of potential malignant brady- and tachyarrhythmias after an acute MI.

Methods: The study included 277 post-MI patients from the CARISMA study with left ventricular ejection fraction ≤ 40%, New York Heart Association class I, II, or III and no history of AF. All patients were implanted with an implantable cardiac monitor within 4 to 27 days after an acute MI and followed every 3 months for 2 years. Time-dependent association between new-onset AF > 30 s and the development of bradyarrhythmias and/or ventricular tachyarrhythmias were investigated using Cox proportional hazard regressions.

Results: New-onset AF was associated with an increased risk of bradyarrhythmias when adjusting for male gender and baseline age, left ventricular ejection fraction and QRS width (HR = 2.8 [1.3-5.8], P = .006). Similarly, new-onset AF predicted ventricular tachyarrhythmias when adjusting for New York Heart Association class ≥ II and baseline QRS width (HR = 2.3 [1.2-4.4], P = .019). After dividing ventricular tachyarrhythmias into subgroups of non-sustained ventricular tachycardia (VT), sustained VT and ventricular fibrillation (VF), new-onset AF was significantly associated with an increased risk of non-sustained- and sustained VT but not VF (non-sustained VT: HR = 3.5 [1.7-7.2], P < .001, sustained VT: HR = 4.2 [1.1-15.7], P = .035, VF: HR = 1.1 [0.2-5.8], P = .877).

Conclusion: In patients surviving a MI with reduced left ventricular systolic function, new-onset AF is associated with a significantly increased risk of developing ventricular brady- and tachyarrhythmias.

Trial registration: ClinicalTrials.gov NCT00145119.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Arrhythmias, Cardiac / complications*
  • Arrhythmias, Cardiac / epidemiology
  • Atrial Fibrillation / complications*
  • Electrocardiography, Ambulatory / methods*
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Myocardial Infarction / complications*
  • Myocardial Infarction / physiopathology
  • Proportional Hazards Models
  • Risk Assessment
  • Risk Factors
  • Ventricular Function, Left

Associated data

  • ClinicalTrials.gov/NCT00145119