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

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.

• Authors: Anne-Christine Huth Ruwald, Poul Erik Bloch Thomsen, Uffe Gang, Rikke Mørch Jørgensen, Heikki V Huikuri, Christian Jons
• Journal: American heart journal (Am Heart J) Vol. 166 Issue 5 Pg. 855-63.e3 (Nov 2013) ISSN: 1097-6744 [Electronic] United States
• PMID: 24176441 (Publication Type: Clinical Trial, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2013.

Topics

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