The predictive value of CHADS₂ risk score in post myocardial infarction arrhythmias - a Cardiac Arrhythmias and RIsk Stratification after Myocardial infArction (CARISMA) substudy.
BACKGROUND
Previous studies have shown substantially increased risk of cardiac arrhythmias and sudden cardiac death in post-myocardial infarction (MI) patients. However it remains difficult to identify the patients who are at highest risk of arrhythmias in the post-MI setting. The purpose of this study was to investigate if CHADS₂ score (congestive heart failure, hypertension, age ≥75 years, diabetes and previous stroke/TCI [doubled]) can be used as a risk tool for predicting cardiac arrhythmias after MI.


METHODS
The study included 297 post-MI patients from the CARISMA study with left ventricular ejection fraction (LVEF) ≤40%. All patients were implanted with an implantable cardiac monitor (ICM) within 5 to 21 days post-MI and followed every three months for two years. Atrial fibrillation, bradyarrhythmias and ventricular tachycardias were diagnosed using the ICM, pacemaker or ICD. Patients were stratified according to CHADS₂ score at enrollment. Congestive heart failure was defined as LVEF ≤40% and NYHA class II, III or IV.


RESULTS
We found significantly increased risk of an arrhythmic event with increasing CHADS₂ score (CHADS₂ score=1-2: HR=2.1 [1.1-3.9], p=0.021, CHADS₂ score ≥ 3: HR=3.7 [1.9-7.1], p<0.001). This pattern was identical when dividing the arrhythmias into subgroups of atrial fibrillation, ventricular tachycardias and bradyarrhythmias. CHADS₂ score was similarly associated with the development of major cardiovascular events defined as reinfarction, stroke, and hospitalization for heart failure or cardiovascular death.


CONCLUSIONS
In the post-MI setting, CHADS₂ score efficiently identifies populations at high risk for cardiac arrhythmias.
Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
Anne Christine
AC
Ruwald
Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
Uffe
U
Gang
Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
Poul Erik Bloch
PE
Thomsen
Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
Rikke Mørch
RM
Jørgensen
Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark.
Martin H
MH
Ruwald
Department of Internal Medicine, University of Oulu, Oulu, Finland.
Heikki V
HV
Huikuri
Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark. Electronic address: chrjoens@gmail.com.
Christian
C
Jons
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D017147:Defibrillators, Implantable / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index
Arrhythmias; Atrial fibrillation; Biomonitor; Bradyarrhythmias; CARISMA study; CHADS(2) risk score; Implantable cardiac monitor; Loop recorder; Prediction