The predictive value of CHADS2 risk score in post myocardial infarction arrhythmias — A Cardiac Arrhythmias and RIsk Stratification after Myocardial infArction (CARISMA) substudy

Abstract 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 CHADS 2 score (congestive heart failure, hypertension, age ≥75years, 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 21days 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 CHADS 2 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 CHADS 2 score (CHADS 2 score=1–2: HR=2.1 [1.1–3.9], p=0.021, CHADS 2 score≥3: HR=3.7 [1.9–7.1], p 2 score was similarly associated with the development of major cardiovascular events defined as reinfarction, stroke, and hospitalization for heart failure or cardiovascular death. Conclusion In the post-MI setting, CHADS 2 score efficiently identifies populations at high risk for cardiac arrhythmias.