Prognostic value of modified ADMIIRE-HF risk score in patients with implantable cardioverter defibrillator: a prospective comparative study with 6-minute walk distance

Abstract Background ADIMIRE-HF risk score is a novel risk score that combines clinical characteristics and MIBG imaging variables to predict serious arrhythmic risk in patients with chronic heart failure (CHF) and recent studies showed that highest occurrence of severe arrhythmic events (SAE) was seen in patients with an intermediate decrease in MIBG uptake rather than the lowest values. Six-minute walk distance (6MWD) has also been shown to detect high risk patients with CHF. However, there is no information available on the long-term prognostic value of these indices for the prediction of ventricular tachyarrhythmias in patients with implantable cardioverter defibrillator (ICD). Methods and Results We prospectively enrolled 231 consecutive outpatients with ICD (age: 65±14 years, male: 81%, NYHA class: 1.7±0.7, LVEF: 47±17%). At entry, cardiac MIBG imaging, echocardiography and 6-minute walk test were performed. Modified ADMIRE-HF risk score was derived from the sum of the point values of the following parameters: LVEF (<25%:5 points), MIBG heart-to-mediastinum ratio on delayed planar image (HMR 1.4-1.9: 12 points) and systolic blood pressure (<120: 3 points, 120-139: 0 point, >140: -3 points). During a follow-up period of 4.4±2.8 years, 72 patients had appropriate ICD therapy (ATx). At multivariate Cox analysis, modified ADMIRE-HF risk score and 6MWD were significantly and independently associated with ATx after adjustment of age, sex, non-sustained ventricular tachycardia and NYHA functional class. ATx was significantly more frequently observed in patients with both higher modified ADMIRE HF risk score (>9: median value) and shorter 6MWD (<300m) and with either, than with none of them (54% vs 34% vs 18%, respectively p<0.0001). Conclusion Combination of modified ADMIRE-HF risk score and 6MWD would be strongly associated with an increased risk for ventricular tachyarrhythmias in ICD patients.