Heart Failure Risk Stratification at the Time of ICD Implantation after Myocardial Infarction: the HF WICD-MI Score.

BACKGROUND:After acute myocardial infarction (AMI) with left ventricular (LV) dysfunction, guideline-recommended reassessment at 40-90 days primarily addresses arrhythmic risk and implantable cardioverter-defibrillator (ICD) candidacy. In this setting, a complementary evaluation of heart failure (HF)-related event risk may refine risk stratification. OBJECTIVE:We aimed to quantify post-ICD HF event risk and develop a simple score usable at the time of ICD decision. METHODS:We analyzed 1,015 patients from the WICD-MI study (41 French centers) with LVEF ≤35% after AMI, equipped with a wearable cardioverter-defibrillator (WCD) and subsequently implanted with an ICD. We hypothesized that early HF features after MI could predict subsequent HF outcomes and therefore assessed five pre-implant HF features: HF history before AMI; cardiogenic shock, congestive HF during AMI; acute HF hospitalization during WCD period; and NYHA status at ICD implantation. The primary outcome was a composite of death or HF events (hospitalization, LV assist device, transplantation) at 1 year post-ICD. RESULTS:The 1-year risk of the composite outcome was 12.7%. All HF features except prior HF independently predicted the primary outcome: cardiogenic shock (aHR=1.63, p=0.013), congestive HF (aHR=2.02, p=0.0004), acute HF hospitalization (aHR=2.96, p<0.0001), and NYHA III/IV (aHR=1.64, p=0.025). Risk increased from 5% (no points/HF features) to 38% (≥3 points/HF features). External validation in HRMI (n=22,418) showed improved discrimination for HF hospitalization versus GRACE (ΔC-index +0.026; p=0.001) and similar performance to VALIANT-HF, with greater simplicity. CONCLUSION:In post-MI patients undergoing ICD implantation, a simple HF-based score identifies patients at higher risk of early post-implant HF events and may support integrated management, including timely HF referral.