ADDED Index or percentage diameter of residual coronary stenosis to risk-stratify patients presenting with STEMI

Background: We compared the prognostic value of the ADDED Index with visually estimated diameter (DS) of residual coronary stenosis (RS) in STEMI patients after successful PCI of the culprit lesion. Even though associated with a positive outcome, the functional assessment of non-culprit stenosis remains largely underused, especially in STEMI patients. The Angiography-DeriveD hEmoDynamic index (ADDED index) showed high accuracy to predict FFR and it might be used to better guide the diagnostic and therapeutic work-up of such patients. Methods: We retrospectively included 596 patients grouped on the basis of either the ADDED Index (ADDED Negative (<2.23, n = 153) vs ADDED Positive (≥2.23, n = 129)) or the DS of the RS (RS Negative (<50%, n = 177) vs RS Positive (≥50%, n = 105)). Patients without any RS served as control (n = 314). Primary endpoints were: 1) major adverse cardiac events (MACE), composite of all-cause death, myocardial infarction (MI), clinically driven revascularizations (CDR); 2) non-culprit vessel oriented clinical events (VOCE), composite of all-cause death, non-culprit vessel related MI and CDR. Results: At 24 months the rate of both MACE and VOCE was significantly higher in both the ADDED Positive and RS Positive groups. However, differently from patients in whom complete revascularization was deferred on the basis of the angiography (RS Negative), no additional risk was found for patients in the ADDED Negative group. Conclusions: In STEMI patients with MVD deferring treatment of RS on the basis of the ADDED index, rather than the visually estimated DS, is associated with a favorable clinical outcome.