Patients with chronic coronary syndrome (CCS) who undergo invasive coronary angiography (ICA) benefit from the use of advanced invasive diagnostics (AID) to identify obstructive and non-obstructive mechanisms of ischemia, a new study shows. The AID strategy is safe to perform during ICA to identify causes of myocardial ischemia in more than 80% of these patients, according to the AID-ANGIO study. These results were presented Tuesday by Adrián Jerónimo, MD, of the Hospital Clinico San Carlos, Compultense University, Madrid, at EuroPCR 2024 in Paris. Many patients with CCS experience ischemia with no obstructive coronary arteries (INOCA), and this can occur both with angiographically normal vessels and functionally non-significant stenoses. It is difficult to diagnose INOCA with just the use of clinical information plus ICA (78% error). An AID strategy would assist in this diagnosis process. The AID-ANGIO (Advanced Invasive Diagnosis Strategy for Patients with Chronic coronary Syndromes Undergoing Invasive ANGIOgraphy) study was a multicenter, prospective trial that examined the effects of the use of an AID to diagnose obstructive and non-obstructive mechanisms of ischemia in CCS patients while ICA is performed. The primary endpoint of this study compared the proportion of patients who had myocardial ischemia identified with solely the use of ICA with the percentage of patients who had the support of the AID strategy. The AID strategy used ICA to diagnose severe stenoses (≥90%), while fractional flow reserve (FFR)/resting full-cycle ratio (RFR) were used to diagnose intermediate stenoses (<90%), the index of microcirculatory resistance (IMR)/coronary flow reserve (CFR) to assess for coronary microvascular dysfunction (CMD) INOCA endotype and acetylcholine to assess vasomotor INOCA endotype. A total of 317 patients (44% female) from four centers in Spain were included in the study. The investigators found there was a 2.6-fold increase in diagnostic yield (p<0.001) in patients who had the assistance of the AID, and the treatment plans of 59.9% of patients were modified after AID. Normal ICA vessels and FFR/RFR negative lesions had equal numbers of INOCA occurrence. Physicians incorrectly diagnosed INOCA, or the absence of INOCA, in 78.2% of cases when using ICA and clinical data alone, said Javier Escaned, MD, PhD, of Hospital Clinical San Carlos, during a EuroPCR news conference Tuesday. Overall, the investigators in this study determined the discrepancy between ICA and the lack of information that ICA alone provides in patients with CCS. The AID component to the procedure is a helpful tool to implement during this procedure. During his presentation in the main arena, Jerónimo added that both European and American clinical guidelines recommend all AID strategy components. Photo Credit: Screenshot by Bailey Salimes/CRTonline.org Photo Caption: Adrián Jerónimo, MD, reports results from the AID-ANGIO study Tuesday at EuroPCR 2024