LAUSR

Little is known about age-related differences in baseline atherosclerotic plaque morphology and composition in patients with diabetes mellites (DM). For this purpose, we studied DM patients from the Combine trial. COMBINE (OCT-FFR, NCT02989740) is a multi-center, prospective study focusing on the natural history of non-ischemic, non-culprit coronary lesions and evaluate whether certain OCT-assessed variables could predict future adverse events originating from these lesions in a DM population. OCT analysis identifies plaque composition, estimates calcium arc (o), lipid arc (o), and measures thickness of the fibrous cap covering the lipid core. Moreover, OCT records the presence of typical plaque vulnerability traits like thin fibrous cap atheroma (TCFA), plaque erosion (PE), plaque rupture (PR), calcification nodule (CN), heterogeneous tissues (a probably healed plaque rupture), and macrophages accumulation (bright spots). A dedicated software estimated the interpolated percentage area stenosis (AS, %) measuring the minimal lumen area (MLA) and reference vessel area. The present analysis reports the baseline morphology of these lesions respectively in young (<70 years) vs. old (≥70 years) DM patients. OCT imaging was performed in 300 patients (361 lesions) from the COMBINE study, of which 203 lesions assessed in young and 158 lesions in old DM patients. There were no significant differences in MLA (mm2) 2.40 (1.85–315 vs. 2.30 (1.80–3.00), p=0.92), lesions length (mm 24.11 (15.10–33.10) vs. 24.20 (15.10–35.10), p=0.78), AS% (%) 63 (1.85–3.15) vs. 64 (56–73), p=0.41; lipid arc (o), 182 (140–250) vs. 175 (128–240), p=0.35), fibrous cap thickness covering the lipid arc (μm), 117 (65–193) vs. 110 (64–168), p=0.45, in the prevalence of TCFA 37 (18%) vs. 33 (21%), p=0.53, PR 17 (18%) vs. 15 (10%), p=0.71, heterogenous tissue 39 (19%) vs. 31 (20%), p=0.92, and bright spots 98 (48%) vs. 69 (44%), p=0.38. The patients ≥70 years had a higher prevalence of calcified plaques 171 (84%) vs. 143 (90%), p=0.08 and wider calcium arc. These lesions included more PE 7 (3%) vs. 13 (8%), p=0.05, CN 73 (36%) vs. 75 (47%), p=0.03, and CN associated with overlying thrombus 11 (5%) vs. 20 (13%), p=0.02. Non-ischemic, non-culprit lesions in elderly DM patients present the same prevalence of soft, vulnerable plaques as it is a younger cohort, however, they have a higher prevalence of calcified plaque including complex calcified plaques as eroded plaques and calcification nodules with overlying thrombus. Whether these complex calcified plaques are associated with a higher risk of adverse events remains questionable and could be further elucidated from longer follow-up data of the COMBINE trial.