Abstract 14591: Incidence of High-Risk Patients After Percutaneous Coronary Intervention for Coronary Stent Thrombosis Without Neointima Formation on Coronary Artery Stent Evaluated by Coronary Angioscopy and With High Whole Blood Platelet Aggregation

Abstract

Introduction: The risk of coronary thrombosis after percutaneous coronary intervention (PCI) is high in the absence of neointima formation on coronary artery stents, evaluated by coronary angioscopy, and high whole blood platelet aggregation. Hypothesis: For high risk patients, despite dual antiplatelet therapy, coronary angioscopy should be used to check for neointima formation and/or whole platelet aggregation measured. Methods: This is a retrospective analysis of 2757 stents from 2757 patients (2024 male, mean 71±10 years) who underwent coronary angioscopy (timing determined by physicians) 3-12 months after PCI. The whole blood platelet aggregatory threshold index (PATI; WBA-Neo, ISK, Osaka, Japan) was calculated. For coronary angioscopy, we categorized neointima formation on stents: Grade 0) no neointima; 1) strut surrounded by neointima but not completely buried; 2) strut completely buried by neointima but still observable through neointima; 3) strut completely buried by neointima and not observable. PATI (μM) measured the minimum concentration of adenosine 5'-diphosphate causing non-reversible platelet aggregation and indicated platelet aggregation (range 0-8). The higher the PATI, the lower the platelet aggregation. Results: On coronary angioscopy, 689, 1341, 543, and 144 stents were Grade 0, 1, 2, and 3, respectively. The 689 stents in Grade 0 from 689 patients consisted of 207 (of 824=25%) Xience, 189 (of 579=33%) Combo, 117 (of 583=20%) Synergy, 91 (of 382=24%) Ultimaster, 26 (of 118=22%) BMX-J, 23 (of 94=24%) Orsiro, 18 (of 108=17%) Resolute, 3/10 (30%) NOBORI, and 1/6 MULTI LINK8 stents. Of 689 patients with Grade 0 stents, 14 had PATI <2 (high platelet aggregation); eight 2-2.99; 29 3-3.99; nine PATI ranged 4-4.99; 10 5-5.99; 13 6-6.99; 17 7-7.99; and 589 >8.00 (low platelet aggregation). Of 14 patients with Grade 0 stents and PATI<2, two underwent single and 12 double antiplatelet drug therapies. Conclusions: 14 of 2757 patients (0.5%) simultaneously showed Grade 0 stents on coronary angioscopy and PATI <2; we speculated such patients required additional antiplatelet drug therapy. The incidence of such high-risk patients after PCI was very low. Whole platelet aggregation should be checked despite dual antiplatelet therapy results.