Abstract 14681: Quantitative Whole Blood Platelet Aggregation Predicts Occurrence of Subacute Thrombosis in Patients After Percutaneous Coronary or Peripheral Intervention

Abstract

Introduction: The risk of subacute thrombosis (SAT) after percutaneous coronary intervention (PCI) or percutaneous peripheral intervention (PPI) is high if patients show high whole blood platelet aggregation. Hypothesis: For such high-risk patients, even though dual antiplatelet therapy is performed, whole platelet aggregation should be quantitated and if high, the indication for additional antiplatelet therapy determined. Methods: This is a retrospective analysis of 12095 stents from 12095 patients (9173 males; mean age 69±11 years; 9470 PCI, 2625 PPI). The whole blood platelet aggregatory threshold index (PATI; WBA-Neo; ISK, Osaka, Japan) was calculated. PATI was used to determine the minimum concentration of adenosine 5'-diphosphate causing a non-reversible aggregation of platelets and indicated platelet aggregation (range 0-8 μM). The higher the PATI, the lower the platelet aggregation. All patients received single or double antiplatelet drug therapy according to physician choice. Results: SAT occurred in 18 (0.19%) of 9470 patients after PCI and in 9 patients (0.34%) of 2625 patients after PPI. Of 9470 patients after PCI, total blood PATI was 4.40 in 18 patients with SAT and 7.00 in 9452 patients without SAT (P<0.001). Of 2625 patients after PPI, the total blood PATI was 4.97 in nine patients with SAT and 6.39 in 2616 patients without SAT; the former was significantly lower than the latter (P<0.001). We combined patients with PCI and PPI. PATI was divided into nine grades: 0-0.99, 1-1.99, 2-2.99. 3-3.99, 4-4.99. 5-5.99, 6-6.99, 7-7.99, and >7.99. Of 12095 patients, if PATI was 0-0.99, the incidence of SAT was greatest at 1.89%. If PATI was >7.99, the incidence of SAT was lowest at 0.09%. We divided 12095 patients into two groups: PATI of 0-4.99 (N=2229) and PATI of >4.99(N=9866); the incidence of SAT was greater in the former (0.72%) than latter (0.11%; P<0.001). No significant differences existed in the percentage of each coronary risk factor between patients with and without SAT after PCI, PPI, and PCI or PPI. Conclusions: In patients after PCI and/or PPI, despite single or double antiplatelet drug therapy, the whole blood platelet aggregation should be checked, and if PATI is 0-4.99 the indication for additional antiplatelet therapy should be considered.