Objectives: The aim of the study was to compare the consistency of VerifyNow System and thrombelastography (TEG) in stroke patients treated with asprin in China.
Methods: Patients hospitalized in Changhai Hospital and Yueyang Hospital with acute ischemic stroke were randomly enrolled into treatment with a 100-mg daily maintenance dose of asprin. Platelet reactivity was evaluated by VerifyNow System (Accumetrics Inc.) and TEG (Hemonetics Corporation) at the same time on the 5th-7th day of asprin treatment. Patients with asprin low response (ALR) were detected by using the methods and criteria published earlier (ARU ≥550 assayed by VerifyNow System or Inhibition% ≤50% measured by TEG). All patients were followed up for 2 years and clinical endpoint was ischemic events, including major adverse cardiac events (MACE), recurrence of stroke, transient ischemic attack (TIA),and the composite of vascular death.
Results: Totally 94 patients were enrolled for the study and there were wide varieties in parameters of VerifyNow System and TEG. Results showed a total of 16 and 15 patients, respectively, identified as ALR assessed by VerifyNow System and TEG, but only three patients were detected to be asprin low responders by both tests. The kappa consistency analysis showed poor consistency between VerifyNow System and TEG results in terms of ALR (Kappa = 0.030, p < 0.01). Of the patients recruited, 83 (88.3%) patients were followed up for 2 year and a total of 15 (18.1%) cases of clinical events were observed. There was no correlation between ALR assessed by TEG (TEG-ALR) and the clinical endpoints (P > 0.05), but a significant relevance was found between ALR assessed by VerifyNow System (VerifyNow-ALR) and the ischemic events in 2 years of follow-up (ORadj: 3.13; 95%CI: 1.3-7.55; P = 0.011). Among the risk factors for cerebrovascular disease, we only found stroke history was related to the clinical endpoints (P = 0.005).
Conclusions: There was poor correlation between VerifyNow System and TEG in platelet function detection. VerifyNow-ALR and stroke history were risk factors for ischemic events, and VerifyNow System may be available to guide individualized antiplatelet therapies in stroke patients in China.