Comparison of ticagrelor and clopidogrel on platelet function and prognosis in unstable angina

Abstract

Purpose: This study aims to compare the effects of ticagrelor and clopidogrel on platelet function, cardiovascular prognosis, and bleeding in patients with unstable angina pectoris.

Methods: Patients with unstable angina pectoris undergoing percutaneous coronary intervention (PCI) were enrolled (January 2018-December 2019). In total, 212 patients were treated with ticagrelor (90 mg twice daily) and 210 patients were treated with clopidogrel (75 mg once daily). Thromboelastography and light transmission aggregometry were used to measure the platelet aggregation rate (PAR). High-sensitivity troponin T (hs-TnT), pro-brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (CRP), and heart-type fatty acid-binding protein (h-FABP) were measured to assess myocardial injury after PCI. Cardiovascular prognosis and bleeding events were evaluated in hospital and 12 months after discharge.

Results: The PAR was significantly slower with ticagrelor (P < 0.001). hs-TnT, NT-proBNP, CRP, and h-FABP increased after compared with before PCI in both groups (P < 0.05). hs-TnT (P < 0.001) and h-FABP (P < 0.001) increased more significantly with clopidogrel. The in-hospital and 12-month major adverse cardiovascular event (MACE) rates were not significantly different between the two groups. The in-hospital total bleeding event rate was higher with ticagrelor (P < 0.05). Minor bleeding and total bleeding were more frequent at the 12-month follow-up in the ticagrelor group (P < 0.05).

Conclusion: Ticagrelor was more effective in suppressing the PAR than clopidogrel and reduced PCI-induced myocardial injury in patients with unstable angina pectoris. However, it increased in-hospital and 12-month bleeding events and had no benefit on in-hospital and 12-month MACEs.

Keywords: Bleeding; Cardiovascular prognosis; Platelet aggregation rate; Ticagrelor; Unstable angina pectoris.

Fig. 1

PAR assessed by TEG at different time points. On days 3 and 30, the PAR in the ticagrelor group was significantly slower than in the clopidogrel group (P < 0.001). Data are presented as mean ± standard deviation. PAR, platelet aggregation rate; TEG, thromboelastography; ADP, adenosine diphosphate; AA, arachidonic acid

Fig. 2

PAR assessed by LTA at different time points. On days 3 and 30, the PAR in the ticagrelor group was significantly slower than in the clopidogrel group (P < 0.001). Data are presented as mean ± standard deviation. PAR, platelet aggregation rate; LTA, light transmission aggregometry; ADP, adenosine diphosphate; AA, arachidonic acid

Fig. 3

TEG showed that the R and K values were prolonged and the α angle and MA value were lower in the ticagrelor group than in the clopidogrel group. Data are presented as mean ± standard deviation. TEG, thromboelastography; MA, mean maximal amplitude

Fig. 4

Blood hs-TnT, NT-proBNP, CRP, and h-FABP concentrations before and after PCI in the clopidogrel and ticagrelor groups. hs-TnT, NT-proBNP, CRP, and h-FABP concentrations were higher after PCI than before PCI (P < 0.05 for all). hs-TnT (P < 0.001) and h-FABP (P < 0.001) increased more significantly after PCI in the clopidogrel group than in the ticagrelor group. Data are presented as mean ± standard deviation. hs-TnT, high-sensitivity troponin T; NT-proBNP, N-terminal pro-brain natriuretic peptide; CRP, C-reactive protein; h-FABP, heart-type fatty acid–binding protein; PCI, percutaneous coronary intervention

Fig. 5

Kaplan–Meier curves for overall MACEs and bleeding outcomes with ticagrelor versus clopidogrel. MACEs showed no significant difference between the two groups, and in-hospital and 12-month bleeding events were significantly more frequent in the ticagrelor group than in the clopidogrel group. MACEs, major adverse cardiovascular events; MI, myocardial infarction; TVR, target vessel revascularization; TIA, transient ischemic attack; CI, confidence interval