No Differences in Gastrointestinal Bleeding Risk among Clopidogrel-, Ticagrelor-, or Prasugrel-Based Dual Antiplatelet Therapy

The Impact of Antithrombotic Therapy in Patients with De-compensated Heart Failure and Iron

Abstract: The iron deficient anaemia is a common medical condition in patients with heart failure receiving antithrombotic therapy. Especially during the COVID19 pandemic period the rate of bleeding complications associated with the antithrombotic therapy tend to be higher, as the patient’s referral to medical services is lower and the interaction doctor-patient is limited. In our retrospective observational study we included 300 consecutive patients with decompensated heat failure associating iron deficient anaemia. For defining the medical conditions we used the ESC guidelines terminology and diagnostic criteria. We assessed the association between the iron deficient anaemia and different antithrombotic therapies, recommended in concordance to ESC Guidelines. We found that aspirin 75mg/day was statistical significant associated with iron deficient anaemia (p 0.012) and anaemia severity (p 0.002), this association being assessed by Chi square and Pearson tests. Also, neither clopidogrel, ticagrelor, VKA or non-VKA were associated to the presence of anaemia. By assessing the mortality rate associated to anaemia severity, the severe anaemia was associated to higher mortality rate, meanwhile no antithrombotic therapy was associated with higher readmission or mortality rate (p<0.001). In conclusion, aspirin was the only antithrombotic therapy associated with the presence of anaemia and anaemia severity, while only severe anaemia was associated with statistic significant increase of patient’s mortality, with nonstatistical result regarding the readmission rate. This finding is concordant to the necessity of a permanent evaluation of the antithrombotic therapy in heart failure patients. Keywords: antithrombotic therapy, decompensated heart failure, iron deficient anaemia, COVID 19 pan-demic, mortality rate

Antiplatelet Activity of Tetramethylpyrazine via Regulation of the P2Y12 Receptor Downstream Signaling Pathway

Background

Tetramethylpyrazine (TMP) is an alkaloid in Chinese herbal medicine, which possesses antiplatelet activity. TMP inhibits platelet activation in many ways. The platelet P2Y₁₂ receptor for adenosine 5′ diphosphate (ADP) plays a central role in platelet function, hemostasis, and thrombosis. Here, we investigated the inhibitory effect of TMP on P2Y₁₂ receptor-related platelet function.

Methods

The inhibitory potential of TMP was assessed using agonist-induced platelet aggregation, flow cytometric analysis of CD62p expression, PAC-1 activation, and fibrin clot retraction. After the P2Y12 receptor-related signaling pathway was inhibited using the blocker, platelet activation was studied by platelet aggregation, CD62p expression, and PAC-1 activation. The secretion of cyclic adenosine monophosphate (cAMP) was measured using enzyme-linked immunosorbent assay (ELISA), and the expression of signaling pathway protein, phosphorylation of vasodilator-stimulated phosphoprotein, and phosphorylation of Akt were investigated using western blotting. The release of platelet inflammatory mediators was measured using ELISA.

Results

TMP had an antiplatelet effect by inhibiting ADP-induced aggregation, P-selectin secretion, and glycoprotein (GP) IIb/IIIa expression and reducing the release of atherosclerotic-related inflammatory mediators (sCD40L and IL-1β). TMP decreased the area of clot retraction, reflecting inhibition of GPIIb/IIIa activation. TMP inhibited adenosine diphosphate-induced platelet activation via increased cAMP production, VASP^ser157 phosphorylation, and Akt dephosphorylation.

Conclusion

TMP selectively inhibits ADP-induced platelet activation via P2Y₁₂ receptor-related signaling pathways.