Quantifying immature platelets as markers of increased platelet production after coronary artery bypass grafting surgery

Platelet transfusion enhances pro-aggregatory status shortly after coronary artery bypass grafting (CABG while modulating platelet pro-inflammatory state 1-week post-surgery

During coronary artery bypass grafting (CABG), the surgical procedure, particularly the manipulation of the major arteries of the heart, induces a significant inflammatory state that may compromise platelet function to the extent that platelet transfusion is required. Given stored platelets as a major source of biological mediators, this study investigates the effects of platelet transfusion on the major pro-aggregatory, pro-inflammatory and immunomodulatory markers of platelets. Platelets from 20 patients, 10 who received platelet transfusion and 10 without, were subjected to flow cytometery where P-selectin and CD40 ligand (CD40L) expressions and PAC-1 binding (activation-specific anti GPIIb/GPIIIa antibody) analysed at five-time points of 24 h before surgery, immediately, 2 h, 24 h and 1 week after surgery. Analysis of intra-platelet transforming growth factor-beta-1 (TGF-β1) was also conducted using western blotting. Patients with platelet transfusion showed increased levels of P-selectin, CD40L and intra-platelet TGF-β1 2-h after surgery compared to those without transfusion (p < 0.05). PAC-1 binding was increased 24 h after surgery in transfused patients (p < 0.05). Given the significant post-transfusion elevation of platelet TGF-β1, P-sel/CD40L reduction in transfused patients a week after was of much interest. This study showed for the first time the significant effects of platelet transfusion on the pro-inflammatory, pro-aggeregatory and immunomodulatory state of platelets in CABG patients, which manifested with immediate, midterm and delayed consequences. While the increased pro-inflammatory conditions manifested as an immediate effect of platelet transfusion, the pro-aggregatory circumstances emerged 24 h post-transfusion. A week after surgery, attenuations of pro-inflammatory markers of platelets in transfused patients were shown, which might be due to the immunomodulatory effects of TGF-β1.

Risk factor analysis of clinical outcomes of total aortic arch replacement and frozen elephant trunk with aortic balloon occlusion

Background

Total aortic arch replacement (TAR) with frozen elephant trunk (FET) requires hypothermic circulatory arrest (HCA) for 20 min, which increases the surgical risk. We invented an aortic balloon occlusion (ABO) technique that requires 5 min of HCA on average to perform TAR with FET and investigated the possible merit of this new method in this study.

Methods

This retrospective study included consecutive patients who underwent TAR and FET (consisting of 130 cases of ABO group and 230 cases of conventional group) in Fuwai Hospital between August 2017 and February 2019. In addition to the postoperative complications, the alterations of blood routine tests, alanine transaminase (ALT) and aspartate transaminase (AST) during in-hospital stay were also recorded.

Results

The 30-day mortality rates were similar between ABO group (4.6%) and conventional group (7.8%, P = 0.241). Multivariate analysis showed ABO reduced postoperative acute kidney injury (23.1% vs. 35.7%, P = 0.013) and hepatic injury (12.3% vs. 27.8%, P = 0.001), and maintained similar cost to patients (25.5 vs. 24.9 kUSD, P = 0.298). We also found that AST was high during intensive care unit (ICU) stay and recovered to normal before discharge, while ALT was not as high as AST in ICU but showed a rising tendency before discharge. The platelet count showed a rising tendency on postoperative day 3 and may exceed the preoperative value before discharge.

Conclusions

The ABO achieved the surgical goal of TAR with FET with an improved recovery process during the in-hospital stay.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01643-3.

Reticulated Platelets in Medicine: Current Evidence and Further Perspectives

Reticulated platelets (RPs) are young thrombocytes, newly released from the bone marrow. The identification and quantification of these cells remained difficult for decades due to a lack of standardized preanalytical and analytical methods. With the introduction of automated hematology analyzers in clinical routine, the determination of RPs, either as a total count or as a fraction, became more reliable, faster and more affordable. Currently, RPs are the focus of research in multiple clinical settings. In cardiovascular medicine, recent studies have focused on the relationship between RPs, coronary artery disease (CAD) and clinical outcomes, as well as the impact of RPs on the effects of antiplatelet therapy. Cohort studies showed increased levels of RPs in patients with acute coronary syndrome (ACS) or cardioembolic stroke. In patients with ACS, increased levels of RPs were also associated with an increased incidence of major ischemic cardiovascular events during follow-up. Further studies showed an association of levels of RPs with the antiplatelet response to less-potent P2Y12 inhibitors. In patients with paroxysmal atrial fibrillation undergoing pulmonary vein isolation, levels of RPs differed significantly depending on the achieved rhythm (sinus rhythm vs. recurrent atrial fibrillation). Levels of RPs appear to also be predictive for bleeding events in patients with various hematological diagnoses. Although no causal relationship has so far been proven, RP values have been associated with a large number of pathologies and clinical scenarios. This review summarizes the current evidence with regard to RPs and their potential diagnostic and prognostic value for noncardiovascular patients and for cardiovascular patients in particular. It describes further perspectives on how the testing of these cells might improve the treatment of cardiovascular patients.