Dynamic monitoring of platelet activation and its role in post-dissection inflammation in a canine model of acute type A aortic dissection

Association of preoperative platelet counts with in-hospital mortality in patients with acute type A aortic dissection: a retrospective single-center study

Background

This study aimed to investigate the relationship between preoperative platelet (PLT) count levels and postoperative in-hospital death and mid-term survival in patients with acute type A aortic dissection (ATAAD).

Methods

A total of 341 ATAAD patients who underwent surgery between January 2019 and December 2023 were enrolled in this retrospective study. Preoperative PLT count levels were compared between the two groups for whether in-hospital death occurred. Then, patients were divided into two groups according to the optimal cutoff value by the maximum Youden index (184.5), and confounders were adjusted by multiple models to confirm whether low PLT count was an independent risk factor for in-hospital death after surgery. Kaplan-Meier method was used to draw the survival curve for the mid-term follow-up.

Results

Patients who suffered in-hospital death had lower preoperative PLT count levels. After grouping by PLT count, patients in the low PLT count group exhibited higher in-hospital mortality (16.9% vs. 5.5%; P = 0.004). Univariate logistic regression analysis indicated that ATAAD patients with low PLT count were prone to death during hospitalization [odds ratio (OR): 4.549; 95% confidence interval (CI): 1.515-13.654, p < 0.05]. After adjustment for the potential confounders, low PLT count remained an independent risk factor with postoperative in-hospital death (OR: 3.443, 95%CI: 1.400-8.468, p < 0.05). Mid-term follow-up showed that there was a significant difference in overall survival between different PLT count groups (HR: 3.154; 95%CI: 1.495-6.654, p < 0.05).

Conclusion

A lower level of preoperative PLT count was an independent risk factor for in-hospital death in patients with ATAAD and had a lower survival rate at mid-term follow-up.

Platelets reprogram monocyte functions by secreting MMP-9 to benefit postoperative outcomes following acute aortic dissection

Platelets have a great ability to modulate immune responses. Monocyte-platelet aggregates (MPAs) are associated with the pathogenesis of cardiac disease. Notably, a low preoperative platelet count often indicates poor postoperative recovery following acute aortic dissection (AAD). The functions of platelets and MPAs in AAD, however, remain poorly understood. We found that, despite decreased platelet counts, platelets were also activated in AAD patients, with significant alterations in immune-modulating mediators. Of interest, monocytes in AAD patients had a suppressed immune status, which was correlated with poor outcomes following surgery. Interestingly, platelets preferentially aggregated with monocytes, and the levels of MPAs were related to recovery after surgical repair in AAD patients. Platelets restored suppressed monocyte functions in AAD patients by forming aggregates and partly by secreting matrix metalloproteinase-9 (MMP-9). Thus, the results point to a previously unknown mechanism for platelets involving monocyte reprogramming, which may improve postoperative outcomes following complex cardiovascular surgery.

High platelet distribution width is an independent risk factor of postoperative pneumonia in patients with type A acute aortic dissection

Background

Platelet distribution width (PDW), as a widely applied and reliable marker of platelet activation, was associated with adverse outcomes in cardiovascular diseases. However, there is little literature on the relationship between PDW and postoperative pneumonia in patients with type A acute aortic dissection (AAAD).

Methods

In this retrospective cohort study, we collected consecutive patients who underwent emergency surgery for AAAD at Xiangya Hospital of Central South University from January 1, 2014 and June 30, 2020. Patients were divided into three tertiles on the basis of the PDW. The independent effect of the PDW on postoperative pneumonia was evaluated using multivariate logistic regression analysis, and smooth curve fitting was performed to visualize the linear relationship between PDW and the risk of postoperative pneumonia in patients with AAAD.

Results

A total of 210 patients with AAAD were enrolled and the overall incidence of postoperative pneumonia was 25.24% (n = 53). Multivariate logistic regression revealed that PDW was positively associated with the risk of postoperative pneumonia (OR: 1.07, 95% CI: 1.02–1.13, P < 0.05) after adjusting the confounders. Compared with the lowest PDW tertile, the risk of postoperative pneumonia increased by 1.21-fold in the medium PDW tertile (OR: 2.21, 95% CI: 0.73–6.72) and by 3.16-fold in the highest PDW tertile (OR: 4.16, 95% CI: 1.40–12.33). A straight-line relationship was observed between PDW and postoperative pneumonia risk in smoothing spline fitting.

Conclusion

Our findings indicate that high PDW is an independent risk factor of postoperative pneumonia in patients with AAAD. Preoperative PDW may serve as an available indicator of pneumonia, which helps identify AAAD patients with a high risk of postoperative pneumonia.

Association of Toll-Like Receptor 4 Gene Polymorphisms with Acute Aortic Dissection in a Chinese Han Population

Background

Inflammation may be involved in the pathogenesis of acute aortic dissection (AAD). Toll-like receptor 4 (TLR4) is known to play a critical role in regulating the immune and inflammatory processes. To date, the relationship between genetic variation of TLR4 and AAD is far from clear. The purpose of our study was to illustrate the relevance of TLR4 polymorphisms with the susceptibility to AAD.

Methods

A total of 222 AAD patients and 222 controls were enrolled in this study. Frequency distributions of TLR4 polymorphisms (rs10759932 in the promoter and rs11536889 in the 3′-untranslated region) were determined by the KASP method. Clinical parameters were acquired from subjects' medical records, and serum TLR4 levels were collected from our previously published data.

Results

We found that rs10759932 polymorphism was associated with a reduced risk of AAD in the overall population (CC vs. TT: OR = 0.393, 95%CI = 0.164‐0.939, P = 0.036; recessive model: OR = 0.439, 95%CI = 0.196‐0.984, P = 0.045) and subgroup analyses stratified by sex. The GC genotype and dominant model of rs11536889 conferred a significantly higher risk of AAD compared with GG genotype in female subjects (GC vs. GG: OR = 3.382, 95%CI = 1.051‐10.885, P = 0.041; dominant model: OR = 3.043, 95%CI = 1.041‐8.900, P = 0.042). In addition, a significant interaction between the rs11536889 recessive model and dyslipidemia was observed for an increased risk of AAD (P_interaction = 0.038, OR = 15.229) after the adjustment for potential clinical covariates. We also used the false-positive report probability (FPRP) analysis to validate the significant results. Furthermore, rs11536889 polymorphism could affect the maximal aortic diameters of AAD (P = 0.037), while AAD patients carrying CC genotype of rs10759932 showed lower serum TLR4 levels than TT genotype carriers (P = 0.043).

Conclusions

Our findings provide evidence for the association between TLR4 polymorphisms and AAD susceptibility in a Chinese Han population, which may have some implications for understanding the role of TLR4 in the pathophysiology of AAD.

Factors Associated with Low Admission Platelet Count in Adults with Acute Aortic Dissection

Purpose: Platelets are crucial components of the coagulation processes, and low admission platelet count (PLC) is associated with adverse clinical outcomes in patients with Stanford type A acute aortic dissection (AAD).

Methods: A total of 130 consecutive patients undergoing Stanford type A AAD surgery in Beijing Anzhen Hospital were enrolled between January 2013 and July 2014. Preoperative clinical and laboratory data from patients were collected. Multiple regression analyses were used to determine the independent factors of low admission platelets.

Results: Adjusted multiple regression analysis showed that age (β: −1.069, 95% confidence interval [CI]: −2.109, −0.029), sex (β: −29.973, 95% CI: −56.512, −3.433), tissue factor pathway inhibitor (TFPI; β: 0.197, 95% CI: 0.039, 0.354), fibrinogen degradation product (FDP) (β: −0.476, 95% CI: −0.879, −0.074), and attack time (β: 11.125, 95% CI: 7.963, 14.287) were significantly associated with admission PLC. Admission PLC increased with attack time up to the 3 days (β: 16.2, 95% CI: 12.1, 20.2).

Conclusions: We found that increasing age, male patients, patients with lower serum levels of TFPI and higher serum levels of FDP, and patients with a shorter attack time were significantly associated with lower PLC at admission. Moreover, the turning point of attack time is 3 days after the onset of dissection.

Effects of Autologous Platelet Rich Plasma on Intraoperative Transfusion and Short-Term Outcomes in Total Arch Replacement (Sun's Procedure): A Prospective, Randomized Trial

OBJECTIVE

To observe the effect of collecting and retransfusing autologous platelet rich plasma (aPRP) on the amount of allogeneic blood usage in total arch replacement (Sun's surgery) and the outcomes 30 days after surgery.

DESIGN

A prospective, randomized trial.

SETTING

A tertiary university hospital specialized in cardiovascular diseases.

PARTICIPANTS

The study comprised 120 patients undergoing Sun's surgery for Stanford type A acute aortic dissection.

INTERVENTIONS

aPRP was harvested before incision and was re-transfused after heparin neutralization for patients in the treatment group.

MEASUREMENTS AND MAIN RESULTS

There was no significant difference in preoperative demographic data between the 2 study groups. Intraoperative transfusions of erythrocyte (p = 0.009), plasma (p = 0.017), cryoprecipitate (p = 0.002), and platelets (p < 0.001) in the treatment group were reduced significantly. In addition, less blood loss was observed in the treatment group (p = 0.002). The durations of postoperative mechanical ventilation (p = 0.029) and hospitalization (p = 0.002) of the treatment group were significantly shorter. There were no statistically significant differences in the length of intensive care unit stay, the incidence of complications, and mortality 30 days after surgery.

CONCLUSION

In total arch replacement (Sun's surgery), collecting and retransfusing aPRP reduced intraoperative transfusions of erythrocyte, plasma, and cryoprecipitate and decreased the duration of postoperative mechanical ventilation and hospitalization. This technique had no significant effect on the incidence of complications and mortality 30 days postoperatively.

Serum levels of matrix metalloproteinase 9 and toll-like receptor 4 in acute aortic dissection: a case-control study

Background

Matrix metalloproteinase 9 (MMP9) and Toll-like receptor 4 (TLR4) play important roles in aortic pathophysiology. However, there is lacking research on serum TLR4 levels in acute aortic dissection (AAD) patients, and the performance of serum MMP9 and TLR4 for the diagnosis of AAD is still unknown. This study aimed to evaluate the serum levels of MMP9 and TLR4 in AAD patients, identify their associations with circulating C-reactive protein (CRP) and D-dimer, which are well-known classical biomarkers of AAD, and further explore the potential diagnostic role of MMP9 and TLR4 in AAD.

Methods

Serum levels of MMP9 and TLR4 were measured by enzyme-linked immunosorbent assay (ELISA) in 88 AAD patients and 88 controls. The clinical test related information was collected from patients’ electronic medical records.

Results

Serum MMP9 and TLR4 levels were significantly higher in AAD patients than those in healthy controls in the general and stratified comparisons. Either serum MMP9 or TLR4 was independently associated with the risk of AAD (all p < 0.001). There was a positive significant association between serum MMP9 and TLR4 (r = 0.518, p < 0.001). Both MMP9 and TLR4 levels were statistically correlated with circulating CRP, but not D-dimer. Based on receiver-operating characteristic (ROC) analysis, the area under the curves (AUCs) of MMP9 and TLR4 alone for the diagnosis of AAD were 0.810 and 0.799 with optimal cut-off points of 379.47 ng/ml and 7.83 ng/ml, respectively. Moreover, a combination of serum MMP9 and TLR4 increased the AUC to 0.89 with a sensitivity of 60.2% and specificity of 94.3%.

Conclusions

Serum MMP9 and TLR4 could be potential biomarkers for identifying AAD, while the combined diagnostic value was higher in safely ruling out AAD.

Cytokines in aortic dissection

Aortic dissection (AD) is one of the most dangerous forms of vascular disease, characterized by endometrial rupture and intramural hematoma formation. Generally, the pathological process is complicated and closely related to the infiltration of inflammatory cells into the aortic wall and apoptosis of vascular smooth muscle cells. Currently, multiple cytokines, including interleukins, interferon, the tumor necrosis factor superfamily, colony stimulating factor, chemotactic factor, growth factor and so on, have all been demonstrated to play a critical role in AD. Additionally, studies of the link between cytokines and AD could deepen our understanding of the disease and may guide future treatment therapies; therefore, this review focuses on the role of cytokines in AD.

Association of Plasma Pentraxin-3 Levels on Admission with In-hospital Mortality in Patients with Acute Type A Aortic Dissection

BACKGROUND

Acute aortic dissection is a life-threatening cardiovascular emergency. Pentraxin-3 (PTX3) is proposed as a prognostic marker and found to be related to worse clinical outcomes in various cardiovascular diseases. This study sought to investigate the association of circulating PTX3 levels with in-hospital mortality in patients with acute Type A aortic dissection (TAAD).

METHODS

A total of 98 patients with TAAD between January 2012 and December 2015 were enrolled in this study. Plasma concentrations of PTX3 were measured upon admission using a high-sensitivity enzyme-linked immunosorbent assay system. Patients were divided into two groups as patients died during hospitalization (Group 1) and those who survived (Group 2). The clinical, laboratory variables, and imaging findings were analyzed between the two groups, and predictors for in-hospital mortality were evaluated using multivariate analysis.

RESULTS

During the hospital stay, 32 (33%) patients died and 66 (67%) survived. The patients who died during hospitalization had significantly higher PTX3 levels on admission compared to those who survived. Pearson's correlation analysis demonstrated that PTX3 correlated positively with high-sensitivity C-reactive protein (hsCRP), maximum white blood cell count, and aortic diameter. Multivariate logistic regression analysis demonstrated that PTX3 levels, coronary involvement, cardiac tamponade, and a conservative treatment strategy are significant independent predictors of in-hospital mortality in patients with TAAD. The receiver operating characteristic curve analysis further illustrated that PTX3 levels on admission were strong predictors of mortality with an area under the curve of 0.89. A PTX3 level ≥5.46 ng/ml showed a sensitivity of 88% and a specificity of 79%, and an hsCRP concentration ≥9.5 mg/L had a sensitivity of 80% and a specificity of 69% for predicting in-hospital mortality.

CONCLUSION

High PTX3 levels on admission are independently associated with the in-hospital mortality in patients with TAAD.