Cardiovascular risk factors are important determinants of platelet-dependent thrombin generation in adult survivors of childhood cancer

A cohort study on blood coagulation in childhood cancer survivors

Cancer survivors are at an increased risk of thromboembolism compared to the general pediatric population. Anticoagulant therapy decreases the risk of thromboembolism in cancer patients. We hypothesized that pediatric cancer survivors are in a chronically hypercoagulable state compared to healthy controls. Children who survived for more than five years from cancer diagnosis at the UT Health Science Center at San Antonio Cancer Survivorship Clinic were compared to healthy controls. The exclusion criteria were recent NSAID use or a history of coagulopathy. Coagulation analysis included platelet count, thrombin-antithrombin complexes (TAT), plasminogen activator inhibitor (PAI), routine coagulation assays, and thrombin generation with and without thrombomodulin. We enrolled 47 pediatric cancer survivors and 37 healthy controls. Platelet count was significantly lower in cancer survivors at a mean of 254 × 10⁹/L (95%CI: 234-273 × 10⁹/L) compared at 307 × 10⁹/L (283-331 × 10⁹/L) in healthy controls (p < 0.001), although not outside the normal range. Routine coagulation assays showed no differences, except for a significantly lower prothrombin time (PT) in cancer survivors (p < 0.004). Cancer survivors has significantly elevated biomarkers of the procoagulant state, such as TAT and PAI, compared to healthy controls (p < 0.001). A multiple logistic regression model controlling for age, BMI, gender, and race/ethnicity documented that a low platelet count, short prothrombin clot time, and higher procoagulant biomarkers (TAT and PAI) were significantly associated with past cancer therapy. Survivors of childhood cancer have a persistent procoagulant imbalance for more than five years after diagnosis. Further studies are needed to establish whether procoagulant imbalance increases the risk of thromboembolism in childhood cancer survivors.

Plasmatic Coagulation Capacity Correlates With Inflammation and Abacavir Use During Chronic HIV Infection

BACKGROUND

D-dimer concentrations in people living with HIV (PLHIV) on combination antiretroviral therapy (cART) are increased and have been linked to mortality. D-dimer is a biomarker of in vivo coagulation. In contrast to reports on D-dimer, data on coagulation capacity in PLHIV are conflicting. In this study, we assessed the effect of cART and inflammation on coagulation capacity.

SETTING

We explored coagulation capacity using calibrated thrombin generation (TG) and linked this to persistent inflammation and cART in a cross-sectional study including PLHIV with viral suppression and uninfected controls.

METHODS

We used multivariate analyses to identify independent factors influencing in vivo coagulation (D-dimer) and ex vivo coagulation capacity (TG).

RESULTS

Among 208 PLHIV, 94 (45%) were on an abacavir-containing regimen. D-dimer levels (219.1 vs 170.5 ng/mL, P = 0.001) and inflammatory makers (sCD14, sCD163, and high-sensitive C-reactive protein) were increased in PLHIV compared with those in controls (n = 56). PLHIV experienced lower TG (reflected by endogenous thrombin potential [ETP]) when compared with controls, after correction for age, sex, and antiretroviral therapy. Abacavir use was independently associated with increased ETP. Prothrombin concentrations were strongly associated with ETP and lower in PLHIV on a non-abacavir-containing regimen compared with those in controls, suggesting consumption as a possible mechanism for HIV-associated reduction in TG. D-dimer concentrations were associated with inflammation, but not TG.

CONCLUSIONS

Abacavir use was associated with increased TG and could serve as an additional factor in the reported increase in thrombotic events during abacavir use. Increased exposure to triggers that propagate coagulation, such as inflammation, likely underlie increased D-dimer concentrations found in most PLHIV.

Midregional pro atrial natriuretic peptide: a novel important biomarker for noise annoyance-induced cardiovascular morbidity and mortality?

Background

Environmental noise exposure has been associated with increased cardiovascular morbidity and mortality. Recently, noise annoyance was shown to induce atrial fibrillation, which was accompanied by significantly increased levels of midregional pro atrial natriuretic peptide (MR-proANP). Therefore, the aim of the present study was to analyze the association between noise annoyance, MR-proANP, incident cardiovascular events, and all-cause mortality.

Methods

Levels of MR-proANP were measured in the first 5000 participants of the population-based Gutenberg Health Study. Annoyance was assessed separately for aircraft, road traffic, railway, neighborhood, and industrial/construction noise during the day and sleep.

Results

In cross-sectional analyses, aircraft noise annoyance during day and sleep, industrial/construction noise annoyance during day, and railway noise annoyance during sleep were independently associated with increased levels of MR-proANP after multivariable adjustment. After a 5-year follow-up period, there were 43 cases of incident atrial fibrillation and 103 of incident cardiovascular disease (comprising atrial fibrillation, coronary artery disease, myocardial infarction, heart failure, or stroke). Moreover, there were 301 deaths after a mean follow-up of 7.42 ± 1.66 years. An odds ratio (OR) of 2.82 ([95% confidence interval (CI) 1.86; 4.35], p < 0.0001) for incident atrial fibrillation and an OR of 1.49 ([95% CI 1.13; 1.96], p = 0.0046) for incident cardiovascular disease per 1-standard deviation (SD) increase in MR-proANP levels were found. A 36% (hazard ratio: 1.36 [95% CI 1.19; 1.55], p < 0.0001) higher risk of death was found per 1-SD increase in MR-proANP levels.

Conclusions

Noise annoyance may contribute to cardiovascular morbidity and mortality and is characterized by increased levels of MR-proANP.

Graphic abstract

Recurrent infective endocarditis versus first-time infective endocarditis after heart valve surgery

OBJECTIVE

Infective endocarditis (IE) may require heart valve surgery. It is well known that heart valve surgery itself and previous IE predispose to IE. However, data are sparse on whether the risk of IE is different among patients undergoing valve surgery due to IE and other causes (i.e. recurrent vs. first-time IE).

METHODS

Using Danish nationwide registries, patients undergoing left-sided heart valve surgery in the course of an IE hospitalization (1996-2017) were identified and matched with controls undergoing left-sided heart valve surgery due to another cause than IE in a 1:1 ratio. Patients were stratified according to type of surgical valve intervention and affected valve. The comparative risk of recurrent vs. first-time IE was assessed by cumulative incidence curves and multivariable Cox regression analyses.

RESULTS

The study population comprised 971 patients with a first-time admission for IE requiring heart valve surgery matched with 971 controls undergoing heart valve surgery due to other causes than IE. The risk of recurrent IE was significantly higher than the risk of first-time IE following heart valve surgery (5.5% and 3.0% by 10 years, hazard ratio (HR) 1.66, 95% confidence interval (CI) 1.02-2.70). The risk of IE recurrence was not significantly different comparing valve replacement and valve repair (5.5% and 5.3%, respectively, HR 1.60, 95% CI 0.71-3.60). Yet, the risk of IE recurrence was significantly higher among patients with biological versus mechanical prostheses (6.3% and 4.6%, respectively, HR 2.00, 95% CI 1.02-3.70).

CONCLUSIONS

Following heart valve surgery, the risk of recurrent IE was significantly higher than the risk of first-time IE.

Clinical Applications, Pitfalls, and Uncertainties of Thrombin Generation in the Presence of Platelets

Platelet-dependent thrombin generation is a helpful tool to assess ex vivo the interaction between platelets and plasma coagulation factors in the initiation, amplification, and inhibition of thrombin generation (TG). This review article discusses the most relevant available data on the clinical applications of fluorogenic TG, the most widely used TG assay, performed in the presence of platelets, i.e., in platelet-rich plasma. With respect to prothrombotic states, arterial hypertension and obesity were the most prominent cardiovascular conditions linked to increased platelet-dependent TG. In addition, platelet-associated hypercoagulability, assessed by the TG assay, has been shown in individuals with active cancer. In terms of bleeding, platelet-dependent TG has been applied to assess bleeding risk in individuals with hemophilia, von Willebrand disease, and Glanzmann thrombasthenia as well as in subjects with other congenital or acquired coagulation factor deficiencies. In addition to risk prediction, a role of the TG assay has been suggested in monitoring antiplatelet therapy in prothrombotic conditions and replacement therapy in bleeding diathesis. Finally, for the routine clinical use and as a biomarker of disease development and progression, better standardization and clinical validation of platelet-dependent TG are still needed.

Relation between platelet coagulant and vascular function, sex-specific analysis in adult survivors of childhood cancer compared to a population-based sample

Female sex is a risk factor for long-term adverse outcome in cancer survivors, however very little is known for the underlying pathophysiological mechanisms rendering the increased risk. This study investigated sex-specifically the relation between thrombin generation (TG) with and without presence of platelets and vascular function in 200 adult survivors of a childhood cancer compared to 335 population-based control individuals. TG lag time, peak height and endogenous thrombin potential (ETP) measured in presence and absence of platelets were correlated to reflection index (RI) and stiffness index (SI). A sex-specific correlation analysis showed a negative relation in female survivors for platelet-dependent peak height and/or ETP and RI only. An age adjusted linear regression model confirmed the negative association between RI and platelet-dependent ETP (beta estimate: −6.85, 95% confidence interval: −12.19,−1.51) in females. Adjustment for cardiovascular risk factors resulted in loss of the association, whereby arterial hypertension and obesity showed the largest effects on the observed association. No other relevant associations were found in male and female cancer survivors and all population-based controls. This study demonstrates a link between platelet coagulant and vascular function of resistance vessels, found in female cancer survivors, potentially mediated by the presence of arterial hypertension and obesity.