Age-related changes in the hemostatic system

Supplementation with l-arginine and nitrates vs age and individual physiological reactivity

Ageing is a natural ontogenetic phenomenon that entails a decrease in the adaptive capacity of the organism, as a result of which the body becomes less adaptable to stressful conditions. Nitrate and nitrite enter the body from exogenous sources and from nitrification of ammonia nitrogen by intestinal microorganisms. This review considers the mechanisms of action of l-arginine, a known inducer of nitric oxide (NO) biosynthesis, and nitrates as supplements in the processes of ageing and aggravated stress states, in which mechanisms of individual physiological reactivity play an important role. This approach can be used as an element of individual therapy or prevention of premature ageing processes depending on the different levels of initial reactivity of the functional systems. A search was performed of the PubMed, Scopus, and Google Scholar databases (n = 181 articles) and the author's own research (n = 4) up to May 5, 2023. The review presents analyses of data on targeted treatment of NO generation by supplementation with l-arginine or nitrates, which is a promising means for prevention of hypoxic conditions frequently accompanying pathological processes in an ageing organism. The review clarifies the role of the individual state of physiological reactivity, using the example of individuals with a high predominance of cholinergic regulatory mechanisms who already have a significant reserve of adaptive capacity. In studies of the predominance of adrenergic influences, a poorly trained organism as well as an elderly organism correspond to low resistance, which is an additional factor of damage at increased energy expenditure.

CONCLUSION

It is suggested that the role of NO synthesis from supplementation of dietary nitrates and nitrites increases with age rather than from oxygen-dependent biosynthetic reactions from l-arginine supplementation.

Sex-specific differences in the clinical profile among psychiatric patients with pulmonary Embolism: a hospital-based retrospective study

BACKGROUND

Pulmonary embolism (PE) is a severe and life-threatening complication of venous thromboembolism. However, there is a lack of systematic studies on differences between female and male PE patients. This paper aimed to compare the sex-specific differences in clinical characteristics and laboratory indicators in psychotic patients with PE.

METHODS

This retrospective study enrolled psychiatric patients with PE from June 2018 to June 2022 at Shenzhen Kangning Hospital (Shenzhen Mental Health Center). Demographic characteristics, factors associated with PE, and laboratory indices were collected to assess sex-specific differences.

RESULTS

Of the 168 patients, 87 (51.8%) were female and 81 (48.2%) were male, with a mean age of 58 years for females and 46 years for male patients. The male group had higher ratio of hyperprolactinemia, more patients using antipsychotic medications, higher D-dimer levels at PE onset, greater D-dimer difference, and a higher rate of D-dimer elevation than the female group (p < 0.05). Female patients were significantly older, exhibited a higher prevalence of diabetes, and had a greater number of patients taking antidepressants and hypnotics/sedatives than male patients (p < 0.05). Schizophrenia spectrum disorders were more prevalent in male patients, while female patients had a higher incidence of mood disorders (p < 0.05). Among patients aged < 45 years, the male group had higher D-dimer levels at PE onset and greater D-dimer difference (p < 0.05). Among all 112 patients aged ≥ 45 years, male patients were more likely than female patients to have respiratory tract infections, higher D-dimer levels at PE onset, greater D-dimer difference, and a higher rate of D-dimer elevation (p < 0.05). The multiple linear regression analysis indicated that hyperprolactinemia and the use of first-generation antipsychotics (FGAs) were associated with D-dimer levels at PE onset in male patients, while the time of PE onset and protective restraints were associated with D-dimer levels at PE onset in female patients (p < 0.05).

CONCLUSION

PE-associated clinical features differ between male and female patients. These differences may imply that the processes and mechanisms of PE onset are sex specific. Male patients are more likely to have respiratory tract infections and higher D-dimer levels at PE onset than female patients. The use of FGAs may be associated with increased D-dimer in male psychiatric patients, while protective restraints may be associated with increased D-dimer in female psychiatric patients.

The Relationship between Fragmented QRS and Myocardial Injury in Patients with Acute Carbon Monoxide Poisoning

Background and Objectives: Carbon monoxide (CO) intoxication is one of the most common causes of poisoning-related deaths and complications. Myocardial injury is an important complication of CO poisoning. In our study, we aimed to evaluate the relationship between the presence and prevalence of fragmented QRS (fQRS) and myocardial injury in patients with CO intoxication. Materials and Methods: We retrospectively evaluated patients who presented to the emergency department of our tertiary care center with CO intoxication between January 2020 and December 2023. In our study, we performed subgroup analyses according to the presence of myocardial injury and fQRS. We evaluated the parameters and risk factors associated with myocardial injury. Results: Myocardial injury was detected in 44 patients, and fQRS was detected in 38 patients. In the myocardial injury (+) group, the fQRS rate was 38.6%, and the median number of leads with fQRS was 3 (2-6) and was significantly higher than in the myocardial injury (-) group (p < 0.001). We found that carboxyhemoglobin had a significant positive correlation with troponin (p = 0.001) and pro-B-type natriuretic peptide (proBNP) (p = 0.009). As a result of multivariate analysis, we determined that age, creatinine, proBNP, fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury. Conclusions: Myocardial injury in CO intoxication patients is associated with proBNP, the presence of fQRS, and the number of leads with fQRS. Age, creatinine level, proBNP, the presence of fQRS, and ≥3 leads with fQRS are independent risk factors for myocardial injury in patients with CO intoxication.

Associations of exposure to disinfection by-products with blood coagulation parameters among women: Results from the Tongji reproductive and environmental (TREE) study

BACKGROUND

Experimental studies have shown that disinfection byproducts (DBPs) induce coagulotoxicity, but human evidence is scarce.

OBJECTIVE

This study aimed to explore the relationships of DBP exposures with blood coagulation parameters.

METHODS

Among 858 women from the Tongji Reproductive and Environmental (TREE) study, urinary dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were detected as internal biomarkers of DBP exposures. We measured activated partial thromboplastin time (APTT), fibrinogen (Fbg), international normalized ratio (INR), prothrombin time (PT), and thrombin time (TT) as blood coagulation parameters. Multivariable linear regression models were utilized to estimate the relationships between urinary DCAA and TCAA and blood coagulation parameters. The effect modifications by demographic and lifestyle characteristics were further explored.

RESULTS

Elevated tertiles of urinary DCAA concentrations were associated with increased PT and INR (11.29%, 95% CI: 1.66%, 20.92% and 0.99%, 95% CI: 0.08%, 1.90% for the third vs. first tertile, respectively; both P for trends < 0.05). Stratification analysis showed that the positive associations were only observed among younger (< 30 years), leaner (body mass index < 24.0 kg/m2), and non-passive smoking women. Moreover, elevated tertiles of urinary TCAA concentrations in positive associations with PT and INR were observed among younger women (17.89%, 95% CI: 2.50%, 33.29% and 1.82%, 95% CI: 0.34%, 3.30% for the third vs. first tertile, respectively; both P for trends < 0.05) but not among older women (both P for interactions < 0.05).

CONCLUSION

Higher levels of urinary DCAA and TCAA are associated with prolonged clotting time among women.

Association of telomere length and mitochondrial DNA copy number, two biomarkers of biological aging, with the risk of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is the third most common cardiovascular disease and occurs in all age groups, albeit the risk increases considerably with age. Previous research indicates mitochondrial dysfunction and telomere shortening in cardiovascular aging. However, in the context of VTE this has not been investigated in detail.

AIM

We aimed to explore biomarkers reflecting biological aging (i.e. human mitochondrial DNA copy number (mtDNA) and telomere length) and their association with VTE.

METHODS

mtDNA and telomere length were measured in a case-control study of 116 patients with a history of VTE and 128 age- and sex-matched healthy individuals from isolated blood using a qPCR-based assay kit. Cases had at least one unprovoked VTE event and were enrolled no earlier than 3 months after the last VTE event.

RESULTS

The mtDNA copy number was significantly lower in VTE cases compared to controls (median [IQR]: 663 per diploid cells [78.75-2204.5] vs. 2832 per diploid cells [724-4350]; p < 0.001). After adjustment for age, sex, BMI, and smoking, mtDNA copy number was independently associated with VTE risk (odds ratio per increase in 400 mtDNA per diploid cell: 0.889, 95%CI 0.834-0.947). mtDNA copy numbers were significantly different between women and men (2375 [455-3737] women vs. 893 [152-3154] men; p < 0.001). The analysis of telomere length showed no significant difference between patients and healthy controls.

CONCLUSION

Lower mtDNA levels were found in patients with VTE compared to controls, indicating an association of biological aging with risk of VTE.

Ocular proteomic and transcriptomic changes with aging in a rabbit model of lensectomy with intraocular lens insertion

Children that undergo intraocular surgery have an exaggerated postoperative response compared to adults that can result in significant postoperative challenges and reduced post-operative visual acuity. Rabbits were used as an animal model for investigating aging differences, treatment options, and surgical techniques for anterior chamber surgical interventions due to similarities in anterior chamber size and decreasing postoperative response with age. In our study, juvenile and adult rabbits underwent lensectomy with intraocular lens (IOL) insertion to determine how ocular RNA transcripts and proteins change with age. Rabbits underwent lensectomy with IOL insertion, and aqueous humor (AH) was collected immediately prior to surgery and at the peak of the postoperative response on post-operative day 3. Proteins related to coagulation and inflammation were assessed using targeted mass spectrometry. In addition, the cornea and iris/ciliary body tissues were dissected, and transcripts analyzed using RNA sequencing. While clinically, juvenile rabbits have greater fibrin formation following intraocular surgery compared to older rabbits, this change does not appear to be related to relative abundance levels of coagulation and inflammatory proteins in the AH. Gene transcript levels from a variety of immune response and inflammatory pathways reflected significant increases when comparing operated to unoperated ocular tissues, indicating the significant impact that surgery has on each ocular structure. This work further advances our understanding of how the rabbit eye proteomic and transcriptomic changes in response to surgery with aging, as we seek to ultimately identify the mechanisms for the exaggerated postoperative responses after pediatric intraocular surgery.

Comparison of 3-Year Outcomes between Early and Delayed Invasive Strategies in Older and Younger Adults with Non-ST-Segment Elevation Myocardial Infarction Undergoing New-Generation Drug-Eluting Stent Implantation

We evaluated the 3-year clinical outcomes of early invasive (EI) and delayed invasive (DI) strategies in older and younger adults with non-ST-segment elevation myocardial infarction (NSTEMI) undergoing successful new-generation drug-eluting stent (DES) implantation to reflect current real-world practice. Overall, 4513 patients with NSTEMI were recruited from the Korea Acute Myocardial Infarction Registry-National Institute of Health and divided into two groups according to age: group A (age ≥ 65 years, n = 2253) and group B (age < 65 years, n = 2260). These two groups were further divided into two subgroups: group EI (A1 and B1) and DI (A2 and B2). The primary clinical outcome was the occurrence of major adverse cardiac and cerebrovascular events (MACCEs), defined as all-cause death, recurrent MI (re-MI), any repeat coronary revascularization, or stroke. The secondary clinical outcome was definite or probable stent thrombosis (ST). In both groups A and B, after multivariable-adjusted and propensity score-adjusted analyses, MACCE (group A, p = 0.137 and p = 0.255, respectively; group B, p = 0.171 and p = 0.135, respectively), all-cause death, cardiac death (CD), non-CD, re-MI, any repeat revascularization, stroke, and ST rates were similar between the EI and DI groups. When including only those with complex lesions, the primary and secondary clinical outcomes were not significantly different between the EI and DI groups. In the era of new-generation DESs, major clinical outcomes were not significantly different between the EI and DI strategies in both older and younger adults with NSTEMI.

Outcomes of early versus delayed invasive strategy in older adults with non-ST-segment elevation myocardial infarction

We evaluated the 3-year clinical outcomes following early invasive (EI) and delayed invasive (DI) strategies in older adults with non-ST-segment elevation myocardial infarction (NSTEMI) undergoing successful new-generation drug-eluting stents (DESs) implantation to reflect current real-world practice. Overall, 2437 older adults (age, ≥ 65 years) with NSTEMI were recruited from the Korea Acute Myocardial Infarction Registry-National Institute of Health. They were divided into two groups: EI (n = 1750) and DI (n = 687). The primary clinical outcome was the occurrence of major adverse cardiac and cerebrovascular events (MACCEs), defined by all-cause death, recurrent MI, any repeat coronary revascularization, and stroke. The secondary clinical outcome was stent thrombosis (ST). After multivariable-adjusted and propensity score-matched analyses, the primary and secondary clinical outcomes were not significantly different between the EI and DI groups. Even after the analysis was confined to those having complex lesions, these major clinical outcomes were similar between these two groups. The EI and DI strategies in older adults with NSTEMI receiving new-generation DES showed comparable results.

Clinical Trial Registration: URL: http://cris.nih.go.kr/cris/en/; Unique identifier: KCT0000863.

The Many Faces of JAKs and STATs Within the COVID-19 Storm

The positive-sense single stranded RNA virus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), resulted in a global pandemic with horrendous health and economic consequences not seen in a century. At a finer scale, immunologically, many of these devastating effects by SARS-CoV-2 can be traced to a "cytokine storm" resulting in the simultaneous activation of Janus Kinases (JAKs) and Signal Transducers and Activators of Transcription (STAT) proteins downstream of the many cytokine receptor families triggered by elevated cytokines found in Coronavirus Disease 2019 (COVID-19). In this report, cytokines found in the storm are discussed in relation to the JAK-STAT pathway in response to SARS-CoV-2 and the lessons learned from RNA viruses and previous Coronaviruses (CoVs). Therapeutic strategies to counteract the SARS-CoV-2 mediated storm are discussed with an emphasis on cell signaling and JAK inhibition.

Age-adjusted D-dimer cut-off levels to rule out venous thromboembolism in patients with non-high pre-test probability: Clinical performance and cost-effectiveness analysis

BACKGROUND

As aging was found to be associated with increased D-dimer levels, the question arose whether D-dimer measurement was useful in the diagnostic strategy of venous thromboembolism (VTE) in elderly patients.

AIM OF THE STUDY

To compare retrospectively the performance of six diagnostic strategies based on the three-level Wells scores and various cut-off levels for D-dimer, evaluated using the HemosIL D-Dimer HS 500 assay, in a derivation cohort of 644 outpatients with non-high pretest probability (PTP) of VTE. The clinical usefulness of the best-performing strategy was then confirmed in a multicenter validation study involving 1255 consecutive outpatients with non-high PTP.

RESULTS

The diagnostic strategy based on the age-adjusted cut-off level calculated by multiplying the patient's age by 10 above 50 years was found to perform the best in the derivation study with a better sensitivity-to-specificity ratio than the conventional strategy based on the fixed cut-off level (500 ng/ml), a higher specificity and a negative predictive value (NPV) above 99%. Such an increase in test specificity was confirmed in the validation cohort, with the NPV remaining above 99%. Taking into account the local reimbursement rates of diagnostic tests, using this strategy led to a 6.9% reduction of diagnostic costs for pulmonary embolism and a 5.1% reduction for deep vein thrombosis, as imaging tests would be avoided in a higher percentage of patients.

CONCLUSION

The diagnostic strategy of VTE based on the age-adjusted cut-off level for D-dimer in patients over 50 years was found to be safe, with NPV above 99%, and cost-effective.

Elderly people are inherently sensitive to the pharmacological activity of rivaroxaban: implications for DOAC prescribing

According to both trial and clinical data on direct oral anticoagulants (DOACs) elderly patients are at greatest risk of bleeding. It is unclear whether age intrinsically affects anticoagulation response. To investigate the age-related sensitivity to DOACs, we compared the pharmacological activity of the direct factor Xa inhibitor, rivaroxaban, between young and elderly subjects ex-vivo. 36 fit elderly and 30 fit young subjects [median (IQR) age: 83(75–87) vs 30(26–38) years] provided a blood sample. Clotting parameters were measured in the resultant plasma samples incubated with rivaroxaban (100–500 ng/ml). Parametric, non-parametric tests and regression lines adjusted for rivaroxaban concentration and baseline values were used to compare data. Rivaroxaban produced a greater prolongation of both Prothrombin Time (PT) and modified Prothrombin Time (mPT) (both p < 0.001) in the elderly compared to young subjects (with difference in mean PT increasing from 1.6 to 6.1s and for mPT from 23.5 to 71.1s at 100 ng/ml and 500 ng/ml plasma rivaroxaban concentration, respectively). Factor X and factor II activity was significantly lower in the elderly in the presence of rivaroxaban (p < 0.001 for both). Rivaroxaban prolonged time-based parameters and suppressed the amount of thrombin generation to a significantly greater extent in the elderly compared to young subjects [%change from baseline for Endogenous Thrombin Potential (ETP): − 35.0 ± 4.4 vs − 29.8 ± 7.4 nM*min; p = 0.002]. The use of validated DOAC assays will be of considerable benefit for monitoring elderly patients who, because of their increased sensitivity to rivaroxaban, may require lower doses of the drug for therapeutic anticoagulation.

Cell senescence and fibrotic lung diseases

Idiopathic pulmonary fibrosis (IPF) is a progressive fatal lung disorder with an unknown etiology and very limited therapeutic options. The incidence and severity of IPF increase with advanced age, suggesting that aging is a major risk factor for IPF. The mechanism underlying the aging-related susceptibility to IPF, however, remains unclear. Cellular senescence, a permanent arrest of cell growth, has been increasingly recognized as an important contributor to aging and aging-related diseases, including IPF. Senescent cells have been identified in IPF lungs and in experimental lung fibrosis models. Removal of senescent cells pharmacologically or genetically improves lung function and reverses pulmonary fibrosis induced by different stimuli in experimental fibrosis models. Treatment with senolytic drugs also improves clinical symptoms in IPF patients. These intriguing findings suggest that cellular senescence contributes importantly to the pathogenesis of fibrotic lung diseases and targeting senescent cells may represent a novel approach for the treatment of fibrotic lung disorders. In this mini review, we summarize the recent advance in the field regarding the role of cellular senescence in fibrotic lung diseases, with a focus on IPF.

Hemostasis in elderly patients with human immunodeficiency virus (HIV) infection-Cross-sectional study

Introduction: Aging and chronic HIV infection are clinical conditions that share the states of inflammation and hypercoagulability. The life expectancy of the world population has increased in the last decades, bringing as complications the occurrence of diseases that undergoing metabolic, bone, cardiological, vascular and neurological alterations. HIV-infected patients experience these changes early and are living longer due to the success of antiretroviral therapy. The objectives of this study was to evaluate some changes in the plasma hemostatic profile of 115 HIV-reactive elderly individuals over 60 years old in the chronic phase of infection, and compare with 88 healthy uninfected elderly individuals. Plasma determinations of D-dimers, Fibrinogen, von Willebrand Factor, Antithrombin, Prothrombin Time, Activated Partial Thromboplastin Time, and platelet count were performed. In the HIV-reactive group, these variables were analyzed according to viral load, protease inhibitor use and CD4⁺ T lymphocyte values. After adjusted values for age and sex, the results showed higher levels of Antithrombin (103%; 88%, p = 0.0001) and Prothrombin Time activities (92.4%; 88.2%, p = 0.019) in the HIV group compared to the control group. We observed higher values of Fibrinogen in protease inhibitor users in both the male (p = 0.043) and female (p = 0.004) groups, and in the female HIV group with detected viral load (p = 0.015). The male HIV group with a CD4⁺ count> 400 cells / mm³ presented higher von Willebrand Factor values (p = 0.036). D-Dimers had higher values in the older age groups (p = 0.003; p = 0.042, respectively). Conclusion: Our results suggest that the elderly with chronic HIV infection with few comorbidities had a better hemostatic profile than negative control group, reflecting the success of treatment. Protease inhibitor use and age punctually altered this profile.

Effect of age on the functioning of hemostasis system during hip joint endoprosthesis

The study was performed on 109 osteoarthritis patients who underwent hip joint endoprosthetics; the effect of age on changes in hemostasis system, blood loss level and deep veins thrombosis development in the background of standard prevention with low-molecular heparins were studied. Before the surgery, it was determined that 56 elderly patients (60.3 ± 6.4 years) compared to 53 middle-aged patients (41.8 ± 6.8 years) had a significantly higher initial and postoperative endothelial dysfunction, higher fibrin formation and lower anticoagulant potential; however, it was found that on the background of pharmacological anticoagulant therapy the changes in the hemostasis functioning in elderly patients did not lead to an increase of either blood loss or the number of thromboses.

The endothelial tumor suppressor p53 is essential for venous thrombus formation in aged mice

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in elderly people. Increased expression of tumor suppressor protein 53 (p53) has been implicated in vascular senescence. Here, we examined the importance of endothelial p53 for venous thrombosis and whether endothelial senescence and p53 overexpression are involved in the exponential increase of VTE with age. Mice with conditional, endothelial-specific deletion of p53 (End.p53-KO) and their wild-type littermates (End.p53-WT) underwent subtotal inferior vena cava (IVC) ligation to induce venous thrombosis. IVC ligation in aged (12-month-old) End.p53-WT mice resulted in higher rates of thrombus formation and greater mean thrombus size vs adult (12-week-old) End.p53-WT mice, whereas aged End.p53-KO mice were protected from vein thrombosis. Analysis of primary endothelial cells from aged mice or human vein endothelial cells after induction of replicative senescence revealed significantly increased early growth response gene-1 (Egr1) and heparanase expression, and plasma factor Xa levels were elevated in aged End.p53-WT, but not in End.p53-KO mice. Increased endothelial Egr1 and heparanase expression also was observed after doxorubicin-induced p53 overexpression, whereas p53 inhibition using pifithrin-α reduced tissue factor (TF) expression. Importantly, inhibition of heparanase activity using TF pathway inhibitor-2 (TFPI2) peptides prevented the enhanced venous thrombus formation in aged mice and restored it to the thrombotic phenotype of adult mice. Our findings suggest that p53 accumulation and heparanase overexpression in senescent endothelial cells are critically involved in mediating the increased risk of venous thrombosis with age and that heparanase antagonization may be explored as strategy to ameliorate the prothrombotic endothelial phenotype with age.

Polymorphism of R353Q (rs6046) in factor VII and the risk of myocardial infarction: A systematic review and meta-analysis

OBJECTIVE

Genetic components substantially contribute to the development of myocardial infarction (MI), and R353Q polymorphism (rs6046) in FVII gene has been suspected to be associated with the risk of MI.

METHODS

A meta-analysis was conducted on the links between R353Q polymorphism and the susceptibility of MI. A comprehensive literature search was performed on 8 electronic databases. The main effects of the genotypes were estimated using a logistic regression approach. The odds ratios with 95% confidence intervals were calculated using the conventional summary method meta-analysis. The possible sources of heterogeneity among the included studies were explored using meta-regression analysis and subgroup analysis.

RESULTS

A total of 18 eligible case-control studies, comprising of 4701 cases and 5329 controls, were included. No overall statistical relationship was identified between R353Q and MI by any of the genetic models. The meta-regression demonstrated that the Asian population, body mass index (BMI) category, and diabetes affected the heterogeneity. In addition, subgroup analyses showed that heterogeneities were identified in Asian population and BMI category, which highly agree with the results of meta-regression.

CONCLUSIONS

The current meta-analysis suggested that R353Q polymorphism was not associated with the MI risk. Asian population, BMI category, and diabetes might be related to the incidence of MI. However, large-scale, case-control studies with rigorous designs are essential to provide accurate evidence.

Predictors of 30-Day Outcomes in Octogenarians with Traumatic C2 Fractures Undergoing Surgery

BACKGROUND

Predictors of surgical outcomes following traumatic axis (C2) fractures in octogenarians remain undercharacterized.

METHODS

Patients age ≥80 years undergoing cervical spine surgery following traumatic C2 fractures were extracted from the National Sample Program of the National Trauma Data Bank (2003-2012). Outcomes include overall inpatient complications, individual complications with an incidence >1%, hospital length of stay (HLOS), discharge disposition, and mortality. Demographics, comorbidities, and injury predictors were analyzed using multivariable regression. Odds ratios (OR), mean differences, and 95% confidence intervals (CIs) were calculated. Statistical significance was assessed at P < 0.05.

RESULTS

The cohort of 442 patients was 48.6% male and had a mean age of 84.3 ± 2.7 years. The distribution of admissions was 42.3% to the hospital floor, 40.3% to the intensive care unit (ICU), 7.7% to telemetry, 2.0% to the operating room, and 7.7% to other/unknown. Mortality was 9.7%, mean HLOS was 13.1 ± 9.2 days, the rate of complications was 38.5%, and 81.5% of survivors were discharged to a nonhome facility. Injury severity was predictive of mortality and overall complications. History of bleeding disorder/coagulopathy predicted mortality (OR, 4.02; 95% CI, 1.07-15.05), overall complications (OR, 3.01; 95% CI, 1.09-8.32), cardiac arrest (OR, 8.19; 95% CI, 1.06-63.54), and renal complications (OR, 10.36; 95% CI, 2.13-50.38). History of congestive heart failure predicted mortality (OR, 3.10; 95% CI, 1.10-8.69). ICU admission (vs. floor) predicted overall complications (OR, 2.01; 95% CI, 1.23-3.27) and pneumonia (OR, 4.65; 95% CI, 1.91-11.30). Telemetry admission (vs. floor) predicted unplanned intubation (OR, 7.76; 95% CI, 1.24-48.49).

CONCLUSIONS

In this cohort of octogenarians undergoing surgery for traumatic C2 fracture, injury severity and a history of bleeding disorder/coagulopathy were identified as risk factors for inpatient complications and mortality. Heightened surveillance should be considered for ICU and/or telemetry admissions for the development of complications. These findings warrant consideration by the clinician, patient, and family to inform clinical decisions and goals of care.

The impact of frailty on coagulation and responses to warfarin in acute older hospitalised patients with atrial fibrillation: a pilot study

BACKGROUND

The evidence on coagulation changes with frailty is not consistent and clinical studies suggest that frail older people may be at an increased risk of bleeding complications with anticoagulant therapy.

AIMS

This study aims to assess the impact of frailty on coagulation function and on response to warfarin.

METHODS

Inpatients aged over 65 years with atrial fibrillation (AF) were recruited. Frailty was determined using the Reported Edmonton Frail Scale. The Overall Haemostatic Potential (OHP) and Calibrated Automated Thrombogram (CAT) were used to globally assess coagulation function.

RESULTS

Data of 95 participants were analysed, mean age 85.5 ± 6.2, 40% female, and 50.5% frail. Among participants not on anticoagulants (N = 36), there was an increased fibrin generation and decreased thrombin generation compared to the local established normal ranges in young healthy volunteers; the frail had significantly reduced fibrin generation compared to the non-frail. In the warfarin-treated group (N = 59), there was no difference on coagulation profiles between the frail and the non-frail from any of the coagulation tests.

CONCLUSION

In this cohort of acute hospitalised patients with AF, the observed decreased fibrin generation in the frail may reflect decreased acute phase response as suggested with the lower plasma fibrinogen in that group. There was no difference in coagulation profiles between the frail and the non-frail amongst those taking warfarin. Compared to young healthy volunteers, older inpatients had increased fibrin generation and decreased thrombin generation. The findings reflect the complex interaction between age, frailty, acute illness, and coagulation.

High Risk of Readmission in Octogenarians Undergoing Primary Hip Arthroplasty

BACKGROUND

As life expectancy increases, more elderly patients with end-stage hip arthritis are electing to undergo primary THA. Octogenarians undergoing THA have more comorbidities than younger patients, but this is not reflected in risk adjustment models for bundled care programs. The burden of care associated with THA in octogenarians has not been well characterized, and doing so may help these value-based programs make adjustments so that this vulnerable patient population does not risk losing access under accountable care models.

QUESTIONS/PURPOSES

The purpose of this study was to describe care use, comorbidities, and complications among octogenarians undergoing primary THA.

METHODS

Five percent of the Medicare national administrative claims data was queried to identify patients diagnosed with hip osteoarthritis between January 1, 1998, and December 31, 2013. Patients who underwent primary THA were identified and followed longitudinally during the study period using their unique, encrypted Medicare beneficiary identifiers. We compared risk factors and complications between the octogenarian group versus those aged 65 to 69 years. Multivariate Cox regression was used to evaluate the effect of patient/hospital factors on risk of revision, periprosthetic joint infection, dislocation, venous thromboembolism (VTE), and mortality. Patient factors in the model included age, sex, race, region, socioeconomic status, and health status based on Charlson comorbidity score 12 months before replacement surgery.

RESULTS

There were 11,960 THAs in the octogenarians in 1998, which increased to 21,620 in 2013, an 81% increase during this study period. Octogenarians were more likely to have a Charlson score of 3 or higher than those patients aged 65 to 69 years (30% versus 17%, odds ratio [OR] 2.07 [1.98-2.20]; p < 0.001), and they were more likely to have coronary artery disease or congestive heart failure (47% versus 29%, OR 2.16 [2.06-2.26]; p < 0.001). The octogenarian group had a greater risk of dislocation (+12%, p = 0.01), VTE (+14%, p < 0.001), and mortality (+150%, p < 0.001) compared with the younger age cohort. A total of 21% of the octogenarians were readmitted after surgery compared with 12% for patients in the younger group (OR=1.64, 95% confidence interval 1.54-1.75; p < 0.001).

CONCLUSIONS

Because octogenarians are at increased risk of dislocation, VTE, medical complications, and mortality after THA, value-based care models that penalize hospitals for readmissions and complications may inadvertently result in loss of access to care for this group of patients as a result of the financial makeup of these bundled care models. Value-based care models were developed to improve care and decrease healthcare costs but may have unintended consequences in the octogenarian with higher complication and readmission risks. Financial losses may lead to institutions from withdrawing from the Bundled Payments for Care Improvement program. To try to prevent this from happening to this vulnerable patient population, bundled care programs should evolve and be modified to allow for risk stratification in the overall payment formula to account for increased age and comorbid conditions to ensure continued successful participation in the program among all the stakeholders.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Structural and functional changes of fibrinogen due to aging

Different factors affect coagulation process. Since fibrinogen is the main coagulation factor, the influence of aging on fibrinogen structure and function was investigated in this study. Fibrinogen was isolated from plasma obtained from healthy persons in the age range 21-83 and examined. Lectin microarray analysis demonstrated increased glycosylation of fibrinogen due to aging, with predominant increase in high-mannose or hybrid type N-glycans, as well as tri-/tetraantennary complex N-glycans with greater content of galactose and N-acetylglucosamine residues. Spectrofluorimetric analysis indicated that fibrinogen molecules have more densely packed structure, but there are no additional advanced glycation end products with increasing age. According to the results of functional analysis, fibrinogen molecules isolated from older persons exhibited reduced clotting time, with significant positive correlation with age, but there were no differences in clotting speed, maximal optical density of fibrin clot, diameter of fibrin fibres, fibrin porosity or reactivity with the insulin-like growth factor binding protein 1. Glycosylation changes of fibrinogen in healthy aging most likely affect its structure and function, namely clotting time. Structural and functional studies of proteins in relation to healthy aging contribute to deeper understanding of mechanisms responsible for longevity.

Atherothrombosis and Oxidative Stress: Mechanisms and Management in Elderly

SIGNIFICANCE

The incidence of cardiovascular events (CVEs) increases with age, representing the main cause of death in an elderly population. Aging is associated with overproduction of reactive oxygen species (ROS), which may affect clotting and platelet activation, and impair endothelial function, thus predisposing elderly patients to thrombotic complications. Recent Advances: There is increasing evidence to suggest that aging is associated with an imbalance between oxidative stress and antioxidant status. Thus, upregulation of ROS-producing enzymes such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and myeloperoxidase, along with downregulation of antioxidant enzymes, such as superoxide dismutase and glutathione peroxidase, occurs during aging. This imbalance may predispose to thrombosis by enhancing platelet and clotting activation and eliciting endothelial dysfunction. Recently, gut-derived products, such as trimethylamine N-oxide (TMAO) and lipopolysaccharide, are emerging as novel atherosclerotic risk factors, and gut microbiota composition has been shown to change by aging, and may concur with the increased cardiovascular risk in the elderly.

CRITICAL ISSUES

Antioxidant treatment is ineffective in patients at risk or with cardiovascular disease. Further, anti-thrombotic treatment seems to work less in the elderly population.

FUTURE DIRECTIONS

Interventional trials with antioxidants targeting enzymes implicated in aging-related atherothrombosis are warranted to explore whether modulation of redox status is effective in lowering CVEs in the elderly. Antioxid. Redox Signal. 27, 1083-1124.

Anxiety and depression in patients three months after myocardial infarction: Association with markers of coagulation and the relevance of age

OBJECTIVE

Anxiety and depression are associated with an activation of coagulation and an impairment of fibrinolysis, which may contribute to the increased cardiovascular risk associated with the two disorders. However, very few studies have examined the impact of psychological distress on coagulation factors in coronary artery disease patients. The aim of this study was to assess the correlation between anxiety/depression and factors of coagulation and fibrinolysis in patients who had suffered an acute MI three months prior.

METHODS

In 148 patients, anxiety and depression were assessed by the Hospital Anxiety and Depression Scale (HADS) shortly after MI and three months later. At the second time of assessment, plasma levels of fibrinogen, factor VII, factor VIII, von Willebrand factor, prothrombin-fragment 1 and 2, tissue-plasminogen-activator, plasminogen activator inhibitor-1, D-dimer, and homocysteine were measured.

RESULTS

In 32% of the patients, elevated levels of anxiety and depression were found three months after a MI. Multiple regression analyses showed that coagulation and fibrinolysis markers were not significantly associated with HADS anxiety and depression scores. We found that age, gender, BMI, and smoking status were significant predictors for haemostasis factors. A higher age was associated with a higher coagulability but lower anxiety levels.

CONCLUSION

We measured parameters of coagulation and fibrinolysis in patients three months after MI and found no predictive value of HADS anxiety and depression scores shortly after MI or at the time of blood sampling. The effects of age on the relationship between anxiety and haemostasis should be further investigated.

Inflammation and hemostasis in older octogenarians: implication in 5-year survival

Social changes and medical advances have increased longevity, but the conditions governing healthy vs unhealthy cardiovascular (CV) aging are not fully known. Factors beyond classical CV risk factors may have an important unrecognized value. We sought to identify proteins differentially expressed in healthy octogenarians (HOs) without a history of cardiovascular disease (CVD) and preserved functional and cognitive state compared with octogenarians with a history of CVD and cognitive decline (UHOs) using a systems biology approach, and investigated how these proteins relate to CV mortality at 5-year follow-up. Plasmas obtained from older octogenarians (87 ± 0 years) were analyzed by 2-DE + MS and bioinformatic pathway analysis in HOs (N = 38) and UHOs with cognitive (MEC<25) and functional (Barthel<90) decline and a previous ischemic event (acute myocardial infarction and/or stroke; N = 27). Results were validated by ELISA in HOs and UHOs and in an additional group of older octogenarians without cognitive impairment but with a previous CVD manifestation (HO-CVD; N = 35). UHOs showed a coordinated change in several inflammation-related proteins (AMBP, RBP4, and ITIH4; P < 0.05), together with a significant increase in the major inducer of the acute-phase reaction, interleukin-6 (P = 0.03). UHOs also showed a coordinated increase in hemostatic proteins that was associated with an impairment of fibrinolysis and an increased 5-year CV mortality (P = 0.003). The combination of inflammation (ITIH4 and interleukin-6) and hemostatic markers (D-dimer, A2AP, and coagulation factor XIII) was able to discriminate the presence of an unhealthy phenotype in the elderly (AUC = 0.750; P = 0.001). Unhealthy older octogenarians show increased levels of several plasma proteins of inflammation and coagulation. In older octogenarians, the increase in hemostatic markers indicated an increase in 5-year CV mortality at follow-up.

Primary and secondary haemostasis changes related to aging

Life expectancy has increased in many countries as a result the world's population is aging. The projections indicate that the proportion of the elderly in a few decades will increase significantly. Aging carries with it a series of physiological changes; one of them is an imbalance in the hemostatic system. Thus the levels or activity of various proteins involved, such as most coagulation factors, natural anticoagulants and the fibrinolytic system are altered so that the hemostatic balance leans toward thrombosis. Also, platelet activity suggests a state of abnormal activation (P-selectin, beta thromboglobulin and platelet factor). In this review we will systematically examine the alterations in the hemostatic components that occur during aging. Therefore, understanding these hemostatic changes could contribute to developing strategies for the proper management of health in old age.

Role of plasminogen activator inhibitor-1 in senescence and aging

The average age of the US population continues to increase. Age is the most important determinant of disease and disability in humans, but the fundamental mechanisms of aging remain largely unknown. Many age-related diseases are associated with an impaired fibrinolytic system. Elevated plasminogen activator inhibitor-1 (PAI-1) levels are reported in age-associated clinical conditions including cardiovascular diseases, type 2 diabetes, obesity and inflammation. PAI-1 levels are also elevated in animal models of aging. While the association of PAI-1 with physiological aging is well documented, it is only recently that its critical role in the regulation of aging and senescence has become evident. PAI-1 is synthesized and secreted in senescent cells and contributes directly to the development of senescence by acting downstream of p53 and upstream of insulin-like growth factor binding protein-3. Pharmacologic inhibition or genetic deficiency of PAI-1 was shown to be protective against senescence and the aging-like phenotypes in kl/kl and N(ω)-nitro-l-arginine methyl ester-treated wild-type mice. Further investigation into PAI-1's role in senescence and aging will likely contribute to the prevention and treatment of aging-related pathologies.

The decay of stem cell nourishment at the niche

One of the main features of human aging is the loss of adult stem cell homeostasis. Organs that are very dependent on adult stem cells show increased susceptibility to aging, particularly organs that present a vascular stem cell niche. Reduced regenerative capacity in tissues correlates with reduced stem cell function, which parallels a loss of microvascular density (rarefraction) and plasticity. Moreover, the age-related loss of microvascular plasticity and rarefaction has significance beyond metabolic support for tissues because stem cell niches are regulated co-ordinately with the vascular cells. In addition, microvascular rarefaction is related to increased inflammatory signals that may negatively regulate the stem cell population. Thus, the processes of microvascular rarefaction, adult stem cell dysfunction, and inflammation underlie the cycle of physiological decline that we call aging. Observations from new mouse models and humans are discussed here to support the vascular aging theory. We develop a novel theory to explain the complexity of aging in mammals and perhaps in other organisms. The connection between vascular endothelial tissue and organismal aging provides a potential evolutionary conserved mechanism that is an ideal target for the development of therapies to prevent or delay age-related processes in humans.

Age and aerobic training status effects on plasma and skeletal muscle tPA and PAI-1

INTRODUCTION

Reductions in fibrinolytic potential occur with both aging and physical inactivity and are associated with an increased cardiovascular disease risk. Plasmin, the enzyme responsible for the enzymatic degradation of fibrin clots, is activated by tissue plasminogen activator (tPA), while plasminogen activator inhibitor-1 (PAI-1) inhibits its activation. Currently, fibrinolysis research focuses almost exclusively on changes within the plasma. However, tPA and PAI-1 are expressed by human skeletal muscle (SM). Currently, no studies have focused on changes in SM fibrinolytic activity with regard to aging and aerobic fitness.

PURPOSE

The purpose of this study was to cross-sectionally evaluate effects of age and aerobic fitness on tPA and PAI-1 expressions and activity in SM.

METHODS

Twenty-six male subjects were categorized into the following groups: (1) young aerobically trained (n = 8); (2) older aerobically trained (n = 6); (3) young aerobically untrained (n = 7); and (4) older aerobically untrained (n = 5). Muscle biopsies were obtained from each subject. SM tPA activity was assessed using gel zymography and SM tPA and PAI-1 expressions were assessed using RT-PCR.

RESULTS

Trained subjects had higher SM tPA activity compared to untrained (25.3 ± 2.4 × 10(3) vs. 21.5 ± 5.6 × 10(3) pixels, respectively; p = 0.03) with no effect observed for age. VO2 max and SM tPA activity were also significantly correlated (r = 0.42; p < 0.04). SM tPA expression was higher in older participants, but no effect of fitness level was observed. No differences were observed for PAI-1 expression in SM.

CONCLUSIONS

Higher levels of aerobic fitness are associated with increased fibrinolytic activity in SM.

Coagulation factors and antithrombin levels in young and elderly subjects in Pakistani population

Aging is associated with increased levels of coagulation factors and decrease in natural anticoagulant factors. This strongly supports that age-related hypercoagulable state occurs in elderly. This study aimed to measure the plasma levels of coagulation factors and anticoagulant levels in young and elderly to observe the effect of age on haemostatic system. Ninety healthy individuals, both men and women were divided into two groups on the basis of age. Group I included participants of less than 40 years of age, whereas, group II comprised of participants more than 60 years of age. Fibrinogen activity was assessed by using Clauss technique. Coagulation factor VII, and factor VIII activity by corresponding one stage assay based on prothrombin time and activated partial thromboplastin time. Antithrombin III was measured by the chromogenic method. Our results showed that significantly increased levels of fibrinogen (P = 0.001) were observed in the elderly population as compared to young. Higher fibrinogen levels in younger women than men and comparatively higher level than other races was observed in our local population. Increase in factor VII levels (P = 0.05) was also observed in the elderly group. This increase was statistically significant with age in women (P = 0.03). Factor VIII rose with age in both sexes (P = 0.001). Higher antithrombin activity was observed in the younger group whereas the older group demonstrated significantly lower antithrombin activity (P = 0.001). We conclude that considerable effects of age and sex are observed on coagulation factors and naturally occurring inhibitors.

Venous thromboembolism in the elderly: the result of comorbid conditions or a consequence of injury?

BACKGROUND

Venous thromboembolism (VTE) is a common complication in trauma patients. Several risk factors have been identified that may place patients at in increased risk for VTE including preexisting medical conditions, iatrogenic factors, and injury-related factors. Advanced age has also been implicated as a risk factor for VTE. The purpose of this study was to determine the incidence and outcomes of VTE in geriatric trauma patients as well as to identify risk factors for VTE in this population.

METHODS

We performed a 10-year retrospective review of all trauma patients aged 65 years or older discharged with a diagnosis of VTE. Demographic data, injuries, mechanism, Injury Severity Score, Abbreviated Injury Score, Glasgow Coma Scale, length of stay, and mortality were collected.

RESULTS

: Of 2,521 trauma patients aged 65 years or older, 82 (3.2%) were diagnosed with VTE. Seventy-two of 82 patients were diagnosed with deep vein thrombosis, and pulmonary embolism was found in 8 patients. Two patients had both a deep vein thrombosis and pulmonary embolism. Independent predictors of VTE included traumatic brain injury (p < 0.05); chest Abbreviated Injury Score ≥ 3 (p < 0.001); mechanical ventilation (p < 0.001); major operation (p < 0.001); and history of VTE (p = 0.05). Other comorbid conditions were not significantly associated with VTE. Preinjury anticoagulation had a trend toward a protective effect. Although length of stay was longer in patients with VTE (adjusted mean difference 14.7 days, p < 0.001), mortality for patients with and without VTE was 8.5% and 7.0%, respectively (p = 0.59).

CONCLUSION

VTE is associated with prolonged length of stay and duration of mechanical ventilation as well as continued medical dependence after discharge. Several risk factors place the elderly trauma patient at an increased risk for VTE, and trauma or injury-related risk factors seem to have a greater impact on the development of VTE in comparison to underlying conditions or increasing patient age (>65 years).

LEVEL OF EVIDENCE

II, prognostic study.

Biological variation in tPA-induced plasma clot lysis time

Hypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Sufficient information about assay variation and biological variation in CLT is not yet available. Thus, this study aimed to determine the analytical, within-subject and between-subject variation in CLT. We collected blood samples from 40 healthy individuals throughout a period of one year (average 11.8 visits) and determined the CLT of each plasma sample in duplicate. The mean (± SD) CLT was 83.8 (± 11.1) minutes. The coefficients of variation for total variation, analytical variation, within-subject variation and between-subject variation were 13.4%, 2.6%, 8.2% and 10.2%, respectively. One measurement can estimate the CLT that does not deviate more than 20% from its true value. The contribution of analytical variation to the within-subject variation was 5.0%, the index of individuality was 0.84 and the reference change value was 23.8%. The CLT was longer in the morning compared to the afternoon and was slightly longer in older individuals (> 40 years) compared to younger (≤40 years) individuals. There was no seasonal variation in CLT and no association with air pollution. CLT correlated weakly with fibrinogen, C-reactive protein, prothrombin time and thrombin generation. This study provides insight into the biological variation of CLT, which can be used in future studies testing CLT as a potential risk factor for thrombosis.

The neurovascular unit and combination treatment strategies for stroke

Tissue plasminogen activator (tPA) administered within 4.5h of symptom onset restores cerebral blood flow (CBF) and promotes neurological recovery of stroke patients. However, the narrow therapeutic time window and the risk of intracerebral hemorrhage after tPA treatment pose major hurdles to its clinical usage. In light of the failures of neuroprotective therapies in clinical trials, emerging concepts suggest that neuroprotection alone without restoration of tissue perfusion and vascular integrity may not be adequate for treatment of acute stroke. Here we review evidence of the use of adjuvant pharmacological agents to extend the therapeutic window for tPA via targeting the neurovascular unit and the underlying mechanisms of the combination therapy in experimental stroke.

Primary prevention of venous thromboembolism

Venous thromboembolism (VTE) is the most common cause of preventable in-hospital mortality and all hospitalized patients should be VTE risk assessed. The VTE risk should be weighed up against risk of bleeding on an individualized basis to guide choice of prophylaxis. The most common method of mechanical thromboprophylaxis is graduated compression stockings, although others, such as intermittent pneumatic devices, are available. Stockings have the greatest benefit when used in combination with pharmacological prophylaxis. However, stockings are contraindicated in some patients, including those with stroke or peripheral arterial disease. Various options for pharmacological thromboprophylaxis are available. The most commonly used agents are the low-molecular-weight heparins, but newer orally active agents may play an increasing role in the future.

12-lipoxygenase: a potential target for novel anti-platelet therapeutics

Platelets play an essential role in the regulation of hemostasis and thrombosis and controlling their level of activation is central to prevention of occlusive clot formation and stroke. Although a number of anti-platelet targets have been identified to address this issue including COX-1, the P2Y(12) receptor, the integrin αIIbβ3, and more recently the protease-activated receptor-1, these targets often result in a significant increased risk of bleeding which may lead to pathologies as serious as the thrombosis they were meant to treat including intracranial hemorrhage and gastrointestinal bleeding. Therefore, alternative approaches to treat uncontrolled platelet activation are warranted. Platelet-type 12-lipoxygenase is an enzyme which oxidizes the free fatty acid in the platelet resulting in the production of the stable metabolite 12-hydroxyeicosatetraenoic acid (12-HETE). The role of 12-HETE in the platelet has been controversial with reports associating its function as being both anti- and pro-thrombotic. In this review, the role of 12-lipoxygenase and its bioactive metabolites in regulation of platelet reactivity, clot formation, and hemostasis is described. Understanding the mechanisms by which 12-lipoxygenase and its metabolites modulate platelet function may lead to the development of a novel class of anti-platelet therapies targeting the enzyme in order to attenuate injury-induced clot formation, vessel occlusion and pathophysiological shifts in hemostasis.

Plasminogen activator inhibitor-1 (PAI-1): a key factor linking fibrinolysis and age-related subclinical and clinical conditions

INTRODUCTION

The close relationship existing between aging and thrombosis has growingly been studied in this last decade. The age-related development of a prothrombotic imbalance in the fibrinolysis homeostasis has been hypothesized as the basis of this increased cardiovascular and cerebrovascular risk. Fibrinolysis is the result of the interactions among multiple plasminogen activators and inhibitors constituting the enzymatic cascade, and ultimately leading to the degradation of fibrin. The plasminogen activator system plays a key role in a wide range of physiological and pathological processes.

METHODS

Narrative review.

RESULTS

Plasminogen activator inhibitor-1 (PAI-1) is a member of the superfamily of serine-protease inhibitors (or serpins), and the principal inhibitor of both the tissue-type and the urokinase-type plasminogen activator, the two plasminogen activators able to activate plasminogen. Current evidence describing the central role played by PAI-1 in a number of age-related subclinical (i.e., inflammation, atherosclerosis, insulin resistance) and clinical (i.e., obesity, comorbidities, Werner syndrome) conditions is presented.

CONCLUSIONS

Despite some controversial and unclear issues, PAI-1 represents an extremely promising marker that may become a biological parameter to be progressively considered in the prognostic evaluation, in the disease monitoring, and as treatment target of age-related conditions in the future.

Combination treatment with VELCADE and low-dose tissue plasminogen activator provides potent neuroprotection in aged rats after embolic focal ischemia

BACKGROUND AND PURPOSE

Treatment with a selective proteasome inhibitor, VELCADE, in combination with tissue plasminogen activator (tPA) extended the therapeutic window to 6 hours in young rats after stroke. However, stroke is a major cause of death and disability in the elderly. The present study investigated the effect of VELCADE in combination with a low-dose tPA on aged rats after embolic stroke.

METHODS

Male Wistar rats at the age of 18 to 20 months were treated with VELCADE (0.2 mg/kg) alone, a low-dose tPA (5 mg/kg) alone, combination of VELCADE and tPA, or saline 2 hours after embolic middle cerebral artery occlusion. To test the contribution of endothelial nitric oxide synthase to VELCADE-mediated neuroprotection, endothelial nitric oxide synthase knockout and wild-type mice were treated with VELCADE (0.5 mg/kg) 2 hours after embolic stroke.

RESULTS

Treatment with VELCADE significantly reduced infarct volume, whereas tPA alone did not reduce infarct volume and aggravated blood-brain barrier disruption in aged rats compared with saline-treated rats. However, the combination treatment significantly enhanced the reduction of infarct volume, which was associated with an increase in endothelial nitric oxide synthase activity compared with saline-treated rats. Additionally, the combination treatment promoted thrombolysis and did not increase the incidence of hemorrhage transformation. VELCADE significantly reduced lesion volume in wild-type mice but failed to significantly reduce lesion volume in endothelial nitric oxide synthase knockout mice.

CONCLUSIONS

Treatment with VELCADE exerts a neuroprotective effect in aged rats after stroke. The combination of VELCADE with the low-dose tPA further amplifies the neuroprotective effect. Endothelial nitric oxide synthase at least partly contributes to VELCADE-mediated neuroprotection after stroke.

Hemostasis and ageing

On March 19, 2008 a Symposium on Pathophysiology of Ageing and Age-Related Diseases was held in Palermo, Italy. The lecture of D. Mari on Hemostasis and ageing is summarized herein. Physiological ageing is associated with increased plasma levels of many proteins of blood coagulation together with fibrinolysis impairment. This may be of great concern in view of the known association between vascular and thromboembolic diseases and ageing. On the other hand, centenarians are characterized by a state of hypercoagulability and possession of several high-risk alleles and well-known atherothrombotic risk markers but this appears to be compatible with longevity and/or health. Parameters considered risk factors for atherosclerotic vascular diseases in young people may lose their biological significance in advanced age and assume a different role.

Strategies to reduce intraluminal clot formation in endoscopically harvested saphenous veins

OBJECTIVE

Residual clot strands within the excised saphenous vein are an increasingly recognized sequela of endoscopic vein harvest. We hypothesized that endoscopic visualization facilitated by sealed carbon dioxide insufflation causes stagnation of blood within the saphenous vein. In the absence of prior heparin administration, this stasis provokes clot formation.

METHODS

Forty consecutive patients having coronary artery bypass grafting underwent endoscopic vein harvest using sealed (Guidant VasoView, n = 30; Guidant Corp, Minneapolis, Minn) or open (Datascope ClearGlide, n = 10; Datascope Corp, Montvale, NJ) carbon dioxide insufflation followed by ex vivo assessment of intraluminal saphenous vein clot via optical coherence tomography. In the sealed carbon dioxide insufflation groups, clot formation was compared with (preheparinized, n = 20) and without (control, n = 10) heparin administration before endoscopic vein harvest, either at a fixed dose or titrated to an activated clotting time greater than 300 seconds. Risk factors for clot formation were assessed.

RESULTS

Residual saphenous vein clot was a universal finding in control veins (sealed carbon dioxide insufflation endoscopic vein harvest without preheparinization). At either dose used, heparin given before endoscopic vein harvest significantly decreased saphenous vein clot burden. A similar reduction in clot was observed when using open carbon dioxide insufflation endoscopic vein harvest without preheparinization. Intraoperative blood loss and blood product requirements were similar in all groups. Patient age and preoperative maximum amplitude of the thrombelastography tracing showed a linear correlation with saphenous vein clot volume.

CONCLUSION

By enabling the quantification of this issue as never before possible, optical coherence tomography screening revealed that intraluminal saphenous vein clot is frequently found after endoscopic vein harvest. Systemic heparinization before harvest or an open carbon dioxide endoscopic vein harvest system are benign changes in practice that can significantly lessen this complication.

Age-related effects of regular physical activity on hemostatic factors in men

BACKGROUND

Age-related changes in blood coagulation and fibrinolytic factors are associated with an increase in risk of thrombotic events. The purpose of this study was to assess the effects of age, regular aerobic exercise and detraining on blood coagulation and fibrinolytic factors in men.

METHODS

Initially, 41 sedentary and 42 physically active men (20-64 years) were analyzed for plasma levels of coagulation and fibrinolytic factors. Twelve sedentary men were then subjected to 16-week aerobic exercise training and subsequent 2-week detraining. Their blood samples taken at rest were assayed for activity levels of prothrombin, coagulation factor (F) V, VII, VIII, IX, X, XI and XIII, antithrombin III, protein C and plasminogen, and for antigen levels of fibrinogen, prothrombin fragment 1 + 2 (F1 + 2), FIX, protein C, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1) and tPA/PAI-1 complex.

RESULTS

Plasma levels of most coagulation factors, particularly for fibrinogen and FIX antigens as well as FXIII activity significantly increased with aging in sedentary men, while that tendency disappeared in physically active men. By the exercise training, plasma antigen and/or activity levels of most blood coagulation factors except for prothrombin and FIX decreased. These training-effects, however, disappeared after detraining, and in some cases even rebounded to higher levels than those of pre-training. Plasma antigen levels of tPA, PAI-1 and tPA/PAI-1 complex decreased with the training and remained low even after detraining.

CONCLUSION

Regular aerobic exercises give complex effects on expression of hemostatic factors, overall favoring the hemostatic balance to less thrombotic, partly cancelling out the age effects.

Hemostasis factors and aging

With advancing age, an increasing number of healthy individuals have laboratory signs of heightened coagulation enzyme activity. Such biochemical hypercoagulability might be the basis of either the increased thrombotic tendency occurring with age or a harmless manifestation of this process. Centenarians had striking signs of heightened coagulation enzyme activity, accompanied by signs of enhanced formation of fibrin and secondary hyperfibrinolysis. Plasma concentrations of fibrinogen and factor VIII were higher than in controls, whereas other coagulation factors were not elevated. It is of interest that centenarians have a significantly higher frequency than young individuals of the high risk 4G allele of the PAI-1-675 (4G/5G) polymorphism, mutant factor V (Arg506Gln) and prothrombin gene G20210A mutation. Von Willebrand factor (VWF), a well-known independent predictor of atherothrombotic disease, was increased in centenarians, independently of the blood group, confirming the previous results of a state of hypercoagulability. The finding that the VWF cleaving proteases levels are low when VWF levels are high in centenarians could be a corollary of the previous described paradox of successful aging, adding another marker of increased risk of atherothrombosis to the scenario. Alike, high prevalence of anti-phospholipids antibodies, not associated with an anti-phospholipid syndrome has been described in centenarians. In conclusion, the data show the oldest old do not escape the state of hypercoagulability associated with aging, but that this phenomenon is compatible with health and longevity. Hence, high plasma levels of the coagulation activation markers in older populations do not necessarily mirror a high risk of arterial or venous thrombosis.

Hemostasis and aging

Many changes in the vasculature, hemostasis and endothelium, including alterations of platelets, coagulation and fibrinolytic factors, occur during aging. While the increasing hypercoagulability observed with aging may account for the higher incidence of thrombotic cardiovascular disorders in the elderly, the lack of genetic protective factors against thrombosis in healthy centenarians suggests that little is yet known about the age-associated changes of hemostasis. The complex inter-relationships between inherited and acquired factors influencing the hemostatic system during aging are discussed in this review.

Relationship of physical fitness, hormone replacement therapy, and hemostatic risk factors in postmenopausal women

This cross-sectional study evaluated the relationship of physical fitness, hormone replacement therapy (HRT), and hemostatic profiles at rest and after an acute bout of maximal exercise in 48 healthy postmenopausal women. Subjects were categorized by fitness and HRT user status into four groups: unfit nonusers, fit nonusers, unfit users, and fit users. Fibrinolytic variables tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) activity, and antigen and prothrombin fragment 1 + 2, a molecular marker of in vivo thrombin generation, were measured before and after maximal exercise. Fibrinogen was also measured at rest. Higher tPA and lower PAI-1 activities ( P < 0.05) were seen in HRT users and fit groups. tPA and PAI-1 antigens were lower in HRT and fit groups ( P < 0.05) but not after correction for body mass index. Prothrombin fragment 1 + 2 was lower in the fit groups regardless of HRT status ( P < 0.05). Fibrinogen was similar in all groups. Favorable hemostatic profiles were observed in physically fit compared with unfit women, especially in HRT nonusers. Thus fitness is more strongly related to these hemostatic risk factors compared with HRT since HRT did not affect these hemostatic variables in fit postmenopausal women.

Aging accelerates endotoxin-induced thrombosis : increased responses of plasminogen activator inhibitor-1 and lipopolysaccharide signaling with aging

Although older subjects are susceptible to thrombosis under septic conditions, the underlying molecular mechanisms have not been fully elucidated. Since elevated plasminogen activator inhibitor-1 (PAI-1) primarily contributes to endotoxin-induced thrombosis, we first compared the induction of PAI-1 by lipopolysaccharide (LPS) between young and aged mice. The higher induction of PAI-1 antigen and mRNA with increased renal glomerular fibrin deposition was observed in LPS-treated aged mice compared to young mice. In situ hybridization analysis showed that the aging-associated induction of PAI-1 mRNA by LPS was pronounced in hepatocytes and in renal glomerular cells. The increased magnitude of the response of aged mice to lower doses of LPS was observed in terms of renal glomerular fibrin deposition and PAI-1 mRNA induction in the tissues. Furthermore, older PAI-1 deficient mice treated with LPS developed much less fibrin deposition in kidneys. Importantly, a larger induction of receptor molecules for LPS (eg, CD14 and Toll-like receptor 4) was demonstrated in LPS-treated aged mice as compared with young mice. The enhanced LPS signaling in aged mice was also demonstrated by the marked induction of nuclear factor-kappaB in the tissues after endotoxin treatment. As a consequence, increases in an inflammatory cytokine, tumor necrosis factor-alpha, were pronounced in plasma and tissues of LPS-treated aged mice. These results emphasize the key role played by PAI-1 in aging-associated deterioration in this thrombosis model, and suggest that the hyperresponse of PAI-1 gene to LPS results from the enhanced LPS signaling and the subsequent inflammatory response in aged mice.

A comparison of low versus standard dose pravastatin therapy for the prevention of cardiovascular events in the elderly: the pravastatin anti-atherosclerosis trial in the elderly (PATE)

Treatment with low drug doses is generally recommended in the elderly. However, the efficacy of low dose 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor treatment in elderly hypercholesterolemic patients has never been examined. Therefore, we compared the effect of low-dose with standard dose pravastatin, an HMG CoA reductase inhibitor, on the incidence of cardiovascular events (CVEs) in elderly patients with hypercholesterolemia in a randomized prospective trial. Subjects aged > or = 60 years (73 +/- 6 years) with serum total cholesterol (TC) levels of 220-280 mg/dL were randomized to the low-dose (groupL, 5 mg/day; n=334) or standard dose (groupS, 10-20mg/day; n= 331). Baseline TC levels were similar in the 2 groups (253 +/-15 mg/dL). Patients were followed for 3-5 years (mean 3.9 years). TC levels decreased from baseline by 11-13% in group L and by 15-17% in groupS. TC levels at 1 year in S and L group were 209 +/- 2 mg/ dL (16 +/- 1% decrease) and 221+/- 2 mg/dL (12 +/- 1% decrease), respectively. Forty two and 29 CVEs occurred in group L and S, respectively. The incidence of CVEs was significantly lower in group S than in group L (P = 0.046, generalized Wilcoxon test; P = 0.096, log-rank test). The risk ratio for group S compared with group L was 0.674 (95% confidence interval: 0.423-1.074). Subgroup analyses suggested that the difference in the incidence of CVEs between the 2 groups was more clear in subjects without diabetes mellitus, with TC levels of < 253 mg/dL, and with TG levels of > or = 133 mg/dL. The incidence of CVEs in group S was significantly lower than that in group L in subjects without both diabetes mellitus and previous cardiovascular disease (P = 0.026, generalized Wilcoxon test; P = 0.032, log rank test). These findings suggest that standard-dose pravastatin (10-20 mg/day) is more effective in reducing the incidence of CVEs in the elderly than low dose pravastatin (5 mg/ day), especially in nondiabetic elderly patients with mild hypercholesterolemia or previous cardiovascular disease.

Need of more frequent International Normalized Ratio monitoring in elderly patients on long-term anticoagulant therapy after influenza vaccination

Previous findings suggest the safety of influenza vaccination for patients on oral anticoagulant therapy (OAT). However, some studies reported a moderate reduction or increase of the anticoagulation. We assessed the effect of influenza vaccination on anticoagulation levels. Seventy-three patients on stable long-term OAT were recruited. Patients were compared with a control group of 72 patients observed during the same period. No differences in the anticoagulation levels were found in patients and in controls during the 3 months before and after the vaccination. However, in patients older than 70 years we observed a reduction of anticoagulation intensity achieved in the month after the vaccination, with a prolonged time spent below the therapeutic range (10% before and 27% after, P = 0.001), and this behaviour was still observed 3 months after vaccination. Influenza vaccination is safe in patients on OAT, but it is associated with a slight reduction in warfarin effect in the elderly, suggesting the need of more frequent International Normalized Ratio monitoring after vaccination in these subjects.