Physician alerts to prevent venous thromboembolism

The Role of Vitamin D in the Relationship Between Gender and Deep Vein Thrombosis Among Stroke Patients

Introduction: Accumulating evidence had demonstrated that females had a higher risk of deep vein thrombosis (DVT) than males, but the mechanism was still unknown. Vitamin D was found to play an essential role in DVT, and gender may influence the serum vitamin D levels. This study aimed to explore whether vitamin D played a role in the gender difference in DVT.

Materials and Methods: A total of 444 patients with acute stroke were recruited, which were divided into the DVT group (n = 222) and the non-DVT group (n = 222). Serum vitamin D levels were measured after admission and were split into three categories, including deficiency (<50 nmol/L), insufficiency (52.5–72.5 nmol/L), and sufficiency (more than 75 nmol/L). Hierarchical regression analysis was adopted to analyze the relationship between gender and DVT, controlling the confounding factors.

Results: Females showed a higher proportion of DVT than males (60.7 vs. 42.5%, p < 0.001), and lower serum vitamin D levels than males (53.44 ± 16.45 vs. 69.43 ± 23.14, p < 0.001). Moreover, serum vitamin D levels were lower in the DVT group than in the non-DVT group (59.44 ± 19.61 vs. 66.24 ± 23.86, p < 0.001). Besides, the DVT group showed a lower proportion of vitamin D sufficiency than the non-DVT group (21.2 vs. 32.9%, p < 0.05). Hierarchical regression analysis showed that females had 2.083-fold (p < 0.001, unadjusted model) and 1.413-fold (p = 0.155, adjusted model) risk to develop DVT. In addition, the sufficiency status of vitamin D showed an independent protective effect on DVT (unadjusted model OR, 0.504, p = 0.004; adjusted model OR, 0.686, p = 0.011).

Conclusion: Females had a higher risk of DVT than males, and vitamin D may play an essential role in this relationship. Further studies are needed to explore whether vitamin D supplementation could reduce DVT risk in stroke patients, especially females.

Venous Thrombus

Venous thromboembolism (VTE) includes pulmonary thromboembolism (PE) and deep venous thrombosis (DVT). Both belonging to thrombus, acute arterial thrombus is white thrombus, while acute venous thrombus is red thrombus. What does the pathological difference mean? Venous thrombosis can autolyze, while arterial thrombosis cannot. For VTE patients, oral anticoagulants are usually recommended for 3, 6, or 12 months and occasionally lifelong, but the course cannot be determined. Furthermore, even with standard anticoagulation therapy and INR, some patients still develop chronic thromboembolic pulmonary hypertension (CTEPH). Thus, the physicians are extremely puzzled about anticoagulant usage. Proposed risk factors for VTE include advanced age, infection, malignancy, autoimmune disease, surgery, trauma, pregnancy, long trip syndrome, family history, AMI, heart failure, and so on. Relevant risk factors are increasing over time. Risk factors are derived from the summary of evidence-based medicine. Although these factors are found to be associated with venous thrombosis, the intrinsic factors have not been well elucidated.

All-cause mortality and use of antithrombotics within 90 days of discharge in acutely ill medical patients

Conflicting evidence exists regarding predictors of and antithrombotic benefit on mortality in hospitalised acutely-ill medical patients. We compared mortality risk within 90 days post-discharge among medically ill patients who did and did not receive antithrombotics. This retrospective claims analysis included patients40 years with nonsurgical hospitalisation2 days between 2005 and 2009 using the HealthCore Integrated Research Database. Antithrombotic use (i.e. anticoagulants and antiplatelets) post-discharge was captured from pharmacy claims. All-cause mortality was determined from Social Security Death Index; cause of death was identified from National Death Index database. Kaplan-Meier survival curves were generated and hazard ratios (HR) for mortality risk were estimated using Cox proportional hazards models. Patients prescribed anticoagulants or antiplatelets post-discharge had lower risk of short-term mortality. For the anticoagulant model, the most significant predictors of mortality were malignant/benign neoplasms (hazard ratio [HR] 1.6, 95 % confidence interval [CI] 1.5–1.7), liver disease (HR 1.6, 95 % CI 1.5–1.7), anticoagulant omission (HR 1.6, 95 % CI 1.4–1.8), gastrointestinal or respiratory tract intubations (HR 1.5, 95 % CI 1.3–1.7), and blood dyscrasias (HR 1.4, 95 % CI 1.4–1.5). For the antiplatelet model, the most significant predictors of mortality were antiplatelet omission (HR 3.7, 95 % CI 3.3–4.1), liver disease (HR 1.6, 95 % CI 1.4–1.7), malignant/benign neoplasms (HR 1.6, 95 % CI 1.5–1.6), gastrointestinal or respiratory tract intubations (HR 1.5, 95 % CI 1.3–1.7), and blood dyscrasias (HR 1.4, 95 % CI 1.4–1.5). These mortality risk factors may guide future studies assessing potential benefits of antithrombotics in specific subsets of patients.

Early diagnosis of venous thromboembolism as a clinical primary symptom of occult cancer: Core proteins of a venous thrombus

Malignancy is one of the risk factors of venous thromboembolism (VTE). As a common accompanying factor of malignant tumors, almost 20% of idiopathic VTEs are identified in patients with occult types of cancer as the primary symptom. The type of internal association that exists between malignant tumors and VTE has not yet been determined. The present review discusses the following: i) Reversible combinations between core proteins of venous thrombi and their ligand proteins. With the condition of immune cell balancing function collapse, which is characterized as dysfunction immune cells and impaired immune functions, the human body loses the function of eliminating infectious/malignant cells quickly and effectively. Thus, integrins β2 and β3 on the membrane of platelets and white blood cells are activated to combine with fibrinogen ligands to form an intravenous mesh-like structure, which acts as an intravenous biological filter that prevents infectious/malignant cells from flowing back into the circulatory system. During the defense process, blood cells (mainly red blood cells) stagnate and fill the filter, which results in venous thrombotic diseases. ii) Tumor cells, which cannot be eliminated quickly, proliferate and invade; or ischemic necrosis destroys peripheral tissues and vessels (veins and arteries), resulting in the formation of a biological filter in injured veins. The filter is filled with stranded tumor cells, which prevents the hemorrhagic metastasis of malignant cells. The formation of an intravenous biological filter results from the transition of the body's own defense capabilities, which is also a physical/histopathological phenomenon. iii) An increase in the number of core proteins in a venous thrombus is a basic molecular step in the formation of intravenous biological filters, which is also defined as a marker of the newly initiated defensive barrier. Increased levels of integrins β1, β2 and β3 are useful in not only the specific diagnosis of VTE, but also in the early recognition of occult malignant tumors in idiopathic VTE patients.

Increased Expressions of Integrin Subunit β1, β2 and β3 in Patients with Acute Infection

OBJECTIVE

Our previous studies have shown that integrin subunits β1, β2 and β3 were the core proteins of venous thrombi and potential useful biomarker of venous thromboembolism (VTE). Patients with acute infection have a high risk of VTE. In this study we explored that is there any relevance between core proteins and acute infection.

METHODS

A total of 230 patients (112 females) with clinically proven acute infection in the emergency unit were recruited into this study, meanwhile 230 patients without acute infection matched in sex and age were recruited as control group. Flow cytometry was done to measure the expressions of blood integrin β1, β2, β3 and cellular immunity (CD3, CD4, CD8, CD4/CD8, CD16CD56 and CD19). The association degree between increased core proteins and acute infection was analyzed by calculating the relative risk (RR).

RESULTS

The expression of integrin β1, β2 and β3 was markedly increased in patients with acute infection (P=0.000, 0.000 and 0.015, respectively). The relative risk ratio (RR) of increased integrin β1, β2 and β3 in acute infection patients was 1.424 (95%CI: 1.156-1.755, P=0.001), 1.535 (95%CI: 1.263-1.865, P=0.000) and 1.20 (95%CI: 0.947-1.521, P=0.148), respectively. Combined integrin β1, β2 and β3 analysis showed that the relative risk ratio (RR) of increased in patients with acute infection was 2.962 (95%CI: 1.621-5.410, P=0.001), and this relative risk (RR) rise to 3.176 (95%CI: 1.730-5.829, P=0.000) in patients with respiratory tract infection (RTI).

CONCLUSION

As the core proteins of venous thrombi, integrinβ1, β2 and β3 were markedly increased expression in patients with acute infection, which maybe explain the increased risk of VTE in acute infection patients. A weakened immune system could be the basic condition of VTE occurrence.

Randomized trial of physician alerts for thromboprophylaxis after discharge

BACKGROUND

Many hospitalized Medical Service patients are at risk for venous thromboembolism in the months after discharge. We conducted a multicenter randomized controlled trial to test whether a hospital staff member's thromboprophylaxis alert to an Attending Physician before discharge will increase the rate of extended out-of-hospital prophylaxis and, in turn, reduce the incidence of symptomatic venous thromboembolism at 90 days.

METHODS

From April 2009 to January 2010, we enrolled hospitalized Medical Service patients using the point score system developed by Kucher et al to identify those at high risk for venous thromboembolism who were not ordered to receive thromboprophylaxis after discharge. There were 2513 eligible patients from 18 study sites randomized by computer in a 1:1 ratio to the alert group or the control group.

RESULTS

Patients in the alert group were more than twice as likely to receive thromboprophylaxis at discharge as controls (22.0% vs 9.7%, P <.0001). Based on an intention-to-treat analysis, symptomatic venous thromboembolism at 90 days (99.9% follow-up) occurred in 4.5% of patients in the alert group, compared with 4.0% of controls (hazard ratio 1.12; 95% confidence interval, 0.74-1.69). The rate of major bleeding at 30 days in the alert group was similar to that of the control group (1.2% vs 1.2%, hazard ratio 0.94; 95% confidence interval, 0.44-2.01).

CONCLUSIONS

Alerting providers to extend thromboprophylaxis after hospital discharge in Medical Service patients increased the rate of prophylaxis but did not decrease the rate of symptomatic venous thromboembolism.

Efficacy, safety, and cost of thrombolytic agents for the management of dysfunctional hemodialysis catheters: a systematic review

Approximately 100,000 patients begin hemodialysis each year in the United States. Although an arteriovenous fistula or graft is the preferred method for long-term vascular access during hemodialysis, as these types of vascular access are the most reliable, approximately 30% of patients require the use of catheters to continue hemodialysis. Tunneled, cuffed hemodialysis catheters are discouraged for permanent vascular access because of their high rates of infection, morbidity and mortality, and thrombotic and technical complications. These catheters have a short functional life span and require medical intervention, often thrombolytic therapy, to treat the catheter malfunction. No thrombolytic agent is specifically indicated for the management of occluded hemodialysis catheters. Thus, we performed a systematic review to critically evaluate all available studies that examined the efficacy, safety, and cost of thrombolytic therapy for the management of dysfunctional hemodialysis catheters. Studies were included if they reported efficacy in a specific proportion of affected dysfunctional hemodialysis catheters; reported the proportion of patients experiencing an adverse outcome (especially bleeding); and described the type of catheter used, dose of thrombolytic agent, administration protocol, dwell time, definition of treatment success, time to follow-up for study end points, and sample size. Eighteen studies met the inclusion criteria. The mean ± SD success rate in clearing dysfunctional hemodialysis catheters was greatest with reteplase at 88 ± 4%, followed by alteplase at 81 ± 37% and tenecteplase at 41 ± 5%. Adverse effects associated with the use of these thrombolytic agents administered at low doses were extremely rare. No serious adverse bleeding events attributed to thrombolytic therapy were reported in any of the trials. Aliquotted reteplase from vials for intravenous use was the least costly thrombolytic agent. Thus, at centers that use high volumes of thrombolytics for dysfunctional hemodialysis catheters, reteplase is the thrombolytic agent of choice.

A simple reminder system improves venous thromboembolism prophylaxis rates and reduces thrombotic events for hospitalized patients1

BACKGROUND

Compliance with venous thromboembolism (VTE) prophylaxis is poor.

OBJECTIVES

We sought to determine whether a simple electronic reminder applicable to all hospitalized patients would increase prophylaxis rates and reduce VTE rates.

METHODS

An electronic reminder was added to the electronic medical record admission note used by all services in our hospital. Prophylaxis, VTE and bleeding rates before and after implementation were compared. Data were analyzed with sas version 9.1.

RESULTS

Among all adult medical and surgical patients admitted to our hospital during the time periods studied, 42.8% (1236/2888) before and 60.0% (1410/2350) after the reminder was added received appropriate prophylaxis as per American College of Chest Physicians (ACCP) guidelines (P < 0.001). The difference reached significance for both medical (51.0% vs. 68.9%; P < 0.001) and surgical (48.0% vs. 61.0%; P < 0.001) services. Fewer patients were diagnosed with VTE after our reminder was added (1.1% vs. 0.3%; P = 0.001), and there was a trend towards fewer bleeds (1.1% vs. 0.6%; P = 0.09). The presence of the reminder was an independent predictor for prophylaxis being given (odds ratio [OR] 1.92, 95% confidence interval [CI] 1.70-2.18; P < 0.001), and was independently associated with a decreased risk for VTE (OR 0.30, 95% CI 0.14-0.64; P = 0.003) after adjustment for other VTE risk factors.

CONCLUSION

Adding an electronic reminder to the admission note improved prophylaxis rates and reduced VTE rates across services. The system is easily reproducible and applicable to other facilities. The improvement obtained was modest, so additional measures will probably be needed to optimize prophylaxis rates.

Pharmacologic prophylaxis for venous thromboembolism and 30-day outcomes among older patients hospitalized with heart failure: an analysis from the ADHERE national registry linked to Medicare claims

BACKGROUND

Hospitalized medically ill patients are at greater risk for venous thromboembolism (VTE). Although pharmacologic prophylaxis regimens have reduced VTE risk in medically ill patients, associations with early postdischarge adverse clinical outcomes among patients with heart failure are unknown.

HYPOTHESIS

We hypothesized that patients receiving pharmacologic VTE prophylaxis during hospitalization for heart failure would have lower rates of postdischarge adverse clinical outcomes than patients not receiving prophylaxis.

METHODS

Using data from the Acute Decompensated Heart Failure (ADHERE) registry linked to Medicare claims, we estimated 30-day postdischarge outcome rates for patients who received in-hospital subcutaneous heparin compared with patients who did not receive in-hospital VTE prophylaxis. We excluded patients who received warfarin or intravenous heparin. Outcomes included mortality, thromboembolic events, major adverse cardiovascular events, and all-cause readmission. We used propensity-score methods to estimate associations between VTE prophylaxis and each outcome. In a secondary analysis, we compared outcomes of patients receiving pharmacologic prophylaxis with unfractionated heparin (UFH) vs low-molecular-weight heparin (LMWH).

RESULTS

Of 36 799 eligible patients in 265 hospitals, 12 169 (33%) received pharmacologic VTE prophylaxis during the hospitalization. In unadjusted analysis and after weighting by the inverse probability of treatment, VTE prophylaxis was not associated with 30-day postdischarge mortality, thromboembolic events, major adverse cardiovascular events, or all-cause readmission. There were no differences in outcomes between patients receiving UFH and those receiving LMWH.

CONCLUSIONS

Pharmacologic VTE prophylaxis is provided to one-third of older patients hospitalized with heart failure. Treatment with LMWH or UFH did not have a statistically significant association with 30-day postdischarge outcomes.