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PubMed2004

The effect of a computerized reminder system on the prevention of postoperative venous thromboembolism.

STUDY OBJECTIVE: To measure the effect of an altered process of care, directed by a computerized reminder system, on rates of symptomatic postoperative venous thromboembolism. DESIGN: Comparisons of preintervention and postintervention measurements. SETTING: A university-affiliated community hospital in Utah. PATIENTS: Two-thousand seventy-seven consecutive patients who underwent major operations in four surgical divisions between January 1, 1997, and October 31, 1997 (preintervention), and 2,093 consecutive patients who underwent the same procedures between January 1, 1998, and October 31,1998 (postintervention). INTERVENTION: A program to prevent venous thromboembolism developed from American College of Chest Physicians guidelines, and an altered work process directed by a computerized reminder system. MEASUREMENTS: Rates of symptomatic, objectively confirmed deep vein thrombosis (DVT), pulmonary embolism (PE), and death attributable to venous thromboembolism occurring within 90 days of the date of surgery. RESULTS: The preintervention and postintervention cohorts did not differ with respect to age, severity of illness, number of risk factors for venous thromboembolism, or individual risk factors for venous thromboembolism. The overall prophylaxis rate increased from 89.9% before implementation of the computerized reminder system to 95.0% after implementation (p < 0.0001). The combined 90-day rate of symptomatic DVT, PE, and death attributable to PE remained the same (preintervention, 1.0%; postintervention, 1.2%; odds ratio, 1.21; 95% confidence interval, 0.67 to 2.20). Forty of 46 venous thromboembolic complications (87%) occurred despite the delivery of American College of Chest Physicians-recommended measures to prevent venous thromboembolism. CONCLUSIONS: Computerized reminder systems combined with altered care procedures increase the rate of prophylaxis against venous thromboembolism without decreasing the rate of symptomatic venous thromboembolism when the baseline rate of prophylaxis is high. A population of surgical patients exists who are resistant to American College of Chest Physicians-recommended prophylactic measures against venous thromboembolism. New strategies are needed to address prophylaxis-resistant venous thromboembolism.

Aged↗

PubMed1996

Frequency of pregnancy-related venous thromboembolism in anticoagulant factor-deficient women: implications for prophylaxis.

BACKGROUND: It has been reported that women with an inherited deficiency of antithrombin, protein C, or protein S have an increased risk for developing venous thromboembolic disease during pregnancy and the postpartum period. However, because the available data on risk are flawed, it is difficult to define a rational, efficacious, and safe policy about prophylaxis for venous thromboembolism in these women. OBJECTIVE: To determine the frequency of venous thromboembolism during pregnancy and the postpartum period in women with heritable deficiencies of anticoagulant factors. DESIGN: Retrospective cohort study. SETTING: University outpatient clinics in the Netherlands and Italy. PARTICIPANTS: 129 otherwise asymptomatic female family members of patients with a history of venous thromboembolism and an established deficiency of antithrombin, protein C, or protein S. MEASUREMENTS: Medical history, with specific attention to episodes of venous thromboembolism and obstetric history, was taken. The anticoagulant factor status of the study participants was determined. If a patient had an episode of venous thromboembolism, subsequent pregnancies in that patient were not analyzed. RESULTS: Of the 129 women who participated in the study, 60 had anticoagulant factor deficiency and 69 did not. In the nondeficient group, 198 pregnancies occurred; 1 of these (0.5%) was complicated by an episode of venous thromboembolism during the postpartum period. In the deficient group, 169 pregnancies occurred; 7 of these (4.1%) were complicated by an episode of venous thromboembolism during the third trimester of pregnancy (2 pregnancies [1.2%]) and the postpartum period (5 pregnancies [3.0%]). The risk for venous thromboembolism was increased eightfold in deficient women compared with nondeficient women (hazard ratio, 8.0 [95% CI 1.2 to 184]). CONCLUSIONS: Anticoagulant factor-deficient women have an increased risk for venous thromboembolism during pregnancy and the postpartum period. Although data from an appropriate randomized clinical trial are lacking, the frequency of venous thromboembolism seen in deficient women might justify the use of anticoagulative prophylaxis during the third trimester of pregnancy and the postpartum period.

Adolescent↗

PubMed2003

[Incidence and risk indicators of thromboembolism during the acute phase of single chamber ventricular pacing].

BACKGROUND: The incidence of thromboembolism may be higher in single chamber ventricular pacing than in physiological pacing. However, the incidence of thromboembolism during the acute phase of single chamber ventricular pacing (within 14 days) is not known. OBJECTIVES: The incidence and the risk indicators of thromboembolism were investigated during the acute phase of single chamber ventricular pacing. METHODS: Fifty-five consecutive patients (22 males, 33 females, mean age 67 +/- 9 years) who required VVI pacemakers due to brady-tachy sick sinus syndrome (42 patients) or brady atrial fibrillation (13 patients) in the period from April 1975 to December 2000 were retrospectively reviewed. The patients were divided into groups with thromboembolism and without thromboembolism, and the risk indicators for thromboembolism were analyzed. RESULTS: Seven patients (13%) suffered systemic thromboembolism. Three patients had thromboembolic events during temporary ventricular pacing, and four patients had thromboembolic events just after permanent VVI pacemaker implantation. The following risk indicators were identified in the patients with thromboembolism: hyperlipidemia, hypertension, organic heart disease (p < 0.05, respectively), and diabetes mellitus (p < 0.0005). CONCLUSIONS: Patients with brady-tachy sick sinus syndrome and brady atrial fibrillation have a significant risk of thromboembolism during the acute phase of single chamber ventricular pacing. Effective anticoagulation is needed in these patients.

Aged↗

PubMedDate not supplied

Prevention of venous thromboembolism in high risk patients.

BACKGROUND AND OBJECTIVE: Venous thromboembolism includes two closely related clinical manifestations: deep vein thrombosis (DVT), more commonly of the lower limbs, and pulmonary embolism. Pulmonary embolism is the most common cause of preventable death in hospitalized patients. The definition of the risk factors for venous thromboembolism should allow to adopt the most suitable prophylactic regimen. Determinants for the risk of venous thromboembolism are patient risk factors, both clinical and molecular, and the clinical setting. In this article the prophylactic regimens most widely employed in the prevention of venous thromboembolism in high-risk clinical settings with be reviewed. Then, the available guidelines for the management of thrombophilic patients will be given. INFORMATION SOURCES: The authors have been working in this field contributing original papers. In addition, the material examined in this review article includes papers published in the journals covered by the Science Citation Index and Medline. STATE OF ART AND PERSPECTIVES: Pharmacological prophylaxis is an effective approach for reducing morbidity and mortality from venous thromboembolism. Nevertheless, prophylaxis for venous thromboembolism is under employed because the incidence of venous thromboembolism is underestimated and there is fear of bleeding side effects. Adopting the proper prophylactic strategy for venous thromboembolism requires defining the patient risk factor. Determinants for the risk of venous thromboembolism are patient risk factors, both clinical and molecular, and the clinical setting. The risk connected with the clinical setting is the only risk defined by properly performed epidemiological studies. High-risk clinical settings are major orthopedic surgery, elective neurosurgery, spinal cord injury, cancer surgery and multiple trauma. The most effective anticoagulant regimens in the prevention of venous thromboembolism in high-risk patients are adjusted-dose unfractionated heparin, low molecular weight heparins (LMWHs) and oral anticoagulants. LMWHs are as effective and safe as the other two agents, but they do not require laboratory monitoring. On the other hand, LMWHs are more expensive than unfractionated heparin and warfarin. The use of effective agents still leaves the patients with a high prevalence of venous thromboembolism. Hence the search for more effective agents such as selective thrombin inhibitors like hirudin and its analogues. In patients undergoing elective hip surgery, hirudin has been recently shown to be more effective than low-dose unfractionated heparin and the LMWH enoxaparin.

Adult↗

PubMed2002

[Prevention of thromboembolism with low molecular weight heparin (Dalteparin-Na) in risk pregnancy].

BACKGROUND: Venous thrombotic events still remain the leading cause of maternal morbidity and mortality. During pregnancy as well as post partum, hemostasis changes also in normal pregnant women. Coagulation is activated and fibrinolysis suppressed, the concentration of particular coagulation factors is increased, while inhibitor potential is decreased. Additionally, the venous blood stream is mechanically hampered by the gravid uterus. As a result of these physiologic changes, the risk of thromboembolism is elevated. The risk increases frequently in women with previous thromboembolic episodes, a family history of thromboembolism, hereditary or acquired thrombotic disorders as well as the appearance of additional exposure prothrombogenic factors such as immobilization, inflammation, and operation. Simultaneous presence of combined prothrombogenic factors conducts a potentiation of the risk of thromboembolism. To avoid thromboembolism or rethromboembolism during pregnancy or puerperium, an individual risk-adapted heparin prophylaxis is indicated. PATIENTS AND METHODS: 17 pregnant women with inherited and/or acquired prothrombogenic disorders, eleven of them with previous thromboembolism episodes, were treated with low molecular weight heparin (LMWH; dalteparin-Na). The daily dose of 5,000-10,000 IU LMWH was applied subcutaneously by self-injection during pregnancy and up to 8 weeks post partum. Every 4 weeks clinical and laboratory monitoring was performed. Basic parameters as well as the special coagulation marker TAT (thrombin-antithrombin complex) and D-dimer were analyzed. RESULTS: Under the therapy with LMWH (dalteparin-Na), no thromboembolic events during pregnancy or post partum could be observed. No serious bleeding complications, except small subcutaneous local hematomas, occurred. Bolus applications of LMWH by self-injection were easy to practice, gained a good acceptance and high compliance. Increased TAT values above normal at the actual state of pregnancy could be suppressed to normal values by raising the LMWH dose. CONCLUSION: The individual thromboembolic prophylaxis with LMWH represents an effective and safe therapy in risk pregnancy with previous thromboembolic events and/or thrombotic disorders. TAT seems to be an effective marker for monitoring of the coagulation activity during pregnancy and puerperium. Under this management, thromboembolic prophylaxis can be optimized.

Adolescent↗

PubMed1975

Oral contraceptives and thromboembolism: a reassessment.

The relationship between oral contraceptive usage and thromboembolism is controversial. Since thromboembolism is often undiagnosed, both clinically and at routine autopsy, most epidemiologic analyses rest or a very uncertain factual base. There are increases in blood coagulation factors in oral contraceptive users similar to, but less than, those seen in pregnancy, which is not associated with increased thromboembolism. Hematologists emphasize that these changes do not define a "hypercoagulable" state, and they do not define or predict the occurrence of thrombosis. Intrinsic vascular wall changes, unrelated to drug use, may play a role in sporadic cases of thromboembolism. When the incidence of thromboembolism in very large Phase III trials of conventional oral contraceptives is compared to that in other populations (patients admitted to the hospital, women who visit a physician, pregnant women, or users of nonestrogenic oral contraceptives), no difference is seen. Epidemiologic studies by the "case-control" ("trohoc") method consistently show an increase "relative risk" associated with oral contraceptive use in subjects with "idiopathic" thromboembolism but no increased risk in thromboembolism patients as a whole or in those with predisposing factors. This retrospective epidemiologic technique, its particular applications, and the inferences drawn are open to serious criticism, as are studies claiming a relationship between estrogen dose and thromboembolism incidence. An Australian prospective survey found no increased risk among users, and a large British study which initially reported an increased risk is currently undergoing recalculation. The only controlled clinical experiment (with random assignment of subjects to vaginal versus high-estrogen contraceptives) showed no increased incidence in the drug-treated group. Statistical associations derived from "trohoc" studies do not establish causal relationships; moreover, their risk estimates are in conflict with the findings of large Phase III clinical surveys including subjects using estrogen-free contraceptives, with at least one prospective clinical survey, and with a randomized, controlled clinical trial. The data relating estrogen dosage to thromboembolism incidence are ambiguous, at best. Thus, the claim of a causal relationship between oral contraceptive steroids and thromboembolism does not appear to be firmly founded, and the belief that predisposing factors increase the risk to contraceptive users is equally insubstantial.

Adolescent↗

PubMed1983

Medtronic-Hall valve: thromboembolic complications.

UNLABELLED: We have studied the incidence of thromboembolic complications in 46 patients. Twenty-one patients had a Medtronic-Hall prosthesis implanted in the mitral position (group A) and 25 patients had the same prosthesis implanted in the aortic position (group B). Several factors were defined initially as "thromboembolic risk factors" and we have tried to establish a correlation between those factors and the actual thromboembolic complications. Group A: 21 patients presented 5 thromboembolic accidents (23.8%). Preeminent factors were: preoperative thromboembolic phenomena, previous heart operations, atrial fibrillation and the presence of congestive heart failure and/or low outpout syndrome in the postoperative period. Group B: 25 patients presented 6 thromboembolic accidents (24%). If we exclude the presence of low outpout syndrome in the postoperative period, there was no correlation between other risk factors and the incidence of thromboembolic complications. We must mention that the incidence of thromboembolic complications in this group diminished significantly (26% to 16%) when oral anticoagulation was continued with aspirin. COMMENTARY: these figures of thromboembolic complications appear too high at first sight if we consider only their absolute value, but are justified when one bears in mind the clinical circumstances of the patients who suffered from thromboembolic complications.

Aortic Valve↗

PubMed2006

Effect of Factor V Leiden and prothrombin G20210-->A mutations on thromboembolic risk in the national surgical adjuvant breast and bowel project breast cancer prevention trial.

BACKGROUND: In the National Surgical Adjuvant Breast and Bowel Project's Breast Cancer Prevention Project (BCPT), tamoxifen use was associated with an increased relative risk for venous thromboembolic events, including deep vein thrombosis and pulmonary emboli, compared with placebo. However, the involvement of hypercoagulability factors in this association is unclear. METHODS: To examine possible associations among the risk of venous thromboembolic events, tamoxifen use, and Factor V Leiden (FVL) and prothrombin G20210-->A (PT20210) mutations, which are involved in promoting blood coagulation, we used a nested, matched, case-control (1 : 4) design and compared women in the BCPT who had experienced venous thromboembolic events (n = 76) with women who did not (n = 295). FVL and PT20210 mutations were detected in genomic DNA that was isolated from blood samples collected at trial enrollment. RESULTS: Venous thromboembolic events occurred in 28 women (deep vein thrombosis in 22 and pulmonary emboli in six) who were taking placebo and in 53 women (deep vein thrombosis in 35 and pulmonary emboli in 18) who were taking tamoxifen (relative risk = 1.90, 95% confidence interval = 1.18 to 3.12). Excessive risk for venous thromboembolic events was observed only in the first 36 months of therapy. There were no differences in age, smoking, and race between the groups, but women with venous thromboembolic events had a higher body mass index than women without (mean +/- standard deviation, 30 kg/m(2) +/- 7.7 versus 27.1 +/- 5.6; P<.001). FVL and/or PT20210 mutations were found in nine women (four on tamoxifen and five on placebo) with venous thromboembolic events and in 20 control subjects (nine on tamoxifen and 11 on placebo). No associations were found between risk of venous thromboembolic events and mutation status in either treatment group. CONCLUSIONS: Venous thromboembolic disease in the BCPT women is associated with tamoxifen use and body mass index, but not with FVL and PT20210 mutations. Screening women at risk for breast cancer for FVL and/or PT20210 appears to offer no benefit in determining the risk of tamoxifen-associated thromboembolic events.

Adenine↗

PubMed1999

Comparison of enoxaparin and warfarin for the prevention of venous thromboembolic disease after total hip arthroplasty. Evaluation during hospitalization and three months after discharge.

BACKGROUND: Venous thromboembolic disease in the form of deep venous thrombosis and pulmonary embolism is a major risk after a total hip arthroplasty. Enoxaparin, a low-molecular-weight heparin, has been shown to reduce the prevalence of deep venous thrombosis after total hip arthroplasty. Warfarin, an orally administered anticoagulant, has been used historically to reduce the risk of deep venous thrombosis after total hip arthroplasty. METHODS: We compared enoxaparin and adjusted-dose warfarin with respect to their safety and their efficacy in the prevention of clinically important venous thromboembolic disease, defined as distal or proximal deep venous thrombosis or pulmonary embolism, or both, during hospitalization after total hip arthroplasty. We also evaluated the prevalence of complications and mortality from venous thromboembolic disease within three months after discharge. RESULTS: Three thousand and eleven patients at 156 centers were randomly assigned to prophylactic treatment with injection of enoxaparin or oral administration of adjusted-dose warfarin during hospitalization. During the study, fifty-five (3.6 percent) of the 1516 patients who were managed with enoxaparin and fifty-six (3.7 percent) of the 1495 patients who were managed with warfarin had venous thromboembolic disease. Twenty-one patients (0.7 percent), which included four (0.3 percent) of those managed with enoxaparin and seventeen (1.1 percent) of those managed with warfarin (p = 0.0083), had venous thromboembolic disease during hospitalization. After discharge from the hospital, venous thromboembolic disease developed in ninety patients (3.0 percent): fifty-one (3.4 percent) of those managed with enoxaparin and thirty-nine (2.6 percent) of those managed with warfarin. One patient who had been managed with enoxaparin died because of a pulmonary embolism, which was confirmed at autopsy. Three additional patients (one who had been managed with enoxaparin and two who had been managed with warfarin) died, and the deaths were attributed to venous thromboembolic disease; however, no autopsies were performed. Twenty-six patients (0.9 percent) (eighteen managed with enoxaparin and eight managed with warfarin) had clinically important bleeding. CONCLUSIONS: Inpatient programs providing treatment with either enoxaparin (thirty milligrams every twelve hours) or adjusted-dose warfarin for a mean of 7.3 days afforded protection against venous thromboembolic disease, with overall rates of morbidity and mortality of 3.7 and 0.6 percent, respectively, and a very low rate of major bleeding complications (0.9 percent) for three months after total hip arthroplasty. During hospitalization, the patients managed with enoxaparin had a lower rate of venous thromboembolic disease than those managed with adjusted-dose warfarin (p = 0.0083). This benefit was lost after the medication was discontinued, with no difference in the prevalences of venous thromboembolic disease between the two groups at three months after discharge from the hospital.

Adolescent↗

PubMed2005

A comparison of reported gastrointestinal and thromboembolic events between rofecoxib and celecoxib using observational data.

BACKGROUND AND OBJECTIVES: Rofecoxib, a selective cyclo-oxygenase (COX)-2 inhibitor, was a widely marketed drug that was used for relief of pain and inflammation in arthritic conditions. It was withdrawn from the market worldwide in September 2004 because of an increased risk of cardiovascular events. Celecoxib, which belongs to the same class of drugs, is now under scrutiny for the risk of similar events. The objective of our study was to compare the incidence of gastrointestinal (GI) [symptomatic and complicated upper GI] events and thromboembolic (cardiovascular, cerebrovascular and peripheral venous) events reported for patients prescribed rofecoxib or celecoxib in primary care. METHODS: A retrospective analysis of selected events was conducted using data collected from previously conducted prescription-event monitoring (PEM) studies for rofecoxib and celecoxib. PEM is an observational cohort technique. Exposure data were derived from dispensed prescriptions for rofecoxib (July-November 1999) and celecoxib (May-December 2000) that were written by primary care general practitioners in England. Outcome data were clinical events and information on potential risk factors reported on simple questionnaires (posted to prescribers approximately 9 months after the date of the first prescription). Incidence rates of the first event during treatment within each thromboembolic and GI group were calculated during the 270 days after the patient started receiving either of the drugs; crude and adjusted rate ratios (RR) were calculated for rofecoxib compared with celecoxib using Poisson regression modelling. RESULTS: The rofecoxib and celecoxib PEM cohorts contained 15 268 and 17 458 patients, respectively. For the GI event groups, the adjusted RRs for rofecoxib compared with celecoxib were: 1.21 (95% CI 1.09, 1.36) for symptomatic upper GI events and 1.60 (95% CI 0.95, 2.70) for complicated upper GI conditions. For the thromboembolic event groups, the adjusted RRs were: 1.04 (95% CI 0.50, 2.17) for cardiovascular thromboembolic events; 1.43 (95% CI 0.86, 2.38) for cerebrovascular thromboembolic events; and 0.36 (95% CI 0.01, 1.34) for peripheral venous thromboembolic events. CONCLUSIONS: This study was a retrospective comparison of PEM studies conducted for rofecoxib and celecoxib. For symptomatic upper GI events, a 21% increase in the relative rate was found for rofecoxib users compared with celecoxib users after adjusting for identified risk factors. For complicated upper GI events, no statistically significant difference in the incidence was observed between rofecoxib and celecoxib users after adjusting for identified risk factors. For the three thromboembolic event groups, no evidence of a statistically significant difference between rofecoxib and celecoxib users was found after adjusting for identified risk factors. This study contributes to the understanding of the association between COX-2 inhibitors and thromboembolic events. However, it should be borne in mind that we had information on only a limited number of confounding variables for thromboembolic events. Further research is required to fully understand the risks and benefits of using celecoxib and other COX-2 inhibitors. Meanwhile, doctors should be cautious when prescribing these products, particularly to patients with risk factors for developing thromboembolic events.

Celecoxib↗

PubMed1995

Prevalence of residual left atrial thrombi among patients with acute thromboembolism and newly recognized atrial fibrillation.

BACKGROUND: Thromboembolism related to atrial fibrillation (AF) is a major cause of morbidity and mortality. Patients with acute thromboembolism and AF are at high risk for early recurrent events. OBJECTIVE: To determine the prevalence of left atrial thrombi in patients who had acute thromboembolism and newly diagnosed AF. PATIENTS AND METHODS: Adult inpatients with AF were screened to identify those with acute (< 36 hours) systemic thromboembolism and newly recognized AF. Of 41 qualifying patients, 31 (76%) agreed to undergo transesophageal echocardiographic study, including 24 with acute neurologic events and seven with peripheral thromboembolism. A control population consisted of 88 adults with newly recognized AF without clinical thromboembolism. RESULTS: Transesophageal echocardiography identified left atrial thrombi in 13 (43%) of the 30 study patients who underwent transesophageal echocardiography compared with nine (10%) of 87 controls (P < .001). Spontaneous echo contrast was identified in 27 (87%) of the study population vs 42 (48%) of controls (P < .001). The prevalence of this marker of blood stasis did not differ between patients with left atrial thrombi without thromboembolism (P = .69). Duration of AF, prevalence of abnormal left ventricular function, left atrial size, and mitral regurgitation were similar in both groups. CONCLUSIONS: Left atrial thrombi were identified in more than 40% of patients with acute thromboembolism and newly recognized AF. These data suggest that a major source of recurrent thromboembolism in this group may be residual thrombus migration. Among patients with AF and atrial thrombi, clinical thromboembolism seems to occur randomly, or is related to an unidentified process.

Acute Disease↗

PubMed1995

Antiarrhythmic prophylaxis vs warfarin anticoagulation to prevent thromboembolic events among patients with atrial fibrillation. A decision analysis.

BACKGROUND: Patients with atrial fibrillation compared with those with sinus rhythm are at increased risk for thromboembolism, often mandating therapy directed at thromboembolism prevention. However, the safest, most efficacious strategy to prevent thromboembolism associated with atrial fibrillation is unknown. We developed a decision analysis to compare the risks and benefits of two common clinical strategies to prevent thromboembolism in the patient with atrial fibrillation: (1) sinus rhythm maintenance with quinidine sulfate or with amiodarone hydrochloride after cardioversion and (2) long-term anticoagulation with warfarin sodium. METHODS: A search was conducted of the English-language MEDLINE databases of the National Library of Medicine dated 1966 through December 1992. The search was conducted by intersecting "quinidine," "warfarin," or "amiodarone" with "atrial fibrillation." Six of 249 articles concerning quinidine and five of 20 articles concerning warfarin were judged by multiple reviewers to meet predetermined inclusion and exclusion criteria. To our knowledge, no randomized, placebo-controlled trials of amiodarone therapy for atrial fibrillation have been published. Five of 112 identified articles concerning amiodarone involved nonrandomized trials that met the remaining selection criteria and were included in this analysis. RESULTS: Thromboembolic events and fatal nonthromboembolic adverse events during the course of therapy (defined as fatal proarrhythmia, fatal hemorrhage, and fatal noncardiac toxic effects) were considered to have equivalent weight. The total risk during therapy, defined as thromboembolic and fatal nonthromboembolic adverse events during the course of therapy, was evaluated over a range of baseline thromboembolism risks, from 1% to 20% per patient-year. Quinidine therapy compared with no therapy was associated with increased total risk, unless baseline thromboembolism risk exceeded 11% per patient-year. Total risk during warfarin therapy was less than total risk during quinidine therapy for the entire range of baseline thromboembolism risks, from 1% to 20% per patient-year. Total risk during warfarin or amiodarone therapy was similar and less than that with no therapy for the entire range of baseline risks. CONCLUSIONS: Based on data from randomized, controlled trials of quinidine and warfarin, warfarin therapy appears to be the safest strategy for thromboembolism prevention in the patient with atrial fibrillation. The role of low-dose amiodarone therapy appears promising and warrants further study in randomized, controlled trials.

Adolescent↗

PubMed2006

Effect of patient's sex on risk of recurrent venous thromboembolism: a meta-analysis.

BACKGROUND: Individual risk of recurrent venous thromboembolism affects patient management and might differ between men and women. We did a meta-analysis to assess from available evidence whether men and women have the same risk of recurrent venous thromboembolism after stopping anticoagulant treatment. METHODS: Eligible articles were identified by searches of MEDLINE (source PubMed, 1966 to February 2005), EMBase (1980 to February 2005), and the Cochrane database 2005, issue 1. Prospective cohort studies and randomised trials were eligible if they included patients with objectively diagnosed venous thromboembolism treated for a minimum of 1 month and followed up for recurrence after anticoagulant treatment was stopped. Data were extracted for study design, study quality, and the number, sex, and age of enrolled patients, risk factors for venous thromboembolism, treatment given, duration of follow-up, and the number of episodes of recurrent venous thrombosis. FINDINGS: 15 studies (nine randomised controlled trials and six prospective observational studies) enrolling a total of 5416 individuals (2729 men), of whom 816 (523 men) had recurrent venous thromboembolism after stopping treatment, were eligible for inclusion. The pooled estimate of the relative risk (RR) of recurrent venous thromboembolism for men compared with for women was 1.6 (95% CI 1.2-2.0). Significant heterogeneity was shown among individual study findings; however, the higher risk of recurrent venous thromboembolism in men than in women was consistent across predefined subgroups. The relative risk for recurrence in men from randomised trials (RR 1.3; 95% CI 1.0-1.8) was lower than that from observational studies (2.1; 1.5-2.9). The lower risk of recurrent venous thromboembolism in women did not seem to be accounted for by a reduced rate of recurrence after venous thromboembolism associated with oestrogen treatment or pregnancy. INTERPRETATION: Men seem to have a 50% higher risk than women of recurrent venous thromboembolism after stopping anticoagulant treatment. If confirmed by further prospective studies, this difference in risk of recurrence should be considered when duration of anticoagulant treatment is determined in individual patients.

Aged↗

PubMed2003

Major genetic susceptibility for venous thromboembolism in men: a study of Danish twins.

BACKGROUND: Although several genetic determinants (mutations or polymorphisms) have been associated with increased risk of venous thromboembolism, the overall influence of genetic factors on this disease is unknown. METHODS: We linked the Danish Twin Registry, which includes twins born 1870-1953, with the Danish National Registry of Patients, comprising all hospitalizations in Denmark since 1977. We then determined the risk of venous thromboembolism as determined from discharge diagnosis. RESULTS: We identified 26,982 twins who were alive on 1 January 1977, and computed measures of familial and genetic association of venous thrombotic disorders. Individuals were classified according to zygosity and hospitalization with venous thromboembolism. Since 1977, 678 twins were hospitalized with an episode of venous thromboembolism. Of these, only 545 pairs (281 male pairs and 264 female pairs) were alive in 1977. For men, the concordance rates for mono- and dizygotic twin pairs, respectively, were 0.22 (95% confidence interval = 0.14 to 0.30) and 0.08 (0.04-0.12). The odds ratio (interpreted as the relative risk of venous thromboembolism for one twin, given venous thromboembolism in the partner twin) was 13.5 (7.3-24.8) among monozygotic twins and 3.8 (1.8-8.3) among dizygotic twins. The respective correlations for venous thromboembolism were 0.55 (0.38-0.70) and 0.26 (0.09-0.42). The proportion of the variance attributable to genetic effects on venous thromboembolism in males was 55% (39%-68%). The remaining variation could be attributed to men's nonfamilial environments. In contrast, for women there was no intra-twin pair similarity for venous thromboembolism. CONCLUSIONS: We found differences in genetic susceptibility to venous thromboembolism between the sexes, with genetic factors playing a substantially stronger role in males than in females.

Denmark↗

PubMed1997

Recurrence of venous thromboembolism in patients with familial thrombophilia.

BACKGROUND: Treatment of patients with deep vein thrombosis and an antithrombin or protein C or S deficiency is based on case reports and personal experience. OBJECTIVE: To systematically assess the risk for recurrence of venous thromboembolism after a first episode in patients with these deficiencies, a literature review and retrospective family cohort study were performed. METHODS: For the literature review, the annual incidence of a first recurrent venous thromboembolism was assessed for each deficiency by dividing the number of venous thromboembolic events by the number of years at risk. For the family cohort study, 1- and 5-year cumulative incidences of first recurrence were calculated based on medical histories taken in relatives of consecutive patients in whom venous thromboembolism and a deficiency were diagnosed. RESULTS: For the literature review, the annual incidence of a first recurrent venous thromboembolism in patients with antithrombin or protein S deficiency ranged from 13% to 17% and 14% to 16%, respectively. For the family cohort study, the 1- and 5-year cumulative incidences of recurrent venous thromboembolism were 10% (95% confidence interval, 1%-19%) and 23% (95% confidence interval, 10%-36%), respectively. Warfarin sodium (Coumadin) prophylaxis was associated with 2 venous thromboembolic events in 141 years at risk (1.4% per year), in contrast with 19 events in 709 years at risk (2.7% per year) without prophylaxis (difference, -1.3%; 95% confidence interval, -3.5% to 1.0%). CONCLUSIONS: The annual incidence of recurrent venous thromboembolism is high during the first years following a first episode, but seems to decline thereafter. Therefore, our results challenge current practice of prescribing lifelong warfarin therapy after a first or second episode of venous thromboembolism in patients with antithrombin or protein C or S deficiency.

Anticoagulants↗

PubMed1996

Lack of improved survival plus increase in thromboembolic complications in patients with clear cell carcinoma of the ovary treated with platinum versus nonplatinum-based chemotherapy.

BACKGROUND: This study was conducted to evaluate survival rates for patients with clear cell ovarian carcinoma who had platinum-based chemotherapy versus nonplatinum-based chemotherapy and the risk of thromboembolic complications. METHODS: One hundred and eleven evaluable patients with clear cell ovarian carcinoma who underwent primary surgery and postoperative therapy were retrospectively evaluated. Median follow-up was 21.3 months (range, 3-280 months). Patients treated with platinum-based chemotherapy and nonplatinum-based chemotherapy were evaluated according to stage, age, grade, extent of surgery, and development of thromboembolic complications. Patient populations were compared using the chi-square test. Estimated 5- and 10-year survivals for each group were calculated using the method of Kaplan and Meier. Differences in survival rates were calculated using the log rank test. The frequency of thromboembolic complications in the clear cell ovarian carcinoma group was compared with its frequency in a matched-control group of 109 patients with epithelial nonclear cell ovarian carcinoma. RESULTS: Seventy-one patients were treated with nonplatinum-based chemotherapy and 40 patients were treated with platinum-based chemotherapy. There was no statistically significant difference in the characteristics of patient populations treated with platinum-based chemotherapy or nonplatinum-based chemotherapy. The estimated 5-year survival for clear cell ovarian carcinoma patients treated with platinum-based chemotherapy did not differ significantly from the estimated 5-year survival for patients with clear cell ovarian carcinoma treated with nonplatinum-based chemotherapy (36% vs. 32%; P = 0.23). Twelve patients with clear cell ovarian carcinoma developed thromboembolic complications remote from primary surgery, whereas in a matched-control group of patients with nonclear cell ovarian carcinoma treated with platinum-based chemotherapy, no patients developed a thromboembolic complications (P = 0.0004). Eight of 40 patients (20%) with clear cell ovarian carcinoma treated with platinum-based chemotherapy developed thromboembolic complications, whereas 4 of 71 patients (6%) treated with nonplatinum-based chemotherapy developed thromboembolic complications (P = 0.03). Multivariate logistic regression analysis demonstrated that the development of a thromboembolic complication was significantly related to clear cell ovarian carcinoma and platinum-based chemotherapy and had a significant (P = 0.009) negative impact on survival. CONCLUSIONS: Platinum-based chemotherapy did not appear to improve survival compared with nonplatinum-based chemotherapy of patients with clear cell ovarian carcinoma. The combination of platinum-based chemotherapy and clear cell ovarian carcinoma significantly increases the risk for thromboembolic complications and has a significant negative impact on survival.

Adenocarcinoma, Clear Cell↗

PubMed2006

Thromboembolism after pneumonectomy for malignancy: an independent marker of poor outcome.

OBJECTIVE: Because venous thromboembolism results in important postoperative morbidity and mortality after pneumonectomy for malignancy, we sought to determine its prevalence, location, management, timing, and risk factors. We also evaluated short- and long-term outcomes of patients in whom venous thromboembolism developed compared with those of patients in whom it did not. METHODS: Between January 1990 and January 2001, 336 patients underwent pneumonectomy for malignancy. Patients were considered to have venous thromboembolism if they were identified as having deep vein thrombosis or pulmonary embolus through chart review, including pulmonary imaging studies. All patients were managed with anticoagulation or anticoagulation plus thrombolysis. RESULTS: Twenty-five (7.4%) patients had postoperative venous thromboembolism, with peak incidence 7 days after the operation; most had already been discharged from the hospital. Higher pack-years of smoking was associated with increased risk, as well as with earlier occurrence of venous thromboembolism (P < .04). Survival was 55% at 6 months and 13% at 18 months; mode of death was cancer in 14 (61%) of 23, respiratory failure in 4 (17%) of 23, multisystem organ failure in 3 (13%) of 23, myocardial infarction in 1 (4.4%) of 23, and uncertain in 1 (4.4%) of 23. Low preoperative forced vital capacity was predictive of poor long-term survival (P = .02). Patients with venous thromboembolism had substantially lower survival than predicted from competing-risks analysis of survival without venous thromboembolism (13% vs 60% at 18 months), and this difference persisted after censoring for deaths directly attributable to venous thromboembolism. CONCLUSIONS: Venous thromboembolism is surprisingly common after pneumonectomy for malignancy and portends poor survival. Improved screening and better prophylaxis might prevent this complication and enhance outcome.

Female↗

PubMed2000

Risk factors for thromboembolism in patients with paroxysmal atrial fibrillation.

There is some controversy concerning which clinical characteristics predict thromboembolism and whether treatment with class I antiarrhythmic drugs reduces thromboembolim in patients with paroxysmal atrial fibrillation (AF). This retrospective, multicenter study was undertaken to determine risk factor or factors for thromboembolism in patients with paroxysmal AF. Seven hundred forty patients with paroxysmal AF (mean age 56 years) without prior thromboembolic events were followed retrospectively. Cerebral thromboembolism, including transient ischemic attack and embolism of peripheral arteries, were selected as primary end points. Independent risk factors were determined with multivariate analysis, and event-free survival curves were estimated. During 3.4-year follow-up period, primary end points occurred in 55 patients (2.2% per year). Patients with thromboembolism had a higher prevalence of underlying heart disease (p <0.01), less frequent treatment with antiarrhythmic drugs (p <0.01), and received diuretics more often (p <0.01) compared with patients without thromboembolism. Age (>/=65 years, RR 3.33, p = 0.0001) and gender (male, RR = 2, p = 0.0291) emerged as predictors of thromboembolism by multivariate analysis with Cox's proportional hazard model. Treatment with antiarrhythmic drugs (RR = 0.57, p = 0.0578) and aspirin (RR = 0.52, p = 0.1094) showed trends toward reducing thromboembolic risks. It is suggested that elderly men (>/=65 years) with paroxysmal AF are at risk for thromboembolism, but the risk tended to be reduced by treatment with antiarrhythmic drugs and aspirin.

Atrial Fibrillation↗