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Duration of oral anticoagulant treatment in patients with venous thromboembolism and a deficiency of antithrombin, protein C or protein S--a decision analysis.

Patients with a first venous thromboembolic event and a deficiency of the coagulation inhibitors antithrombin, protein C or protein S have an increased risk of recurrent venous thromboembolism compared to patients without such a deficiency. A decision analysis was performed to assess the effect of continuing treatment with vitamin K antagonists on mortality by a reduction in fatal recurrent pulmonary embolism and an induction of fatal haemorrhages associated with their use. The treatment decision involves continuation or discontinuation of vitamin K antagonists in patients with a first spontaneous or secondary venous thromboembolism and an antithrombin, protein C or S deficiency. Although the efficiency of oral anticoagulation is high in all age groups early after the first thromboembolic event, it decreases over time. Our analysis indicates that the optimal treatment duration will vary, depending on the type of the initial event (spontaneous or secondary; deep venous thrombosis or pulmonary embolism), age, and time passed since the initial thromboembolic episode. Moreover, life-long duration of the prophylaxis seems not warranted in all patients.

Administration, Oral↗

[Clinical analysis of 12 cases with venous thromboembolism during pregnancy and puerperium].

OBJECTIVE: To study the incidence, cause and clinical manifestation of venous thromboembolism during pregnancy and puerperium, and its diagnosis and treatment. METHODS: 12 cases of venous thromboembolism admitted in our hospital from 1984-1997 were analysed retrospectively. The plasma protein C, protein S and antithrombin III activities were measured in 4 of the cases and activated protein C resistance (APC-R) were assayed by activated partial thrombinplastin time (APIT) in the presence and absence of APC (APC-APIT) and FV Leiden gene mutation were analysed by PCR restriction fragment length polymorphisms (RFLP) methods as well. RESULTS: Four cases occurred before delivery and 8 postpartum. Two cases complicated by pulmonary thromboembolism, and of them 1 died. APC-R(+), reduced activity of antithrombin-III and protein S each were found in 3 separate cases. No FV Leiden gene mutation was found in the 4 cases. CONCLUSIONS: The formation of venous thromboembolism during pregnancy and puerperium is highly associated with the deficiency of anticoagulant proteins. Anticoagulation is recommended in the high risk women of thromboembolism.

Adult↗

Inherited thrombophilia and first venous thromboembolism during pregnancy and puerperium.

Venous thromboembolism is a rare but threatening complication of pregnancy. Little conclusive information is available on the actual risk of venous thromboembolism during pregnancy or puerperium in women with inherited thrombophilia, particularly in carriers of factor V Leiden and of the G20210A prothrombin gene mutation. To determine the pregnancy-related and puerperium-related risk of venous thromboembolism in women with inherited thrombophilia, we performed a case-control study on 119 women who had a first episode of deep vein thrombosis and/or pulmonary embolism during pregnancy or puerperium and 232 healthy women who had at least one pregnancy without thrombosis. Inherited thrombophilia was diagnosed in 47 patients (39.5%) and 15 controls (6.5%). The relative risk of venous thromboembolism was 10.6 (95% CI, 5.6-20.4) for heterozygous carriers of factor V Leiden, 2.9 (95% CI, 1.0-8.6) for heterozygous carriers of the prothrombin mutation and 13.1 (95% CI, 5.0-34.2) for those with antithrombin, protein C or protein S deficiency taken together. Sixty-eight of the 119 women (57%) had thrombosis after delivery, confirming the puerperium as a particularly high-risk period. When women were divided into two groups of those with antenatal or postnatal thrombosis. the relative risks associated with each type of inherited thrombophilia were of similar magnitude. In conclusion, women with inherited thrombophilia have an increased risk of venous thromboembolism during pregnancy. Among thrombophilic abnormalities, the prothrombin mutation was the weakest risk factor. Thrombosis occurred more frequently in puerperium than in pregnancy, whether or not thrombophilia was diagnosed.

3' Untranslated Regions↗

Risk of thromboembolic complications in patients with permanent atrial fibrillation undergoing cardioverter-defibrillator implantation.

BACKGROUND: Cardioversion of atrial fibrillation (AF) carries the risk of thromboembolic complications and, therefore, anticoagulation therapy is routinely administered before and after this procedure. In patients with permanent AF who undergo implantation of cardioverter-defibrillator (ICD), anticoagulants are usually withdrawn during the perioperative period. However, in some patients sinus rhythm may be restored during defibrillation threshold (DFT) testing which potentially may increase the risk of thromboembolic complications. AIM: To assess the frequency of sinus rhythm restoration during ICD implantation in patients with permanent AF and the rate of both thromboembolic events and local bleeding complications which may occur due to temporary withdrawal of anticoagulation therapy and its re-initiation early after the procedure. METHODS: Permanent AF was present in 23 (12%) of 193 patients selected for ICD implantation. All patients received prolonged oral anticoagulation according to the generally accepted standards. Anticoagulation therapy was stopped few days before the procedure and replaced by low molecular weight heparin which was administered up to 24 hours before ICD implantation and re-initiated 12-24 hours afterwards. RESULTS: During DFT testing sinus rhythm was restored in 5 (21.7%) patients with AF. Clinical and DFT characteristics were similar in those who were converted to sinus rhythm and those who remained in AF. No thromboembolic events were noted in either group. Local haematoma at the site of ICD implantation occurred in two (8%) patients. CONCLUSIONS: Sinus rhythm was restored in 21.7% of patients with permanent AF who underwent ICD implantation. Temporary withdrawal of anticoagulation therapy did not increase the risk of thromboembolic complications, however, its early re-initiation after implantation resulted in an increase in local bleeding complication rate.

Journal Article↗

[Pulmonary thromboembolism associated with glioblastoma multiforme: imaging diagnosis of a case and a review of the literature].

INTRODUCTION: The incidence of deep vein thrombosis and pulmonary embolism in patients with cerebral neoplasia has been estimated at 120/100,000 (the second highest rate for any kind of malignant neoplasia). A timely diagnosis is an indispensable requisite in the clinical evaluation of neurological patients. Patients suffering from glioblastoma multiforme present a generalized state of hypercoagulability with a deep vein thrombosis incidence after surgery of between 3 and 60%. The incidence with which pulmonary embolism occurs is 5% in patients following neurosurgical operations, with a mortality rate of between 9 and 50%. CASE REPORT: We report the case of a 64 year old male patient with a suspected diagnosis of pulmonary thromboembolism and thrombosis of the right lower limb. Clinical studies included a simple chest X ray, a Doppler ultrasound recording of the lower limbs, a spiral computed tomography (CAT) scan of the thorax, and a magnetic resonance (MR) scan of the head. The spiral CAT scan showed filling defects in the main pulmonary arteries, a tram track appearance and central filling defects. All these findings are compatible with an imaging diagnosis of pulmonary thromboembolism. CONCLUSIONS: The main aim of this study was to describe the use of spiral CAT scanning as a primary tool in the diagnosis of a case. The concurrence of the spiral scan image, the abnormal increase in D dimer and the clinical information left no doubts about the diagnosis. The clinical manifestations of pulmonary thromboembolism are not specific and therefore the patient s life is at risk. In addition, few reports have been published about the association between glioblastoma multiforme and the later appearance of pulmonary thromboembolism (a search was conducted in the medical literature from the last 10 years using MEDLINE), and hence we have presented a communication dealing with this pathological association together with a brief review of the clinical diagnosis of pulmonary thromboembolism and its physiopathogenic mechanisms.

Brain Neoplasms↗

[Pulmonary thromboembolism: long term course and clinical epidemiology].

BACKGROUND: Long-term clinical course of pulmonary thromboembolism is not well-known. Our aim was to know the events which occur to in-patients diagnosed of pulmonary embolism. METHODS AND PATIENTS: This is a prospective observational study from May-92 to December-2002 with all in-patients diagnosed of pulmonary thromboembolism at a clinical area of Internal Medicine. Main targets were to know survival, relapses, major hemorrhage rate (Defined as those episodes of bleeding which needed blood transfusion and readmission) and cancer associated rate (Previous and newly diagnosed cancer). Follow up were carried out with telephone contacts with patients and relatives in case of death, and with the computerized system of patients and clinical events of Health Service of Navarra. RESULTS: One hundred and sixteen patients were included in the study (Mean age 72 SD 11 years male 54%). During index episode 4 (3.7%) patients dead. Ten patients were lost in follow up. The rest 102 patients were traced for 31.81 SD 31.23 months (Range 1-127). Relapse rate was 19.6% that occurred 22.64 SD 24.57 (Range 1-73) months after index episode (Twelve pulmonary embolisms, 5 deep venous thromboses and 3 sudden death with dyspnea). Major hemorrhage rate was 10.4%. During follow up 14 (13.7%) new cancers were diagnosed (Lung 4, prostate 2, bladder 2, and colorectal, ovary, breast, liver and kidney one each one). At all prevalence of cancer associated with pulmonary thromboembolism was 31%. Mortality rate was 37% (Men 25%, women 49%, p < 0.01). Main causes of death were cancer (32%) and relapse of pulmonary thromboembolism when joined with treatment complications 24%. Half of deaths occurred in the first year of follow up, showing a shortened survival those patients with cancer (p = 0.02) and patients with relapses of pulmonary embolism (p = 0.06). Beyond the first year, mortality declines to a rate of 10% per year mainly because of cardiovascular causes. Mortality associated factors were age > 75 years (p < 0.001) gender female (p < 0.01), a delayed admission and treatment from the beginning of symptoms (p < 0.05), higher LDH level (p < 0.01) and coexistence of cancer (p < 0.05). In logistic-regression analysis age, delayed admission and treatment and higher LDH levels were predictors of long-term death. CONCLUSIONS: Patients with pulmonary embolism show a high mortality rate, with a critical period during the first year after index episode, being deaths associated to cancer and to a composite of relapse of venous thromboembolic disease and bleeding complications. Mortality rate beyond the first year declines, being deaths explained because of cardiovascular causes. An advanced age, a delayed diagnosis and treatment and serum LDH may predict long-term mortality.

Aged↗

[Pulmonary thromboembolism].

Thromboembolism used to be a rare disease in Japan, however, more frequent occurrence and mortality was reported in recent periods. This is considered to relate with the rapid change of food intake, so called food westernization. The authors herein described the etiology and its countermeasures against acute and chronic pulmonary thromboembolism. Formation of thrombus relates with congestion, damage of venous vessels and change of blood component. Pulmonary thromboembolism during airflight, so called "economy syndrome" occurs due to the formation of thrombus at the large veins of lower extremities. Anti-coagulant treatment was applied first, and then surgical intervention was performed in acute phase. Pulmonary thromboembolectomy for chronic pulmonary thromboembolism is one of the most difficult techniques in thoracic surgery. Careful and cautious dissection between fibrous intima of the thrombus and media of the vein is needed. In conclusion, urgent and appropriate medical and surgical treatment is crucial to rescue the life of patients suffered from pulmonary thromboembolism.

Anticoagulants↗

[Fatal pulmonary thromboembolism. A study of 178 cases].

A retrospective study was undertaken on 178 cases of fatal pulmonary thromboembolism, 86 males and 92 females, in whom major pulmonary emboli were found at autopsies, performed from 1971 to 1988. The 178 cases represent 6.9% from 2569 autopsies. In 43 cases (24.2%) the fatal pulmonary thromboembolism developed after surgery. The clinical diagnosis was performed in 59 cases (33.1%). The conditions at risk for fatal pulmonary thromboembolism were orthopedic surgery and radical surgery for malignancy among the surgical patients, and heart diseases and neoplasias among the medical patients. The death by fatal thromboembolism occurred in the 63.5% in the first six hours after onset of symptoms. The data suggest that recognition of those conditions which coexist with pulmonary thromboembolic disease can facilitate early diagnosis, and that when high risk is present antithrombotic prevention is of critical importance.

Adult↗

[The occurrence of late thromboembolic complications after elective abdominal surgery].

Forty-five consecutive patients who were submitted to elective major abdominal surgical interventions under optimal thromboembolic prophylaxis participated in an investigation as regards the occurrence of late thromboembolic complications. The patients were followed postoperatively with 125I-fibrinogen scanning every second day for a week or until discharge from hospital. If deep venous thrombosis was suspected, intravenous phlebography was carried out. Thirty-five patients completed the investigation. None of the patients developed deep venous thrombosis during thromboembolic prophylactic treatment. In two patients (6%) (95% confidence limits 1-19%), deep venous thrombosis was demonstrated after conclusion of prophylaxis, 13 and 28 days postoperatively, respectively. It is concluded that despite optimal thrombosis prophylaxis, late thromboembolic complications may occur. Prospective investigations are required to elucidate the clinical significance of late thromboembolic complications and to illustrate the value of prolonged thrombosis prophylaxis.

Adult↗

[Thromboembolism of the lung and lower extremities in patients with chronic global congestive heart failure].

The results of a prospective study on the incidence of pulmonary thromboembolism and deep leg veins phlebitis in patients with congestive heart failure are presented. Pulmonary thromboembolism was diagnosed by means of pulmonary isotopic scanning and angiography; deep leg veins were studied using conventional and isotopic phlebography. A total incident of 60% for pulmonary thromboembolism and 92% for deep leg veins phlebitis was found, being of little significance the results suggested by clinical signs. ECG, chest X rays and laboratory tests such as arterial PO2, transaminase and lactic dehidrogenases. Among patients with pulmonary thromboembolism, the hospitalization periods were longer and more frequent, the incidence of deep leg veins phlebitis was 100%, mortality was slightly higher and the degree of hemodynamic derrangement was more advanced in patients without pulmonary thromboembolism. The rutinary use of pulmonary scanning and isotopic phlebography for detection of these complications in patients with congestive heart failure is recommended, emphasizing the need for prophylactic anticoagulant treatment in most of these patients.

Heart Failure↗

Post discharge clinically overt venous thromboembolism in orthopaedic surgery patients with negative venography--an overview analysis.

A high incidence of post-discharge venous thromboembolism in orthopaedic surgery patients has been recently reported drawing further attention to the unresolved issue of the optimal duration of the pharmacological prophylaxis. We performed an overview analysis in order to evaluate the incidence of late occurring clinically overt venous thromboembolism in major orthopaedic surgery patients discharged from the hospital with a negative venography and without further pharmacological prophylaxis. We selected the studies published from January 1974 to December 1995 on the prophylaxis of venous thromboembolism after major orthopaedic surgery fulfilling the following criteria: 1) adoption of pharmacological prophylaxis, 2) performing of a bilateral venography before discharge, 3) interruption of pharmacological prophylaxis at discharge in patients with negative venography, and 4) post-discharge follow-up of the patients for at least four weeks. Out of 31 identified studies, 13 fulfilled the overview criteria. The total number of evaluated patients was 4120. An adequate venography was obtained in 3469 patients (84.1%). In the 2361 patients with negative venography (68.1%), 30 episodes of symptomatic venous thromboembolism after hospital discharge were reported with a resulting cumulative incidence of 1.27% (95% C.I. 0.82-1.72) and a weighted mean incidence of 1.52% (95% C.I. 1.05-1.95). Six cases of pulmonary embolism were reported. Our overview showed a low incidence of clinically overt venous thromboembolism at follow-up in major orthopaedic surgery patients discharged with negative venography. Extending pharmacological prophylaxis in these patients does not appear to be justified. Venous thrombi leading to hospital re-admission are likely to be present but asymptomatic at the time of discharge. Future research should be directed toward improving the accuracy of non invasive diagnostic methods in order to replace venography in the screening of asymptomatic post-operative deep vein thrombosis.

Humans↗

Natural and acquired inhibitors of hemostasis in selected symptomatic outpatients with venous thromboembolic disease.

BACKGROUND AND OBJECTIVE: Deficiencies of natural inhibitors and the presence of lupus anticoagulant are important risk factors leading to venous thromboembolic events. Before resistance to activated protein C (APC-R) was identified, the overall prevalence of inherited abnormalities of hemostasis in non-selected outpatients with venous thromboembolic disease was under 10%. This cast doubts on the of cost effectiveness and clinical significance of assaying hemostasis inhibitors in all such patients. The goal of this study is to evaluate the prevalence of inherited and acquired abnormalities of hemostasis in younger symptomatic outpatients with objectively diagnosed venous thromboembolic disease (VTD). METHODS: From October 1994 to October 1996, we diagnosed, treated and followed 191 consecutive outpatients with an objective diagnosis of venous thromboembolic disease, and assayed natural and acquired hemostasis inhibitors in 81 of them aged less than 50; in addition, 129 relatives of patients with inherited deficiencies were evaluated. RESULTS: Twenty-six of the patients under age 50 showed inherited deficiencies of natural inhibitors (3 antithrombin, 5 protein C, 3 protein 5 and 14 APC-R, 1 dysfibrinogenemia) and 8 patients had lupus anticoagulant (LA): abnormalities of hemostasis were found in 41.9% (95% confidence interval 31.1-53.5). In older selected patients, 60% (95% confidence interval 40.6-77.3) of the subjects showed abnormalities. Seventy-two of the relatives displayed natural inhibitor deficiencies; 88.5% of the families studied had at least one relative with the same defect as the propositus. INTERPRETATION AND CONCLUSIONS: A simple selection based on age, clinical and family history shows the existence of a high prevalence and the important clinical significance of abnormalities of hemostasis in symptomatic outpatients with venous thromboembolic disease.

Adult↗

The 4G/5G sequence polymorphism in the promoter of plasminogen activator inhibitor-1 (PAI-1) gene: relationship to plasma PAI-1 level in venous thromboembolism.

Impaired fibrinolysis due to increased plasminogen activator inhibitor-1 (PAI-1) is observed in up to 40% of patients with venous thromboembolism and might be causally related to the disease. There is evidence that genetic variations in the promoter of the PAI-1 gene and metabolic factors contribute to increased plasma PAI-1 levels. A single nucleotide insertion/deletion (4G/5G) polymorphism in the promoter region of the PAI-1 gene and metabolic factors were studied in 158 unrelated patients below the age of 61 years (43 +/- 11 years, mean +/- standard deviation) with history of objectively confirmed venous thromboembolism and in 145 apparently healthy controls. Patients had on average two times higher PAI activity (11.9 vs. 6.1 IU/ml) and by 40% higher PAI-1 antigen (14.8 vs. 10.7 ng/ml) than healthy controls, and also higher body mass index, lipid levels, fasting glucose and insulin. Patients differed significantly from healthy controls neither in the frequency of the 4G and 5G alleles (0.57/0.43 in patients and 0.52/0.48 in controls) nor in the distribution of the 4G/5G genotypes. Possession of the 4G/4G or the 4G/5G genotype did not increase relative risk for venous thromboembolic disease and the distribution of the 4G/5G genotypes was neither associated with recurrent nor with spontaneous disease. In patients association between the 4G/5G genotypes and PAI activity (adjusted for body mass index, triglyceride and glucose level) was observed, with the highest PAI activity values in the 4G/4G genotype (14.6 IU/ml), intermediate in the 4G/5G genotype (13.3 IU/ml) and the lowest in the 5G/5G genotype (5.2 IU/ml, all values means). Association between PAI activity and triglyceride level was the strongest in the 4G/4G genotype (correlation coefficient r = 0.47, p < 0.01) and the weakest in the 5G/5G genotype (r = -0.04, not significant). In conclusion, the present case-control study shows an association between the 4G/5G polymorphism in the promoter of the PAI-1 gene and plasma PAI-1 levels in patients with venous thromboembolism. Similar distribution of the 4G/5G genotypes in patients and healthy controls suggests that this genetic variation by itself is not a major risk factor for venous thromboembolism.

Adult↗

Hyperhomocysteinemia is a risk factor of recurrent venous thromboembolism.

Hyperhomocysteinemia is a risk factor of venous thromboembolism. The risk of recurrence in patients with hyperhomocysteinemia is unknown, and the optimal therapy for these patients after acute venous thromboembolism is uncertain. In a multicenter study, 264 patients with an objectively documented single episode of idiopathic venous thromboembolism were prospectively followed after discontinuation of oral anticoagulants. Patients were classified as hyperhomocysteinemic if their homocysteine levels exceeded the 95th percentile of the controls. The outcome events studied were objectively confirmed deep-vein thrombosis and/or pulmonary embolism. Homocysteine levels were elevated in 66 patients (25%) and normal in 198 patients (75%). Recurrent venous thromboembolism occurred in 12 of 66 patients with hyperhomocysteinemia (18.2%) and in 16 of 198 patients without hyperhomocysteinemia (8.1%). The cumulative probability of recurrence 24 months after discontinuation of oral anticoagulants was 19.2 percent (95 percent confidence interval 8.7-27) in patients with hyperhomocysteinemia and was 6.3 percent (95 percent confidence interval 2.4-10.1; p = 0.001) in those without hyperhomocysteinemia. The relative risk of recurrent thrombosis was higher in patients with hyperhomocysteinemia [RR 2.7 (1.3-5.8), p = 0.009]. Patients with hyperhomocysteinemia are at high risk of recurrent venous thromboembolism. The high prevalence of hyperhomocysteinemia in thrombosis patients together with the increased risk of recurrence warrants extended patient screening. The impact on the risk of recurrence of prolonged anticoagulation, supplementation of folate and vitamin B12, or both have to be investigated.

Adolescent↗

Low-molecular-weight heparin versus a coumarin for the prevention of recurrent venous thromboembolism in patients with cancer.

BACKGROUND: Patients with cancer have a substantial risk of recurrent thrombosis despite the use of oral anticoagulant therapy. We compared the efficacy of a low-molecular-weight heparin with that of an oral anticoagulant agent in preventing recurrent thrombosis in patients with cancer. METHODS: Patients with cancer who had acute, symptomatic proximal deep-vein thrombosis, pulmonary embolism, or both were randomly assigned to receive low-molecular-weight heparin (dalteparin) at a dose of 200 IU per kilogram of body weight subcutaneously once daily for five to seven days and a coumarin derivative for six months (target international normalized ratio, 2.5) or dalteparin alone for six months (200 IU per kilogram once daily for one month, followed by a daily dose of approximately 150 IU per kilogram for five months). RESULTS: During the six-month study period, 27 of 336 patients in the dalteparin group had recurrent venous thromboembolism, as compared with 53 of 336 patients in the oral-anticoagulant group (hazard ratio, 0.48; P=0.002). The probability of recurrent thromboembolism at six months was 17 percent in the oral-anticoagulant group and 9 percent in the dalteparin group. No significant difference between the dalteparin group and the oral-anticoagulant group was detected in the rate of major bleeding (6 percent and 4 percent, respectively) or any bleeding (14 percent and 19 percent, respectively). The mortality rate at six months was 39 percent in the dalteparin group and 41 percent in the oral-anticoagulant group. CONCLUSIONS: In patients with cancer and acute venous thromboembolism, dalteparin was more effective than an oral anticoagulant in reducing the risk of recurrent thromboembolism without increasing the risk of bleeding.

Acenocoumarol↗

Incidence and time course of thromboembolic outcomes following total hip or knee arthroplasty.

BACKGROUND: Little is known about the incidence and time course of clinical thromboembolic events after total hip or knee arthroplasty, particularly after hospital discharge. METHODS: We used a linked hospital discharge database provided by the State of California to identify cases diagnosed as having deep vein thrombosis or pulmonary embolism within 3 months of unilateral total hip or knee arthroplasty. Also, we surveyed orthopedic surgeons to estimate the frequency of postoperative thromboprophylaxis during July 1991 through June 1993. Medical charts were audited to determine the accuracy of the coded records. RESULTS: Among 19,586 primary hip and 24,059 primary knee arthroplasties, the cumulative incidence of deep vein thrombosis or pulmonary embolism within 3 months of surgery was 556 (2.8%) after hip arthroplasty and 508 (2.1%) after knee arthroplasty. The diagnosis of thromboembolism was made after hospital discharge in 76% and 47% of the total hip and total knee arthroplasty cases, respectively (P<.001), with a median time of diagnosis of 17 days and 7 days after surgery, respectively (P<.001). Questionnaire results indicated that 95% of all cases received thromboprophylaxis and that the frequency, type, and duration of thromboprophylaxis was virtually identical after hip and knee arthroplasty. CONCLUSIONS: There is a difference in the temporal patterns of clinically symptomatic thromboembolic complications after total hip and total knee arthroplasty, suggesting differences in pathogenesis or natural history. The findings suggest that to further reduce thromboembolic outcomes, earlier, more intense prophylaxis may be needed for total knee arthroplasty, and more prolonged prophylaxis may be required after total hip arthroplasty.

Aged↗

Lowering the intensity of oral anticoagulant therapy: effects on the risk of hemorrhage and thromboembolism.

BACKGROUND: Oral anticoagulation is effective in the prevention of arterial thromboembolism. The major drawback of coumarin therapy is the increased risk of hemorrhage. Implementing the optimal intensity of oral anticoagulation, ie, the level at which thromboembolic events are prevented without introducing an excessive bleeding risk, is an important step to improve the safety of oral anticoagulant therapy. METHODS: We observed all patients of the Leiden Anticoagulation Clinic who were treated because of a mechanical heart valve or atrial fibrillation between January 1, 1995, and January 1, 1998, or because of cerebral ischemia between January 1, 1994, and January 1, 1998. In 1996, at the halfway point of follow-up, the target intensity for patients with a mechanical heart valve was lowered from 4.0 (range, 3.6-4.8) to 3.5 (range, 3.0-4.0) international normalized ratio, and for atrial fibrillation and cerebral ischemia, from 3.5 (range, 3.0-4.5) to 3.0 (range, 2.5-3.5) international normalized ratio. We compared incidence rates of hemorrhage and thromboembolism before and after the introduction of lower target intensities. RESULTS: Higher target treatments were given to 2341 patients (2863 patient-years) and lower target treatments to 2256 patients (2260 patient-years). After introduction of the lower target ranges, the overall incidence rate of major untoward events declined from 5.7 (95% confidence interval [CI], 4.9-6.7) to 3.6 (95% CI, 2.8-4.4) per 100 patient-years. The incidence of major bleeding fell from 3.6 (95% CI, 2.9-4.4) to 2.7 (95% CI, 2.1-3.5) and the incidence of major thromboembolism from 2.0 (95% CI, 1.5-2.5) to 0.8 (95% CI, 0.5-1.3) per 100 patient-years. CONCLUSION: Implementation of lower target intensities for coumarin therapy decreased the complication risk.

Aged↗

Thromboembolism from occult subclavian arterial stenosis during chemotherapy for breast carcinoma.

Cancer chemotherapy has been associated with hypercoagulability, causing thromboembolic complications. Three unusual and strikingly similar cases of upper-extremity arterial thromboembolism were encountered in women undergoing chemotherapy following surgical treatment for breast carcinoma. In all cases, previously asymptomatic stenosis of the subclavian artery due to extrinsic cause was suspected as the source of distal thromboembolism. These cases illustrate the interplay between transient hypercoagulability and underlying arterial disease in the pathogenesis of arterial thromboembolism.

Adult↗