Cathy Emery

The Worcester Venous Thromboembolism Study: A Population‐Based Study of the Clinical Epidemiology of Venous Thromboembolism

AbstractBACKGROUND: While there have been marked advances in diagnostic and therapeutic strategies for venous thromboembolism, our understanding of its clinical epidemiology is based on studies conducted more than a decade ago. OBJECTIVE: The purpose of this observational study was to describe the incidence and attack rates of venous thromboembolism in residents of the Worcester Statistical Metropolitan Area in 1999. We also describe demographic and clinical characteristics, management strategies, and associated hospital and 30-day outcomes. DESIGN AND MEASUREMENTS: The medical records of all residents from Worcester, MA (2000 census=477.800), diagnosed with International Classification of Diseases, 9th revision (ICD-9) codes consistent with possible venous thromboembolism during 1999 were independently validated, classified, and reviewed by trained abstractors. RESULTS: A total of 587 subjects were enrolled with validated venous thromboembolism. The incidence and attack rates of venous thromboembolism were 104 and 128 per 100,000 population, respectively. Three quarters of patients developed their venous thromboembolism in the outpatient setting — a substantial proportion of these patients had undergone recent surgery or had a recent prior hospitalization. Less than half of the patients received anticoagulant prophylaxis during high-risk periods before their venous thromboembolism. Thirty-day rates of venous thromboembolism recurrence, major bleeding, and mortality were 4.8%, 7.7%, and 6.6%, respectively. CONCLUSION: These data provide insights into recent incidence and attack rates, changing patient profiles, management strategies, and subsequent outcomes in patients with venous thromboembolism. The underutilization of prophylaxis before venous thromboembolism, and relatively high 30-day recurrence rates, suggest a continued need for the improvement of venous thromboembolism prophylaxis and management in the community.

Patient Outcomes After Deep Vein Thrombosis and Pulmonary Embolism The Worcester Venous Thromboembolism Study

BACKGROUND Despite advances in the management of deep vein thrombosis (DVT) and pulmonary embolism (PE), relatively few contemporary data describe and compare outcomes in patients with these common conditions from a more generalizable community-based perspective. The purpose of this study was to measure and compare clinical characteristics and outcomes of patients with validated symptomatic PE and isolated DVT in a New England community. METHODS The medical records of residents from the Worcester area with International Classification of Diseases, Ninth Revision (ICD-9) codes consistent with possible venous thromboembolism (VTE) during 1999, 2001, and 2003 were independently validated and reviewed by trained abstractors. RESULTS Patients who presented with PE or isolated DVT experienced similar rates of subsequent PE, overall VTE, and major bleeding during 3-year follow-up (5.9% vs 5.1%, 15.0% vs 17.9%, and 15.6% vs 12.4%, respectively). Mortality was significantly increased at 1-month follow-up in patients who initially presented with PE (13.0% vs 5.4%); this difference persisted at 3 years (35.3% vs 29.6%). Patients whose course was complicated by major bleeding were more likely to experience recurrent VTE or to die at 3 years than those without these complications. CONCLUSIONS Patients who presented with PE had similar rates of subsequent PE or recurrent VTE compared with patients with isolated DVT. However, rates of recurrent VTE and major bleeding after DVT and PE remain unacceptably high in the community setting. Efforts are needed to identify patients most at risk for VTE-associated complications and to develop better anticoagulation strategies conducive to long-term use in the community setting.

A population-based study of inferior vena cava filters in patients with acute venous thromboembolism

BACKGROUND Our study objective was to describe the frequency, indications, and outcomes after inferior vena cava (IVC) filter placement in a population-based sample of residents of the Worcester, Massachusetts, metropolitan area who had been diagnosed as having acute venous thromboembolism (VTE) in 1999, 2001, and 2003. METHODS A retrospective chart review of inpatient and outpatient medical records was conducted. Recorded indication(s) for IVC filter placement was determined among a subset of cases from 3 Worcester tertiary care hospitals. Three thrombosis specialists assessed the appropriateness of IVC filter placement. RESULTS Of 1547 greater Worcester residents with validated acute VTE and without a prior IVC filter, 203 (13.1%) had an IVC filter placed after acute VTE. Patients with an IVC filter were older, had more comorbidities, and had a higher mortality rate during 3 years of follow-up. There was unanimous agreement by panel members that the use of an IVC filter was appropriate in 51% of cases and inappropriate in 26% of cases, with no consensus in the remaining 23%. CONCLUSIONS In this community-based study, IVC filters were frequently used in the treatment of patients with acute VTE. Placement was deemed to be appropriate in approximately 50% of the patients but was not appropriate or debatable in the remaining cases. Given the increasing use of IVC filters, prospective studies are clearly needed to better define the indications for, and efficacy of, IVC filter placement.

Venous Thromboembolism in Heart Failure: Preventable Deaths During and After Hospitalization

OBJECTIVE Our aim was to compare the clinical characteristics, prophylaxis, treatment, and outcomes of patients with venous thromboembolism with and without heart failure. METHODS We studied patients with heart failure in the population-based Worcester Venous Thromboembolism Study of 1822 consecutive patients with validated venous thromboembolism. RESULTS Of the 1822 patients with venous thromboembolism, 319 (17.5%) had a history of clinical heart failure and 1503 (82.5%) did not. Patients with heart failure were older (mean age 75 vs 62 years, P<.0001) and more likely to have been immobilized (65.2% vs 46.1%, P<.0001). Thromboprophylaxis was omitted in approximately one third of patients with heart failure who had been hospitalized for non-venous thromboembolism-related illness or had undergone major surgery within the 3 months before diagnosis. Patients with heart failure had a higher frequency of in-hospital death (9.7% vs 3.3%, P<.0001) and death within 30 days of venous thromboembolism diagnosis (15.6% vs 6.4%, P<.0001). Heart failure (adjusted odds ratio [OR] 2.04; 95% confidence interval [CI], 1.15-3.62) and immobility (adjusted OR 4.37; 95% CI, 2.42-7.9) were associated with an increased risk of in-hospital death. Heart failure (adjusted OR 1.57; 95% CI, 1.01-2.43) and immobility (adjusted OR 3.05; 95% CI, 2.01-4.62) also were independent predictors of death within 30 days of venous thromboembolism diagnosis. CONCLUSION High mortality was observed among patients with heart failure and venous thromboembolism both during and after hospitalization. Heart failure and immobility are potent risk factors for in-hospital death and death within 30 days in patients with venous thromboembolism.

Factors Associated With Adverse Outcomes in Outpatients Presenting With Pulmonary Embolism The Worcester Venous Thromboembolism Study

Background— Data from clinical trials suggest that short-term mortality in outpatients presenting with pulmonary embolism (PE) is low and that outpatient therapy may be appropriate. However, subjects enrolled in these studies may not be representative of patients seen in the community setting. Methods and Results— The medical records of residents from Worcester, Mass, with International Classification of Disease, Ninth Edition, codes consistent with potential venous thromboembolism during 1999, 2001, and 2003 were independently validated and reviewed by trained abstractors. A total of 305 patients presented with PE from the outpatient setting. The rates of recurrent PE, major bleeding, mortality, or occurrence of any 1 of these end points at 90 days were 1.4%, 9.5%, 11.1%, and 20.1%, respectively. Patients with a history of congestive heart failure, recent intensive care unit discharge, cancer, severe infection, systolic blood pressure <100 mm Hg, and male sex were at increased risk for the composite end point. Conclusions— In the present population-based study, morbidity and mortality after outpatient PE were much higher than what was observed in clinical studies. Our findings raise questions about broad-based outpatient treatment of PE in the community setting. In our study, comorbid conditions and recent illness were important determinants of adverse outcomes, suggesting that these variables should be carefully considered before embarking on outpatient therapy of PE.

Venous thromboembolism and bleeding in a community setting - The Worcester Venous Thromboembolism Study

Bleeding is the most frequent complication of antithrombotic therapy for venous thromboembolism (VTE). However, little attention has been paid to the impact of bleeding after VTE in the community setting. The purpose of this investigation was to describe the incidence rate of bleeding after VTE, to characterize patients most at risk for bleeding, and to assess the impact of bleeding on rates of recurrent VTE and all-cause mortality. The medical records of residents of the Worcester (MA, USA) metropolitan area diagnosed with ICD-9 codes consistent with potential VTE during 1999, 2001, and 2003 were individually validated and reviewed by trained data abstracters. Clinical characteristics, acute treatment, and outcomes (including VTE recurrence rates, bleeding rates, and mortality) over follow-up (up to 3 years maximum) were evaluated. Bleeding occurred in 228 (12%) of 1,897 patients with VTE during our follow-up. Of these, 115 (58.8%) had evidence of early bleeding occurring within 30 days of VTE diagnosis. Patient characteristics associated with bleeding included impaired renal function and recent trauma. Other than a history of prior VTE, the occurrence of bleeding was the strongest predictor of recurrent VTE (hazard ratio [HR] 2.18; 95% confidence interval [CI] 1.54-3.09) and was also a predictor of total mortality (HR 1.97; 95%CI 1.57-2.47). The occurrence of bleeding following VTE is associated with an increased risk of recurrent VTE and mortality. Future study of antithrombotic strategies for VTE should be informed by this finding. Advances that result in decreased bleeding rates may paradoxically decrease the risk of VTE recurrence.

Venous thromboembolism in patients with symptomatic atherosclerosis

Patients with atherosclerosis have an increased risk of venous thromboembolism (VTE). We studied patients in the population-based Worcester VTE Study of 1,822 consecutive patients with validated VTE to compare clinical characteristics, prophylaxis, treatment, and outcomes of VTE in patients with and without symptomatic atherosclerotic cardiovascular disease, defined as history of ischaemic heart disease, history of positive cardiac catheterisation, percutaneous coronary intervention, or coronary artery bypass graft surgery, or history of peripheral artery disease. Of the 1,818 patients with VTE, 473 (26%) had a history of symptomatic atherosclerosis. Patients with atherosclerosis were significantly older (mean age 71.9 years vs. 61.6 years) and were more likely to have immobility (57.2% vs. 46.7%), prior heart failure (36.9% vs. 10.7%), chronic lung disease (26.4% vs. 15.5%), cerebrovascular disease (18.1% vs. 9.8%), and chronic kidney disease (4.9% vs. 1.9%) (all p<0.001) compared with non-atherosclerosis patients. Thromboprophylaxis was omitted in more than one-third of atherosclerosis patients who had been hospitalised for non-VTE-related illness or had undergone major surgery within the three months prior to VTE. Patients with atherosclerosis were significantly more likely to suffer in-hospital major bleeding (7.6% vs. 3.8%, p=0.0008). In conclusion, patients with atherosclerosis and VTE are more likely to suffer a complicated hospital course. Despite a high frequency of comorbid conditions contributing to the risk of VTE, we observed a low rate of thromboprophylaxis in patients with symptomatic atherosclerosis.

Factors Associated With Adverse Outcomes in Outpatients Presenting With Pulmonary Embolism

Background— Data from clinical trials suggest that short-term mortality in outpatients presenting with pulmonary embolism (PE) is low and that outpatient therapy may be appropriate. However, subjects enrolled in these studies may not be representative of patients seen in the community setting. Methods and Results— The medical records of residents from Worcester, Mass, with International Classification of Disease, Ninth Edition, codes consistent with potential venous thromboembolism during 1999, 2001, and 2003 were independently validated and reviewed by trained abstractors. A total of 305 patients presented with PE from the outpatient setting. The rates of recurrent PE, major bleeding, mortality, or occurrence of any 1 of these end points at 90 days were 1.4%, 9.5%, 11.1%, and 20.1%, respectively. Patients with a history of congestive heart failure, recent intensive care unit discharge, cancer, severe infection, systolic blood pressure <100 mm Hg, and male sex were at increased risk for the composite end point. Conclusions— In the present population-based study, morbidity and mortality after outpatient PE were much higher than what was observed in clinical studies. Our findings raise questions about broad-based outpatient treatment of PE in the community setting. In our study, comorbid conditions and recent illness were important determinants of adverse outcomes, suggesting that these variables should be carefully considered before embarking on outpatient therapy of PE.

Venous Thromboembolism in Patients with Chronic Obstructive Pulmonary Disease

OBJECTIVE Our aim was to compare the clinical characteristics, prophylaxis, treatment, and outcomes of venous thromboembolism in patients with and without previously diagnosed chronic obstructive pulmonary disease. METHODS We analyzed the population-based Worcester Venous Thromboembolism Study of 2488 consecutive patients with validated venous thromboembolism to compare clinical characteristics, prophylaxis, treatment, and outcomes in patients with and without chronic obstructive pulmonary disease. RESULTS Of 2488 patients with venous thromboembolism, 484 (19.5%) had a history of clinical chronic obstructive pulmonary disease and 2004 (80.5%) did not. Patients with chronic obstructive pulmonary disease were older (mean age 68 vs 63 years) and had a higher frequency of heart failure (35.5% vs 12.9%) and immobility (53.5% vs 43.3%) than patients without chronic obstructive pulmonary disease (all P<.0001). Patients with chronic obstructive pulmonary disease were more likely to die in hospital (6.8% vs 4%, P=.01) and within 30 days of venous thromboembolism diagnosis (12.6% vs 6.5%, P<.0001). Patients with chronic obstructive pulmonary disease demonstrated increased mortality despite a higher frequency of venous thromboembolism prophylaxis. Immobility doubled the risk of in-hospital death (adjusted odds ratio, 2.21; 95% confidence interval, 1.35-3.62) and death within 30 days of venous thromboembolism diagnosis (adjusted odds ratio, 2.04; 95% confidence interval, 1.43-2.91). CONCLUSION Patients with chronic obstructive pulmonary disease have an increased risk of dying during hospitalization and within 30 days of venous thromboembolism diagnosis. Immobility in patients with chronic obstructive pulmonary disease is an ominous risk factor for adverse outcomes.

Venous Thromboembolism in Patients With Prior Stroke

Patients with prior stroke are susceptible to venous thromboembolism (VTE). We studied patients with stroke in the Worcester VTE study of 2488 consecutive patients hospitalized with VTE. In all, 288 (11.6%) had a clinical history of stroke and 2200 (88.4%) did not. Patients with stroke were more likely to die inhospital (9.2% vs 4%) and within 30 days of VTE diagnosis (16.7% vs 6.9%) compared with patients without stroke (all P < .001). Recent immobilization (adjusted odds ratio [OR] 2.15; 95% confidence interval [CI] 1.15-4.09) and inferior vena cava (IVC) filter insertion (adjusted OR 2.1; 95% CI 1.15-3.83) were associated with a doubling of inhospital death. Recent immobilization (adjusted OR 1.84; 95% CI 1.19-2.83) and IVC filter insertion (adjusted OR 1.94; 95% CI 1.2-3.14) were associated with an increased risk of death within 30 days of VTE. In conclusion, patients with VTE and prior stroke were more than twice as likely to die while hospitalized and within 30 days of VTE diagnosis.