ALBERT

Description: Background We examined data from acutely ill medical patients enrolled in The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) to determine factors that are independently associated with an increased risk of bleeding during hospitalization. Methods Patients ≥18 years old, hospitalized for ≥3 days with an acute medical illness have been enrolled consecutively since July 2002. Exclusion criteria are: therapeutic antithrombotics/thrombolytics at admission; major surgery or trauma during 3 months prior to admission; and venous thromboembolism (VTE) treatment within 24 hours of admission. Patients with bleeding immediately prior to, or at admission were excluded from this analysis. Factors considered were: age, ICU stay, reduced creatinine clearance, severe infection, cerebrovascular stroke, cancer, diabetes, severe renal failure, hypertension, lower limb paralysis, bleeding disorders, hemorrhagic stroke, thrombocytopenia, gastro-duodenal ulcer, hepatic failure, central venous catheter at admission, hormonal therapy for cancer, platelet count, BMI, immobility, and length of hospital stay. Factors increasing the risk of bleeding were identified by univariate analysis (P≤0.20) and included in a multiple logistic regression model. Factors with significance of P≤0.05 were retained in the model. Bleeding events were defined as major or clinically significant non-major according to published criteria (Büller HR et al. N Engl J Med.2003;349:1695–702). Results . Data were from 2816 patients enrolled up to 30 June 2004 in 34 hospitals in 10 countries. Patients were: 48% female, mean age 64 years, mean weight 72 kg, mean length of hospital stay 12 days, and 37% were immobile for ≥3 days (median duration of immobility 6 days, including immobility immediately prior to admission). Only 89 (3.2%) patients had in-hospital bleeding: 1.2% major, 1.9% clinically significant non-major, 0.1% unspecified. Factors that were independently associated with an increased risk of bleeding (major or non-major) in acutely ill medical patients are shown in Table 1. Conclusion Only 3.2% of acutely ill medical patients in IMPROVE had in-hospital bleeding. Major bleeding (1.2%) was similar to that observed in a major clinical trial on VTE prophylaxis, MEDENOX (1.0%; Samama et al. N Engl J Med.1999;341:793–800). Advanced age, contrary to the belief of many physicians, was not independently associated with an increased risk of bleeding. Final results will be presented with adjustment for the influence of VTE prophylaxis and antiplatelet drugs. Table 1. Factors independently associated with an increased risk of bleeding in acutely ill medical patients Factor OR 95% CI *compared with creatinine clearance 〉60 mL/min (normal renal function) Bleeding disorder 8.38 3.53–19.90 Active gastro-duodenal ulcer 4.26 1.86–9.76 Hepatic failure 2.97 1.26–6.96 Creatinine clearance

Description: Background: The EXtended CLinical prophylaxis in Acutely Ill Medical patients (EXCLAIM) trial was a randomized, double-blind, placebo-controlled, multicenter, international study that demonstrated a 38% relative risk reduction (RRR) for venous thromboembolism (VTE) with extended-duration enoxaparin prophylaxis compared with placebo (2.5% vs 4.0%; absolute difference [AD], −1.5% 95.8% CI −2.5 to −0.5%; P=0.002). Major bleeding occurred in 0.7% (20/2975) and 0.2% (7/2988) of patients who received enoxaparin and placebo, respectively (AD, 0.4% [CI 0.1% to 0.8%]; P=0.012). As age is a known independent risk factor for VTE, we conducted a pre-specified sub-analysis of the EXCLAIM trial to compare the efficacy and safety of extended-duration enoxaparin prophylaxis in patients 〉75 years old with patients ≤75 years old. Methods: EXCLAIM eligibility required a recent (≤3 days) reduction in mobility due to acute medical illness, an anticipated level 1 (total bed rest/sedentary) or level 2 (level 1 with bathroom privileges) decreased mobility, and age ≥40 years. During the latter part of the study, a protocol amendment required patients with level 2 mobility to have ≥1 of 3 additional pre-specified risk factors (i.e., active or prior cancer, history of VTE, age 〉75 years). Of the 7500 patients enrolled, 7415 received open-label enoxaparin 40 mg SC od for 10±4 days. Of these, 6085 were randomized to double-blind therapy (enoxaparin 40mg SC od or placebo) of 28±4 additional days duration. The incidence of VTE, the primary efficacy end point, was defined as the composite of symptomatic or asymptomatic proximal deep vein thrombosis (DVT), symptomatic pulmonary embolism (PE), or fatal PE during the double-blind treatment period. Patients were screened for DVT with bilateral proximal lower extremity compression ultrasound at the end of randomized therapy. The incidence of major bleeding, the primary safety end point, was assessed through 48 hours after the last dose of study treatment. Results: Of the 5963 randomized patients that received at least one dose of double-blind therapy, 29.9% (1781) were 〉75 years of age (mean age 81.5 years) and 70.1% (4182) were ≤75 years old (mean age 61.8 years). In patients 〉75 years old, the incidence of VTE was 2.5% (18/725) in the enoxaparin group compared with 6.7% (50/743) in the placebo group (AD −4.2% [95.8% CI −6.5 to −2.0%]; P75 years old (0.6% vs 0.2%; AD 0.3%, 95% CI −0.2 to 0.9%; P=0.282) and significantly higher in patients ≤75 years old (0.7% vs 0.2%; AD 0.5%, 95%CI 0.1 to 0.9%; P=0.041). Though the older group had a higher death rate compared to the younger group (3.2% vs 1.6%), the survival between the treatment groups was similar within the two age groups. Without extended prophylaxis (i.e., placebo group), patients 〉75 years old had a significantly higher risk of VTE than those 75 years of age.

Description: Introduction : Cancer patients undergoing surgery have double the risk for VTE compared with non-cancer patients (Thromb Haemost2003;90:446–55). Current ACCP guidelines advocate the use of VTE prophylaxis in patients with active malignancy undergoing major surgical procedures. The recent ENDORSE survey reported that globally, 64% of patients admitted to surgical wards were at risk for VTE, and only 59% of these received ACCP-recommended prophylaxis (Lancet2008;371:387–94). In this subanalysis of ENDORSE, we evaluated the prevalence of VTE risk and prophylaxis practices in surgical patients with active malignancy. Methods: The ENDORSE study evaluated data from 30,827 patients admitted to surgical wards in 358 hospitals across 32 countries (Lancet2008;371:387–94). The influence of active malignancy on VTE risk and prophylaxis use was assessed in patients who had undergone abdominal, urological or gynecological surgery. Patient data were grouped and analyzed according to whether the surgery was related to a cancer diagnosis (surgery for cancer) or performed in patients without a cancer diagnosis (no cancer). Risk for VTE and use of appropriate prophylaxis was evaluated according to the 2004 ACCP-guidelines (Chest2004;126:338S–400S). Bleeding risk factors considered sufficient to present a contraindication to anticoagulant use included intracranial hemorrhage, bleeding at hospital admission, presence of a known bleeding disorder and clinically relevant hepatic impairment. Results: Of the 30,827 patients in surgical wards evaluated in ENDORSE, 18,461 had undergone major surgery as of the date of the survey, including 6172 patients who had abdominal, urological or gynecological operations and were considered at risk for VTE. All patients with a cancer diagnosis who underwent these types of surgery were considered at-risk for VTE, including 1767 patients whose surgical procedure was related to their diagnosis and 101 patients who underwent surgery unrelated to cancer. The proportion of patients receiving any ACCP-recommended prophylaxis ranged from 60% in patients undergoing surgery for urologic cancer to 86% in patients undergoing surgery for rectosigmoid cancer. Patients who had surgery related to their cancer had a higher rate of ACCP-recommended prophylaxis use, compared with patients who underwent surgery with no cancer diagnosis (Table). The proportion of patients considered to have bleeding risk sufficient to present a contraindication to anticoagulant use was 10.4% (surgery for cancer) and 10.9% (no cancer; Table). Fewer patients without a cancer diagnosis received anticoagulant prophylaxis, compared with those undergoing cancer-related surgery (Table). Table: VTE prophylaxis practice according to the presence of active malignancy. Surgery type At-risk receiving ACCP-recommendedprophylaxis n/N (%) Contrain-dications to anticoagulant use, n (%) Anticoagulant alone, n (%) Mechanical alone, n (%) Both, n (%) *4304 of 5097 patients without a cancer diagnosis were considered at risk for VTE Surgery for cancer (N=1767) 1295/1767 (73.3) 183 (10.4) 820 (46.4) 136 (7.7) 412 (23.3) No cancer (N=5097) 2495/4304* (58.0) 470 (10.9) 1455 (33.8) 426 (9.9) 762 (17.7) Conclusion: The use of any type of ACCP-recommended VTE prophylaxis varied according to the type of cancer for which the surgery was performed. Although all cancer patients who undergo abdominal, urological or gynecological surgery are at risk for VTE, the results suggest that up to 30% of cancer patients where surgery is performed related to a cancer diagnosis do not receive ACCP-recommended prophylaxis. Less than 11% of patients who had surgery regardless of whether it was related to a cancer diagnosis had a bleeding risk sufficient to present a contraindication to anticoagulant use. These findings suggest that despite the existence of clear evidence-based guidelines, the use of VTE prophylaxis in cancer patients remains suboptimal.

Description: Background : Thrombocytopenia in the patient on heparin can have various etiologies, including benign reversible causes and serious, potentially life-threatening ones, such as heparin induced thrombocytopenia (HIT). Knowledge about the prevalence of and timecourse of thrombocytopenia in heparin-treated patients may be helpful to develop systems of alerting clinicians to possible HIT and determining how frequently to check blood counts to detect thrombocytopenia that may be heralding HIT. Methods : The CATCH registry is a prospective registry of inpatients enrolled between March 2003 and April 2004 at over 50 US hospitals in 3 strata: [1] receiving 〉 96 hours of unfractionated heparin (UFH) or low molecular weight heparin (LMWH), [2] developing thrombocytopenia (platelets 〉50% reduction from baseline or 96 hours. A platelet count decrease of 〉 50 % from baseline was seen more frequently in patients on UFH than in patients on LMWH (10.7% and 7.9 %, respectively; p = 0.03). The parameters that predicted development of thrombocytopenia in the UHF group were length of heparin therapy, body mass index, and admission to a cardiac service; the only parameter predicting thrombocytopenia in the LMWH group was length of LMWH treatment. Of the patients with decreased platelet count by 〉 50 % from baseline (for UFH n = 120; for LMWH n = 68), this drop occurred in the UFH group at a median of 3.0 days after initiation of heparin and at a median of 4.0 days in the LMWH group. The difference in timing between the 2 groups was not statistically significant (p = 0.205). The platelet nadir was reached after a median /mean of 4.0 / 7.4 days in the UFH group, and 8.0 / 11.4 days in the LMWH group. This was statistically significantly different between the 2 groups (p-value = 0.0025). Conclusions : A platelet count decrease of 〉 50 % from baseline occurs frequently in inpatients treated with prolonged heparin. It occurs slightly more frequently on UFH than on LMWH. The median time to onset of thrombocytopenia (〉 50 % decrease from baseline) occurs early, at 3–4 days. Daily platelet count checks in the first few days of heparin therapy may be helpful to rapidly discover thrombocytopenia that may then prompt HIT testing.

Description: Recent studies have suggested that binding of oxygen to hemoglobin (Hb) facilitates reactions of nitric oxide (NO) that lead to production of S-nitrosohemoglobin (SNO-Hb), and that vasodilator S-nitrosthiol (SNO) is dispensed by red blood cells (RBCs) at low oxygen tension (pO2) to dilate blood vessels. In human lungs, NO bioactivity serves to attenuate hypoxic pulmonary vasoconstriction (HPV). We therefore considered the possibility that RBC-SNO may oppose HPV and that defective vasodilation by RBCs may contribute to the pathophysiology of pulmonary arterial hypertension (PAH). Here we report that RBCs from patients with PAH exhibit substantial depletion of SNO-Hb and consequent impairment in hypoxia-mediated vasodilation. Furthermore, levels of RBC-NO correlated inversely with pulmonary artery pressures. A SNO-Hb deficiency characteristic of PAH was reproduced in control RBCs by hypoxia: loss of SNO-Hb was accompanied by a buildup of heme-NO species that are deficient in the pO2-governed intramolecular transfer of NO to cysteine thiol, yielding RBCs deficient in NO bioactivity. SNO-deficient RBCs produced exaggerated HPV responses as compared to SNO-replete RBCs. In PAH patients, SNO-Hb repletion fully restored the hypoxic vasodilator activity of RBCs. Our results suggest that a deficiency in RBC-SNO contributes to pulmonary hypertension and hypoxemia, and that repletion of RBC-SNO represents a rational strategy for treating PAH patients.

Description: Background Patients with previous or current cancer have an increased risk for venous thromboembolism (VTE). However, little data is available on physician’s practices for providing VTE prophylaxis to these patients. The aim of this analysis of the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) was to characterize VTE prophylaxis practices in acutely ill hospitalized medical patients who had previous cancer or currently active cancer. Methods Patient recruitment began in July 2002. Patients ≥18 years old and hospitalized for ≥3 days with an acute medical illness are enrolled consecutively. Exclusion criteria are: therapeutic antithrombotic agents or thrombolytics at admission, major surgery or trauma during 3 months prior to admission, and VTE treatment within 24 hours of admission. Results Data were from 4315 patients enrolled up to 30 June 2004 in 37 hospitals in 11 countries. 578 (13%) patients had currently active cancer (6% as the primary admission diagnosis). Patients with current cancer, previous cancer only, and no cancer were: 40%, 54% and 51% female, median (IQR) ages 72 (60–79), 77 (64–82) and 66 (47–80) years, median length of hospital stay 9 (5–18), 8 (5–12) and 8 (5–14) days, median duration of immobility 8 (5–19), 5 (4–11) and 6 (4–14) days (including immobility immediately prior to hospital admission). The percentages of patients with current or no cancer who received any pharmacologic prophylaxis were similar (see Table 1). However, aspirin was less likely to be prescribed, and intermittent pneumatic compression (IPC) more likely to be used in patients with current cancer than in those without cancer. Patients with previous cancer were more likely to receive pharmacologic prophylaxis, with increased use of unfractionated heparin (UFH) and aspirin, compared with patients without cancer. Conclusions Despite acutely ill medical patients with previous or current cancer having a higher risk for VTE, less than half received VTE prophylaxis, reflecting poor awareness of the benefits of prophylaxis. Physician’s perceptions of bleeding risks in cancer patients may influence prophylaxis practices; patients with current cancer were less likely to receive aspirin, but more likely to receive IPC, than patients without cancer. However, patients with previous cancer were more likely to receive pharmacologic prophylaxis than those without cancer, reflecting recognition by some physicians that these patients have an increased risk for VTE. Table 1. VTE prophylaxis in acutely ill medical patients with current, previous or no cancer VTE prophylaxis Current cancer (%) n=578 Previous cancer (%) n=266 No cancer (%) n=3471 *P

Description: Introduction Despite various medical illnesses/conditions and patient-related factors known to increase venous thromboembolism (VTE) risk in medical patients, there is no worldwide consensus regarding which of these patients should receive VTE prophylaxis. As a result, many medical patients remain at risk from this potentially fatal disease. Our objective was to develop a simple risk assessment model (RAM) that could be used at the bedside to identify medical patients who should receive prophylaxis. Methods Acute medical illnesses/conditions and risk factors were included in the RAM if there was strong evidence from prospective clinical studies to show that they significantly increase VTE risk in medical patients, or VTE prophylaxis was beneficial in these cases. If strong evidence was not available, the illness/condition or factor was only included if there was consensus from the authors that VTE prophylaxis is beneficial for these patients. Results Table 1 shows acute medical illnesses/conditions and factors associated with significant VTE risk that are included in the RAM. If a medical patient is 〉40 years old with an acute medical illness and reduced mobility and has one of the illnesses/conditions or factors shown in Table 1, the RAM recommends prophylaxis with low-molecular-weight heparin (LMWH: enoxaparin 40 mg o.d. or dalteparin 5000 IU o.d.) or unfractionated heparin (5000 IU q8h). LMWH is preferred due to a better safety profile. If pharmacologic prophylaxis is contraindicated, mechanical prophylaxis is recommended. Conclusion Acute medical illnesses/conditions and patient-related factors that increase the risk for VTE in medical patients have been identified and used to develop a novel RAM. The RAM is evidence-based wherever possible, and can be easily revised as new evidence becomes available. The RAM is simple in design, and can assist physicians to assess whether VTE prophylaxis is warranted in an individual medical patient. Table 1. Factors that increase the risk of VTE in medical patients Acute medical illnesses/conditions Risk factors *Note: The risk of hemorrhagic transformation should be assessed before giving VTE prophylaxis. Evidence-based: Acute MI, acute heart failure (NYHA III/IV), active cancer requiring therapy, severe infection/sepsis, respiratory disease (respiratory failure with/without mechanical ventilation, exacerbation of chronic respiratory disease), rheumatic disease (including acute arthritis of lower extremities, and vertebral compression), ischemic stroke*, paraplegia Consensus view only: Inflammatory disorder with immobility, inflammatory bowel disease Evidence-based: History of VTE, history of malignancy, concurrent acute infectious disease, age 〉75 years Consensus-based from strong evidence in other settings: Prolonged immobility, age 〉60 years, varicose veins, obesity, hormone therapy, pregnancy/postpartum, nephrotic syndrome, dehydration, thrombophilia, thrombocytosis

Description: Introduction: Despite the publication of international consensus guidelines for the provision of venous thromboembolism (VTE) prophylaxis, the recent ENDORSE survey reported that 64% of patients admitted to surgical wards in hospitals worldwide are at risk for VTE, and of those only 59% received appropriate prophylaxis (Lancet2008;371:387–94). In this sub-analysis of ENDORSE data, we assess the provision of VTE prophylaxis according to surgery type, and evaluate the key factors associated with the decision to provide VTE prophylaxis to surgical patients. Methods: ENDORSE was a multinational, cross-sectional survey of patients admitted to medical and surgical wards in 358 hospitals across 32 countries (Lancet2008;371:387–94). VTE risk and prophylaxis use were assessed in evaluable patients according to the 2004 American College of Chest Physicians (ACCP) guidelines (Chest2004;126:338S–400S). Major surgery was grouped into the following categories: major orthopedic (hip replacement, knee replacement, hip fracture repair); abdominal/thoracic (colon/small bowel, rectosigmoid, gastric, hepatobiliary, thoracic); vascular; urological/gynecological; and other (curative arthroscopy, other orthopedic trauma, other surgeries). Independent factors associated with the use of ACCP-recommended prophylaxis in surgical patients at risk for VTE were evaluated using multivariable logistic regression analyses. Results: Of the 30,827 patients in surgical wards included in ENDORSE, 18,461 had undergone major surgery as of the date of the survey. Of these, 17,018 (92.2%) were considered to be at risk for VTE, although only 10,710 (58.0%) received ACCP-recommended types of VTE prophylaxis. The proportion of patients at risk for VTE and the use of ACCP-recommended prophylaxis varied according to surgery type (Table). Multivariable analysis confirmed that surgery type was the factor that was most strongly associated with the provision of ACCP-recommended VTE prophylaxis. Patients undergoing major orthopedic surgery were most likely to receive recommended VTE prophylaxis, with patients undergoing hip replacement surgery 6 times more likely to receive ACCP- prophylaxis (OR 6.2; 95% CI 5.0–7.9). Curative arthroscopy and rectosigmoid surgery were also strongly associated with the provision of ACCP-recommended prophylaxis: (OR 3.6; 95% CI 2.3–5.4 and OR 2.3; 95% CI 1.7–3.0, respectively). When surgery type was excluded from the multivariable analysis, obesity (OR 1.9; 95% CI 1.7–2.1), rheumatologic or inflammatory disease (OR 1.7; 95% CI 1.3– 2.2), and previous VTE (OR 1.7; 95% CI 1.3–2.1) were the clinical characteristics most strongly associated with the use of recommended VTE prophylaxis. Conclusion: The provision of ACCP-recommended VTE prophylaxis was primarily driven by the fact that patients underwent a major operation and rates of prophylaxis use varied substantially according to the type of surgery. Patients undergoing major orthopedic surgery are most likely to receive appropriate VTE prophylaxis, however up to 45% of at-risk patients undergoing non-orthopedic procedures do not receive ACCP-recommended prophylaxis. Surgery type was the most important factor associated with the decision to provide ACCP-recommended prophylaxis in surgical patients at risk for VTE. Table: Prevalence of VTE risk and use of ACCP-recommended prophylaxis according to surgery type. Surgery type N Patients at risk For VTE n (%) At-risk receiving ACCP-Recommended prophylaxisn (%) Major orthopedic 2300 2300 (100) 1979 (86.0) Abdominal/thoracic 5028 4527 (90.0) 3023 (66.8) Vascular 1038 946 (91.1) 676 (71.5) Urological/gynecological 2653 2344 (88.4) 1261 (53.8) Other 7442 6901 (92.7) 3771 (54.6)

Description: Introduction: Findings from the recent EXCLAIM study demonstrate that selected acutely ill medical patients with reduced mobility benefit from extended-duration enoxaparin venous thromboembolism (VTE) prophylaxis (Blood2007;110:1862). However, it is unknown whether the EXCLAIM population is representative of acutely ill medical patients admitted to hospitals worldwide. In this subanalysis, we assessed whether the EXCLAIM population was representative of the medical patients enrolled in the multinational IMPROVE (Chest2007;132:936–45) and ENDORSE (Lancet2008;371:387–94) registries known to be at risk for VTE. Methods: Using patient data from IMPROVE and ENDORSE, we applied the EXCLAIM eligibility criteria to a representative, multinational population of acutely ill medical patients at risk for VTE. The IMPROVE and ENDORSE studies assessed VTE-risk and prophylaxis use of enrolled patients according to the 2004 American College of Chest Physicians (ACCP) guidelines (Chest2004;126:338S–400S). ACCP criteria for VTE risk were met in 46% (6,907/15,156) of IMPROVE and 43% (15,487/36,351) of ENDORSE study patients (Chest2007;132:936–45; Lancet2008;371:387–94). The EXCLAIM eligibility criteria required patients to be confined to total bed rest (level 1 immobility), or bed rest with bathroom privileges (level 2 immobility) and have at least 1 of 3 predefined risk factors for VTE (i.e., age 〉 75 years; history of VTE; active or prior cancer). Results: EXCLAIM eligibility criteria were met in 30% (2,072/6,907) IMPROVE and 36% (5,535/15,487) ENDORSE medical patients considered at risk for VTE by ACCP. During hospitalization, ACCP-recommended prophylaxis was provided to 69% (1,426/2,072) and 46% (2,548/5,535) of EXCLAIM-eligible patients enrolled in IMPROVE and ENDORSE, respectively. Following discharge from hospital (median length of stay 5 days for US, 8 days for non-US), only 9% (153/1,719) of EXCLAIM-eligible patients in the IMPROVE study received any type of ACCP-recommended VTE prophylaxis. Conclusions: Evidence from the EXCLAIM study demonstrated that the benefit-to-risk ratio in selected hospitalized medical patients favors the use of prolonged VTE prophylaxis. This population corresponds to one in three of the representative hospitalized patients with acute medical illness enrolled in IMPROVE and ENDORSE. Data on prophylaxis use from the IMPROVE registry suggest that only 9% of such patients are currently receiving optimal VTE prophylaxis following hospital discharge.

Description: Introduction Estimates for patients at risk of venous thromboembolism (VTE) in US acute care hospitals total approximately 4 million surgical and 8 million medical patients annually. However, limited data are available regarding practices in VTE prevention in the acute care setting. The ENDORSE (Epidemiologic International Day for the Evaluation of Patients at Risk of Venous Thrombosis in the Acute Hospital Care Setting) study is a worldwide survey of inpatients in acute hospital care. We assessed data from US acute care hospitals to determine the prevalence of VTE risk and proportion of at-risk patients receiving prophylaxis in accordance with current ACCP guidelines. Methods During the period August 2006 to January 2007, 9257 patients were enrolled from 81 randomly-selected US acute care hospitals. All medical patients ≥40 years, surgical patients ≥18 years, or patients ≥18 years admitted for non-surgical trauma were eligible for the study. Patients admitted to an ineligible ward, with missing data, or admitted solely for the treatment of VTE were excluded from the analysis. Patient charts were reviewed during a single day, pre-defined visit, with the evaluation criteria including medical history, admission and post-admission diagnoses, type of surgery, bleeding risks, and initiation and type of prophylaxis. The ACCP consensus guidelines were used to evaluate VTE risk and prophylaxis use in enrolled patients. Results Of the 9257 study patients, 44% and 56% were surgical and medical, respectively. 78% and 52% of surgical and medical patients were judged at risk for VTE, respectively. Of these, 29% of surgical patients and 52% of medical patients failed to receive recommended types of prophylaxis (Table). Among at-risk patients who received recommended types of VTE prophylaxis, a majority received anticoagulants (90% surgical, 97% medical). Table: VTE risk and prescription of recommended types of prophylaxis in US acute care hospitals US patients [X, range*] At-risk for VTE [X, range*] At-risk patients who received ACCP-recommended prophylaxis [X, range*] *Mean and range across all 81 US hospitals All (N=9257) 5885 [64%] 3536 [60%] Surgical (N=4061) [44%,13–94] 3165 [78%, 21–100] 2244 [71%, 0–100] Medical (N=5196) [56%, 6–87] 2720 [52%, 19–100] 1292 [48%, 0–100] Conclusions These data from US acute care hospitals parallel the global ENDORSE study findings of the high prevalence of VTE risk and suboptimal provision of ACCP-recommended prophylaxis. Although a higher proportion of surgical patients were judged to be at risk of VTE, the absolute number of hospitalized medical patients was higher and half of these did not receive adequate VTE prophylaxis. Our data highlight the continued need for strategies to ensure that hospital patients at risk of VTE are identified and provided with adequate VTE prophylaxis.