- Email: [email protected]
Thromboprophylaxis for patients at high risk of VTE
Thromboprophylaxis for patients at high risk of VTE Alexander Cohen and colleagues (Feb 2, p 387)1 use American College of Chest Physicians (ACCP) guidelines2 to assess thromboprophylaxis regimens in hospitals worldwide. The ACCP guidelines recommend heparin for patients at moderate to high risk of venous thromboembolism (VTE). We would like to point out that a Cochrane systematic review3 of patients at the very highest risk of VTE (after hip fracture) found no evidence that any type of heparin reduces mortality. Furthermore, Scottish Intercollegiate Guidelines Network (SIGN) guidance4 on VTE prevention does not recommend heparin but supports use of aspirin. The SIGN guideline includes a statement explaining the differences between SIGN and ACCP guidance. To explore these differences further, we have studied the effects of different types of thromboprophylaxis on survival after hip fracture in 8470 participants in the Scottish Hip Fracture Audit, using Cox proportional hazards regression to adjust for age, sex, American Society of Anesthesiologists grade, and other factors described previously.5 A year after admission for hip fracture, 2531 (30%) patients had died. Compression stockings and aspirin seemed protective against death, with adjusted hazard ratios of 0·88 (95% CI 0·80–0·97) and 0·85 (0·76–0·95), respectively, but heparin did not (adjusted hazard ratio 0·97, 0·87–1·08). These findings support advice in SIGN rather than ACCP guidelines, but might be due to residual confounding. These observations highlight the need for large randomised controlled trials of mortality in patients at high risk of VTE that compare the effect of different types of thromboprophylaxis including aspirin, compression stockings, and heparin. We declare that we have no conflict of interest.
www.thelancet.com Vol 371 June 7, 2008
*D Graham Mackenzie, Andy Elders, Sarah Wild, Rod Muir [email protected] Department of Public Health and Health Policy, NHS Lothian, 148 Pleasance, Edinburgh EH8 9RS, UK (DGM); Public Health Department, NHS Fife, Leven, UK (AE); School of Clinical Sciences and Community Health, University of Edinburgh, Edinburgh, UK (SW); and Information Services, NHS National Services Scotland, Edinburgh, UK (RM) 1
2
3
4
5
Cohen AT, Tapson VF, Bergmann J-F, et al, for the ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet 2008; 371: 387–94. Geerts WH, Pineo GF, Heit JA, et al. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126 (suppl 3): 338S–400S. Handoll HHG, Farrar MJ, McBirnie J, Tytherleigh-Strong G, Milne AA, Gillespie WJ. Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures. Cochrane Database Syst Rev 2002; 4: CD000305. Scottish Intercollegiate Guidelines Network. Prophylaxis of venous thromboembolism. Edinburgh: SIGN, 2002. http://www.sign. ac.uk/guidelines/fulltext/62/index.html (accessed May 12, 2008). Mackenzie DG, Wild S, Muir R. Mortality associated with delay in operation after hip fracture: Scottish data provide additional information... BMJ 2006; 332: 1093.
The findings of the multinational, cross-sectional ENDORSE study1 reinforce the knowledge that venous thromboembolism (VTE) prophylaxis is underused. In this study, Alexander Cohen and colleagues show that more than half of hospital inpatients are at risk of VTE, only half of whom received adequate prophylaxis as recommended by the American College of Chest Physicians (ACCP). It is interesting to analyse these findings in parallel with those of the multicentric Trombo Risk study2— an observational, cross-sectional study that analysed the VTE prophylaxis profile in hospitals in Brazil (1454 surgical and clinical patients). Three risk assessment models were used: ACCP guidelines, Caprini score, and the International Union of Angiology consensus statements. Like the ENDORSE investigators, we also found that VTE prophylaxis is underused. 80% of the patients studied
were at risk of thromboembolism, yet around a third of these patients were not receiving adequate prophylaxis. Additionally, and by contrast with the ENDORSE study, we found that the underuse of thromboprophylaxis was more prevalent in the older patients, despite their higher risk of VTE. This fact showed that improvement of thromboprophylaxis is more urgent in older patients, and that measures should be taken in this specific population in the first instance.
Science Photo Library
Correspondence
See Department of Error page 1914
I declare that I have no conflict of interest. I thank Luciana Fornari, Maristela Monachini, Danielle Gualandro, Daniela Calderaro, Andre Marques for their contribution to this letter.
Bruno Caramelli [email protected] University of Sao Paulo, Sao Paulo, SP, Brazil 1
2
Cohen AT, Tapson VF, Bergmann JF, et al, for the ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet 2008; 371: 387–94. Dehenzelin D, Braga AL, Martins LC, et al, for the Thrombo Risk Investigators. Incorrect use of thromboprophylaxis for venous thromboembolism in medical and surgical patients: results of a multicentric, observational and cross-sectional study in Brazil. J Thromb Haemost 2006; 4: 1266–70.
Alexander Cohen and colleagues’ finding of low prescribing rates for thromboembolism prophylaxis in the acute hospital-care setting1 mirrors an audit in our acute hospital. We investigated 190 inpatients and found that 135 had an acute medical condition, had no contraindication for anticoagulation, and met established thromboprophylaxis criteria.2 Only 18 (13%) were prescribed thromboprophy laxis. We found that the major limiting factor for thromboprophylaxis in these acutely ill patients was the lack of documentation of risk assessment for venous thromboembolism (VTE) on admission. Such assessment occurred in only 7% of the 190 cases looked at. It is crucial that VTE risk assessment is done at the time of admission for VTE prophylaxis to be effective. The issue is further compounded in the UK because the Chief Medical
Submissions should be made via our electronic submission system at http://ees.elsevier.com/ thelancet/
1911
www.thelancet.com Vol 371 June 7, 2008
*D Graham Mackenzie, Andy Elders, Sarah Wild, Rod Muir [email protected] Department of Public Health and Health Policy, NHS Lothian, 148 Pleasance, Edinburgh EH8 9RS, UK (DGM); Public Health Department, NHS Fife, Leven, UK (AE); School of Clinical Sciences and Community Health, University of Edinburgh, Edinburgh, UK (SW); and Information Services, NHS National Services Scotland, Edinburgh, UK (RM) 1
2
3
4
5
Cohen AT, Tapson VF, Bergmann J-F, et al, for the ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet 2008; 371: 387–94. Geerts WH, Pineo GF, Heit JA, et al. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126 (suppl 3): 338S–400S. Handoll HHG, Farrar MJ, McBirnie J, Tytherleigh-Strong G, Milne AA, Gillespie WJ. Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures. Cochrane Database Syst Rev 2002; 4: CD000305. Scottish Intercollegiate Guidelines Network. Prophylaxis of venous thromboembolism. Edinburgh: SIGN, 2002. http://www.sign. ac.uk/guidelines/fulltext/62/index.html (accessed May 12, 2008). Mackenzie DG, Wild S, Muir R. Mortality associated with delay in operation after hip fracture: Scottish data provide additional information... BMJ 2006; 332: 1093.
The findings of the multinational, cross-sectional ENDORSE study1 reinforce the knowledge that venous thromboembolism (VTE) prophylaxis is underused. In this study, Alexander Cohen and colleagues show that more than half of hospital inpatients are at risk of VTE, only half of whom received adequate prophylaxis as recommended by the American College of Chest Physicians (ACCP). It is interesting to analyse these findings in parallel with those of the multicentric Trombo Risk study2— an observational, cross-sectional study that analysed the VTE prophylaxis profile in hospitals in Brazil (1454 surgical and clinical patients). Three risk assessment models were used: ACCP guidelines, Caprini score, and the International Union of Angiology consensus statements. Like the ENDORSE investigators, we also found that VTE prophylaxis is underused. 80% of the patients studied
were at risk of thromboembolism, yet around a third of these patients were not receiving adequate prophylaxis. Additionally, and by contrast with the ENDORSE study, we found that the underuse of thromboprophylaxis was more prevalent in the older patients, despite their higher risk of VTE. This fact showed that improvement of thromboprophylaxis is more urgent in older patients, and that measures should be taken in this specific population in the first instance.
Science Photo Library
Correspondence
See Department of Error page 1914
I declare that I have no conflict of interest. I thank Luciana Fornari, Maristela Monachini, Danielle Gualandro, Daniela Calderaro, Andre Marques for their contribution to this letter.
Bruno Caramelli [email protected] University of Sao Paulo, Sao Paulo, SP, Brazil 1
2
Cohen AT, Tapson VF, Bergmann JF, et al, for the ENDORSE Investigators. Venous thromboembolism risk and prophylaxis in the acute hospital care setting (ENDORSE study): a multinational cross-sectional study. Lancet 2008; 371: 387–94. Dehenzelin D, Braga AL, Martins LC, et al, for the Thrombo Risk Investigators. Incorrect use of thromboprophylaxis for venous thromboembolism in medical and surgical patients: results of a multicentric, observational and cross-sectional study in Brazil. J Thromb Haemost 2006; 4: 1266–70.
Alexander Cohen and colleagues’ finding of low prescribing rates for thromboembolism prophylaxis in the acute hospital-care setting1 mirrors an audit in our acute hospital. We investigated 190 inpatients and found that 135 had an acute medical condition, had no contraindication for anticoagulation, and met established thromboprophylaxis criteria.2 Only 18 (13%) were prescribed thromboprophy laxis. We found that the major limiting factor for thromboprophylaxis in these acutely ill patients was the lack of documentation of risk assessment for venous thromboembolism (VTE) on admission. Such assessment occurred in only 7% of the 190 cases looked at. It is crucial that VTE risk assessment is done at the time of admission for VTE prophylaxis to be effective. The issue is further compounded in the UK because the Chief Medical
Submissions should be made via our electronic submission system at http://ees.elsevier.com/ thelancet/
1911