Introduction-Venous Thromboembolism Management in the Real World: Your Opportunity to Participate in a Critical Assessment

A valuable opportunity to see ``real-world'' registry data was afforded to participants at a second satellite symposium, organized by Aventis Pharma during the XVIIIth Congress of the International Society on Thrombosis and Haemostasis in Paris, on July 11, 2001. In contrast to the comprehensive and research-focused presentations that form the first part of these Proceedings, this interactive satellite meeting, entitled ``Venous Thromboembolism Management in the Real World: Your Opportunity to Participate in a Critical Assessment,'' offered participants the chance to review and discuss unique data from new regional venous thromboembolism (VTE) registries in Europe, the United States, Latin America, and Asia.

Data from the U.S. Hip and Knee Registry offered insights into trends in thromboprophylaxis in high-risk orthopedic patients. In the United States, nearly 90% of patients undergoing elective hip or knee replacement surgery receive recommended thromboprophylaxis. Interestingly, whereas the average length of hospital stay appears to be decreasing, the duration of thromboprophylaxis is increasing with approximately half of all hip or knee replacement patients receiving prophylaxis for more than 21 days. In Europe and the United States, much attention is focused on optimizing thromboprophylaxis in high-risk medical patients. In Europe, the results of French epidemiological surveys confirm the high prescription rates for low-molecular-weight heparin (LMWH) in medical patients and highlight the need to target prophylaxis for the patients genuinely at significant risk of VTE, such as those with acute infections or severe cardiopulmonary disease. Current trends are toward overuse of LMWH as prophylaxis in elderly medical patients confined to prolonged bed rest and underuse in acutely ill patients.

The situation in Western countries contrasts markedly with that in other regions such as Latin America. Initial results from the Brazilian Registry, presented during the symposium, reflect a low awareness of VTE and highlight that a quarter of all high-risk and up to half of moderate-risk Brazilian patients do not receive any form of thromboprophylaxis. Nevertheless, a pilot study demonstrated a dramatic improvement in outcomes with increased LMWH use, an indication of the potential benefit of improved VTE prevention. Clearly, initiatives such as the Brazilian Registry are urgently needed in South America to improve awareness levels and understanding of the risk factors for VTE and increase the prescription of appropriate prophylaxis.

A fascinating aspect of the satellite symposium was that it took advantage of the opportunity to poll the international audience, by region, on their practice of thromboprophylaxis. The answers show that although we do indeed see the same patients, treatment varies a great deal. For example, roughly equal percentages of physicians from North America, Central and South America, Europe and Australia/New Zealand, and Asia would use prophylaxis in all hospitalized patients at bed rest, but the proportion was only about 60%; the remainder would not. If cost were not an issue, the majority of physicians preferred LMWH for prophylaxis, but a significant proportion, about a third, would add pneumatic compression for combination therapy.

Regarding the necessity to provide prophylaxis regimens to nonorthopedic patients on the basis of published evidence, or to provide the same regimen to all medical and surgical nonorthopedic patients, about 60% in all regions favored following the evidence. Hence, a significant number of attendees, all interested and many experts in treating thrombosis, did not feel that nuances in evidence for nonorthopedic patients required different prophylactic schemes.

A striking variance occurred when the attendees were asked if they would provide thromboprophylaxis with LMWH to intensive care unit patients, such as those receiving mechanical ventilation [the latter were excluded from the Prophylaxis in Medical Patients with Enoxaparin (MEDENOX) trial and have been shown to have an increased risk of bleeding], or avoid it to lower bleeding risk. In North America, 80% would avoid LMWH and, indeed, it is rarely used in American intensive care units in my experience. In contrast, in Central and South America, Europe, Australia and New Zealand, and Asia, LMWH was favored by 86 to 100% of attendees.

Regarding the necessity to perform echocardiography in patients with pulmonary embolism (PE) to help decide whether to provide thrombolytic therapy, attendees were offered three choices: send stable patients home with LMWH without echocardiography, perform echocardiography in all PE patients to ensure the absence of right heart strain before sending stable patients home, or express uncertainty about whether early treatment at home is safe for PE and whether echocardiography is required. In North America, none were uncertain but 50% favored each of the other two choices (the author is from North America and is uncertain but did not vote!). In Central and South America, 25% were uncertain, 50% favored echocardiography, and 25% favored treatment at home without echocardiography for stable patients. In Europe, Australia, and New Zealand, 33% were uncertain, 25% favored echocardiography for all, and 42% favored home treatment without it. In Asia, 40% were uncertain, 40% favored echocardiography, and 20% favored treatment at home without it. This is an area in which evidence from clinical trials is sorely needed.

Finally, attendees were polled about whether prolonged prophylaxis after discharge for bedridden patients (e.g., medical patients) should be practiced more or whether more evidence is needed. In North America, 75% required more evidence. In Central and South America, only 40% required more evidence. In Europe, Australia, and New Zealand, 50% required more evidence; in Asia, 70% required more evidence.

It is evident that consensus is lacking among expert physicians in many important areas of thromboprophylaxis, and opinions may vary markedly between continents. Continuing education, critical analyses, and useful evidence from carefully performed clinical trials will help bridge these differences and optimize the prophylaxis of VTE so that fewer patients suffer this largely preventable disease.