Defining Venous Thromboembolism and Medically Ill Patients

Deepak Bhatt, MD, MPH: Patients hospitalized for medical illness are at increased risk for developing venous thromboembolism, VTE, during their hospital stay, and for up to 3 months after discharge. While thromboprophylaxis in hospitals is an accepted practice for many, the practice of extended thromboprophylaxis remains unsettled.

Today, we will look at how management of VTE risk after hospital discharge is evolving with the availability of evidence showing the extent of VTE risk and agents, with evidence of benefit in reducing this risk during the critical post-discharge period.

I am Dr Deepak Bhatt, the executive director of Interventional Cardiovascular Programs at Brigham and Women's Hospital Heart & Vascular Center in Boston, Massachusetts, and a professor of medicine at Harvard Medical School in Boston, Massachusetts.

Joining me today are 3 good friends; Dr Mike Gibson, a Harvard professor in the Department of Medicine at Beth Israel Deaconess Medical Center and the CEO of the Baim Institute for Clinical Research in Boston, Massachusetts, and a very skilled painter as well.

Also joining is Dr Gregory Piazza, an associate professor of medicine at Harvard Medical School and a cardiovascular medicine specialist, and particularly vascular medicine specialist, at Brigham and Women’s Hospital in Boston, Massachusetts.

Also joining is Dr Gary Raskob, dean of the Hudson College of Public Health and regents professor of epidemiology and medicine at the University of Oklahoma Health Sciences Center in Oklahoma City, Oklahoma.

And Dr Alex Spyropoulos, a professor of medicine at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, the director of Anticoagulation and Clinical Thrombosis Services at Northwell Health, and a professor in the Center for Health Innovations and Outcomes Research at the Feinstein Institutes for Medical Research in Manhasset, New York. That’s a lot of hats to wear. I just got tired saying what all you do. It must be exhausting doing it.

Thank you for joining today. It’s a great faculty. I think we’re going to have a lot of fun here. I’ll start off with Dr Piazza. He gets a lot of referrals for venous thromboembolic disease. What is VTE exactly? What does it encompass?

Gregory Piazza, MD, MS: When we talk about venous thromboembolism, we’re thinking of deep vein thrombosis [DVT], blood clots in the legs, or pulmonary embolism, a blood clot in the lungs. Occasionally there are other types of blood clots like cerebral venous thrombosis or mesenteric vein thrombosis. Typically, we’re talking about lower extremity DVT and pulmonary embolism.

Deepak Bhatt, MD, MPH: What counts as a DVT? Obviously something in the thigh. What about below the knee? What about soleal DVTs? What actually counts as a DVT?

Gregory Piazza, MD, MS: Typically any deep venous thrombosis, even in the calf veins, would count as DVT. There’s a lower risk of pulmonary embolism associated with calf vein DVT, so sometimes a more conservative, non-anticoagulant-based regimen may be picked for those, but they’re still deep. Whereas you can get superficial vein thrombosis in the greater saphenous vein or some of the other surface veins where really the management is conservative and symptomatic.

Deepak Bhatt, MD, MPH: I think that’s really important information for the audience. That’s often a confusing point. An appreciation with respect to VTE that I’d say is a relatively recent appreciation, maybe not for aficionados in the field but more broadly, is that there are medically ill patients who are high risk of VTE, not just during their in-hospital phase but even afterward for a period. Alex, what are your thoughts about these medically ill patients? Who exactly are they?

Alex C. Spyropoulos, MD, FACP, FCCP, FRCPC: Yes, Deepak. I think the first thing we should do is maybe define the scope of the problem, which is quite large. There are an estimated, just in the United States alone, about 7.2 million patients hospitalized each year…from acute medical illness. Now, modeling estimates are quite consistent, and they point to the fact that about 50% of these patients are at risk of VTE during their hospitalization, but up to a quarter more of these patients are at high risk of VTE, especially in the post-hospital discharge.

This represents a heterogeneous group of patients, but now we have I think a better sense of who these patient subtypes are that are at real risk of VTE. These tend to include patients who present with exacerbations of underlying cardiopulmonary disease, such as congestive heart failure or chronic obstructive pulmonary disease. These are patients who may have an acute onset because of maybe underlying risk of getting a cardiovascular event such as acute stroke. These are patients again who may have rheumatic disease and have exacerbations of their rheumatic disease or simply patients who may present with an acute severe infection. These are the kind of subtypes of these patients who are at risk for VTE.

Deepak Bhatt, MD, MPH: In terms of immobility, what exactly counts as immobile? Let’s say somebody is hospitalized with heart failure, but they get up to go to the bathroom a couple of times a day. Is that mobile or immobile?

Alex C. Spyropoulos, MD, FACP, FCCP, FRCPC: It’s an important point because these hospital admissions are almost associated with some level of immobility, either moderate or severe mobility. The reason why patients are immobile is not because they feel like staying in bed, it’s because their disease severity is enough that it renders them immobile. It’s immobility based on their disease severity.

Deepak Bhatt, MD, MPH: That’s a really important point.

Transcript edited for clarity.