Best Practices for the Management of Thromboembolism - Episode 5
Practice Pearl 1: Tools Used for VTE Risk Assessment
Panelists review the tools, specifically the Padua and IMPROVE models used to identify VTE risks.
Charles Kurt Mahan, PharmD, RPh, PhC: Let’s shift a bit. We’ll talk about different tools for identifying patients at risk of VTE [venous thromboembolism] and various VTE risk-assessment tools, like the Padua Prediction Score [PPS], the IMPROVE [International Medical Prevention Registry on Venous Thromboembolism] model, and any recommendations that you may have, like what you’re using in your facility. I know there are other risk-assessment models, so I’ll go to you on this, Riley.
Riley Bowers, PharmD, BCCP, BCPS: It can be difficult to nail down 1 scoring system at our institution because practitioners in different areas are going to use different systems. Unlike at Paul’s institution [Excela Health], we don’t have 1 automatically built into our order sets. When I’m not at Campbell University, I’m practicing at Cape Fear Valley Medical Center in Fayetteville, North Carolina, as an internal medicine pharmacist.
In our medicine use units, we typically use either the Padua Prediction Score or, probably more frequently over the last year or so, the IMPROVE model, so I can best speak to those. The PPS was developed initially for use on medical inpatients, and it is probably the most commonly used model. It’s very useful, especially in establishing patients who may not need drug therapy for VTE. For those who are unfamiliar with the PPS, it provides a scaled, ranked score based on some of the risk factors we discussed earlier.
It includes active cancer, previous VTE, reduced mobility, and hypercoagulable conditions. All those are worth more points, I believe 3 each. By having just 1 of those, you’re 1 away from the high-risk score of 4, which means pharmacological prophylaxis is recommended. I believe other risk factors that go into that are age, previous MI [myocardial infarction], heart failure, obesity, and recent surgery. These are all at play in the Padua Predictive Score, but there are some limitations. The first, which is also a limitation to some others risk-assessment tools, is that the population with which it was developed was patients from general medicine wards, so it’s not well validated in ICU [intensive care unit] and surgical patients, but it does work very well for our medically ill patients.
I will also note that, in that original study where the Padua Predictive Score was developed, there a large percentage of the patients who developed VTE also had active cancer, so you have to take that into account. Those are 3 points that they take into account for the system. The biggest limitation is that it doesn’t factor in hemorrhagic risk, bleeding risk. Usually when the pharmacist and I fail to get someone put on pharmacological prophylaxis, it’s because I have a different perception of the bleed risk of that patient than the provider may have. That can be a major limitation in using the PPS. I’ll see if Paul has any insights on the PPS as well before transitioning to the improved model.
Paul Ament, PharmD: The only thing I’ll add to that, Riley, is that in the Padua Predictive Score, the risk of immobility becomes important at day 3. When you’re admitting the patients, you haven’t achieved that yet. In our order sets, the VTE adviser comes back and alerts the clinician at day 3 to reevaluate because at that point, if the patient has that limited mobility at 3 points, you’re basically at the 4 points where appropriate pharmacological therapy is going to be recommended.
Riley Bowers, PharmD, BCCP, BCPS: It’s a dynamic tool, and it’s something that you need to look at more than once. I encourage my learners—students and residents—to look at their scores not only at admission but also periodically, especially before discharge because we have very dynamic changes in our patients from day 1 especially to day 5 or so. The IMPROVE model is something that we’ve been using more recently. The IMPROVE model has a few versions, but the option that’s caught on most is more of the modified or associative IMPROVE model, which had up to 11 variables.
Then they have another IMPROVEDD model, which includes D-dimer. Whichever option you choose, they are very simple tools to use, just as Padua gives us that 90-day VTE occurrence risk. A couple of other things I want to note about the IMPROVE model is that it has a bleeding assessment tied to it, so it has a validated bleeding assessment for those medically ill patients as well. You’ll see the IMPROVE referenced in some of our extended VTE prophylaxis trials, such as the MARINER trial. Because of those newer data and because it’s the 1 used in some of the extended VTE prophylaxis trials, I found myself shifting to it more. As I said, it’s not very hard to use.
There are other risk-assessment scores that we didn’t talk about. You have the Caprini VTE score, which can be used for nonorthopedic surgical patients. There is also the Geneva VTE score, which is an older option for admitted medical patients. You have risk scores for cancer patients. I’m sure there are more out there. These are just the ones I can think of off the top of my head. The big takeaway is that no matter which 1 you pick, you should pick 1 because it makes you more aware of assessing these patients’ risk for VTE.
Charles Kurt Mahan, PharmD, RPh, PhC: I am biased a bit toward the IMPROVE model. Some of my closer colleagues derived both the IMPROVE VTE model and then the IMPROVE Bleed Risk Assessment Model. I then validated that at 3 McMaster hospitals, at least the IMPROVE VTE. I do feel it’s a little more simple, and we have built that into Epic, our EMR [electronic medical record] for both the VTE and bleeding, and it gives physicians and clinicians real-time information about what the patient’s score is. To Dr Ament’s point, 1 of the most important things is to reassess these patients consistently; you don’t just assess them once on admission and then that’s their risk. We need to be looking at their risk often. Every 24 hours is probably best practice in reassessing. Did bleed risk go down? Were they bleeding and are now stable?