Clot Chronicles: Inflammatory Bowel Disease & Thrombotic Risk

Hello, this is Dr. Sean Fine with Brown Physicians Medicine Division of Gastroenterology IBD Center. Today on Clot Chronicles, I will be discussing inflammatory bowel disease (IBD) and its risk for venous thromboembolism (VTE). I thank you for joining me. 

As we know, VTE is a very important topic to address because the morbidity and mortality that are associated with it in the general population alone is quite high – at least in the US and around the world. Specific to IBD, we have found and learned over the past several years that VTE is actually a very important risk factor, and we actually classify it as an extra-intestinal manifestation for patients with IBD. 

So, when we look at IBD and compare it to other chronic diseases, such as diabetes or rheumatologic issues such as rheumatoid arthritis, those disease processes don’t seem to confer the same risk for VTE IBD. When we’re trying to understand what actually goes into causing these clots to form, it really seems to be related to numerous different factors.

We actually learned about this risk several years ago when some studies were able to identify this unique phenomenon that was occurring in patients that had developed clots. It was in 2014, when a meta-analysis was performed looking at the association of VTE and IBD and found that patients with IBD, when they were matched similarly to patients without IBD (age- and sex-matched), that they had a 3-fold increased risk for the development of VTE, so quite significant. 

Importantly, when patients have a flare or suffer an acute exacerbation of their IBD, they actually have a 6-fold risk for clot development – so pretty significant to be aware of. 

One of the issues that we have run into, at least in the hospital setting, is that these patients with IBD with a flare would be coming in and would be presenting with things like rectal bleeding or hematochezia and patients would actually often not get placed on DVT prophylaxis because of the risk or fear that putting them on it would cause more bleeding. 

So, one of the things that we have strongly encouraged and tried to educate providers on is the importance of placing patients on DVT prophylaxis, even if they’re having episodes of bleeding during a flare, because that’s when they’re actually at higher risk. And I did say that we really don’t understand the exact mechanism of clot formation, but again it seems to stem from multifocal issues. Patients with disease or flare, if they’re not feeling well, are less ambulatory – they’re not moving around as much. We know that active inflammation is a factor; there are certain proteins that are floating around the patient’s bloodstream called cytokines, and they actually may turn on procoagulant factors or increase the risk for clotting. And one of the most important drugs that we use, at least now we use it short term, are what we call glucocorticoid steroids. Those have been found to actually increase the risk for clotting as well. So, it’s something that we just need to mindful of when we’re managing these patients. 

One of the factors that we’re currently trying to address and study now in our patients with IBD is once they do come out of the hospital, and we know that they’re having a flare, do we keep them on prophylaxis or DVT-preventing medications to prevent them from developing a clot as an outpatient? We’re still kind of working through this at this point, but we do understand that this is an important factor that we at least need to be considering for some of these high-risk patients. 

So, what about patients with IBD who are hospitalized for non-IBD-related issues or for getting an outpatient elective surgery – do they need to be on DVT prophylaxis when they’re hospitalized for those issues? And the answer, again, is yes with the understanding that patients with IBD—even if they’re not having an active flare—have these heightened risk factors for developing clots, especially after undergoing nonabdominal surgeries (such as orthopedic interventions and joint replacements). Those patients, again, still need to be placed on DVT prophylaxis. 

So, what other factors do we consider for our patients with IBD, at least in in terms of risk? Things like smoking come into play as well. Not only do we want our patients with IBD not to be smoking for all the other health benefits, but smoking does also seem to be a heightened risk factor for the development of clots and VTE. 

Another important note is in regard to patients’ disease phenotype, meaning that when we’re classifying patients with IBD—whether it be ulcerative colitis (UC) or Crohn’s disease—there have been some studies looking at what predicts heightened risk for the development of VTE in certain patient types. What we’ve seen, at least through studies that have been performed, is that patients with Crohn’s disease (fistulizing disease) that seems to be a more aggressive phenotype pertains to a heightened risk for clot development. Also, Crohn’s disease that’s located to the colon seems to also be a little bit more heightened for the development of clots. And for UC, severity really does boil down to the involvement of the entirety of the colon, which will heighten patients’ risk for the development of clots.

I’d like to thank you for allowing me to partake in this and discuss this very important topic.