Cancer-associated thrombosis (CAT) is an important and increasingly common complication of cancer and cancer treatments. Implementing a CAT clinic can be instrumental for the early recognition of signs and symptoms and management of patients with cancer.
The Cleveland Clinic has created a CAT clinic, which relies on a combination of supervising physicians and advanced practice providers. The CAT clinic takes care of any patient with a new diagnosis or even a suspicion of thromboembolism, treating them using pre-determined algorithms.
CAT clinics can improve patient outcomes by providing standardized outpatient care. Many patients can avoid hospital admissions or emergency room visits using an outpatient care setting that ensures compliance and adherence to medications. To do so, in the CAT clinic, patients are followed up at 30 days and at six months.
CAT clinics can also provide education to patients about the warning signs and symptoms of deep venous thromboembolism and pulmonary embolism.
In this podcast, Alok Khorana describes the successful model of the Cleveland CAT Clinic
Summary podcast. Building a CAT Clinic: Real-World Systems Approaches to Prevention and Treatment
Alok Khorana, Professor of Medicine, Cleveland Clinic Lerner College of Medicine, CaseWestern Reserve University
Full podcast. Building a CAT Clinic: Real-World Systems Approaches to Prevention and Treatment
Full podcast trascript:
Hi, my name is Alok Khorana, I am a medical oncologist with an interest in cancer-associated thrombosis, and I work at the Cleveland Clinic in Cleveland, Ohio, part of the case comprehensive center and Case Western Reserve University.
Today I will be discussing the topic “building cancer-associated thrombosis clinic: real-world system approaches to prevention and treatment.” Let’s start off with the question about what a cancer-associated thrombosis clinic is.
As many of you who take care of patients with cancer know, thrombosis is very common in people with cancer. It can occur before the diagnosis of cancer, it can occur while the patient is receiving systemic treatment, it can occur after surgery, so there are many settings in which cancer-associated thrombosis can occur.
And it can occur in the venous system, which is the most common type, particularly DVT (deep vein thrombosis) or pulmonary embolism (PE), and it can also occur in the arterial system, particularly stroke and myocardial infarctions.
These facts have been known for a really long time. As since the treatment of cancer has evolved and more of our patients are now treated in the outpatient setting, I would say most of our patients are now treated in the outpatients setting; we have tried to figure out ways to better deliver care for our cancer patients with thrombosis in the outpatients’ service.
And one of the ideas that we had a few years ago was to create a specific cancer-associated thrombosis clinic to better improve outcomes in cancer patients and potentially to also screen them for future risk of DVT or PE.
We started this CAT Clinic, this Cancer-Associated Thrombosis Clinic, in my institution, the Cleveland Clinic, as I mentioned several years ago, and we set up an outpatient format. So it was for any cancer patient with a new diagnosis of DVT or PE would be brought to the clinic and treated.
The purpose of this was twofold: one was that we wanted to avoid to sending patients to the emergency room after hours or admitting them directly to the hospital for the diagnosis and treatment of a new and acute DVT or PE.
And it felt that if we had a clinic that was staffed by three or four people who only take care of cancer thrombosis, and so who knows the algorithm of treatment, we would be able to get people in faster, we would be able to provide standardized care, and we would be able to reduce emergency room visits and hospital admissions.
And in fact, it did turn out to be the case. When we started this clinic, we trained what in the US are called advanced practice providers; these can be nurse partitioners or physician assistants, so they are not necessarily physicians, although they work under the supervision of a physician.
We created an algorithm for treating the new onset of acute DVT or PE in cancer patients. We created rules around which patients needed to be admitted and of which patients could be treated in the outpatient setting, and most patients could, in fact, be treated in the outpatient setting unless they were hemodynamically unstable or very symptomatic.
Next, we created an algorithm around which drug to use. When we started out our CAT clinic, we knew that low molecular weight heparin (LMWH) monotherapy was a standard—and so based on the availability of LMWH in the US, we chose enoxaparin once daily for our standard treatment.
So, if a patient came in with leg swelling, the whole Cancer Center knew to page the CAT clinic pager. The CAT clinic would evaluate the patient, and they would do an ultrasound; if DVT was found, they would recommend starting LMWH unless there were exceptions or reasons why you could not.
We published on this before, and we had a very high rate of compliance with LMWH monotherapy, over 90%, and, at the time, in the US, only 50% of patients nationally received LMWH monotherapy.
So, we felt that this not only reduced the emergency room visits and admissions but also provided patients with a standard of treatment.
In the past few years, as new data emerged for Direct Oral Anticoagulants (DOACs) such as rivaroxaban or apixaban, we also transitioned our patient’s treatment algorithm, and we added these options for our patients.
In the US, many of these options are dictated by which drug would be covered by the patient’s insurance and formulary, so we created a decision tree where for most patients, we would recommend DOACs, the exception being patients for whom insurance would not cover DOACs or who are at high risk of mucosal bleeding, specifically patients with gastric cancer or esophageal cancer. And for those patients, we continued to recommend LMWH monotherapy
We now have treated hundreds of patients over the years, both in the initial era of LMWH monotherapy or the new era of either DOACs or LWMH. And again, we achieved very good results in terms of standardization of treatment; most patients fit this algorithm and receive treatment appropriately.
In addition, we have measured outcomes in these patients, and our rates of recurrent venous thromboembolism and our rates of major bleeding are quite low, based on the patient’s selection algorithm that we outlined.
So, we believe that this type of standardized outpatients care is beneficial for patients because it keeps them out of having to go to urgent care, and it helps them receive standardized treatment. It is beneficial for the health system because you have a standardized approach, you can measure outcomes properly, if you do something wrong, you can restrategize.
And we think this is something that should be adopted in larger academic medical centers worldwide, which is why my colleague, Dana E. Angelini (who helps around this clinic and is, in fact, at our institution the leader of this clinic) and I wrote about this for the ICTHIC meeting, and this paper is going to be published in thrombosis research.
We also believe that the CAT clinic can provide education to patients. Many cancer patients are not aware of the warning signs of DVT or PE, they don’t know what to do in terms of reporting recurrence or consulting for recurrence, and they don’t know where to call if you know they have a new onset shortage of breath or cough, those types of symptoms.
And so that’s another purpose of the CAT clinic that increases awareness about DVT or PE in cancer patients.
A new approach that we are starting to take is looking at primary prevention.
This was not, as I mentioned, an original mission of the CAT clinic, but things have evolved, new data have come out, and guidelines have been updated about primary prevention. And we feel that the CAT clinic staff could help oncologists with decisions about primary prevention.
We have created an electronic risk score that calculates the patients’ risk of developing DVT or PE after initiating systemic therapy. High-risk patients are identified, and between the cat clinic and the patient’s primary oncologist, we help offer services for screening and discussion about primary prevention.
This is still ongoing as a pilot project; we only started this a few months ago so we don’t have our consultant yet. But at another institution of the US that also has a CAT clinic, the University of Vermont, Dr. Holmes and colleagues reported this type of primary prevention offering to cancer patients is also very well received.
And in their study that has been going on for two years, they were able to identify high-risk patients. And of those patients that had a discussion about primary prevention, 90% of patients chose to go on prophylaxis and remained in prophylaxis.
So, in addition to providing a service when there is an acute diagnosis of DVT or PE, we believe that the CAT clinic may also serve as a support system for primary oncology teams to help discuss primary prevention and thereby reduce the public burden on both initial DVT and PE and also recurrent DVT or PE.
Once patients are diagnosed, we also tend to follow these patients at our clinics. So, we set up an appointment at 30 days from diagnosis to make sure that there are no concerns about taking anticoagulation, and we can monitor them for anticoagulation, toxicity, instruct them about bleeding issues, and so on.
And we check in again with those patients at 6 months to discuss whether they should remain on anticoagulating at that time point, or stop, or switch to a lower dose.
So overall, this is how we constructed our CAT clinic, which, as I mentioned, it has been functioning for several years.
I hope you found this information useful as a successful model on cancer-associated thrombosis clinic, and we will discuss this in greater detail in the upcoming ICTHIC meeting in Bergamo. We hope to see you there.
Thank you very much for your attention.