Anticoagulation clinics that have historically monitored patients receiving warfarin therapy are broadening their focus to include the direct oral anticoagulants—dabigatran, rivaroxaban, apixaban, edoxaban—and in some cases are even zeroing in on them entirely.
“As the growth of the new oral anticoagulation therapies has increased, anticoagulation clinics have had to redefine their role to serve their primary function as warfarin management clinics and to serve more broadly as education and medication reconciliation clinics that are particularly focused on anticoagulants,” said Margaret Fang, MD, a hospitalist and medical director of the University of California, San Francisco (UCSF), Anticoagulation Clinic.
So far, the more than 3,000 anticoagulation clinics in the U.S. have seen little to no decrease in their patient load, according to Geoffrey Barnes, MD, ACP Member, clinical lecturer in cardiovascular medicine and vascular medicine at the University of Michigan Health System in Ann Arbor. Many patients remain on warfarin because they have been taking it for years and are comfortable with the monitoring schedule, he said. Some patients also choose warfarin, preferring its features over the new agents, as well as its much lower cost.
However, declining use of warfarin is anticipated in coming years, Dr. Barnes said. Some people outside the anticoagulation world have a misperception that if warfarin is replaced, there will be no need for these clinics, he added. “That is not true, but it also means that we need to justify the roles that we serve” by taking advantage of the many highly trained nurses and pharmacists who are experts in anticoagulation care. “We can bring that same expert level of care to patients using other anticoagulants,” he said.
Dr. Fang agreed. “We have had to learn about these new medications and identify where anticoagulation clinics can offer the most benefit for patients,” she said.
Although direct oral anticoagulation does not require the same level of monitoring as warfarin, medication management is still critically important for patients treated with these drugs, particularly those who are scheduled for a medical procedure and may need to discontinue therapy for a certain period of time, according to Dr. Barnes.
“All of this is somewhat complex, and many clinicians are not very well versed in how to manage that safely,” he said. “Anticoagulation providers have that expertise and know-how to help prevent perisurgical or periprocedural complications.”
A key role for an anticoagulation clinic is reducing bleeding risk due to inappropriate dosing, which can result from renal dysfunction or high or low body weight. Patients' renal function is usually checked before direct oral anticoagulation is prescribed, but prescribing physicians sometimes overlook ongoing monitoring of renal function, Dr. Barnes said. If a patient develops renal dysfunction while on a direct oral anticoagulant, the dosage may need to be lowered.
Patients on direct oral anticoagulation should also be monitored for side effects, adverse events, and drug-drug interactions when the drug is first prescribed and during ongoing treatment. Expert management of therapy is also important for patients who have treatment failure. Patients also need to understand the importance of adherence and why doses should not be skipped, Dr. Fang said.
A black-box warning on all of the new drugs highlights the higher risk of thrombosis after they are discontinued, and patients “need education about that risk, should be monitored in some way, or have a regular check-in with a group who will make sure they are adherent and are aware of the risks of nonadherence,” she said.
Hospitalists should refer most patients on anticoagulation to a clinic at discharge, as well as educate patients about why the clinic visits will be important to their health, Dr. Fang advised. “It is reasonable to refer the patient to an anticoagulation clinic after discharge unless the patient's primary care doctor explicitly states that they would be able to manage the patient in the same ways as the clinic,” she said.
Transitions under way
When patients arrive at the anticoagulation clinics, they may find new and improved models for care.
At UCSF, the anticoagulation clinic is staffed by nurse practitioners and pharmacists and has expanded to treat patients on the newer agents. Before this expansion of services, clinic leaders examined how physicians handled patients taking direct oral anticoagulation before major surgery. According to Dr. Fang, the study found variability among physicians, with some not considering a patient's renal function when advising the patient to stop the drug before the procedure. “There was a lot of heterogeneity in the recommendations,” she said.
Today, patients prescribed the new agents at UCSF are asked to come to the clinic for an initial visit and a detailed medication history. Patients are given an option to check in by phone or e-mail so that staff can monitor their medication adherence, side effects, and upcoming procedures. The clinic also periodically monitors each patient's renal and liver function and assesses for any changes in overall health. Patients with a surgical procedure scheduled are encouraged to come in or at least consult with the clinic via email and or phone.
“No one really knows what the optimal frequency of monitoring or check-ins is for [direct oral anticoagulants], but it is very important when people are initiating the therapy,” Dr. Fang said.
For patients in treatment for a venous thromboembolism, the UCSF clinic has a visit at the time of any dose de-escalation and then, if there are no questions, 1 to 3 months later, followed by a check-in at 6 months and more periodically thereafter.
On varying schedules, the clinic also serves patients being treated with one of these new agents for other indications, including prevention of stroke and systemic embolism in patients with atrial fibrillation and prevention of venous thromboembolism following hip or knee arthroplasty.
Another model is pharmacist-only management of anticoagulation clinics. Two emergency medicine fellows at Eskenazi Health in Indianapolis started a clinic for patients with venous thromboembolism who were not admitted to the hospital but were discharged home with a prescription for rivaroxaban.
When the fellows graduated, pharmacists stepped in to staff the clinic under a collaborative practice agreement which allows them to see patients independently, evaluate them, manage adherence to therapy, and monitor for side effects. The agreement between the physicians and pharmacists has now expanded to include apixaban. “These patients are a perfect patient group for pharmacists to serve,” said Todd A. Walroth, PharmD, BCPS, BCCCP, pharmacy manager of clinical services at Eskenazi Health.
At discharge from the emergency department, eligible patients are given a clinic appointment and a prescription for enough medication to get them to that appointment. The appointment includes education about the disease state, discussion of the drug's side effects, and a focused physical exam, according to Baely M. Crockett, PharmD, BCPS, a clinical pharmacy specialist in cardiology at Eskenazi.
Pharmacists check for drug interactions and whether the dose is appropriate based on the patient's renal function. The clinic also helps patients navigate options to pay for the drug if they lack sufficient insurance coverage.
Beyond these tasks of making sure the new agents are managed well, anticoagulation clinics could expand even further to become broader medication safety clinics promoting safe and effective care across a wide range of cardiovascular conditions for patients taking high-risk medications, according to Dr. Barnes.
For example, this broadened mission could ensure posthospital follow-up for patients with acute deep venous thrombosis and potentially help the health care system avoid emergency department visits and admissions.
A medication safety clinic could also benefit patients on high-risk medications, such as digoxin, aldosterone antagonists, and amiodarone, by helping to reduce drug-related complications, Dr. Barnes and colleagues proposed in an article in the March Circulation: Cardiovascular Quality and Outcomes.
At these clinics, patients' potassium, liver, lung, and thyroid function, as well as drug concentrations, could be periodically monitored. Currently, clinicians do not always make sure this monitoring is performed as recommended, Dr. Barnes said. “These functions could all be rolled in together into 1 set of providers—a medication safety clinic to make sure they are getting safe care.”
With an expanded mission, the “business justification supporting a medication safety clinic would be even greater than that of a more narrowly focused anticoagulant clinic,” Dr. Barnes and colleagues said in the study.
Dr. Barnes noted that most anticoagulation clinics currently face financial challenges because they do not directly charge for services, but many health care systems “understand the benefit that these clinics offer and know that it is worth their financial investment.”
The exact future form of anticoagulation clinics is still uncertain, according to Dr. Fang. “Physicians and clinics are still trying to figure out the optimal way we can provide benefit for our patients and reduce adverse events,” she said. “I'm not sure what that will be, but I do believe that anticoagulation clinics will continue to serve an important function, even though it may be a different function than in past years.”