New Oral Anticoagulants Advance Treatment Options, Create Complications for Hospitalists


Key trials investigating new oral anticoagulants

  • Extended duration rivaroxaban versus short-term enoxaparin for the prevention of venous thromboembolism after total hip arthroplasty: a double-blind, randomised controlled trial. Lancet. 2008;372(9632):31-39.
  • Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med. 2011.8;365(10):883-891.
  • Apixaban versus warfarin in patients with atrial fibrillation. N Engl J Med. 2011;15;365(11):981-992.
  • Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med. 2009;17;361(12):1139-1151.

New oral anticoagulants promise to impact hospitalists and their patients—but the question is how much

When the FDA gave the nod to factor Xa-inhibitor rivaroxaban in November for use in treating acute DVT and pulmonary embolism (PE), it was just the latest development in the swiftly evolving world of oral anticoagulants—a world that hospitalists had better get used to living in, and quick.

As many as 80% of the patients that hospitalists encounter are on some kind of anticoagulant, experts say. But the extent to which the emergence of the new drugs— particularly rivaroxaban, which also is approved for stroke prevention in nonvalvular atrial fibrillation (afib) and for DVT and PE prevention in knee and hip replacement patients—will affect the daily routines of hospitalists remains to be seen.

Hospitalists specializing in VTE prevention and vascular experts say that the new drugs will make life simpler for hospitalists in some ways, mainly because for some patients, a pill will replace the injectable enoxaparin that has been used to bridge patients to warfarin. But with more options available, things will become more complicated as well, they say.

Approvals for the new agents, which aim to replace warfarin and its need for constant monitoring and concern over drug and food interactions, have been coming rapid-fire. Along with rivaroxaban in the new oral anticoagulant group are dabigatran, approved in late 2010 for stroke prevention in nonvalvular afib, and apixaban, which is expected to be approved for the same indication this year.

“Of all three drugs, [rivaroxaban] has the broadest indications for use,” said Hiren Shah, MD, assistant professor of medicine at Northwestern University’s Feinberg School of Medicine and medical director of hospital medicine at Northwestern Memorial Hospital in Chicago. “Because of that, it’s likely that it’s going to be the agent that will be adopted much more broadly and more easily than dabigatran.”

But apixaban might come on strong in the U.S. when it’s approved because it shows better promise for patients with renal impairment and has a lower risk of intracranial hemorrhage, says Geno Merli, MD, director of the Jefferson Center for Vascular Disease and chief medical officer at Thomas Jefferson University Hospital in Philadelphia.

“I think the two other [manufacturers] are afraid of apixaban because apixaban’s safety profile was much better,” he says.

Steven Deitelzweig, MD, FACP, SFHM, secretary of the Gulf State chapter of SHM and a DVT prevention specialist at Ochsner Health System New Orleans, says hurdles to adoption of the new agents will include whether a system is integrated and can assure appropriate follow-up and concerns over proper patient selection and cost, as the cost-benefit analyses haven’t been done yet.

“The learning curve, or the adoption curve, is really going to be very variable around the country,” he says.

Experts agree changes are on the way as the new anticoagulants gain more traction. Here are some things they say hospitalists should watch out for.

Care and Discharge

Dr. Shah says the availability of the oral agents will streamline care and discharge of patients.

“The care and coordination process that needs to occur with the use of parenteral agents and warfarin is significantly more complex than the patient education and care coordination that will be required with the new oral anticoagulants,” he says. “That’s where there’s a significant time savings.”

Ian Jenkins, MD, assistant professor in the division of hospital medicine at the University of California at San Diego, says the windfall of time saved might not hit hospitalists directly, at least at some centers.

“The education is being done by pharmacy here for warfarin, and nurses handle enoxaparin injection teaching,” he says. “So the workload that benefits may be that of our colleagues.”

Dr. Shah notes that the responsibility in patient counseling ultimately falls within hospitalists’ purview, so he predicts that any greater simplicity in that regard would help hospitalists.

Who Ends up Hospitalized?

The option of oral agents might help diminish the number of patients who have to stay in the hospital for enoxaparin injections that bridge them to warfarin, a topic at a recent roundtable discussion Dr. Shah attended.

“It was shocking to me that I have many colleagues throughout the country who have patients who are in the hospital simply to get parenteral injections because they can’t take them themselves at home and have no loved ones or friends to help them,” he says.

Dr. Merli agrees that the new agents might affect hospitalists’ patient census. Many patients, he says, will be discharged straight from the ED.

“The DVT patients probably won’t get [admitted]. You’re going to put them on rivaroxaban and send them home,” he says. “You’re not going to get [admitted] with a DVT anymore, unless it’s extensive. And if it’s an extensive DVT, you’re not going to get rivaroxaban. You’re going to get enoxaparin or you’re going to get thrombolytics therapy followed by IV heparin followed by enoxaparin. So I don’t see rivaroxaban jumping into the marketplace and being a boon to hospitalists immediately.”

If patients skip hospitalization and are discharged straight from the ED, Dr. Deitelzweig says, “there will be patients who will backfill those spots.”

“I think most of the people will come in as observation status, if not inpatient,” he says, although simpler DVT patients will be likelier candidates for discharge from the ER. He predicts that stays might be shorter, though.

But Dr. Merli says hospitalists shouldn’t expect a big effect on length of stay.

“I don’t think you’re going to reduce dramatically length of stay because you have an oral pill,” he says.

QI Initiatives

What might be a boon, though, are opportunities for quality-improvement (QI) initiatives related to the new therapies, Dr. Jenkins says. “Many of these projects that are being done with anticoagulants … do focus on warfarin safety; it’s a frequent part of readmission and patient harm,” he says. “Having it much simpler to treat and educate these patients is actually going to be a boon, I think, for hospitalists working on quality-improvement projects, and for people who do that education, whether that is a hospitalist or a pharmacist or some other member of the staff.”

There are downsides, though, he notes. One is cost. Another is reversibility. Warfarin can be easily reversed in the event of a bleed, but that’s not the case with rivaroxaban and dabigatran. And none of the new therapies are suitable for patients with renal failure.

“Right now, we’re stuck with IV heparin and Coumadin in the hospital, and rivaroxaban won’t change this,” he says. “Rivaroxaban patients one might help with PCC; but with dabigatran, I don’t think much will help besides time and dialysis, which is dangerous in unstable anticoagulated patients.”

Dr. Shah, though, says he’s aware of only two times that bleeding reversal protocols—based on anecdotal evidence, because no method has been scientifically proven—had to be invoked at Northwestern in the past year.

It might be “more of a theoretical problem than one in reality,” he explains, “simply because we have not found the need to reverse oral anticoagulants very often given their short half-lives.”

The new agents, all the experts agree, will require hospitalists to stay on their toes.

“There are so many different facets in each case, whether it’s the age or the renal function or whether there’s a fall risk and what their compliance is, what their funding is, what the exact indication is,” Dr. Jenkins says. “Keeping up with those things is actually quite challenging.”

His main resources are the American College of Chest Physicians’ guidelines on anticoagulants, his center’s own protocols, and the primary literature for the main trials (see “Additional Reading,” right). He also looks to the inpatient pharmacist for guidance.

Dr. Shah says it is important to be aware of the patient-inclusion criteria, study design, and outcomes measured for each agent through their trials.

“There is a lot of information out there, and there are very subtle aspects of some of these trials and you’ve got to really understand: Does it apply to the patient that is front of me?” he said. “There’s a lot to know, there’s no doubt about it.”

Thomas R. Collins is a freelance writer in South Florida.

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