VTE PROPHYLAXIS for patients in the hospital is a well-accepted practice, but extended prophylaxis for medically ill patients after discharge is a different story. While studies show that medically ill patients face a heightened risk of VTE events once they’re discharged, data show that fewer than 5% of those patients receive any kind of extended thromboprophylaxis after they leave the hospital.
“We know that being in the hospital places patients at risk for DVT, so we’ve been prophylaxing hospitalized patients since the late ’90s,” says hospitalist Hiren Shah, MD, assistant professor of medicine in the division of hospital medicine at Northwestern University. “It’s only in the last four or five years that we’ve started to appreciate that the risk persists even after hospitalization.”
Read our related article: How to use DOACs in extended VTE prophylaxis without raising bleeding risk.
Geno Merli, MD, associate chief medical officer of Thomas Jefferson University Hospitals in Philadelphia and co-director of the Jefferson Vascular Center, says that most hospitalists don’t view extended VTE prophylaxis in medical patients the same way they think about prophylaxis in surgical patients. “They know there’s a VTE risk among surgery patients because of all the studies that have been done,” he explains. “I would say that 90% of physicians do not prophylax their medically ill patients after hospitalization.”
“I would say that 90% of physicians do not prophylax their medically ill patients after hospitalization.”
~ Geno Merli, MD
Thomas Jefferson University Hospitals
Part of the problem, says Dr. Shah, is that many patients are discharged so quickly, often within three to four days. “Because patients are being discharged earlier,” he notes, “many of these patients still have an acute medical illness at discharge that hasn’t been fully resolved. And when it’s not resolved, these patients have a higher level of generalized inflammation that places them at risk for VTE.”
Just how serious is the risk of VTE to patients post-discharge? A 2012 study in the Journal of Hospital Medicine found that in one group of discharged patients, just over half of VTE events in a group of medically ill patients occurred after discharge. The study found that the risk of VTE in post-discharge medical patients remained high during the first 19 days after admission.
Dr. Shah conducted his own research looking at three years of data on patients who came to Northwestern with a diagnosis of DVT or PE from the emergency room over a three-year period. Those data, which were presented in an abstract at an SHM meeting, found that half those patients had been discharged within the last 90 days and that 25% had been discharged in the previous 30 days.
VTE risk factors
When it comes to risk factors for VTE in medically ill patients, Dr. Merli says the most significant ones include age greater than 60, immobility, previous VTE and cancer. “When I look at the medically ill hospitalized patient,” he explains, ”it’s the age of the patient, degree of immobility, co-morbid conditions, and underlying etiology that resulted in the hospitalization that are important in my decision making.
He adds that pinpointing VTE risk in the medically ill isn’t always straightforward. “The medically ill patient is a little more complex because there are multiple factors.”
One thing is usually clear with these patients, however: Their risk isn’t necessarily reduced when they go home. Consider the patient with stage 4 heart failure who is deemed high risk. “Does that risk change when the patient leaves?” Dr. Merli asks. “Does the heart failure return to normal? No, their heart failure went from stage 4 to stage 3, but they’re still in controlled heart failure. Their age didn’t change, and their immobility remain remains limited.”
Growing body of research
Because so many medically ill patients face a risk of VTE, a growing body of research has examined DOACs for extended prophylaxis. Earlier this year, the FDA used data from the MAGELLAN trial to approve the DOAC rivaroxaban for extended prophylaxis. In 2017, the agency approved betrixaban, another DOAC, for a similar indication, based on data from the APEX trial.
The good news is that data from MAGELLAN showed similar bleeding risks (about 1%) in both the rivaroxaban arm and the enoxaparin/placebo arm. Dr. Merli, however, predicts that concerns about bleeding will likely persist among hospitalists.
“Hospitalists are not convinced that the risk of bleeding isn’t greater than the benefit of preventing thrombosis in medically ill patients,” he says. “I suspect most clinicians think the bleeding risk outweighs the benefit, and will not extend VTE prophylaxis for home use.”
Another factor may give hospitalists pause in using rivaroxaban for VTE prophylaxis: While DOACs have commonly been approved primarily to target existing indications for prevention of VTE in orthopedic surgery, treatment of VTE and atrial fibrillation, rivaroxaban and betrixaban are the only DOACs approved for VTE prevention in the hospitalized medically ill for inpatient and extended prophylaxis.
“This is a completely new indication of extended therapy for DOACs,” Dr. Shah explains. “We don’t anticoagulate patients leaving the hospital except for orthopedic patients. The challenge we’re going to face is educating providers on doing something they’re never done in the past with an anticoagulant.”
What will it take for hospitalists to embrace the newest data on DOACs in extended prophylaxis? Dr. Merli believes that as hospitals transition over to DOACs for inpatient prophylaxis, in part because of the shortage of heparin, physicians will become more comfortable with using rivaroxaban post-discharge. “The first step will be conversion to use in the inpatient setting.”
An important next step will be addressing the transition of care surrounding extended VTE prophylaxis so hospitalists and PCPs are on the same page. “The transition of care is a huge challenge for this population,” Dr. Merli says. “The data on the effects of extending prophylaxis are good, but the question is how we get hospitalists and primary care physicians to work together at the transition to the next level of care. The transition of care piece is really not very well done for thrombotic disorders.”
Dr. Merli points out that the Society of Hospital Medicine is launching an eight-hospital study looking at the safe and effective transition of care for patient hospitalized with VTE.
Finally, Dr. Merli says another key to increasing extended prophylaxis will be the creation of performance measures that collect and report data on hospitals’ use of prophylaxis. “Everybody does fantastic on heart failure prevention and readmissions,” he says. “In part, that’s because we developed a transition of care model. But that requires resources.”