Pharmacy-run anticoagulation service validated by study

May 15, 2011

A 2-year study found that a pharmacy-directed anticoagulation service boosted the quality and efficiency of care for heparin-induced thrombocytopenia in patients using direct thrombin inhibitors.

Key Points

Pharmacists pushing for greater involvement in patient care have new support from Henry Ford Hospital in Detroit. A 2-year study found that a pharmacy-directed anticoagulation service boosted the quality and efficiency of care for heparin-induced thrombocytopenia (HIT) in patients using direct thrombin inhibitors (DTIs). This may be the first before-and-after study on the safety and efficiency of DTI use by primary care teams compared to a pharmacist-directed anticoagulation service.

"What we have done is to put pharmacists in charge of outcomes for all of our patients on anticoagulation," said James Kalus, PharmD, senior clinical pharmacy manager at Henry Ford and principal investigator on the study. "Pharmacists are uniquely qualified to fill this role. We understand pharmacodynamics and pharmacokinetics and the patient-specific factors that contribute to response. We are just beginning to figure out some of the opportunities to insert the pharmacist at the bedside."

HIT is a recognized problem in the inpatient population, affecting up to 3% of patients on heparin. The actual rate of HIT could be higher as closer patient monitoring tends to uncover more borderline thrombocytopenia associated with heparin use. Patients with confirmed or suspected HIT are typically taken off all heparin products and placed on DTI therapy, either argatroban (Argatroban, GlaxoSmithKline), lepirudin (Refludan, Berlex Labs), or bivalirudin (Angiomax, The Medicines Company).

The problems with all 3 DTIs include an extremely narrow therapeutic window and different organ toxicities, Kalus said. Patients must reach anticoagulation target levels quickly and maintain appropriate therapeutic levels to avoid thromoboembolic complications, amputations, or death.

During the study there were significant improvements in target levels of time to anticoagulation, 6.4 hours versus 18.9 hours (P<.001), and time within therapeutic range, 84.7% versus 64.4% (P<.001), with pharmacists running Henry Ford's anticoagulation service. The study used matched case controls from 2005 to 2007, when primary care teams oversaw all aspects of inpatient anticoagulation therapy.

But the key improvement resulting from pharmacist oversight of anticoagulation might have been an increase in positive HIT assays from 55.4% to 75.6% (P=.0005). That means more patients were treated appropriately and avoided potentially serious adverse events.

Risk stratification of patients

"Avoiding inappropriate treatment of HIT - including times it is unlikely to be HIT - is a lot of what we do," he said. "Risk stratification of these patients, in regard to the pretest likelihood of HIT, may be one of the greatest contributions pharmacists can bring to overall patient safety when utilizing direct thrombin inhibitors."

The Henry Ford study parallels results of the pharmacist-directed anticoagulation service at Sanford USD Medical Center, Gulseth said. "These are the kinds of changes we have seen as we got the anticoagulation program off the ground. It was a positive contribution to include DTI management in this study. Physicians don't have a lot of focused experience with DTIs, and that makes for an easy medical staff buy-in."

Focusing the team

As have many hospitals, Henry Ford long had primary care teams overseeing and treating patients on anticoagulation therapy. In September 2007, the hospital moved to a mandatory pharmacist-directed anticoagulation service. A team of 5 pharmacists took responsibility for all anticoagulation services, including the use of DTIs.

Focusing anticoagulation care in a small team allowed for more uniform training, better standardization of practice, and a concentration of expertise, Kalus said. The focused care team also showed a higher frequency of monitoring than the multidisciplinary teams could provide.

"We started this program before the Joint Commission set the National Patient Safety goal to reduce the likelihood of harm from the use of anticoagulation therapy," Kalus said. "We saw safety issues in our own anticoagulation processes. We needed better coordination of care, better efficiency, better safety, better transition to outpatient care. What we found is that a pharmacist-directed anticoagulation service is a viable approach to standardize the use of DTIs for improving both the efficiency and safety of these medications in the inpatient setting."