Anti-clotting treatment underused at many hospitals

May 19 2004

That’s one of the findings of a study presented today at the American Heart Association’s 5^th annual Scientific Forum on Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke.

Among patients diagnosed with heart attack, 84.3 percent of those studied received aspirin upon arrival at academic hospitals, while just 65.8 percent at community hospitals and 60.2 percent at VA hospitals received it. 

“This is really important because early administration of aspirin improves both the survival and reperfusion rates of the patients,” said Joseph A. Caprini, M.D., director of surgical research at Evanston Northwestern Healthcare and Feinberg School of Medicine.

The only exception was that VA hospitals performed better in using drugs to prevent blood clots in patients with atrial fibrillation, an irregular heartbeat that increases the risk for stroke. 

“Although the guidelines recommend the use of anticoagulants, in actual practice, for one reason or another, the patients aren’t getting the drug,” Caprini said.

“Some of the hospitals in this study were among the best in the country.  We need to bridge the gap between evidence-based guidelines and treatment based on good results in clinical practice.  These differences are not because doctors don’t know enough, it’s because clinical practice is complicated.”

The study compared treatment among 38 hospitals: 21 academic (2,077 patients), 13 community (1,295 patients) and four VA hospitals (406 patients).  The researchers reviewed records for patients diagnosed with atrial fibrillation, heart attack, deep vein thrombosis (blood clot in the leg), hip fracture or patients undergoing total hip or knee replacement surgery.  These conditions increase the risk of blood clots. 

Patients at the academic hospitals were age 64 on average, with 48 percent having two or more other disorders, such as high blood pressure, diabetes, etc.  At community hospitals, patients were age 70 on average and 48 percent had two or more other disorders.  The VA patients were age 69 on average and were more likely (61 percent) to have other diseases.

Researchers found that VA hospitals were more likely to treat atrial fibrillation patients with warfarin, an anticoagulant recommended in the American Heart Association/American College of Cardiology guidelines.  On average the VA hospitals treated 68 percent of these patients with warfarin, while 52.9 percent of patients at academic hospitals and 52.8 percent at community hospitals received it.  Atrial fibrillation patients at VA hospitals had more contraindications to warfarin compared with patients at community or academic hospitals.  There were no differences in the occurrence of contraindications between community and academic hospitals.

“Surprisingly, neither aspirin nor warfarin was prescribed in 20.6 percent of high-risk patients in all of the hospitals,” the researchers said.

Additionally, low molecular weight heparin was used in only about 56 percent of patients with blood clots in the legs or phlebitis, an inflammation of the vessels in the legs.  And, only 27 percent of patients were discharged on bridge therapy, in which the guidelines recommend heparin and warfarin together, despite a 4.1-day reduction in stay.  About one-third of VA hospitals and less than one-third of academic hospitals discharged patients on bridge therapy, versus community hospitals which discharged patients on bridge therapy in about one-fifth of cases.

The researchers also found that doctors weren’t prescribing adequate therapy to prevent blood clots in the legs of high-risk patients undergoing orthopedic surgery for hip and knee replacement.  This treatment was absent in 14 percent of orthopedic surgery patients.  One in 10 patients in the VA system did not receive an anticoagulant to prevent blood clots after surgery, while 6 percent in academic hospitals and 5 percent in community hospitals didn’t receive preventive therapy.

The researchers concluded that a broad sample of American hospitals aren’t following evidence-based guidelines.  “A significant percentage of patients at risk for blood clots and stroke do not receive risk-modifying agents,” they said.

Part of this may be due to an increasing number of older patients with more complex diseases, which put these people at higher risk for side effects from anticoagulant therapy, Caprini said.

“It is becoming clear that system-based approaches, like the American Heart Association’s Get With The Guidelines program, help simplify the complexities of patient care and allow the healthcare team to translate evidence-based guidelines into clinical practice at the point of service,” said Alice K. Jacobs, M.D., incoming president of the American Heart Association.

Co-authors are David J. Ballard, M.D.; Richard C. Becker, M.D.; Thomas M. Hyers, M.D.; Roger Khetan, M.D.; Victor F. Tapson, M.D.; Albert L. Waldo, M.D.; Ann K. Wittkowsky, Pharm. D.; Kevin J. Colgan, M.A.; and Alicia S. Shillington, Ph.D.