Anticoagulation services: quality improvement direction pursuing a certification process. Anticoagulation Provider Certification Working Group.

There is still in a certification process for anticoagulant therapy providers. The primary, and certainly most important, goal is to improve patient care. Defining measurable competencies to which the anticoagulation provider is made accountable is but one mechanism to help improve quality in patient care. Great improvements have been achieved in the field of anticoagulation. For example, determining optimum intensity levels, for the traditional as well as the newer indications for treatment, have yielded greater efficacy and safety. Additionally, the acceptance of the INR reporting system has greatly reduced hemorrhagic and thromboembolic complications. However, the process of care, that is, how patients are managed and by whom, remains a variable that is difficult to quantify and measure. Anticoagulation providers are comprised of professionals from three major disciplines, namely, medicine, nursing, and pharmacy. This multidisciplinary approach enriches the quality of care for patients. However, this very fact presents a dilemma when seeking an appropriate certifying body. Nevertheless, keeping quality patient care as the primary focus, a multidisciplinary group has developed a body of knowledge that is unique to anticoagulant and antithrombotic therapies. The foundation of this project stems from the Fourth American College of Chest Physicians Consensus Conference on Antithrombotic Therapy and the recently published paper by Ansell et al. on consensus guidelines for coordinated outpatient oral anticoagulation therapy management. This work in progress includes a mission statement and outlines five major knowledge domains along with measurable competencies for each section. This effort will help standardized the process of care across the country.

International Normalized Ratio (INR): an improved way to monitor oral anticoagulant therapy.

Oral anticoagulant therapy may be inappropriately managed and thus potentially place the warfarin-treated patient at an increased and unnecessary risk of bleeding or thromboembolic complications. This management issue is largely due to variations in measuring the pro-thrombin time. These variations may lead to an inaccurate and inconsistent assessment of the patient's true level of anticoagulation. The adoption of the International Normalized Ratio (INR) is recommended because it provides a mathematical correction for one of these variations--specifically, the thromboplastin reagents currently used. This article focuses on the appropriate use of the INR to monitor patients' responses to warfarin sodium therapy. It is vitally important for health care providers to be aware of the INR, to use it in clinical practice, and to interpret it correctly.

Effect of low-intensity warfarin anticoagulation on level of activity of the hemostatic system in patients with atrial fibrillation. BAATAF Investigators.

BACKGROUND AND PURPOSE: The Boston Area Anticoagulation Trial for Atrial Fibrillation (BAATAF) demonstrated that low-intensity warfarin anticoagulation can, with safety, sharply reduce the rate of stroke in patients with nonvalvular atrial fibrillation. The beneficial effect of warfarin was presumably related to a decrease in clot formation in the cardiac atria and subsequent embolization. METHODS: To assess the effect of warfarin therapy on in vivo clotting in patients in the BAATAF, we measured the plasma level of prothrombin activation fragment F1+2. One sample was obtained from 125 patients from the BAATAF; 62 were taking warfarin and 63 were not taking warfarin (control group). RESULTS: The warfarin group had a 71% lower mean F1+2 level than the control group (mean F1+2 of 1.57 nmol/L in the control group compared with a mean of 0.46 nmol/L in the warfarin group; P < .001). F1+2 levels were higher in older subjects but were consistently lower in the warfarin group at all ages. Fifty-two percent of patients in the control group were taking chronic aspirin therapy at the time their F1+2 level was measured. Control patients taking aspirin had F1+2 levels very similar to control patients not taking aspirin (mean of 1.52 nmol/L for control patients on aspirin compared with 1.64 nmol/L for control patients off aspirin; P > .1). CONCLUSIONS: We conclude that prothrombin activation was significantly suppressed in vivo by warfarin but not aspirin among patients in the BAATAF. These findings correlate with the marked reduction in ischemic stroke noted among patients in the warfarin treatment group observed in the BAATAF.

The effect of aspirin on the risk of stroke in patients with nonrheumatic atrial fibrillation: The BAATAF Study.

Recent randomized trials have consistently demonstrated the marked efficacy of warfarin in reducing the risk of stroke caused by nonrheumatic atrial fibrillation. These trials have provided conflicting evidence on the effect of aspirin. We report the aspirin analysis from the BAATAF study, a trial in which control patients could choose to take aspirin. There we two strokes in 446 person-years with warfarin (annual rate of 0.45%); eight strokes in 206 person-years with aspirin, most at 325 mg per day (annual rate of 3.9%); and five strokes in 271 person-years among patients taking neither aspirin nor warfarin (annual rate of 1.8%). Simultaneously controlling for the other significant determinants of stroke in the BAATAF study (age, mitral annular calcification, and clinical heart disease), the relative rates (95% confidence interval) of stroke were: (1) warfarin/aspirin = 0.135 (0.029 to 0.64); (2) aspirin/(no aspirin and no warfarin) = 1.95 (0.64 to 5.97); and (3) warfarin/(no aspirin and no warfarin) = 0.263 (0.051 to 1.36). Our "treatment received" analysis argues that warfarin is strikingly more effective than aspirin in preventing stroke in nonrheumatic atrial fibrillation.

The impact of long-term warfarin therapy on quality of life. Evidence from a randomized trial. Boston Area Anticoagulation Trial for Atrial Fibrillation Investigators.

To determine the effect of long-term warfarin sodium therapy on quality of life, we surveyed 333 patients participating in a randomized, controlled trial of warfarin for the prevention of stroke in nonrheumatic atrial fibrillation. No significant differences between warfarin-treated and control patients were found on well-validated measures of functional status, well-being, and health perceptions. For example, the summary score for health perceptions was 68.8 in the warfarin-treated vs 66.6 in the control group (scale of 0 to 100; 95% confidence intervals for the difference, -1.6 to 6.0). In contrast, patients taking warfarin who had a bleeding episode had a significant decrease in health perceptions (-11.9; 95% confidence interval, -4.1 to -19.6). Warfarin therapy is not usually associated with a significant decrease in perceived health, unless a bleeding episode has occurred. Negative effects of warfarin treatment on health perceptions may be balanced by confidence in its protective effects.

Atrial enlargement as a consequence of atrial fibrillation. A prospective echocardiographic study.

To test the hypothesis that atrial enlargement can develop as a consequence of atrial fibrillation, left and right atrial dimensions were measured echocardiographically at two different time points in patients with atrial fibrillation. Patients were selected who initially had normal atrial sizes and who had no evidence of significant structural or functional cardiac abnormalities other than atrial fibrillation either by history or two-dimensional and Doppler echocardiography. Fifteen patients were studied (12 men and three women; mean age, 67.3 years). Average time between studies was 20.6 months. Three orthogonal left atrial dimensions and two right atrial dimensions were measured, and all were found to increase significantly between studies. Also, highly significant increases in calculated left atrial volume (from 45.2 to 64.1 cm3, p less than 0.001) and right atrial volume (from 49.2 to 66.2 cm3, p less than 0.001) were observed. The relative extents of left and right atrial volume increase did not differ, and left ventricular size did not change significantly between studies. These results indicate that atrial enlargement can occur as a consequence of atrial fibrillation. The maintenance of sinus rhythm, therefore, may prevent atrial enlargement and its adverse clinical effects.

The dilemma of cerebral vasospasm treatment.

Symptomatic cerebral vasospasm following subarachnoid hemorrhage from ruptured saccular aneurysms is a major factor in the neurologic deterioration of these patients. Many therapeutic interventions have been proposed to treat this cerebral vasospasm; however, the most effective means to counteract this development still eludes the health care team. Faced with this dilemma, recent investigators have examined subarachnoid blood as visualized on CT scan. These studies have enabled them to identify those patients most at risk for developing symptomatic cerebral vasospasm. Predicting the occurrence as well as the severity and location of symptomatic cerebral vasospasm will facilitate early implementation of preventative measures. This knowledge may help to minimize the frequent unfavorable outcomes following subarachnoid hemorrhage and the subsequent development of vasospasm. The neuroscience nurse can apply this information to the clinical setting by being able to identify those patients at high risk for developing symptomatic cerebral vasospasm, to improve assessment skills, and to plan and anticipate the patient's future needs. A case study is offered to illustrate how this is accomplished.