Stroke is the leading cause of disability in the United States and the third leading cause of death. It is therefore an important factor in both health care budgets and the emotional economy of families. Although much is known about modifying risk factors to prevent first stroke (primary prevention) or recurrent stroke (secondary prevention), too often a consistent, systematic assessment of stroke risk factors is lacking in clinical practice.
Underutilization of stroke risk assessment strategies creates a gap between existing evidence and actual practice. "This gap is especially concerning for patients after they have already had a stroke, because of the risk of recurrent stroke and the increased likelihood of certain medical disorders," explains Kelly D. Flemming, M.D., a Mayo Clinic neurologist who is investigating the use of new clinical models for stroke prevention.
Among the serious consequences of stroke:
Secondary stroke prevention is well suited to a new model of care aimed at preventing long-term morbidity and mortality for two main reasons:
|Stroke Risk Factor Strategies|
|Risk Factor||Clinical Intervention|
|Hypertension control||Physicians manage prescription medications (e.g., diuretics, ACE inhibitors) and nurses educate on lifestyle changes. Antihypertensive medications are considered for every patient with ischemic stroke or transient ischemic attack.|
|Cholesterol level control||Physicians evaluate the need for statin drugs in patients with atherosclerotic stroke.|
|Tobacco cessation counseling||Interventions range from patient education to outpatient and inpatient treatment|
|Weight loss, increase exercise, metabolic syndrome||Educating, motivating and supporting dietary changes and daily activity levels|
|Diabetes mellitus||Tight control of diabetes may not reduce stroke risk. Important in these patients, however, are tight blood pressure control and cholesterol lowering, with a goal of <70 mg/dL.|
|Atrial fibrillation||Abnormal cardiac contractions can lead to thrombus formation. The physician evaluates the need for warfarin therapy, which can reduce risk of stroke by 70 percent to 80 percent in the highest risk groups.|
|Asymptomatic carotid artery stenosis||Selection of patients for carotid endarterectomy or carotid angioplasty with stenting is highly individualized. Many factors should be considered.|
|Elevated homocysteine level||Data are not conclusive that lowering this amino acid reduces stroke. In young patients with early atherosclerosis, however, screening for this amino acid and treatment with vitamin B6, vitamin B12 and folate may be considered.|
|Sleep apnea||If oximetry results suggest sleep apnea, the physician may order a polysomnogram for definitive diagnosis. Continuous positive airway pressure or other treatments are available.|
|Hormone therapy||Research on this topic is changing, but patients with history of stroke should be advised against hormone therapy without a medically compelling reason.|
|Stress||Nurses educate on the negative effects of stress and offer ways to improve stress levels.|
To help close the evidence-practice gap in stroke prevention — and to prepare for the changing demographics of stroke as the population ages and more people are at risk of stroke — Mayo Clinic in Rochester, Minn., is evaluating a physician-led, nurse-assisted stroke management program.
The program is currently being assessed for its long-term effectiveness to manage cerebrovascular disease. It aims to achieve with stroke the success that cardiac rehabilitation clinics have obtained with secondary prevention of coronary heart disease. Through this approach, neurologists play a leading role in meeting the emerging demand for preventive stroke services:
The neurologic team can closely collaborate with the patient's primary care provider to optimize management.
Data for similar nurse-assisted, physician-led clinics such as the Stanford Coronary Risk Intervention Project have shown that this approach can improve patient outcomes while reducing use of medical resources.
In the Mayo Clinic secondary stroke prevention initiative, nurses guided by physicians provide intensive multiple risk factor reduction counseling and support in the outpatient setting. This outpatient clinic is the next step in the continuum of care of the stroke patient, after acute treatment and evaluation have been provided in the Saint Marys Hospital inpatient stroke center and, if needed, a stay in the stroke rehabilitation unit.
The goals of this ongoing outpatient care are to support lifestyle changes known to reduce the risk factors of stroke, to prescribe appropriate medications to assist in reducing these risk factors, and to enhance use of appropriate antithrombotic agents.