Commonality of stroke can be prevented, says new AHA/ASA guidelines

To better understand the onset of a first stroke, members of the American Heart Association’s Stroke Council and the American Stroke Association, worked to assess what common factors—either modifiable or non-modifiable—puts patients most at risk.

“This is a fairly complete update of the guidelines published in 2006,” Larry B. Goldstein, MD, chairman of the statement writing committee, told Cardiovascular Business News.

“We have had a fairly significant 30 percent decline in stroke-related mortality in this country. Much of that reduction, if not most of it, was related to improved prevention,” said Goldstein, who is director of the Duke Stroke Center at the Duke University Medical Center in Durham, N.C.

Along with other healthcare organizations, the AHA set the goal of decreasing cardiovascular and stroke mortality by 25 percent over 10 years. Between 1996 and 2006, the death rate for stroke fell by 33.5 percednt, with the total number of stroke deaths declining by 18.4 percent. The goal of a 25 percent reduction was exceeded in 2008.

Almost 795,000 people in the U.S. experience stroke annually, which has resulted in 134,000 deaths annually. And even though the rates of stroke death declined by 33.5 percent between 1996 and 2006, the incidence of stroke, stroke-related hospitalizations and costs continue to rise.

To help understand how to curb these high numbers, Goldstein and colleagues evaluated multiple factors that have the potential to increase the risk of a stroke and outlined preventive strategies to reduce patient risk. The guidelines were published in the Dec. 2 issue of Stroke.

The authors looked at both modifiable—hypertension, cigarette smoke exposure, diabetes, atrial fibrillation (AF)—and non-modifiable—sex, low birth weight, race/ethnicity and genetic predisposition—factors that have been previously outlined to increase a patient’s risk of stroke.

Goldstein said that the new set of guidelines addresses hemorrhagic stroke in addition to ischemic stroke, a series of diseases and the role that preventive tools can help decrease risk.

“There are two sets of messages,” Goldstein offered. “One is for the general public and another is for the healthcare practitioner. I think it’s particularly important to know that people need to take charge of their own lives. A lot of the reduction in stroke risk that we are seeing is likely due to improved risk factor management from the standpoint of lifestyle changes.

"Doing things like not smoking and avoiding secondhand tobacco smoke, exercising regularly and following a diet that’s rich in fruits and vegetables … can account for an 80 percent reduction in the risk of stroke,” Goldstein noted.

“The document itself goes through a variety of well documented and well established modifiable risk factors, as well as a series of risk factors that aren’t necessarily modifiable but that people should know about because they do put them at an increased risk.”

For example, for the modifiable condition of hypertension, which can cause cerebral infarction and intracranial hemorrhage, the authors recommended that lifestyle modifications for patients with elevated blood pressure should be undertaken, and in nonhypertensive patients with an elevated blood pressure (120 mm Hg to 139 mm Hg systolic or 80 mm Hg to 89 Hg diastolic).

While previous studies have shown that first-line drug therapy including beta-blockers, ACE inhibitors and thiazide diuretics can help reduce blood pressure, the researchers wrote that “although the benefits of lowering blood pressure as a means to prevent stroke are undisputed, there is no definitive evidence that any class of antihypertensive agents offers special protection against stroke.

“Hypertension remains the most important well-documented, modifiable risk factor for stroke, and treatment of hypertension is among the most effective strategies for preventing both ischemic and hemorrhagic stroke,” the authors wrote.

The guidelines recommend the following for the other modifiable conditions:

• Diabetes: A comprehensive program that includes tight control of hypertension with ACE inhibitors or ARBs reduces risk of stroke in persons with diabetes. The authors recommended that patients with type 1 or type 2 diabetes should undergo blood pressure control to reduce the risk of cardiovascular events. In addition, the committee recommended the treatment of hypertension for diabetic adults with an ACE inhibitor or ARBs and statins for those with additional risk factors.
• Dyslipidemia: Research has outlined an association between cholesterol and ischemic stroke. Therefore, the committee recommended treatment with HMG-CoA reductase inhibitor medication in addition to therapeutic lifestyle changes. Additionally, the authors said that fibric acid derivatives should be considered for patients with hypertriglycceridemia and niacin for patients with low HDL cholesterol or elevated lipoprotein.
• Atrial Fibrillation: The researchers recommended: active screening for AF in patients over the age of 65 (pulse taking followed by an ECG), an adjusted dose of warfarin for patients with nonvalvular AF, antiplatelet therapy with aspirin for low-risk and moderate-risk AF patients, dual-antiplatelet therapy with clopidogrel and aspirin for high-risk AF patients and aggressive blood pressure management in addition to antithrombotic prophylaxis in elderly AF patients.
• Physical Inactivity: Sedentary behavior can lead to adverse health events and increase the risk of stroke. The committee recommended increased physical activity including the engagement of 150 minutes per week of moderate intensity or 75 minutes per week of vigorous intensity physical activity.

“As medical research progresses, these new guidelines incorporate the latest information we have available,” Goldstein offered.

The guidelines also outline the potential role the emergency department (ED) has at the beginning of treatment and its potential to identify and refer patients for treatment who are identified with stroke risk factors.

“Millions of Americans don’t have healthcare insurance and they get their healthcare on an emergent basis or urgent basis by going to EDs and that’s a potential time where additional factors that aren’t necessarily the cause of the visit can be identified—high blood pressure or AF,” said Goldstein. He said that the ED is an important setting that can provide patients treatment to reduce their risk of stroke and offer disease prevention strategies like screening, intervention, education and referral.

In addition, Goldstein offered that the use of risk assessment tools such as the Framingham stroke risk assessment tool or the AHA’s Life’s Simple 7 can provide patients with a free, easy tool to provide assessment of risk and tools that can help monitor important body changes.

“Effective primary, secondary and tertiary stroke preventions can occur in EDs, but significant healthcare organizational changes are required,” the authors wrote. “These changes must address limitations of healthcare provider health promotion training, program funding, resource availability and lack of referral resources.”