Last month we wrote about the signs and symptoms of a stroke as well as the new ways to treat an acute stroke. There has been remarkable progress against this life-threatening and/or potential life-changing event, but more needs to be done and undoubtedly will be done in the future.
What are the Numbers?
First and foremost for readers of this column is the fact that age plays a most important part in risk. About 75 percent of strokes occur in people 65 or older. In other words it is an increasing problem the older we get. It has been estimated that the chance of having a stroke double every decade after 55.
Stroke afflicts about 800,000 people a year and is estimated to occur at the rate of one American every 40 seconds. About three-fourths of the annual strokes are first-time strokes and the other quarter are recurrent. In other words most strokes are first-time episodes.
Stroke is the third leading cause of death among Americans. It kills about 140,000 people a year. However, only about 18 percent of strokes are fatal, and last month we emphasized the importance of getting immediate help when a stroke occurs. Since most people will survive a stroke, the amount of residual damage is in part related to how quickly the stroke is treated. (See last month’s column.)
Because so many people survive their stroke(s), it is the leading cause of long-term disability in this country. Thus, the name of the game needs to be prevention.
Risk Factors for Stroke
Table 1 lists the proven risk factors for stroke. There are some factors that you can control and or eliminate. Smoking is the prime one. Current smokers double their risk for ischemic stroke (the most common of strokes) over non-smokers with other similar risk factors Hypertension or high blood pressure is another treatable risk factor that with good medical care can be controlled. Diabetes, too, is associated with ischemic strokes and if the diabetes is well controlled the risk from it is minimized. The fairly common heart arrhythmia, atrial fibrillation, is associated with a five-fold higher incidence of stroke than people without it. If you have atrial fibrillation, your physician may have or may want to put you on an anticoagulant to prevent clot formation in the heart that can embolize or flow to the brain. Age is a major risk factor as mentioned above. The older we are the more risk we have of incurring a stroke.
Table 1: Risk Factors for Stroke
- High blood pressure
- Tobacco use (second hand, too)
- High cholesterol
- Physical inactivity and obesity
- Carotid and other arterial disease
- Atrial fibrillation and other heart diseases
- Certain blood disorders (such as sickle cell disease)
- Excessive alcohol ingestion
- Drug abuse (cocaine)
- Increasing age*
- Gender (male more common)*
- Heredity and race (family history and African American race)*
- Prior stroke*
* These factors are not controllable or treatable
Calculating Your Own Stroke Risk
Learning your personal stroke risk can be done by simply going to the American Heart Association’s Webpage. Every reader should do this and discuss the results with your physician. (Before going to the Website be sure to have a record of recent blood pressure and blood lipid results, and when on the Website be sure to click on the small box entitled “Download CV Risk Calculator.”) If your risk is greater than 10 percent you need to discuss primary stroke prevention with your doctor.
Much has been learned about stroke as well as other vascular related problems like heart attack. Since heart attack and ischemic strokes are both related to interruption of blood flow to the heart and brain, respectively, some of the strategies for prevention of both are the same. These include, controlling blood pressure if hypertensive, blood glucose if diabetic, and elevated cholesterol to prevent atherosclerosis which can obstruct blood flow to critical arteries. Related to these are diet and exercise: It is important to engage in moderate to vigorous exercise regularly (3 - 4 or more times a week) and to eat a diet free of fat and other cholesterol-rich foods, but high in fruits and vegetables. A Mediterranean diet supplemented with nuts should be considered to reduce stroke risk. The American Heart Diet is lower in fats than the typical Mediterranean diet. (See table 2 asterisk footnote.)
Table 2 contains the major stroke prevention strategies. Some prevention may be specific to you, the patient. If the potential for ischemic stroke is high, aspirin or some other anti-clotting drug may be recommended or prescribed by your doctor.
Surgery is sometimes indicated in patients with transient ischemic attacks if the carotid arteries are found to be significantly obstructed by a painless Doppler artery test.
Table 2: Stroke Prevention Strategies (from the American Heart Association)
- Assess your stroke risk
- Do not smoke
- Engage in moderate to vigorous physical activity 40 min./day 3 to 4 days a week
- Take prescribed “statins” if stroke risk is high (see 1)
- Take daily baby aspirin if 10-year risk is greater than10 percent
- Reduce sodium and increase potassium and eat fruits vegetables (See American Heart Association diet recommendations)
- Maintain blood pressure less than 140/90 mm Hg
- Optimize weight: have BMI less then 25 to 29 kg/m
- Take anticoagulant if atrial fibrillation and certain heart valve lesions are present
- If internal carotid artery stenosis is present consult with physician/surgeon
- Reduce migraine headache frequency with medication
- Have annual influenza vaccination
The Bottom Line
Strokes are increasingly common as we age. They can be fatal but more often are not; however, they can leave us disabled for the remainder of our lives. A great deal has been learned about risk of stroke as we age. Likewise there are a number of well-proven things we can do to lower our risk. Since risk reduction is a combination of medical advice and prescription medicines in some cases with a large dose of our life style decisions, it is important for us to do all we can to prevent this ever-present danger to our healthy aging.