James has been your patient for 20 years and his stroke came as a total surprise to everyone, including you. He is only 52 years old and he is currently in a state of disbelief. “How could this happen to me?” He knew that older people had strokes, but it was never anything he thought could happen to him, especially before the age of 60. One thing is certain: he wants to do everything he can to make sure it doesn’t happen again and he’s looking at you for a lot of help.
An article in the New England Journal of Medicine on “Secondary Prevention after Ischemic Stroke or Transient Ischemic Attack” provides an excellent review of what you need to do.(1)
What Are the Odds?
It is important that you and your patient start working on secondary prevention as soon as possible. Most people and even many doctors don’t realize that the risk of a recurrent stroke is as high as 12.8% in the first week after a TIA (transient ischemic attack) (2). If you do not change certain lifestyle factors, the risk of a second stroke within the next 5 years can be as high as 30%. Waiting is not an option. A large study carried out in 22 countries identified 10 risk factors that account for 90% of all strokes (in no particular order). (3)
- High blood pressure
- Waist size-obesity
- Poor diet
- Lack of physical activity
- Diabetes Mellitus
- Excessive alcohol consumption
- Psychosocial stress/depression
- Atrial fibrillation or previous heart attack
- High cholesterol
Fortunately, additional studies estimate that 80% of recurrent strokes can be prevented with diet modification, exercise, blood pressure control, cholesterol reduction with the help of statins and treatment with anti-platelet medications.(4) Ideally, you would focus on every possible risk factor. However, at first that can be overwhelming. Start with the big three.
The Big Three
Blood Pressure Control
Hypertension is the single most common cause of stroke and it is estimated that 75 million people—that’s one-fourth of the United States population—have high blood pressure. When you control blood pressure through the use of antihypertensive medication you reduce the risk of a first stroke by 32%. In patients who have had a TIA or a stroke, treatment of high blood pressure reduces the risk of a recurrent stroke by 28%. (5) The exact blood pressure number you need to shoot for is a decision unique to each person and should be made taking into account their age and the unique circumstances of your patient. .
Statins to Lower Cholesterol
Statins have revolutionized the treatment of high cholesterol. They have also been touted for the treatment of many other disorders, but the facts are clear: statins reduce the risk of a recurrent stroke by 25%. (6). Statins work by
- Lowering the overall risk of stroke
- Slowing the progression of atherosclerosis
- Decreasing the “stickiness” of platelets in the blood
- Decreasing heart disease and myocardial infarction and therefore reducing the risk of blood clots traveling from the heart to the brain
Statins lower LDL— our “bad cholesterol.” Over the last few years doctors have steadily lowered the ideal level for LDL in people who are at risk for stroke or have an elevated LDL. The latest goal is less than 70mg/dl. The lower we drive the LDL level, the greater we can reduce the risk of a stroke or myocardial infarction.
Most physicians now add statin therapy to their discharge instructions for stroke survivors. An exception may be hemorrhagic strokes.
Commonly referred to by patients as “blood thinners,” anti-platelet agents attack the tiny platelets and make the blood less sticky and less likely to form blood clots. They prevent the formation of clots in arteries in the brain or heart. More good news—anti-platelet agents reduce the risk of a recurrent stroke by 25%.
The most commonly used medication is low-dose aspirin (25mg to 325mg), which is just as effective as higher doses and has fewer side effects. Clopidogrel (Plavix®) and aspirin plus dipyridamole (Aggrenox®) both decrease the risk of recurrent stroke to the same degree as aspirin. All three are acceptable forms of treatment, but low dose aspirin is much less expensive. A study looked at whether the combination of aspirin and clopidogrel might be more effective, but the study was discontinued because of excessive episodes of bleeding in the brain and death. As a result, combination therapy is recommended for only 21 days after mild stroke or TIA, but may be continued for 90 days in patients with intracranial stenosis. After that time the patient should be switched to aspirin alone. (7-8)
Many patients ask the obvious question, “Should I take a daily low dose aspirin even I have not had a stroke or heart attack?” The less than satisfying answer is, “It depends.” As a rule the answer is “no,” unless you have multiple risk factors that put you at high risk for stroke or heart disease.
Break the Old Habits
For James, there is lots of good news. 25% seems to be the magic number. If he controls his blood pressure, takes statins and anti-platelet agents, he can decrease his risk of another stroke by at least 25%. If you both start working on the longer list of 10 risk factors you can drive that number much lower.
It is easy for patients to revert back to old habits and continue to put themselves at a high risk for another stroke or heart attack. Take a few moments, meet with them and their families to start changing the way they live—it just may save their life.
- Davis SM, Doinnan GA: Clinical Practice. Secondary prevention after ischemic stroke or transient ischemic attack. NEJM 2012; 366:1914-22.
- Giles MF, Rothwell PM: Risk of stroke early after transient ischemic attack: a systemic review and meta-analysis. Lancet Neurol 2007; 6:1063-72.
- O’Donnell MJ, Xavier D, et al: Risk factors for ischemic and intracerebral hemorrhagic stroke in 22 countries: a case control study. Lancet 2010; 376:112-123.
- Hackam DG, Spence JD: Combining multiple approaches for the secondary prevention of vascular events after stroke: A quantitative modeling study. Stroke 2007; 38:1881-1885.
- Progress Collaborative Group: Randomised trial of a perindopril based blood pressure lowering regimen among 6105 individuals with previous stroke or transient ischemic attack. Lancet 2001; 358 1033-41.
- Collins R, Armitage J, et al: Effects of cholesterol lowering with simvastatin on stroke and other major vascular events in 20536 people with cerebrovascular disease or other high-risk conditions. Lancet 2004; 363:757-67.
- Xie W, Zheng F et al.: Long term antiplatelet mono and dual therapies after ischemic stroke or transient ischemic attack: Network Meta-analysis. J Am heart Assoc; August 24, 2015.
- Gouya G, Arrich J. et al: Antiplatelet treatment for prevention of cerebrovascular events in patients with vascular diseases: A systematic review and meta-analysis; Stroke 2014; 45:492-503
By Richard C. Senelick MD
Dr. Senelick is a neurologist who specializes in neurorehabilitation. For 30 years he was the medical director of HealthSouth Rehabilitation Institute of San Antonio (RIOSA) and is currently the editor- in- chief of HealthSouth Press.