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Keeping blood pressure under control reduces risk of second stroke

Posted By Howard LeWine, M.D. On March 28, 2014 @ 12:41 pm In Heart Health,Hypertension and Stroke | Comments Disabled

For anyone who has had a stroke, working to prevent a second one should be Job No. 1. Keeping blood pressure under control is an important part of that job.

A study published yesterday in the journal Stroke shows that good blood pressure control after a stroke cuts the chances of having a repeat stroke by more than half. But it also brought some bad news: less than one-third of stroke survivors in the study managed to get their blood pressure under control.

In the report, researchers from the University of California crunched data from the Vitamin Intervention for Stroke Prevention (VISP) Trial. This trial had found that taking a daily pill that contained high doses of three B vitamins — folic acid, B6, and B12 — did nothing to prevent a second stroke. But the data collected as part of this trial has been a great resource for other research.

The volunteers in VISP had their blood pressure checked in a doctor’s office multiple times during the course of the two-year trial. Only 30% of the volunteers were able to keep their blood pressure in a good range (under 140/90) on 75% or more of the measurements. Meanwhile, more than one-third of the participants had controlled blood pressure less than 25% of the time.

The odds of having a second stroke were directly related to blood pressure control — better control, fewer strokes; poorer control, more strokes. The same held true for the connection between blood pressure control and having a heart attack or dying from heart disease.

Check BP at home

High blood pressure damages artery walls throughout the body. This damage can lead to stroke or heart attack. People who have survived a stroke or heart attack are at very high risk of having another of the same — or the other. The new study in Stroke shows that controlling blood pressure is a good way to reduce that risk.

There are many ways to control blood pressure. One advance that has been extremely helpful is the ability to check blood pressure at home. When the VISP trial ended in 2003, just about the only way to check blood pressure was in a doctor’s office, so the participants had their pressures checked a few times at the beginning of the trial and then once every six months. What happened in between is anyone’s guess. Today, home blood pressure monitors are readily available and relatively inexpensive. Instead of a twice-a-year snapshot, you can now get a more reliable look at your blood pressure. Knowing the numbers is a big step toward controlling blood pressure.

Lifestyle changes for all

Making changes to your lifestyle can help a lot to lower blood pressure or keep it under control. These changes can also help prevent a heart attack or stroke, and can strengthen your body in other ways.

  • Exercise often — at least 30 minutes five times a week. More is better.
  • Lose weight if needed.
  • Eat more fruits, vegetables, and whole grains, and less processed or highly refined food.
  • Cut back on salt.
  • Include foods rich in potassium in your diet (unless you have kidney disease).
  • If you drink alcohol, keep it moderate — no more than two drinks a day for men, no more than one a day for women.
  • Don’t smoke.

Medications may be needed

Many people need medicine in addition to lifestyle changes to lower blood pressure. There are a number of proven options for medications that lower blood pressure. Recent guidelines suggest the following:

  • If you are black and you have normal kidney function, start with a low daily dose of a thiazide-type diuretic (water pill) such as chlorthalidone or hydrochlorothiazide, or a calcium-channel blocker. Another option is a pill that contains low doses of both drug types.
  • If you are not black and you have normal kidney function, start with a low dose of one of these drug types:
    • angiotensin-converting–enzyme (ACE) inhibitor
    • angiotensin-receptor blocker (ARB)
    • thiazide-type diuretic
    • calcium-channel blocker
    • A pill that contains low doses of two different drug types
    • If your kidneys aren’t working as well as they should, your doctor might recommend that you start on a low dose of an ACE inhibitor or ARB (but not both together). These types of drugs help protect the kidneys from further damage.

How low should you go?

Normal, healthy blood pressure is anything under 120/80. For years, people with high blood pressure were urged to get their pressure under 140/90. New recommendations suggest that for some people, it’s okay to let blood pressure drift a bit higher, to under 150/90. The thinking is that driving it down further could cause problems like feeling lightheaded when standing up or getting out of bed, which could cause falls. And lower pressure usually means more medications, which can cause harmful side effects.

The new Stroke study and others provide strong evidence that keeping blood pressure under 140/90 is the best goal for stroke prevention. I plan to use a blood pressure goal of less than 140/90 for my most of my patients. The exceptions will be older individuals with high blood pressure when sitting or lying down but low blood pressure when they stand up.

If you have high blood pressure, aim for getting at least 75% of your blood pressure readings under 140/90 — as long as you don’t get dizzy when you stand up. If you do, or your blood pressure continues to stick above 140/90, let your doctor know.

Related Information: Stroke: Preventing and treating “brain attack”


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