Stroke out the numbers

Originally published in The Ottawa Citizen December 14, 2004

According to the Heart and Stroke Foundation of Canada, stroke accounted for 20 per cent of the 79,389 deaths from cardiovascular diseases in 1998. The Canadian statistics are indeed disconcerting, reflecting tremendous suffering and financial burdens to families and society.

There are 40,000 to 50,000 strokes a year and 300,000 people are living with the debilitating consequences — loss of independence, paralysis, cognitive impairment, dementia, recurrent pneumonias and skin ulcers, among others.

The outcome of a first stroke is alarming: 15 per cent of stroke victims will die, 10 per cent will completely recover, 25 per cent will recover with a minor impairment or disability, 40 per cent will be left with a moderate to severe impairment, and the remaining 10 per cent will require long-term care.

Twenty per cent of people who survive their first stroke will succumb to another stroke within two years. More women than men die each year from stroke. One can regrettably assume this number will continue to increase in the future.

Strokes cost the Canadian economy about $2.7 billion a year and account for about three million days in hospital each year.

The incidence of stroke can be reduced with a good knowledge of prevention strategies that are proven to be effective. There are certain risk factors that cannot be modified, like older age, male sex, non-white race, a family history of stroke or heart attack, and the presence of pre-existing coronary heart disease or congestive heart failure.

Most risk factors are associated with the buildup of plaques and clots within the arterial network. The areas that are prone to formation of these clots include the carotid arteries in the neck, the coronary arteries, and areas around the heart valves.

What are some of the modifiable factors that you can proactively incorporate into your life?

Lifestyle modifications are assumed to be of benefit. Although there have not been many randomized clinical trials that have studied the effect of obesity, lack of regular exercise, alcohol intake and smoking on stroke risk, there is indeed great observational data that supports the modification of these factors. Indeed, the elevated stroke risk in smokers will disappear within five years of quitting — it is never too late to stop.

The major modifiable risk factors include: high blood pressure (hypertension), diabetes, elevated cholesterol levels (hypercholesterolemia), and a heart beat irregularity called atrial fibrillation.

– A plethora of high-quality randomized placebo-controlled trials indicates that lowering blood pressure in hypertensive patients decreases the relative risk of stroke from bleeding (hemorrhagic stroke) and arterial clots that block oxygen-rich blood to the brain (ischemic stroke) by 35 to 45 per cent within three years of starting therapy. This risk reduction even applies to people older than 80.

Of the group of 4.5 million Canadians with hypertension, only 16 per cent are treated and controlled. Twenty three per cent are treated and uncontrolled. Most worrisome are the 19 per cent that is aware they have hypertension but remain untreated, and that the remaining 42 per cent are unaware that they have hypertension. You cannot feel or sense this disease. It cannot be seen, hence many people suffer a terrible fate that seems to come out of the blue.

There are many effective medications like thiazide diuretics and angiotensin-converting enzyme inhibitors (ACEs) to treat hypertension. New studies continue to show the benefits for heart health and stroke prevention.

High cholesterol levels play a major role in heart disease and, by extension, the development of stroke risk. Although many studies focus on the effect of cholesterol on the heart, the information has been used to determine that cholesterol reduction does reduce stroke risk. Studies are ongoing to help to improve treatment guidelines.

Cholesterol-lowering medications like the statins (Crestor, Lipitor, Zocor, Pravachol and Mevacor) are effective and are offered to patients with multiple risk factors.

Type 2 diabetes often occurs concurrently with hypertension and elevated blood cholesterol. Tight control of sugar levels will reduce the risk of damage to the small arteries or microvasculature.

Atrial fibrillation describes the unco-ordinated contractions of the walls of the left atrium of the heart. It can cause the formation of clots within this chamber. Pieces of these clots or emboli can travel to the brain. The death rate for people with this condition is double that of people without atrial fibrillation. For those with clots near the valves, this risk increases to 17 times normal, controlling for age and sex.

Your doctor can offer you a wealth of information about stroke prevention. You can change your history.

More information is available at the Heart and Stroke Foundation of Canada website

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