Blood pressure at the high end of normal still a risk for heart disease

Oct 26 2004

If you’re male, and your systolic blood pressure is a little bit on the high side, even though it is still within the normal range, you could be at an increased risk of having heart attack compared to men whose systolic blood pressure is on the low end of normal, Heart and Stroke Foundation researchers say.

In a study presented today in Calgary at the Canadian Cardiovascular Congress 2004, co-hosted by the Heart and Stroke Foundation of Canada and the Canadian Cardiovascular Society, Dr. Gilles R. Dagenais and colleagues found that Quebec men aged 35 to 64 with a systolic blood pressure between 133 and 140 mm Hg were almost twice as likely to have a heart attack or suffer sudden cardiac arrest than men whose systolic blood pressure was less than 125 mm Hg during a 23-year follow-up.

The study, called the Quebec Cardiovascular Study, randomly selected 4836 men from the electoral lists in seven suburbs of Quebec City in 1973, and divided them into five groups according to their systolic blood pressure: less than 125 mm Hg, 125-132 mm Hg, 133-140 mm Hg, 141-152 mmHg, and more than 153. The group with blood pressure in the 133-140 range was considered to be the high-normal group for the purposes of this study.

All 4836 men did not have known heart disease or previous stroke on entering the study. The men were re-evaluated in 1975, 1980, and 1985. Their blood pressure was taken, and they were also given electrocardiograms, blood tests, and large questionnaires to fill out.

In 1990 and 1997, the men responded to more questionnaires about their health. The results of the study showed that the high-normal systolic blood pressure group had a significantly increased likelihood of having angina, heart attack or sudden cardiac arrest. The major risk was the occurrence of fatal heart attack and sudden death.

The take home message here? “Even if you think you’re fine and you have no history of heart or artery disease, get your blood pressure checked, know your numbers, and if necessary, get your systolic blood pressure down to below 125,” said Dr. Dagenais, a cardiologist at the Quebec Heart Institute and professor emeritus at Laval University. “Although further research is required to ascertain the impact of reducing high-normal to optimal blood pressure, reduction in blood pressure can be achieved in the meantime not necessarily by medication but by lifestyle changes.”

Heart and Stroke Foundation spokesperson Dr. George Honos agrees. “Managing your blood pressure is important. Lifestyle changes – losing weight, being physically active, and reducing alcohol consumption - can result in lower blood pressure readings,” says Dr. Honos. “These lifestyle changes, and being smoke free, have a major impact on the risk of developing heart disease or stroke.”

The Heart and Stroke Foundation is a leading funder of heart and stroke research in Canada. Our mission is to improve the health of Canadians by preventing and reducing disability and death from heart disease and stroke through research, health promotion and advocacy.