1.3M Canadians could benefit if doctors lowered blood pressure targets: study

A study out of the University of Calgary found 1.3 million Canadians could benefit if physicians switch to a lower blood pressure target when treating patients.

Guideline recommends a target systolic blood pressure of 120, not 140

A University of Calgary researcher is recommending doctors adopt a guideline that lowers target systolic blood pressure from 140 to 120 for patients over 50. (Joe Raedle/Getty Images)

A study out of the University of Calgary found 1.3 million Canadians could benefit if physicians switched to a lower blood pressure target when treating patients. 

Traditionally, the target systolic blood pressure for patients over 50 at risk of heart complications was 140 — meaning that anyone above that number should receive treatment, usually medication, with the intention of lowering their blood pressure to a safer level.

The systolic number measures how much pressure blood exerts on the walls of arteries every time the heart beats. 

In 2016, Hypertension Canada changed its guidelines to recommend that number be lowered to 120, following a landmark U.S. study — the Systolic Blood Pressure Intervention Trial (SPRINT) — that found that lowering the systolic target number could reduce deaths by 27 per cent among adults at a high risk of heart disease but without diabetes, stroke or heart failure.

That's 100,000 fewer deaths per year.

A study, released by the Canadian Journal of Cardiology on Friday, found that 1.3 million Canadians would be impacted by the guideline, and 14 per cent of those (182,600 people) would not have been previously considered to have hypertension.

Of the four million Canadians over 50 who are already receiving treatment, nearly 19 per cent, or 754,400 people, could benefit from increased treatment to lower their blood pressure. 

Leading cause of death

"High blood pressure is recognized to be the leading risk factor for heart disease, and heart disease is the leading cause of death in Canada," said the study's author, Dr. Alex Leung, who is an endocrinologist with Alberta Health Services and an assistant professor at the University of Calgary.

"This actually has very large implications that have many downstream effects," said Leung, adding that it doesn't only affect clinical outcomes for patients, but health-care policy at large and resource utilization in the health-care system. 

"That will perhaps also lead to more testing, more health care expenditures for that reason. In terms of benefits, we believe it will reduce the rates of heart disease and death as well."

Guidelines can take years to be adopted

Leung said that while the guidelines were changed in 2016, it can take years for those suggestions to be adopted into practice by doctors and other frontline health-care workers.

"We're looking at about 450,000 health-care professionals that need to learn a new way to treat blood pressure. So it does take some time and it takes a concerted and persistent effort," said Hypertension Canada CEO Angelique Berg.

She said she hopes the new study increases knowledge and awareness of the benefits of lower blood pressure.

"Studies like this are highly beneficial, it helps inform the work that we're doing. It is incredibly far-reaching and really encouraging," she said. 

May is Measurement Month, a global initiative by hypertension agencies that encourages people to test, and if necessary treat, their blood pressure.

Leung is encouraging people to speak to their doctors as to whether a lower blood pressure target might be a goal for them.

"This recommendation should be taken as a broad recommendation for everyone," he said.

With files from Jennifer Lee