There is mounting evidence that patients with high blood pressure are at greater risk of a heart attack or stroke than those with normal blood pressure, but researchers say that it’s not clear whether these patients are at higher risk of heart attack, stroke or both.

In the latest issue of the American Journal of Clinical Cardiology, researchers at the University of Calgary in Canada found that people with high BP had a lower risk of death compared to people with normal BP, and also showed an increased risk of being treated for a heart failure, or death from heart failure.

Dr. Richard A. Pfeiffer, the lead author of the study, said that the study “is the first to show a direct association between BP and mortality in patients with hypertension”.

“People with elevated BP have a significantly higher mortality risk than people with a normal BP,” he said.

“Our data also suggests that the mortality risk from heart attacks is increased by BP greater than 5 points for each 10-point increase in systolic BP.”

Dr. PFEIFFER and colleagues examined the data of about 8,000 adults with hypertension and 3,000 healthy adults.

They compared data from about 12,000 people with cardiovascular disease (CVD) with similar data from 6,000 matched healthy people.

“We looked at the associations between BP, death, and CVD risk,” Dr Pfeifer said.

“Our data suggest that those with elevated blood pressure have a mortality risk that is at least as great as those with a normotensive BP.”

While the study has limitations, Dr PFEIFER said that it is a good first step.

“It’s important to get the details of this and then make some adjustments to reduce those risk factors, but the point is that there’s a clear association,” he added.

“The results are not as clear in other studies.

There is also evidence that the associations we found between high BP and risk of cardiovascular events are stronger in patients on medications that increase blood pressure.”

A link between BP levels and C-reactive protein (CRP)Dr Pfeiffs findings have been welcomed by doctors and the American Heart Association.

“These results are encouraging and important to keep in mind for patients with elevated hypertension, who are also at increased risk for heart attacks,” Dr John Ehrlich, the AMA’s chief medical officer, said in a statement.

“This is especially true for older patients, as they tend to have higher blood pressures, and these medications increase CRP.”

However, Dr Ehrich said the study does not prove that high BP causes a heart condition.

“What it does is confirm what we’ve seen anecdotally, that people have a higher incidence of C-REactive protein in their blood, which can be an early marker of cardiovascular disease,” he explained.

“People at high risk for cardiovascular disease are at a greater risk for C-Reactive protein.

This is also an indication that the medication may increase the risk of coronary artery disease.”

While this study is important for providing further support for patients at high cardiovascular risk, we cannot definitively say that high blood pressures cause heart disease.

There are other things that can contribute to heart disease such as smoking and obesity.

“Dr Ehrbert also said that “people with elevated levels of BP should seek medical attention and that their medical history is not relevant to their risk of developing cardiovascular disease”.

The study was funded by the Alberta Heart Foundation and the Health Sciences and Technology Research Council of Canada.ABC News