High Normal Blood Pressure Linked To Cardiovascular Risk
A new study of more than 10,000 patients, conducted by the Universities of Cambridge and Cardiff in the United Kingdom using AtCor Medical Holdings Limited's SphygmoCor has found that more than 70 percent of patients identified as having "high normal" systolic blood pressure through traditional cuff blood pressure measurement may be at serious cardiovascular risk. This is because those individuals have elevated central systolic blood pressure, which is associated with increased incidence of heart attack, stroke and kidney disease. SphygmoCor is a non-invasive central blood pressure assessment technology that has been used by researchers over the past several years.
The Anglo Cardiff Collaborative Trial, a cooperative effort of the Universities of Cambridge and Cardiff in the United Kingdom, tracked the blood pressure of 10,613 patients with two systems -- traditional blood pressure measurement using an inflatable arm cuff, and non-invasive central blood pressure assessment using SphygmoCor. The investigators found that more than 70 percent of patients with brachial systolic blood pressure in the "high normal" range (130-139 mm Hg) had central systolic blood pressures corresponding to those seen in patients with Stage One Hypertension (140-159 mm Hg measured brachially). Treatment guidelines call for anti-hypertensive drug therapy for stage one hypertension whereas life-style changes only are guided in the "high normal" range. Elevated central pressure was also found to be associated with an increase in cardiovascular risk factors.
"The real significance of these findings is that central and brachial blood pressures are not the same, meaning that central pressure cannot simply be inferred from the brachial pressure measurement, but should also be assessed," said Dr. Carmel McEniery, the study's lead author. "Current guidelines for the diagnosis and management of hypertension are based solely on brachial pressure, yet this results in a large number of individuals being mis-classified based on their central pressure, leading to sub-optimal treatment."
Dr. Michael Weber, Professor of Medicine at SUNY Downstate Medical Center in Brooklyn, New York, added, "The work of Dr. McEniery and her colleagues emphasizes that conventional blood pressure measurements cannot always identify people at risk of heart attacks and strokes. They are finding that new methods for estimating central blood pressure, which is more closely related to these serious medical outcomes, promises an important new direction in clinical medicine."
"According to recent estimates, over half of American's who suffer a heart attack had no prior signs of heart disease. Early identification of patients at risk, early intervention and effective patient management are critically important, not only to the health of individual patients, but also to the economic health of national health care systems," said Duncan R. Ross, President and CEO of AtCor.
The findings of this new study further confirm the results of the CAFE and Strong Heart studies, both of which showed that individuals with elevated central pressure were at a significantly higher risk of cardiovascular events such as heart attack, stroke and kidney disease. In both studies, elevated central pressure in patients could not be predicted by conventional brachial blood pressure measurement.
The results have been published in the June issue of the American Heart Association's journal Hypertension in a study titled "Central Pressure: Variability and Impact of Cardiovascular Risk Factors".