Physicians at the Hypertension and Vascular Disease Center at Wake Forest University Baptist Medical Center have proven that a new medical device improves blood pressure management in patients with the most common form of uncontrolled hypertension.
In their study, the Consideration of Noninvasive Hemodynamic Monitoring to Target Reduction of Blood Pressure Levels (CONTROL), hypertension researchers hypothesized that hypertension therapy guided by a new noninvasive device called impedance cardiography (ICG) could aid primary care physicians in reducing blood pressure more effectively. ICG devices measure hemodynamics, the study of how rapidly blood circulates through the body (cardiac output) and the force the heart pumps against (systemic vascular resistance).
“Hypertension is a hemodynamic-related disorder,” said Carlos M. Ferrario, M.D., director of the Hypertension and Vascular Disease Center at Wake Forest Baptist, and lead researcher of the CONTROL study recently published in Hypertension, a Journal of the American Heart Association. “Blood pressure rises as a result of increased systemic vascular resistance, cardiac output, fluid volume or a combination of these factors.”
Historically, physicians could not assess either cardiac output or systemic vascular resistance without invasive or expensive methods. The ICG test (brand name BioZ? manufactured by CardioDynamics Inc., a funding source of the study) measures both of these parameters noninvasively and inexpensively.
In the CONTROL trial, Ferrario’s team discovered that ICG-guided treatments improved blood pressure control rates in resistant hypertension commonly treated by primary care physicians.
“Our study shows that we can do much better clinically in tailoring anti-hypertensive therapy based on actual determination of the hemodynamic cause, in the office of a primary care practitioner,” said Ferrario.
Impedance cardiography-aided patients in the study experienced a significant reduction in blood pressure. They were 35 percent more likely to achieve a blood pressure goal of <140/90mm Hg and 103 percent more likely to achieve the more aggressive goal of 130/85mm Hg.
Hypertension is a common disease shared by approximately 65 million Americans and 1 billion people around the world. Of this population, it is estimated that only one-third of patients diagnosed with hypertension have controlled blood pressure (<140/90mm Hg). A major public health concern, it’s the most common reason adults visit physicians in the United States and a significant risk factor for stroke, heart attack, renal disease and heart failure.
Revision date: July 3, 2011
Last revised: by Janet A. Staessen, MD, PhD