USC Health Now

February is American Heart Month. Here, USC experts talk about hypertension, a major risk factor for heart disease. Are you at risk?

by Jennifer Chan

In a recent poll of USC Health Now readers, less than half of respondents said they take measured steps to prevent against heart disease. Yet approximately 65 million people in the United States suffer from hypertension, which can affect individuals of any age, gender or race. That’s almost one in every four adults.

Hypertension, or high blood pressure, is a condition in which the blood pressure is chronically elevated. It is a major risk factor for cardiovascular disease, and is estimated to cause one in every eight deaths worldwide. The good news is that, in most cases, it is highly treatable.

“Oftentimes, patients can drop their blood pressure simply by changing their diets, cutting salt or caffeine intake, losing weight and exercising,” says Mitra Nadim, M.D., co-director of the USC Center for Hypertension and Renovascular Care.

A simple measure

Diagnosing hypertension is as easy as getting regular readings of your blood pressure, says Nadim, who is also an assistant professor of clinical medicine at the Keck School of Medicine at USC. So when was the last time you had your blood pressure taken, and do you know what the numbers mean?

According to the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure, optimal blood pressure is considered below 120/80 mm Hg. People with blood pressures above 140/90 mm Hg are considered to have high blood pressure, and physicians advise lifestyle modifications and generally prescribe medication to manage the condition.

Lifestyle factors that contribute to high blood pressure include lack of exercise, being overweight, unhealthy diets, smoking or excess alcohol. Certain medical conditions can cause hypertension such as kidney disease or sleep apnea.

“For many patients with hypertension, lifestyle modification is not sufficient and the use of medications is frequently required. In about 10 percent of hypertension cases, a separate condition is causing the high blood pressure and if that problem is treated, hypertension may disappear,” says Nadim.

Serious consequences

Left untreated, hypertension increases the strain on blood vessels and arteries, which can narrow and harden. Hardened vessels, often referred to as atherosclerosis, increase the risk of blood clots and stroke and can damage vital organs including the heart, brain and kidneys. The heart, for instance, has to pump harder, which can lead to heart attack or heart failure.

“High blood pressure is often referred to as the silent killer,” says Nadim. “Even when physicians detect hypertension and prescribe medication, sometimes patients won’t take it because they just don’t feel bad.”

People who are of African-American descent, are over the age of 55 or have a family history of hypertension are particularly at risk for high blood pressure.

“Death and heart disease associated with hypertension are preventable in many cases,” says Nadim. “But people need to take steps to diagnose the condition and work with their doctors on a plan to prevent or lower high blood pressure.”

Nadim recommends as a general rule of thumb to have your blood pressure checked annually. “Work with your physician to determine if your blood pressure needs to be monitored more closely and decide if you need a personalized management program to control the condition.”

Uncontrolled high blood pressure

It is important to note, however, that 25 percent of the people with hypertension have uncontrolled high blood pressure, despite the use of medications. Luckily, recent advances in research have pinpointed a possible new avenue in treatment of uncontrolled high blood pressure.

In the first such procedure on the West Coast, USC surgeons recently treated a patient’s previously uncontrollable high blood pressure with an implanted medical device.
The patient is one of the first to be studied in the Rheos Pivotal Trial, a study of an implantable medical device that sends electrical impulses to the brain to activate the body’s own blood pressure control system.

“A small percentage of the population with hypertension does not respond to medications or lifestyle changes such as diet and exercise. As a result, extreme high blood pressure significantly increases their risk for cardiovascular disease or death,” said Fred Weaver, M.D., chief of the division of vascular surgery at the Keck School of Medicine and lead trial investigator.

“The Rheos Therapy is an innovative treatment that is designed to electrically activate the body’s own monitoring system to watch and control blood pressure. This ‘physiological rational’ treatment takes advantage of the function of the body’s natural pressure sensors to reduce blood pressure and improve cardiovascular function,” said Weaver, who is also affiliated with USC’s Cardiovascular Thoracic Institute.

“The Rheos system may be a future therapeutic option in patients with drug-resistant hypertension,” says Nadim.

For more information on hypertension, heart disease or American Heart Month, visit the American Heart Association at: www.americanheart.org.
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If you’re interested in learning more about the Rheos Pivotal study, please call 1-866-913-2584 or email cpappas@surgery.usc.edu.