Blood test helps physicians diagnose patients’ risk for coronary artery disease

A simple blood test is helping primary care physicians recognize patients who are at risk for coronary artery disease, which is the leading killer among men and women in the U.S. (Thinkstock)
A simple blood test offers relief to potentially at-risk patients

WTOP's Rachel Nania | November 30, -0001 12:00 am

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WASHINGTON — When the results from Susan Garcia’s most recent physical came back, the 52-year-old personal trainer and nutrition coach was shocked.

Normally, the Gaithersburg, Maryland, woman — who makes a living from working out and eating right — gets a glowing report. But this year, Garcia’s blood work came back with a “very elevated” genetic cholesterol test.

Garcia’s physician, Dr. Rita Ghosh, of Rockville, Maryland, went over the unusual results, and asked Garcia if she had been experiencing any symptoms, such as pain, pressure or shortness of breath.

“As we were talking, I told her about this nagging upper back pain that I had been having,” Garcia says.

Ghosh explained that the pain could be a symptom of coronary artery disease, a condition that develops when the major blood vessels that supply the heart with blood and oxygen become damaged, often due to cholesterol and inflammation.

That realization immediately struck a chord with Garcia, who lost her father and her grandfather to cardiovascular disease. She wanted to know if she was at the same risk.

And with the help of a relatively new test, Garcia was able to face her fate — right in Ghosh’s office.

Coronary artery disease, or CAD, is the most common type of heart disease. And in the U.S., it’s the leading cause of death in both men and women.

Typical symptoms for CAD include chest pain and shortness of breath. However, Ghosh says women have more “vague” symptoms, which often go missed or misdiagnosed.

The atypical symptoms common in women can range from pain in the arm, jaw or throat, to abdominal pain and discomfort.

“And sometimes they just feel tired,” Ghosh says. “And so that has led physicians not to think of women as having coronary artery disease.”

When a primary care physician identifies symptoms of CAD in a patient, the patient is referred to a cardiologist for further testing, which may include an electrocardiogram, a stress test, a heart scan or a cardiac catheterization.

Ghosh says women are not only at a disadvantage when it comes to the warning signs of CAD; conventional testing gives a higher rate of false-positive and false-negative results in female patients as well.

“Women have different anatomy,” Ghosh says. “Women have smaller hearts and breast tissue that impacts the interpretation of the nuclear medicine testing, so that gives a false-positive or false-negative results.”

According to WebMD, plaque may also build up differently in a woman’s arteries, making it difficult for a doctor to detect blockage during a cardiac catheterization test.

Because of this, it’s not unlikely for women to receive a delayed diagnosis of CAD. And sometimes, that diagnosis is too late to save a life.

About a year ago, Ghosh started using a diagnostic tool to help her better identify the patients who really need to see a cardiologist for further CAD testing and treatment — regardless of their sex and symptoms.

The test is called Corus CAD. Ghosh, who disclosed she is a speaker for Corus, says the blood test takes into consideration the age, sex and the gene expression of the patient. It can be done in a matter of minutes in the primary care physician’s office, and results are available in 72 hours.

How does it work? The Corus CAD blood test scores each patient on a scale from 1 to 40. If a patient’s test comes back with a score below 15, the patient is at low risk of CAD; a score between 16-27 means the patient is at intermittent risk.

However, patients who score above 28 are at high risk for CAD. Ghosh says these patients usually end up with 50 percent blockage in their coronary arteries, which may require an angioplasty or bypass surgery.

With Susan Garcia’s elevated cholesterol score and her family history of cardiovascular disease, both she and Dr. Ghosh decided to do the Corus CAD blood test to see if she was at risk for CAD.

Garcia’s test came back with a very low score, and Ghosh felt confident that Garcia didn’t need to spend time and money on further imaging tests with a cardiologist.

“Talk about being relieved,” Garcia says.

And that nagging pain in her back?

“It just ended up being something I did in the gym; I’m sure of it,” she says.

However, that does not mean Garcia is off the hook, so to speak. With a family history of heart disease, she has to continue to monitor her cholesterol and maintain a healthy lifestyle.

Ghosh says the Corus CAD blood test is currently used in patients at risk for CAD; it is not used as a screening test.

“It likely won’t be used in healthy patients,” Ghosh says. “Those who use it will be those who have high blood pressure, high cholesterol, they have a family history and they are having the pain. I think it’s for those patients.”

Ghosh says in the past year that she has been using the blood test, she has seen a range of results. Some patients have been relieved to learn that they are at low risk for the silent killer. Others have been able to diagnosis CAD early and seek treatment right away.

And because the test is sex-specific, Ghosh says it has especially helped her female patients, who don’t always exhibit CAD’s traditional warning signs.

Some  insurance companies cover the cost of the Corus CAD test (the list price is $1,245), including Medicare, Aetna and Coventry Health Care. But even still, it’s much less expensive than undergoing repeated imaging tests. Plus, Ghosh says, it’s more comfortable for patients.

“Patients are very comfortable with their primary care physicians; they trust their primary care physicians. And it can be done in the comfort of the physician’s office,” she says.

Ghosh says she plans to continue to use the test in her office, and sees it as a lifesaver.

But even before the blood test, the first step to tackling CAD is having an open and honest conversation with your doctor. Ghosh says this advice especially holds true for women.

“Women should understand that they should not ignore their symptoms because they’re not always going to be having the typical symptoms,” she says.

UPDATE 3:01 P.M. — Editor’s Note: The cost of the Corus CAD test was updated to reflect the company’s list price. The previous price ($200) was the cost quoted by Dr. Ghosh’s office.  Insurance information was also added. 

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