Listening To Her Heart
Personal tragedy drives engineer to market a device that can detect coronary artery disease.
Michael Barbella, Managing Editor
Marie Johnson is a firm believer in fate. Like countless numbers of generations before her (and numerous others sure to follow), Johnson trusts that life’s purpose can be found amid a series of presumably unconnected and meaningless accidents or coincidences.
Such “coincidences,” Johnson believes, are neither random nor accidental. Rather, they are part of a larger tapestry of events that help shape and define our existence.
Johnson’s own life is perhaps the best proof of this concept. Through a series of“coincidences” and“pre-ordained” events, the biomedical engineer founded AUM Cardiovascular LLC, a Farmington, Minn.-based company that is developing a non-invasive, handheld device that can detect coronary artery disease.
The engineer side of Johnson realizes that last April’s founding of AUM Cardiovascular had as much to do with choices as it did with fate. Yet the spiritual side of her can’t help but think that a pre-determined course of events played a role as well.
Marie Johnson, Ph.D., sits next to an image of a device she developed that is capable of identifying irregular heart sounds. Photo courtesy of Marie Johnson. |
“I was sitting at my kitchen table grading some papers one day and I got an email from the Whitaker Foundation about a program at Stanford [University] that teaches medical device commercialization. I was right at that stage—commercialization,” Johnson recalled. “I had no idea that this was one of the most successful, exclusive programs in the country. I couldn’t believe it when I was offered a fellowship position. It was not serendipity, but it was meant to be. It was pre-ordained.”
Ironically, coming up with a business plan for her new company has been a more daunting task for Johnson than actually developing the device. In addition to providing a clear and thorough explanation of the product, Johnson’s business plan must discuss the target market for her device, detail a marketing strategy, identify company management, and assess the competition.
At least one component of AUM’s business plan will be relatively easy for Johnson: identifying the company objective. “My goal is to get it on the market and save lives. That’s all I think about,” she said. “I want to reduce the number of widows and little kids that don’t have their dads.”
Tragedy Strikes
Johnson’s quest to spare wives and children the pain of losing a loved one is a direct result of her own grief. In 2002, as she worked with 3M scientists to develop an automated diagnostic system for detecting heart murmurs, Johnson’s husband died suddenly at age 41. Details of his death remain seared in Johnson’s memory, still as fresh eight years after the tragic turn of events as they were on the day itself.
“My son Joshua was 7 weeks old, and my doctor had just given me the OK to exercise again. I called my husband on the day the doctor released me to exercise and asked him to meet me at the YMCA,” Johnson said, recounting the final hours of her husband’s life. “I pulled into the YMCA parking lot and I saw a body with a white sheet on top of it by an ambulance. I turned to my 4-year-old daughter and said ‘we need to pray because someone has died here today.’ ”
That “someone” turned out to be Johnson’s husband Robert Guion, a vibration engineer at Lockheed Martin who was studying to be a minister. Johnson had no inkling of the impending tragedy when she walked into the YMCA with her two children in tow.
“I went into the YMCA and had my card swiped. Somebody who worked there said ‘this is his wife,’ but I didn’t have any idea what they were talking about,” Johnson said. “Then a group of police officers surrounded me and walked me to an office. One of them looked at me and said, ‘I’m sorry but your husband died here today.’ At that point, the world started spinning. You could have written on a chalkboard 1 million things that would have happened to me next and I never would have thought that would be on the list.”
Guion’s cause of death was a shock to Johnson: The 6-foot, 2-inch 180-pound man she considered in “perfect condition” was felled by a heart attack. An autopsy showed that several of Guion’s coronary arteries were blocked, including the LAD (left anterior descending) vein, which supplies blood to the front of the heart. His left ventricle, the heart’s main pump chamber, also was enlarged.
Coronary artery disease (CAD) such as the kind diagnosed in Guion is the leading cause of death for men and women in the United States, according to the American Heart Association (AHA). In 2005, the
disease claimed nearly one in every five victims, or 144.4 people per 100,000 population. Adults 20 years of age and older comprised 21 percent (16.8 million) of all cardiovascular disease cases in 2006, AHA data indicated.
‘I Knew I Had Something’
Despite her beliefs in fate and destiny, Johnson is certain that neither played a part in her husband’s death (she attributes Guion’s demise to “choices, entropy and outside factors such as genetics and the environment”). But it can be argued that both fate and destiny most likely were at work long before that tragic day to shape the path she took upon being widowed.
Coincidentally (or not), Johnson had gathered hundreds of pieces of data about her husband’s heart months before his death by using a prototype of the heart murmur detection system she was developing with 3M scientists. An expert in auscultation—the technical term for listening to the body’s internal sounds, usually through a stethoscope—Johnson listened to Guion’s heart and detected an intermittent third heart sound (otherwise known as S3).
Most healthy adults have two normal heart sounds, often described as a “lub” and a “dub” (or “dup”) that occur in sequence with each heartbeat. Medical professionals refer to them as the first heart sound (S1) and the second heart sound (S2), produced by the closing of the atrioventricular valves and semilunar valves. A third heart sound is normal in children and young adults, but can be indicative of heart failure in people who are older than 40. The sound often is referred to as a protodiastolic gallop or ventricular gallop.
Johnson picked up on such a gallop rhythm in her husband’s heartbeat, but was hesitant to come to any definitive conclusions because she is not a medical doctor (she has bachelor’s degree in mechanical engineering and both a master’s and Ph.D. in biomedical engineering).
“I’m an engineer. It wasn’t until I started doing the math on it and using the clinical literature that I figured out that [Rob] had an S3,” Johnson explained. “I’m not a doctor. I was just an engineer doing frequency analysis. I looked at it and I actually took it over to the cardiologist I was working with and I said, ‘do you hear something kind of weird in that?’ He said, ‘yes, I hear an intermittent S3.’ ”
Naturally, Johnson told her husband about the sound she had detected in his heart. He shared those results with his own doctor, who failed to hear the S3.
Guion’s untimely death after that doctor’s visit gave Johnson a new purpose in her career. She decided to apply the principles of the heart murmur detection system to create an acoustic device that can identify symptoms of coronary artery disease.
Such a device required Johnson to create an algorithm that could identify a specific acoustic signature associated with a lack of blood flow (otherwise known as “ischemia”) in the proximal left anterior descending coronary artery. She also had to create a sensor that could effectively filter out excessive noise and design data mining software that could quantify the risk of stenosis in a meaningful way.
“As I was data mining, I started extracting the information that was relevant,” Johnson said, explaining the process that culminated in the creation of the device she named CADence. “Then I started stripping out what I thought was noise until finally I landed on this signature. I knew I had something. I went to a cardiologist who I worked with and told him what I had and he agreed to conduct a clinical study with me.”
That clinical study took place in 2006 and was presented to the AHA. Johnson and her team of researchers used the detection system on 52 patients who later underwent angiograms at the University of Minnesota and were found to have coronary artery disease. When Johnson factored in the data from her device, she discovered that her system identified 100 percent of the patients with normal arteries and 72 percent of the patients whose angiograms showed LAD stenosis.
A Promising Market
After completing the clinical study in 2006, Johnson traveled to Torino, Italy, to further study the genesis of the sound associated with stenosis in the small coronary artery. Johnson said that sound rarely is audible because it is masked by many other noises. “It’s always there. It’s just a matter of being able to extract it,” she noted.
Johnson’s device extracts the sound by using a high-fidelity microphone to record acoustic data originating from the fourth left intercostal space in the heart. Software powered by a proprietary algorithm evaluates the data to determine whether any arteries are jammed with plaque.
Johnson currently is conducting two additional clinical trials with the device to refine the algorithm contained in the software. Once those trials are complete, she will focus on getting the product approved by the U.S. Food and Drug Administration, though Johnson is still mapping out a strategy for that goal.
To prove specificity and sensitivity associated with her device, Johnson must conduct multi-center clinical trials. She estimates she will need about $3 million to accomplish that goal—$2 million to finance the cost of conducting multi-center trials and $1 million to prepare clinical trial-ready products.
Johnson’s company, AUM Cardiovascular, already has received $1 million in seed funding from an undisclosed angel investor. That investor, no doubt, realizes the earnings potential for Johnson’s device in the global cardiovascular device market. Industry data indicate that the global market will reach $54.9 billion in 2016, growing annually at 7 percent over the next seven years. That growth most likely will be driven by several key factors, including an increasing prevalence of of cardiovascular diseases, an aging population, the introduction of innovative products, and an increasing prevalence of such co-morbidities as diabetes and obesity.
Johnson is fully aware of the potential fiscal rewards of marketing her device but they don’t really matter to her. She is motivated by a more important factor: children.
“My whole goal in marketing this device is widows and little kids without their Dads,” Johnson asserted. “I keep doing this for the children. I have to do it for them. That is what keeps me moving forward.”
Lifting the Veil of Silence on Coronary Artery Disease
Doctors call it“The Widow Maker.”Journalists deem it a “top killer.” And patients—well, they really don’t have a nickname for it.
Many names have been assigned to Coronary Artery Disease (CAD) over the last several decades, but perhaps none have been as appropriate as “Silent Killer.” Though it is the nation’s leading cause of death (trumping cancer, diabetes and accidents), CAD is often hard to detect and predict, particularly in patients that have no symptoms.
CAD, also known as Coronary Heart Disease, is caused by the buildup of plaque in the arteries that supply blood and oxygen to the heart. Plaque can narrow and sometimes completely block a coronary artery, triggering chest pain, arrythmias and heart attacks. The severity of these conditions can vary depending on the artery that is affected. For example, a complete blockage in the left anterior descending coronary artery is almost always fatal—thus the nickname “Widow Maker.”
Nearly 18 million Americans aged 20 and older were diagnosed with CAD between 2003 and 2006, according to statistics from the American Heart Association. The agency estimates that about 195,000“silent” heart attacks occur annually; studies have shown that as many as 40 percent to 60 percent of all heart attacks are silent ones (defined as those that are unrecognized or are not accompanied by the usual symptoms of chest pain, shortness of breath, fainting and nausea).
Silent heart attacks certainly add to the overall annual death toll from CAD. But the nature of the disease itself plays a more crucial role in its high mortality rate. Though it is treatable and in some cases, preventable, CAD nevertheless remains a difficult disease to predict and detect. Measuring blood pressure and levels of low-density liptoids are not reliable indicators of stenosis, medical experts said. Neither are stethoscopes—even the newer electronic ones.
Studies have shown that scanning technologies such as computer tomography, magnetic resonance imaging and ultrasounds can improve the detection of stenosis by measuring various factors, ranging from the thickness of artery walls to calcium deposits. But those tests can be expensive and are not always approved for reimbursement. Plus, primary care doctors are unlikely to recommend those tests for patients that do not display symptoms, experts noted. —MB