Evolving ‘Miami Heart Study’ – Led by Baptist Health Miami Cardiac & Vascular Institute – is Redefining Preventive Cardiology Field

The evolving data behind the landmark Miami Heart Study, or MiHeart, launched in 2015 by teams at Baptist Health Miami Cardiac & Vascular Institute, is reverberating throughout the preventive cardiology field in the U.S. and globally.

Medical experts and professional organizations are keeping a close eye on the unique, diverse population being studied — more than 2,500 asymptomatic volunteers from South Florida, aged 40-65, at the beginning of MiHeart.

The study is innovative on many fronts, including the focus on such a large group of individuals free of established cardiovascular disease or symptoms when recruited, and the use of coronary computed tomography angiography (CCTA) for baseline testing. A CCTA combines a CT scan and sophisticated computer analysis to provide detailed, 3D images of blood vessels and tissues. 

Jonathan Fialkow, M.D., chief population health officer for Baptist Health and chief of cardiology at Miami Cardiac & Vascular Institute.

The first detailed report of the MiHeart more than a year ago found “substantial prevalence of coronary plaque in asymptomatic individuals.” Specifically, 49 percent of participants had coronary plaque, and 6 percent had stenosis (narrowing of arteries) of greater than 50 percent, the most serious risk factor for heart attack or stroke if untreated. 

Dozens of medical publications nationwide have featured the progress of MiHeart. Prominent organizations, such as the American College of Cardiology and the American Heart Association, have had featured presentations focusing on its vital data.

MiHeart is poised to advance preventative cardiology by better defining factors that lead to cardiovascular artery disease in adults that have no symptoms or obvious risk factors, explains Jonathan Fialkow, M.D., deputy medical director and chief of cardiology at Baptist Health Miami Cardiac & Vascular Institute. He is senior author on many ongoing MiHeart publications and manages the Institute’s follow-up strategies involving the study’s participants.

Tracking MiHeart Participants

“Now, we have patients with coronary artery disease, but we need to know exactly what were the factors that best correlated with this diagnosis,” said Dr. Fialkow. “We want to determine five years later what happened to those patients who developed heart disease. In those that got worse, what were the parameters that we could identify that could have predicted they would get worse. And, for those who got better or didn’t develop heart disease, what were the factors that got them better?"

A major next step for MiHeart is conducting a significant written survey among all 2,400 participants to determine exactly how they progressed, and what medical or lifestyle factors could have played a role in their condition.

“it’s a very extensive survey,” explains Dr. Fialkow. “Some of the questions: What drugs have you been taking? Have you had any cardiac conditions? How do you feel? How much exercise do you do? We will then compare the surveys to the initial surveys taken more than five years ago.”

The next major step is to have the participants re-tested. The baseline tests also include the CCTAs and a coronary artery calcium (CAC) scoring, an exam that takes cross-sectional images of the vessels that supply blood to the heart muscle (coronary arteries) to look for the buildup of calcified plaque. A CAC score of 100 to 300 represents moderate plaque deposits, but a score greater than 300 is associated with a relatively high risk of heart disease.

Future projects will delve even deeper into the landmark databank of MiHeart. One ongoing collaboration will see the Institute join forces with major academic centers for a potential National Institutes of Health (NIH) to develop a DNA sequencing of the MiHeart participants, said Dr. Fialkow.

“At the onset of the Miami Heart Study, we drew blood and serum, which are different parts of blood, and stored them,” he explains. “We still have them; they are bio-banked. They're part of the plan: A full gene DNA sequencing of all the subjects. And that would be something to correlate. This will help us determine which certain genes correlated with the patients that developed coronary artery disease, and which correlated with those who don't have coronary disease.”

The Growing Field of Preventive Cardiology

There is little doubt that MiHeart will help reshape or redefine preventive cardiology, a field of expertise with which Dr. Fialkow is very familiar. He specializes in the prevention, diagnosis and treatment of complex cardiovascular disease and its risk factors. He has extensive experience in cardiac prevention, including nutrition and exercise management, as well as lipid disorders, hypertension, coronary artery disease and congestive heart failure.

The field is often misunderstood, he says. It’s not necessarily about preventing risk factors, such as diabetes or high blood pressure.

“Prevention in the cardiovascular world is taking people with high-risk cardiac or other medical conditions, and preventing a heart attack, stroke, heart failure and death,” emphasizes Dr. Fialkow. “People think prevention is preventing diabetes. That's wellness. We're taking the diabetic and making sure they're controlled and treated, or optimized, so they don't suffer a heart attack. With MiHeart and other extensive research and clinical trials, we are still improving these prevention services.”

Learn more about the Institute’s Cardiovascular Disease Prevention Program.