Miami Heart Study: Landmark Project Tracks Early Coronary Artery Disease in Diverse Group

The Miami Heart Study, or MiHeart, launched in 2015 by teams at Miami Cardiac & Vascular Institute, part of Baptist Health, with the enrollment of 2,549 volunteers from South Florida, aged 40-65. It has already acquired landmark status by prominent leaders in the cardiovascular medical field and those who chronicle milestone advancements.

Many aspects of MiHeart make it so unique that experts nationwide and around the world are following its progress. Among those standout features: The study includes a significant proportion of Hispanics (47 percent), and 49 percent of all participants are females. Both Hispanics and females are often underrepresented in cardiovascular studies.

Another significant accomplishment that sets MiHeart apart from other studies is that all participants underwent detailed baseline testing that included including coronary artery calcium (CAC) scoring, coronary computed tomography angiography (CCTA) scanning and a host of additional blood and vascular biomarker screenings. The goal with all the testing is to track how much plaque has developed in the arteries of this middled-aged group of adults (mean age 53 at start).

The Goal of MiHeart

Jonathan Fialkow, M.D., deputy medical director and chief of cardiology at Miami Cardiac & Vascular Institute, and senior author of MiHeart.

The primary mission of MiHeart is to follow the primary factors involved in the development of coronary artery disease, or heart disease, in patients who don’t have symptoms or problems yet — meaning that none of the participants started out with heart disease, but the disease process may have already started in many of them. That puts them in the “subclinical” category.

Coronary artery disease — when the arteries that supply blood to the heart muscle become hardened and narrowed — is the most common type of heart disease. It’s the leading cause of death in the United States in both men and women.

“All these patients who were asymptomatic would not normally have a coronary CT scan,” explains Jonathan Fialkow, M.D., deputy medical director and chief of cardiology at Miami Cardiac & Vascular Institute and senior author of MiHeart, who manages the Institute’s teams that are following up with the study’s participants. “We’ve got this incredible level of imaging which is not just what people tend to look to determine blockage, but we actually have the level of detail now of what the actual blockage is made up of. Is it calcium? Is it liquid? All these things relate to the plaque composition.”

Khurram Nasir, M.D., chief of the Cardiovascular Prevention and Wellness Division of Houston Methodist Hospital, is MiHeart’s principal investigator. Dr. Nasir was part of Miami Cardiac & Vascular Institute when the study launched in 2015. He has been instrumental in spurring national and international interest in MiHeart. (Listen to Drs. Fialkow and Nasir on the latest Baptist HealthTalk podcast.)

Early Intervention to Prevent Heart Disease

MiHeart will have a “snowball effect” in understanding how to intervene in the early stages of coronary artery disease and help prevent heart attacks and the full development of heart disease, explains Dr. Nasir.

Khurram Nasir, M.D., chief of the Cardiovascular Prevention and Wellness Division of Houston Methodist Hospital, and MiHeart’s principal investigator.

“The new paradigm not only involves how to detect it, but also how to prevent it,” explains Dr. Nasir. “That is the biggest impact or the value proposition of Miami Heart Study, which I believe will be the crown jewel of the Baptist Health research activities. Not only are we helping our own community, but we’re generating new knowledge that will change the way cardiovascular disease is perceived, managed and treated.”

The most recent data released on the study participants show the development of detectable plaque from CCTAs and scores from coronary artery calcification (CAC) testing. About 45 percent of participants had detectable plaque. Nearly one-third of the group had CAC scores of more than 100 had “significant stenosis” — or narrowing of arteries.

“The rest of the world is looking at how much plaque they have and we’re now at the level of what’s the differences in the kind of plaque,” explains Dr. Fialkow. “And then — between that and the blood tests, and the genomics, we’ll follow the people and see who winds up with heart attacks or not. And, also, what are the determinants that separates a person who might have high cholesterol who will live forever, versus a person with high cholesterol who will have a heart attack at 55.”

Redefining Cardiovascular Risk Management

The Miami Heart Study still has years to go and much data to collect, but the progress will unfold through various publicized reports that are being closely read my medical experts.

“There is still a lot of work ahead and much data to collect,” says Dr. Nasir. “But we are truly excited. Over the next three years, I would say, we’re going to see many highlights of the Miami Heart Study, where we will start bringing out the new information that will help us redefine the paradigm of cardiovascular risk assessment and management.”

Dr. Fialkow said U.S. researchers are assisting in developing genomic sequencing of the blood of MiHeart’s participants “so we’ll be so we’ll be able to get all the DNA, all the sequencing, of all the people who have been tested.”

The long-term benefits of MiHeart could save millions of lives, experts say.

“In 10 years or so, Miami Heart Study at Baptist Health South Florida will resonate across the nation and the world,” said Dr. Nasir. “As a community and as a health system, everyone you should be very proud of this accomplishment because there is no other one like it. Rather than waiting for others or being led, Baptist Health decided to lead.”