UM’s AFib Center Delivers Advanced Care and Innovative Research to Treat Irregular Heart Rhythms

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For patients with dangerous irregular heartbeats, the Center for Atrial Fibrillation at the University of Miami Health System and the Miller School of Medicine offers leading-edge personalized care.

Jeffrey Goldberger, M.D., MBA, observes as patient Marvin Pickholz checks his pulse.

From a new National Institutes of Health-funded clinical trial that examines the role of epicardial fat and a special “4D” MRI to measure velocity of blood flow in the heart to comprehensive treatment options and risk modification programs, the University of Miami’s expert cardiology team delivers in-depth and comprehensive care to each patient.

“Atrial fibrillation [AFib] is a serious condition that can lead to strokes or other serious problems,” said Jeffrey J. Goldberger, M.D., MBA, chief of the Cardiovascular Division. “It requires careful risk assessment and a personalized plan of care. AFib is not something you should ignore.”

About 33 million people worldwide have AFib, which is the most common of arrhythmias or irregular heartbeats that cause the heart to beat too slowly, too fast or erratically. With AFib, the heart’s two upper chambers (atria) contract very fast and irregularly. This causes blood to pool in the heart, where it may form a clot that travels to the brain, causing a stroke. About 25 percent of all strokes are related to AFib, and these cardioembolic strokes have worse outcomes than other types of strokes, according to Dr. Goldberger.

“We take a whole patient approach to treating AFib, which is a progressive condition that can worsen over time,” said Raul D. Mitrani, M.D., professor of clinical medicine and director of clinical cardiac electrophysiology. “Along with treating the immediate problem, we look for ways to reduce the risk of stroke and recurrent atrial fibrillation. For patients who undergo catheter ablation, we emphasize the importance of patients following a diet and exercise regimen, as well as taking medications to control blood pressure or other medical conditions.”

Screening for AFib

Dizziness, lightheadedness, and palpitations caused by an increased heart rate are classic symptoms of AFib. A physician can screen for an arrhythmia like AFib through a physical exam, or an electrocardiogram (ECG) test. However, identifying an irregular heartbeat is just the start of the evaluation process in determining a patient’s risk for stroke.

Raul Mitrani, M.D., viewing heart on screen.

Last August, Dr. Goldberger and Dr. Mitrani contributed an editorial to the Journal of the American Medical Association about new recommendations from the U.S. Preventive Services Task Force regarding the use of electrocardiogram screening to prevent cardioembolic strokes related to AFib.

In their editorial, the Miller School cardiologists concluded that primary screening to prevent cardioembolic stroke may need to extend beyond ECGs.

“ECG screening at-risk populations is effective in identifying AFib cases, with more cases detected by more intensive screening,” they wrote. However, the current screening options are not sensitive or precise enough to use as a sole approach.

In their article, Dr. Goldberger and Dr. Mitrani also emphasized that devising an effective screening strategy to prevent AFib-related cardioembolic stroke “should be a public health priority.”

Reducing Stroke Risk

Traditionally, cardiologists have relied on a checklist of factors when assessing their patients’ risks for stroke. Patients considered at high risk may be given blood thinners to reduce potential clot formation. However, the situation is more complicated in patients with AFib.

Dr. Goldberger has been a pioneer in trying to find a better way to assess the risk of stroke in AFib patients.

“Patients are typically treated with blood thinners, which may not be necessary and could create a different set of risks.” said Dr. Goldberger, who co-developed a state-of-the-art 4D Flow MRI diagnostic procedure to measure how fast blood moves through the heart. That’s because the faster the blood flow, the lower the likelihood of clot formation.

“I think this has the potential to really revolutionize the way we treat patients with atrial fibrillation,” he said. “It could also reduce the harmful and often unnecessary blood thinners prescribed to patients with AFib.”

Multiple Treatment Approaches

UM’s Center for Atrial Fibrillation offers a full array of diagnostic tools and treatments, including rhythm control medications, blood thinners, and catheter ablation, which destroys the abnormal heart tissues that trigger the arrhythmia. Another advanced option, now in a clinical trial led by Dr. Mitrani, involves placing a small device called the Watchman in the atria to prevent blood clots from forming.

The 4-D flow MRI provides information about the velocity of blood flow in the heart’s left atrium.

Until recently, AFib patients were mainly treated with antiarrhythmic drugs, which are helpful to some, but not all, patients. Dr. Goldberger and Dr. Mitrani participated in a multi-center international study, Catheter Ablation versus Antiarrhythmic Drugs for Atrial Fibrillation (CABANA), which showed ablation outperformed medication in terms of preventing atrial fibrillation and improving quality of life.

“Rhythm control drugs are effective less than 50 percent of the time,” Dr. Mitrani said. “The CABANA study allowed us to evaluate patients more carefully and to discuss the pros and cons of catheter ablation. It showed a decrease in cardiac hospitalizations, and even improved survival in some patients.”

In the cardiology team’s quest to further improve ablation outcomes, Dr. Goldberger has developed new mapping tools to identity which channels may be causing the irregular and chaotic heartbeats.

“We are now in the midst of testing this approach with AFib patients,” he said. “It has the potential to advance our knowledge.”

As for current clinical practice, Dr. Goldberger notes even patients whose heart rhythms return to normal through medication or ablation should receive enhanced follow-up care.

“Even if the AFib is corrected, they may still need to take a blood thinner,” he said. “AFib is a chronic condition and needs to be managed for the long term. Prevention of progression of atrial disease is a key component of treatment.”

Addressing Epicardial Fat

Epicardial fat around the heart can release enzymes or other substances that promote inflammation or the thickening of the cardiac wall.

“Research has shown that fat tissue releases substances that can have bad effects on the body, especially around the heart,” Dr. Goldberger said. “Since epicardial fat tissue sits right on top of the heart muscle, there is no barrier to the diffusion of these harmful substances into the heart muscle tissue.”

A new $2 million study funded by the NIH involves testing the effectiveness of the diabetes and obesity drug Liraglutide, as well as a diet and exercise regimen, in reducing epicardial fat in patients with persistent AFib.

Dr. Goldberger and Gianluca Iacobellis, M.D., Ph.D., professor of clinical medicine in the Division of Endocrinology, are leading the study, whose goal is to improve ablation outcomes. A multidisciplinary team of co-investigators from the University of Miami will be joining them in this study.

Modifying Risk Factors

Along with innovative diagnosis and treatment options, UM’s AFib Center offers the Atrial Fibrillation Risk Factor Modification Program, designed to address the root cause of a dangerous irregular heartbeat.

Obesity, hypertension, diabetes and sleep apnea are among the chronic conditions that increase the risk of AFib, and life-threatening strokes. “We offer a physician-guided exercise and diet regimen,” Dr. Mitrani said. “Patients are assessed and followed by a nurse practitioner who tracks their progress. Our goal is to prevent AFIB disease from developing in the left atrium.”

Looking ahead, Dr. Goldberger says ongoing medications may be helpful for patients who find it difficult to reduce their stroke risk through lifestyle modification.

“We are committed to improving the health and well-being of every AFib patient,” he said. “Our center will continue to be in the forefront of advancing care for this progressive disease.”

This image shows a color map of the similarity between each electrical signal at one particular location in the atrium during atrial fibrillation. Typically, the morphology of this signal varies significantly over time. Signals that are most similar to one another are coded red, with lower levels of similarity yellow, green, and blue. Sites with a lot of red (the “hot spots”) may be important areas maintaining atrial fibrillation.

Tags: AFib, atrial fibrillation