From heart-mapping technology to interventions that help prevent strokes, South Florida hospitals are offering innovative treatments to help regulate heartbeats in people living with atrial fibrillation, the most common type of irregular heartbeat.
AFib or AF, as it’s known, affects approximately 2.7 million people nationwide. The fluttery heartbeats happen because the heart’s electrical signals are out of sync. Instead of one even beat, the top part of the heart, called the atria, compresses first, followed by the bottom part (the ventricles).
The abnormal rhythms prevent blood from flowing correctly, which could lead to heart failure. Blood clots could also form inside the heart and could cause a stroke if a clot travels from the heart to the brain.
In catheter ablation, a small area of the heart tissue that is causing the irregular heartbeat is destroyed using radiofrequency energy, or radio waves. Eliminating the bad tissue helps restore the heart’s natural rhythm.
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Mount Sinai Medical Center conducted a study, which concluded over the summer, that combined ablation both inside and outside of the heart. The study looked at whether AFib could be treated without additional follow-up ablation treatments and without the patient needing to take heart rate and rhythm drugs on a long-term basis.
“We are currently studying how effective and safe a convergent approach, also called hybrid ablation, is in the treatment of atrial fibrillation compared to catheter ablation alone,” said Dr. Gervasio Lamas, the chairman of medicine and chief of the Columbia University Division of Cardiology at Mount Sinai Medical Center.
“Most ablation procedures performed today involve the use of catheters that enter the heart through the veins in the upper leg(s), and either heating or cooling is used to treat (ablate, or scar) the areas that start and maintain the electrical disturbance,” said Dr. Angelo La Pietra, a cardiovascular surgeon at Mount Sinai.
“The potential advantage is that the ablation lines ... can be placed with direct vision during the surgical part of the procedure,” said La Pietra.
The procedure is done in stages. The first stage lasts about 90 minutes (outside the heart) and the second stage (inside the heart) lasts about 60 minutes. Both procedures are performed in the same setting and facilitated by general anesthesia. Patients typically stay overnight in the hospital.
The study was conducted at 25 sites in the U.S. Mount Sinai was the only participating center in South Florida. The procedure is a FDA-cleared technology for tissue coagulation, but the FDA would have to approve this for the treatment of atrial fibrillation.
Another factor that affects people with AFib is the fatty tissue around the heart, known as epicardial fat. Initially, doctors thought it was a trivial condition, but then they realized that the enzymes released from the tissue perpetuate inflammation and thickening of the cardiac wall, making it harder for the heart to pump blood.
Armed with a new $2 million NIH-funded study, University of Miami Health System (UHealth) cardiologists are testing to see if a weight loss and diabetes drug, when paired with diet and exercise, can reduce epicardial fat in patients with persistent AFib who typically have a 50 percent success rate with ablation.
“If you look at patients who are receiving catheter ablation, those who have more epicardial fat have worse outcomes,” says Dr. Jeffrey Goldberger, chief of the cardiovascular division at UHealth, who’s conducting the study. “We know that there is a relationship between the amount of epicardial fat and outcomes, but with the study we’re investigating whether reducing epicardial fat actually improves ablation.”
Goldberger said that one of the ways to reduce epicardial fat is by losing weight, though it’s not easy for everyone to do. The drug, Liraglutide, “is a pharmacological approach to reducing fat around the heart,” said Goldberger.
“For AFib, diet and exercise are part of our risk factor modification program to help reduce the level of disease in the left atrium where AFib occurs,” he said.
Marvin Pickholz, 76, of Fort Lauderdale, was sent to UHealth via ambulance when his non-cardiac doctor heard that he had an AFib during a check-up.
“You could have it and not even know about it,” said Pickholz. “Research is extremely valuable to better understand how people operate.”
He took part in Goldberger’s study. Pickholz’s father died of a heart attack at 60, and he was feeling pain in the same part of his heart as his father did before he passed. “Your genes are still your genes,” he said.
The study will begin enrolling participants at the end of this month. Candidates would need to have some degree of obesity, have a BMI of at least 27, and opt to undergo catheter ablation for treatment of their AFib, said Goldberger.
“We expect to see a significant reduction of epicardial fat in all study participants and an improvement in ablation outcome,” he said. “The study will show us how much of a reduction in fat and the rate to which ablation improves.”
He also co-developed an MRI that measures blood flow velocity and a heart-mapping system to make ablation more precise.
“It’s based upon the notion that the regular mapping that we use for a lot of other arrhythmias is time-based and doesn’t really work for AFib,” he said of the heart mapping system. “With the other arrhythmias, the rhythm of the heart is the same beat after beat, whereas, in atrial fibrillation, the heart rhythm changes every beat, so we can’t use the exact same technology that’s used to map other arrhythmias.”
Cleveland Clinic’s latest procedure, dubbed The Watchman, is also giving hope to patients with AFib.
“Patients with atrial fibrillation have a much higher tendency to develop blood clots within the heart,” said Dr. Robert Cubeddu, interventional cardiologist and chairman of the department of cardiology at Cleveland Clinic of Florida in Weston. “These blood clots can have the potential to migrate to the brain and cause a life-threatening stroke.” he said.
“The goal of the Watchman procedure is to close off the left atrial appendage where clots form that lead to stroke in patients with atrial fibrillation.”
The hour-long procedure is performed through a catheter and requires general anesthesia. Currently, the Watchman procedure is the only approved interventional treatment for closure of the left atrial appendage for stroke prevention, said Cubeddu.
The procedure also reduces the need to take anticoagulants, or blood thinners.
Since its FDA approval in March 2015, the Watchman has been implanted into nearly 50,000 patients with non-valvular atrial fibrillation. Cubeddu said the results are “excellent.”
“The risk of stroke after a Watchman procedure is approximately 1.6 to 1.8 percent per year,” he said, “and therefore substantially lower than a stroke rate in excess of 5 percent seen in patients with atrial fibrillation who cannot take an anticoagulant.
“Atrial fibrillation, or irregular heartbeat, is very common among patients over 65 years of age,” he added, “and is therefore prevalent in South Florida – a retirement hub.”