For many people, a quickened heart beat is a normal physiologic response to physical activity or stress. But for approximately six million Americans with atrial fibrillation, (1) an untreated, irregular heartbeat can lead to blood clots, stroke, heart failure and other heart-related complications.
I left the hospital after the overnight procedure feeling transformed
Normally, the heart contracts and relaxes to a regular beat. In atrial fibrillation, irregular electrical signals impede the upper chambers of the heart (called the atria) from beating. This impediment limits blood flow to the heart and body.
Christopher Woods, M.D., PhD, FHRS, an electrophysiology physician and Medical Director of the Atrial Fibrillation and Complex Ablation Center at Mills Peninsula Medical Center (MPMC) offers an analogy: “For people with this illness, it’s like losing a fuel injector and the heart has difficulty adjusting to the altered electrical wiring that normally propels its functioning.”
People with atrial fibrillation may experience irregular heartbeat, shortness of breath, chest pain, fainting, a feeling of fluttering in the chest, dizziness and weakness. They are also at higher risk for stroke, which can cause disability and death. Atrial fibrillation-induced strokes result when poor blood flow causes clots to form in the heart. The illness causes one in every seven strokes in the U.S. (1)
The current, standard treatment for atrial fibrillation focuses on two cornerstone strategies: restore normal heart rhythm so that people feel better, and prevent the occurrence of stroke.
To restore normal cadence, treatment includes anti-arrhythmic medications to help reset and control the heart’s rhythm, and a procedure called ablation.
“Ablation is a therapy whereby energy is delivered to the heart through a minimally invasive procedure to eliminate the triggers that lead to atrial fibrillation. It is more effective than anti-arrhythmic drugs, and at least equally safe,” says Dr. Woods.
Stroke prevention hinges on the use of either: 1) anticoagulation treatment with drugs such as direct oral anticoagulants, to lower the risk of clots that form as a result of atrial fibrillation, or 2) mechanically eliminating the areas where over 90% of clot formation occurs—the left atrial appendage in the heart—with a procedure known as “left atrial appendage exclusion.”
“A common misconception is that, with an ablation, anticoagulation can be stopped. However, the standard approach to stroke prevention regardless of ablation is the use of anticoagulation to reduce this risk in patients with high enough risk of stroke,” says Dr. Woods. “Large studies are ongoing to address this question. At present, current national guidelines recommend continuing anticoagulation after successful ablation guided by stroke risk. This should be considered the standard of care.”
Dr. Woods adds that anticoagulation is not without risks. “Many patients develop bleeding complications from these medications. Furthermore, anticoagulation reduces stroke risk in atrial fibrillation by only two thirds, and so it is not a panacea. In addition, these medications are costly.”
A new clinical trial called OPTION (Comparison of Anticoagulation With Left Atrial Appendage Closure After AF Ablation) is aiming to solve both problems of atrial fibrillation without the need for ongoing medication. “If the study achieves its aims to decrease the risk of stroke in patients who have undergone ablation for atrial fibrillation, the landscape for therapy may change dramatically,” says Dr. Woods.
Launched at MPMC, OPTION is a prospective, open-label, randomized study testing the efficacy and safety of a small implanted device placed in the heart that can reduce the risk of stroke in patients with atrial fibrillation—versus continued anticoagulation in patients already treated with cardiac ablation. Approximately 1,600 patients will be enrolled in the study worldwide. The device, WATCHMAN FLX™, was developed by Boston Scientific, the sponsor of the OPTION study.
Sutter patient Edward (Bud) Hamilton, aged 82, was the first patient enrolled in the OPTION study at MPMC. Initially referred to Dr. Woods in 2013 for atrial fibrillation, Hamilton had two ablation procedures in 2019 that freed him of symptoms. At high risk of stroke, he remained on anticoagulation medication. Keen to stop therapy with anticoagulants, Hamilton readily agreed to join the study after Dr. Woods, the primary investigator for the study at MPMC, described the study aims, as well as the potential risks and benefits.
In December 2019, Hamilton had the WATCHMAN FLX™ device implanted in his heart at MPMC. Both ablation and the WATCHMAN FLX™ are minimally invasive and involve a small incision in the groin blood vessels to reach the heart.
“I left the hospital after the overnight procedure feeling transformed,” says Hamilton, a San Mateo resident. “I can breathe easier and no longer experience the bleeding and bruising from stroke prevention medications. This research and the personal care I received at Sutter have made a real difference in how I can enjoy my days with friends and family.”
Hamilton, and other patients enrolled in the OPTION study, will be followed for 36 months after the study intervention (implantation of the WATCHMAN FLX™ device, or oral anticoagulants).
“This clinical trial may help us realize a future vision for the management of atrial fibrillation. The study may demonstrate that the appropriate care pathway for patients is to simultaneously undergo symptom and stroke management in one procedure, and fully come off all medications thereafter, except for a baby aspirin. We are proud to be part of that discovery process,” says Dr. Woods.
Curious to learn more about research and clinical trials for atrial fibrillation? Discover Sutter research.
1. U.S. Centers for Disease Control and Prevention.