When it comes to implanting state-of-the-art devices to reduce the risk of strokes in patients with an irregular heartbeat, Miami Cardiac & Vascular Institute  has taken a leading role for years in clinical studies that have led to approvals by the U.S. Food and Drug Administration.
Such is the case now with the Amplatzer Amulet, from Abbot Medical, which received FDA approval in August. Recently, a team at the Institute led by Ramon Quesada, M.D. , medical director of Structural Heart and Complex Percutaneous Coronary Intervention, became the first in Florida to implant the device in patients — a man in his 70s and a woman in her 80s. Both are doing well.
Both patients fit the profile of ideal candidates for this device — those who suffer from an irregular heartbeat, or atrial fibrillation (AFib), at high risk for stroke; and those who cannot, for whatever reason, tolerate long-term, blood-thinning medications called anticoagulants. Many patients with AFib can safely take these medications for years without serious side effects. But some cannot, making them good candidates for the Amulet device.
Dr. Quesada was principal investigator for the clinical trial resulting in the Amulet device’s approval. The device provides several advantages over older generation implants. Those advantages include a different size and structure to enable a smoother procedure with a seal that is complete, says Dr. Quesada.
How the Device Can Prevent Strokes
The Amulet device effectively closes off an area of the heart called the left atrial appendage (LAA) to keep harmful blood clots from entering the blood stream and potentially causing a stroke.
“Having multiple sizes make a difference,” explains Dr. Quesada. “You don’t have to be so deep inside the appendage to deploy this device. And that’s very important. Because being deeper into the appendage could carry higher potential for complications.”
In a randomized clinical trial in which the Institute and a team led by Dr. Quesada played a key role, the Amulet provided a better “sealing” of the LAA, compared to the older technology known as WATCHMAN (a superior and updated version of this device, WATCHMAN FLX from Boston Scientific, is being used by the Institute in addition to the Amulet).
“But there was better sealing with the Amulet,” says Dr. Quesada. “From the clinical point of view, it’s good that we have an alternative. We have two devices (the Amulet and WATCHMAN FLX), and we can select one of them based on the patient’s anatomy. And that’s really important.”
The Heart’s Left Atrial Appendage (LAA)
The left atrial appendage (LAA) is a small sac on the left side of the left atrium of the heart. It has a key role when the heart pumps blood through the atria and the ventricles. The LAA fills with blood when the left atrium receives blood, and then it pushes the blood out of the left atrium. For most people, the LAA functions normally, but for those with atrial fibrillation, or AFib, which is when the heart is beating erratically, the LAA can become a serious issue.
With AFib, the heart’s two upper chambers of the heart no longer contract normally. As a result, the blood flow within the atria can be slower than normal. This slowdown in blood flow may cause blood clots to form, especially in the LAA.
The Amulet Procedure to Close the LAA
With the vital assistance of cardiac Imaging procedures, the Amulet implant procedure begins with a physician inserting ay catheter into a blood vessel, or vein, in the groin and advancing it to reach the right upper chamber of the heart (right atrium). A small hole is made in the wall between the two upper chambers of the heart so that the catheter can pass through to reach the left atrial appendage. Then, through the catheter, the Amulet device is delivered to the left atrial appendage. When positioned properly, it covers the opening of the appendage.
Over time, a thin layer of tissue will grow over the surface of the Amulet device. This keeps any blood clots in the left atrial appendage from entering the bloodstream.
“There’s a learning curve with the Amulet, obviously, and we have to go through that process,” says Dr. Quesada. “But once we master both (the Amulet and WATCHMAN FLX), then we have the best options. Like in everything in medicine, we need options, and we suit the best device to the anatomy of each individual patient.”