To celebrate February as American Heart Month, the News Blog is highlighting some of the latest heart-centric news and stories from all areas of Penn Medicine.
At first pass, lariat seems like just a hifalutin' word for the more down-to-earth, lasso – a long, noosed rope. For most, either word will bring to mind images of cowboys and rodeos, not human hearts. However, thanks to a new technology making its way onto the medical scene, lariat has a new meaning and is helping to treat the most common of cardiac arrhythmias, atrial fibrillation.
Let’s take a few steps back though, before we make the leap from rodeo ring to hospital.
New Heart Procedure to Treat Atrial Fibrillation Atrial fibrillation (AFib) is an irregular heartbeat that feels like a fluttering or quivering of the heart that affects close to three million Americans. According to the National Heart, Lung and Blood Institute, when AFib occurs, rapid, disorganized electrical signals cause the heart’s two upper chambers to fibrillate, or contract very quickly and irregularly.
AFib causes blood to pool in the upper chambers of the heart. This keeps the heart from pumping blood completely into the heart’s two lower chambers. While for some, the symptoms of AFib can feel very frightening, others have no signs at all. But symptomatic or not, make no mistake about it: AFib is not a simple “heart flutter” and certainly not something to ignore. The biggest threat from atrial fibrillation is the threat of blood clots and stroke.
“Patients with atrial fibrillation are six times more at risk of having a stroke and 15 to 20 percent of all strokes a year are related to AFib,” said Daniel J. McCormick, DO, FACC, FSCAI, an interventional cardiologist at Pennsylvania Hospital. “This is not only significant from a direct health care standpoint, but a societal one as well since stroke is one of the biggest drivers of disability and health care costs in the U.S.”
The standard treatment for AFib is the use of anticoagulants, more commonly known as blood thinners, such as warfarin, and heparin. While there will always be a need for blood thinners in medicine, the truth is, their effectiveness is precisely what makes them so dangerous. Warfarin, the most commonly used for example, is also used to poison rats and mice. Its anti-clotting properties produce death through internal hemorrhaging – a trait you want to control rodent populations, not your AFib.
This is why warfarin is considered a “black box drug” by the U.S. Food and Drug Administration (FDA). The black box is the strictest warning the FDA can give a medicine while still permitting it to remain on the market. According to Dr. McCormick, patients on blood thinners must be monitored weekly to make sure their medication levels are safe, which limits one’s mobility and quality of life. Striking a balance between effective, therapeutic levels of blood thinners and hazardous ones is delicate and requires constant diligence on part of both the patient and physician – a level of diligence many patients aren’t capable of maintaining. “Even with careful monitoring only about 20 percent of all patients on warfarin are within the proper range at any one given time,” explained Dr. McCormick. “These patients are living on a very short leash.”
According to McCormick, herein lies a primary challenge of treating patients with AFib: there is a real need for other therapies to treat patients that:
1) Have a prior history of stroke and can’t take anti-coagulants because of bleeding complications.
2) Are extremely difficult to manage despite diligence and monitoring.
More invasive treatments for AFib include implants (currently still in clinical trials) and surgery to place sutures, clips and staples to close off the affected trouble areas of the heart.
A little less invasive in that it doesn’t leave anything in the heart, is radiofrequency ablation, where a small, flexible catheter is inserted through a vessel in the groin and up to the heart. Using fluoroscopy, a live x-ray image, an interventional cardiologist carefully guides the catheter up into the heart where small electrodes are placed. The electrodes, connected to monitors to help locate what exact areas of the heart are causing the AFib, are also used to send electrical energy to the problem areas, effectively destroying them and creating a tiny bit of scar tissue. It’s the scarring that halts the irregular heart rhythm. While ablation can often control AFib and many patients do well, it’s not full-proof. “There’s a high recurrence rate of AFib in ablation patients – about 30 percent,” said Dr. McCormick.
Enter the lasso! Or more specifically, PLACE™ a LARIAT®. By using the PLACE procedure of Permanent Ligation Approximation Closure and Exclusion, a physician is able deploy the LARIAT, an FDA-approved Left Atrial Appendage Occlusion Device, to seal off the malfunctioning area of the heart where dangerous blood clots can form.
Dr. McCormick performed the first two LARIAT cases on January 30, at Pennsylvania Hospital, the first in the region to use the new technology and second in the state.
Performed in the hospital’s cardiac catheterization lab, the procedure takes approximately two hours with a patient under general anesthesia. Two small catheters are threaded through the groin up to the heart allowing for two magnetic tipped wires to hold the affected area in place. Then a balloon is inflated to confirm the proper position of the area to be sutured off with a micro-mini lasso. The suture/lasso/lariat is then cinched up around the base of the appendage, sealing off the problem area. After a year, the whole affected area just naturally withers away to nothing. While still in the early stages of employment, previous use so far suggests there are low complications and a high success rate associated with the procedure.
Patients are required to stay on bed rest for four hours once out of recovery and stay over the night in the hospital. “The LARIAT provides a permanent solution for stroke risk associated with atrial fibrillation without leaving any devices or other objects behind in the heart.” said McCormick. “But what’s really exciting is that the patient is off warfarin immediately after the procedure. It’s terrific to be able to add another tool to our arsenal of treatments for atrial fibrillation.
Want to learn more about reducing your risk for heart disease this? Visit the Penn Heart and Vascular update on Penn Medicine’s website.