Thursday, April 17, 2014
Marilynn Marchione / The Associated Press
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Atlanta cardiologist Dr. Spencer King demonstrates how doctors can open blocked heart arteries by going through an arm, using a model, at the American College of Cardiology conference in San Francisco recently.
Atlanta cardiologist Dr. Spencer King holds a replacement heart valve. Millions of people have valve problems – each year, more than 100,000 people in the United States alone have surgery for them.
"Essentially, this was a death sentence," said Dr. John Harold, a Los Angeles heart specialist who is president of the College of Cardiology.
That changed just over a year ago, when Edwards Lifesciences Corp. won approval to sell an artificial aortic valve flexible and small enough to fit into a catheter and wedged inside the bad one. At first it was just for inoperable patients. Last fall, use was expanded to include people able to have surgery but at high risk of complications.
Gary Verwer, 76, of Napa, Calif., had a bypass operation in 1988 that made surgery too risky when he later developed trouble with his aortic valve.
"It was getting worse every day. I couldn't walk from my bed to my bathroom without having to sit down and rest," he said. After getting a new valve through a catheter last April at Stanford University, "everything changed; it was almost immediate," he said. "Now I can walk almost three miles a day and enjoy it. I'm not tired at all."
"The chest cracking part is not the most fun," he said of his earlier bypass surgery. "It was a great relief not to have to go through that recovery again."
Catheter-based treatments for other valves also are in testing. One for the mitral valve — Abbott Laboratories' MitraClip — had a mixed review by federal Food and Drug Administration advisers this week; whether it will win FDA approval is unclear. It is already sold in Europe.
Heart rhythm problems
Catheters can contain tools to vaporize or "ablate" bits of heart tissue that cause abnormal signals that control the heartbeat. This used to be done only for some serious or relatively rare problems, or surgically if a patient was having an operation for another heart issue.
Now catheter ablation is being used for the most common rhythm problem — atrial fibrillation, which plagues about 3 million Americans and 15 million people worldwide. The upper chambers of the heart quiver or beat too fast or too slow. That lets blood pool in a small pouch off one of these chambers. Clots can form in the pouch and travel to the brain, causing a stroke.
Ablation addresses the underlying rhythm problem. To address the stroke risk from pooled blood, several novel devices aim to plug or seal off the pouch. Only one has approval in the U.S. now — SentreHeart Inc.'s Lariat, a tiny lasso to cinch the pouch shut. It uses two catheters that act like chopsticks. One goes through a blood vessel and into the pouch to help guide placement of the device, which is contained in a second catheter poked under the ribs to the outside of the heart. A loop is released to circle the top of the pouch where it meets the heart, sealing off the pouch.
A different kind of device — Boston Scientific Corp.'s Watchman — is sold in Europe and parts of Asia, but is pending before the FDA in the U.S. It's like a tiny umbrella pushed through a vein and then opened inside the heart to plug the troublesome pouch. Early results from a pivotal study released by the company suggested it would miss a key goal, making its future in the U.S. uncertain.
Some people have a hole in a heart wall called an atrial septal defect that causes abnormal blood flow. St. Jude Medical Inc.'s Amplatzer is a fabric-mesh patch threaded through catheters to plug the hole.
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