In the news:
Heart-repair breakthroughs replace surgeon’s knife
Heart conditions that used to require opening the chest to work on the heart now can be treated using catheters.
The Associated Press
SAN FRANCISCO — Have a heart problem? If it’s fixable, there’s a good chance it can be done without surgery, using tiny tools and devices pushed through tubes into blood vessels.
Heart care is being transformed. Many problems that once required sawing through the breastbone and opening up the chest for heart surgery now can be treated with a nip, twist or patch through a tube.
These procedures used to be done just to unclog arteries and correct less common heart-rhythm problems. Now some patients are getting such repairs for valves, irregular heartbeats, holes in the heart and other defects — without major surgery.
All rely on catheters — hollow tubes that let doctors burn away and reshape heart tissue or correct defects through small holes into blood vessels.
“This is the replacement for the surgeon’s knife. Instead of opening the chest, we’re able to put catheters in through the leg, sometimes through the arm,” said Dr. Spencer King of St. Joseph’s Heart and Vascular Institute in Atlanta.
“Many patients after having this kind of procedure in a day or two can go home” rather than staying in the hospital while a big wound heals, said King, former president of the American College of Cardiology, whose conference this month featured research on these novel devices.
They may lead to cheaper treatment, although the initial cost of the devices often offsets the savings from shorter hospital stays.
Not everyone can have catheter treatment, and some promising devices have hit snags in testing. Others are so new that it will take several years to see if their results last as long as the benefits from surgery do.
Here are some common problems and newer treatments for them:
Millions of people have leaky heart valves. A common one is the aortic valve, the heart’s main gate. It can stiffen and narrow, making the heart strain to push blood through it. Without a valve-replacement operation, half of these patients die within two years, yet many are too weak to have one.
That changed just over a year ago, when Edwards Lifesciences won approval to sell an artificial aortic valve flexible and small enough to fit into a catheter and wedge 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.
Catheter-based treatments for other valves also are in testing. One for the mitral valve — Abbott Laboratories’ MitraClip — had a mixed review by Food and Drug Administration advisers; whether it will win FDA approval is unclear. It is already sold in Europe.
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’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’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, 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’s Amplatzer is a patch threaded through catheters to plug the hole.
The patch is also being tested for a more common defect — PFO, a hole that results when the heart wall doesn’t seal the way it should after birth. This can raise the risk of stroke. In two new studies, the device did not meet the main goal of lowering the risk of repeat strokes in people who had already suffered one, but the results encouraged some doctors.
The original catheter-based treatment — balloon angioplasty — is still used hundreds of thousands of times each year in the U.S. alone. A Japanese company, Terumo, is one of the leaders of a new way to do it that is easier on patients — through a catheter in the arm rather than the groin.
Newer stents that prop arteries open and dissolve over time, aimed at reducing the risk of blood clots, also are in late-stage testing.
HIGH BLOOD PRESSURE
About 75 million Americans and 1 billion people worldwide have high blood pressure, a major risk factor for heart attacks. Researchers are testing a possible long-term fix for dangerously high pressure that can’t be controlled with medications.
It uses a catheter and radio waves to zap nerves, near the kidneys, which fuel high blood pressure. At least one device is approved in Europe and companies are testing devices in the United States.