Wave of the Future

woman hunched over

A new device uses sonic pressure to break up hard-to-remove plaque.

The coronary stent—a tiny but powerful thin mesh tube that props open blocked heart arteries—was first used in 1986 and has since transformed care for coronary artery disease (CAD). Today, more than 600,000 coronary stents are implanted through catheters each year in the U.S., helping to restore blood flow to patients’ hearts without open heart surgery.

Now, a newly approved technology, available locally at Clara Maass Medical Center (CMMC), could make stents even more effective for people with the most severe and potentially life-threatening coronary artery blockages.

Elie Chakhtoura, MD
Elie Chakhtoura, MD

The device, called the Shockwave C2 Coronary Intravascular Lithotripsy Catheter, uses sonic waves to destroy heavy buildups of hard, calcified plaque within the arteries. “This allows us to open stents fully within an artery, regardless of the amount of plaque buildup within that artery,” says interventional cardiologist Elie Chakhtoura, MD, Director of the Cardiac Catheterization Laboratory at CMMC and a member of RWJBarnabas Health Medical Group.

Shockwave received U.S. Food and Drug Administration (FDA) approval for use in coronary arteries in February 2022. Dr. Chakhtoura began using it in heart patients in early fall and has treated more than a half-dozen patients successfully at CMMC thus far. “It’s an excellent way to remove hardened calcium from a coronary artery and improve stent expansion,” he says.

Not All Blocked Arteries Are Alike

Symptoms such as chest pain, shortness of breath and nausea are telltale signs of CAD. But the only way to know the full severity of a person’s blocked coronary arteries is to perform a procedure called coronary angiography.

During coronary angiography, doctors in a cardiac catheterization lab thread a catheter into the wrist or groin and up into the coronary arteries, where they inject dye and acquire images. If a blocked artery is identified, percutaneous coronary intervention (PCI), or balloon angioplasty, is performed. Doctors inflate a balloon to open the blockage, then insert a stent to hold the artery open.

But doctors performing a PCI find that if an artery has a severe calcified buildup of plaque, which is seen in an estimated 18 to 26 percent of PCI cases nationwide, a stent can’t fully open.

“When that happens, it can lead to several potential problems,” Dr. Chakhtoura explains. “For one, a patient will not get the benefits of a wide open vessel. For another, drug-eluting stents- that slowly release medication to reduce the risk for repeat artery blockages face an additional problem. If a drug-eluting stent is under-deployed, the delivery of the medication to vessel wall is severely compromised leading to a higher possibility of re-occlusion. This also increases the risk of stent thrombosis, which happens when blood clots form in a stent.”

Patients with severely calcified arteries who receive drug-eluting stents— those that slowly release medication to reduce the risk for repeat artery blockages—face an additional problem.

“If a drug-eluting stent is under-deployed, there’s a chance that the medication will separate from the stent because the stent is rubbing against a calcified artery wall,” says Dr. Chakhtoura.

How Shockwave Therapy Helps

Shockwave provides a new and potentially more effective option for people with severely calcified coronary arteries. It delivers the same type of sonic wave therapy—called lithotripsy—that doctors have used to break up hardened kidney stones since the 1980s.

The Shockwave device includes a generator and catheter and looks similar to a small household pressure washer. The catheter resembles those used during traditional balloon angioplasty, with one major difference: The tip of the catheter, located within the balloon, includes several tiny transducers.

Once the Shockwave catheter is threaded into the artery during PCI, Dr. Chakhtoura inflates the balloon. He then uses the generator to deliver a therapy called intravascular lithotripsy (IVL).

“The IVL generator sends pulses of sonic waves up through the catheter and into the transducers,” Dr. Chakhtoura says. “The waves then break down the calcium inside an artery into tiny particulate material, making the vessel more expandable and allowing full deployment of a stent.”

The procedure carries a low risk of complications such as serious bleeding or blood vessel damage. Most patients who receive Shockwave treatment at CMMC will return home from the hospital the same day.

Early Success For Other Applications

Prior to receiving approval to treat blocked coronary arteries, Shockwave therapy was approved to help remove blockages located within the arteries of the legs and pelvis. Dr. Chakhtoura used the device initially during transcatheter aortic valve replacement (TAVR) procedures at CMMC’s sister hospital, Cooperman Barnabas Medical Center.

“When doing a TAVR procedure, if you encounter a severely calcified femoral artery in the pelvis, you can’t advance the device up and into the heart,” says Dr. Chakhtoura. “We began using Shockwave to clear those femoral vessels and found it to be extremely effective.”

Now that Shockwave is approved for CAD treatment, Dr. Chakhtoura says he expects to do several PCI procedures with the device each month. He’s already seen the benefits in the patients with severe calcification that he’s treated with IVL.

“Shockwave gives us another tool we can use to take care of people’s hearts here in our community, using the latest and safest minimally invasive approaches available,” he says.

Whoever your heart beats for, our hearts beat for you. To connect to a top cardiovascular expert at Clara Maass Medical Center, call 888-724-7123.