When plaque builds up inside your coronary arteries, it can increase your risk for heart attack. Restenosis or in-stent restenosis occurs when a stent previously placed to treat coronary artery disease or CAD becomes narrowed in the artery.
Renarrowing can happen because of two main reasons, says Amar Krishnaswamy, MD, an interventional cardiologist in Cleveland Clinic’s department of cardiovascular medicine.
The first occurs with a stent too small for the artery. Plaque builds up around the stent just like it did when the artery first became blocked. “The stent area can narrow from the deposit of just a tiny bit of plaque,” he says. Restenosis may also occur when plaque forms inside a large stent, and causes renarrowing.
To best determine the cause, cardiologists may choose to do a cardiac catheterization. This is an invasive imaging procedure that enables evaluation of heart function. Often, the cardiologist may also use a special camera called an intravascular ultrasound or IVUS, placed on the tip of the coronary catheter.
“To treat the problem, an initial stent now too small for the artery can simply expand further when we use a balloon during the procedure,” says Dr. Krishnaswamy. “Patients with an appropriately-sized stent who still develop restenosis present us with more of a challenge.”
Bare metal stents demonstrate a higher rate of renarrowing. Patients with those in place may require a different, drug-coated stent. Patients who already have a drug-coated stent may either require another variety of drug-coated stent or their cardiologist may recommend a coronary artery bypass graft surgery (CABG).
“I’ve described very specific situations for specific patients, so please talk to your cardiologist about the best treatment option for you,” says Dr. Krishnaswamy.
Restenosis treatment outcomes generally fare better when experienced cardiac interventionalists who understand and practice multiple treatment options perform the procedures. Cleveland Clinic averages about 10,000 diagnostic cardiac catheterizations and 3,000 interventional procedures annually, and routinely treat patients with multiple stents.