New Treatments For

Coronary Artery Blockages

A new combination device for treating coronary artery blockages was approved by the Food and Drug Administration and has been put into use at area hospitals.

In clinical trials, the drug-eluting, or drug-dispensing, stent almost totally eliminated the incidence of restenosis (reblockage) in cleared arteries and the need for follow-up procedures, including bypass surgery.

“With this first generation of drug-eluting stents, we have entered a new era in cardiology,” said Dr Mitchell Driesman, director of interventional cardiology at Bridgeport Hospital. “No longer do we use a stent only to mechanically push open and buttress a blocked artery, but now it can also deliver high concentrations of potent medication to the artery and interrupt the disease process itself.”

The stent is coated with sirolimus, a naturally occurring antibiotic. While the stent –– a tiny metal mesh tube –– buttresses the artery, the medication is continuously released at the site of the blockage, preventing excess cell growth and scarring that can cause restenosis. This scar tissue growth, known as in-stent restenosis, occurs when scar tissue forms around the site of the stent and occurs in about 20 percent of patients who receive stents. The scar tissue may eventually cause reclosure of the artery, which in turn may require another artery-clearing procedure.

If restenosis occurred, the doctor had four treatment options: perform another balloon angioplasty, put in another stent, use radiation to burn away the scar tissue, or perform a coronary bypass operation.

Nearly ten years ago, specialists in the Heart Institute at Bridgeport Hospital were the first in Fairfield County to use stents during balloon angioplasty procedures. In balloon angioplasty, a catheter is threaded through the patient’s groin or arm to the point of the blockage in his or her heart. A tiny balloon at the tip of the catheter is inflated, pushing the blockage (a fatty substance known as plaque) outward toward the artery wall. This helps restore blood flow to the heart.

Even when working at their best, however, stents alone are not always effective. Sometimes scar tissue or blood clots can form in or around the stent, again causing the artery to become blocked. Last year, cardiologists at Bridgeport Hospital began using stents coated with heparin, an anticlotting drug, and earlier this year, working with radiation medicine specialists, they began administering small does of radiation after angioplasty to stunt the regrowth of scar tissue in cleared arteries.

“The introduction of drug-eluting stents takes artery-clearing measures to the next level,” said Dr Driesman, who has been performing angioplasty procedures at the hospital for more than 20 years. “Now the odds are better than ever that patient undergoing angioplasty will not require a follow-up procedure, possibly including cardiac bypass surgery, to address the problem of reblockage.”

Even with the recent advances in stent technology, not every patient is a candidate for angioplasty. In cases of multiple blockages, or if the blockage is too long or not reachable with a catheter, bypass surgery may be necessary. These may be traditional open-heart bypass procedures or minimally invasive surgery, including off-pump or “beating heart” surgery, which allows arteries to be repaired without artificially stopping a patient’s heart and temporarily using a heart-lung machine.

“Never before have there been so many effective treatment options for patients with coronary artery disease,” said Dr Stuart Zarich, chief of cardiology at Bridgeport Hospital. “The range of treatments available in the Heart Institute means having the right solution for nearly every patient..”