Your health: Caring for your heart

Unblocking arteries and keeping them open

By Marc A. Singer, MD, FACC

Issue of Nov. 7, 2008 / 9 Cheshvan 5769

It’s been more than 30 years since cardiologists learned how to alleviate blocked arteries by gaining access to the blockages through arteries in the arms or legs. By threading catheters to their destination under radiographic guidance, they are able to restore normal blood flow and relieve symptoms of angina. But that is only the beginning of the story.

It is one thing to open a blocked artery; it is another to keep it open. Historically, blockages were alleviated using a small balloon at the end of a catheter. These angioplasties had a tremendous Achilles’ heel called restonisis. One out of every three angioplasties was likely to close down, or re-stenose, within three months. For years, scientists toiled to fix this problem. Many different medications were tried, and though in principle they all should have worked, in practice it was difficult to get sufficient doses of medication to areas that needed it.

Sometimes, where chemistry fails, mechanical strength can help. About 10 years ago, stents were introduced. Resembling a section of chain-link fence, stents work to buttress an artery and keep it open. They are loaded onto a wire, and placed inside an artery after it was unblocked.

The results were encouraging, and certainly an improvement over angioplasty, reducing the re-closure rate down to about 10 percent. However, one out of every 10 stents required a repeat procedure (among other problems), a less than satisfactory success rate.

Of course, improvement came when two approaches were successfully combined: stents were impregnated with medications. The medication would slowly be released over the course of time and, since they were on the stent, were delivered to where they were needed the most. Drug eluding stents, as they are known, further reduced the need for repeat procedures for re-stenosis. But the story does not end there.

Stents are made of metal, and therefore are thrombogenic, or prone to develop clot. This presented a new challenge: preventing stents from closing due to clots. The clotting issue was addressed with a combination of medications, including aspirin. They prevented clots by working against the blood cells that play a key role in forming clots: platelets. These medications need to be taken for a full year.

In 2008 we still are faced with challenges. What if someone with a drug eluding stent develops a bleeding ulcer? What if someone needs surgery and the anti-platelet medications increase bleeding? This dilemma is one that clinical cardiologists frequently have to deal with.

Though I am certain research will continue to find even better methods to address coronary artery blockages, I must emphasize that it is best to avoid developing blockages to begin with. Eating healthy foods, getting regular exercise and living a healthy lifestyle make for a good start. You might say that an ounce of prevention is worth a stent of cure.

Dr. Marc Singer practices cardiology and internal medicine in Lake Success and is on staff at both Long Island Jewish Medical Center and North Shore Hospital, Manhasset.