Every year over 300,000 North Americans have a stent implanted to increase the flow of blood to the heart’s muscle. Stents have been inserted for decades because of cardiologists’ concern that, without a stent, a heart attack may occur. Or, a coronary attack may have already caused angina, due to inadequate blood supply. Now, a study published in the medical journal, The Lancet, reports that some stents are life-saving, while others could have been avoided.
But this is not the first review that has cast a shadow over stents. In 2007, the highly respected New England Journal of Medicine reported second thoughts about the value of stents. A survey of 2,287 volunteers showed that adding stents to drug therapy had no effect on heart attacks or death, compared to just using drugs alone.
This debate will not end quickly as doctors’ habits rarely change overnight. Moreover, these studies could be wrong. So I’m sure that more will follow. In the meantime, when the heart’s muscle is not getting enough blood and angina occurs, what is the best treatment?
There are two kinds of angina, stable and unstable. Stable angina causes chest pain when walking, exercising, or during emotional stress, and is relieved by resting. Coronary arteries have to be about 70 percent blocked to trigger angina.
Unstable angina in contrast can occur without exercise. For instance, it can suddenly waken you during the night, and is not quickly eased by resting or using nitroglycerin. This is a critical condition, as heart attack may occur in a short time. In this case, the insertion of a stent can be life-saving.
In spite of this analysis many cardiologists continue to use stents. They reason that, even if stents do not save lives, they at least reduce or relieve angina pain. Now, even this conclusion is been questioned by further interesting research. For the first time, researchers decided to see if the power of placebo treatment could match the success of stents. This was a double-blind study, in which neither researchers nor patients were aware of who had been given a stent, and who had not received one.
Two hundred patients in their 60s were followed. They had obstruction of coronary arteries causing chest pain. They were given six weeks of drug therapy to decrease angina. Then another group was treated with stents. Lastly, a third group was given sedation; catheters were inserted, but no stents were deployed. It was sheer sham, fake therapy without the patients’ knowledge.
Six weeks following the procedure, patients were tested on a treadmill to evaluate the result. What was found shocked the researchers. For years they had known that a sugar pill could often help those in pain. But it was a surprise for them to discover no statistical difference between those who had received stents and those who had the phony procedure. So, never underestimate the psychological power of sham therapy, and its effect on the accuracy of clinical trials.
So what is the solution? It makes sense to try drugs first as they could be as effective as using stents. But if drugs fail, stents should be considered. And remember, if a stent is inserted, drugs to keep the stent open are needed, and more drugs to stop blood from clotting.
But what is the initial risk of having a stent inserted? Doctors have inserted millions of stents, and the risk is small. But as I‘ve often stressed, there is no such thing as risk-free surgical procedure. So what can go wrong?
During and following the stent, insertion bleeding can occur. This can happen at the area where the stent is inserted, and a hematoma (blood clot) can form. It’s not a serious complication, but it worries patients as it may take several weeks to resolve. There’s also the risk of allergic reaction or stroke. And always the chance that the stent will become blocked in the weeks or months following its insertion.
Remember, if chest pain occurs at rest and lasts over five minutes, forget everything and call 911. An immediate stent can be life-saving.
Dr. Ken Walker (Gifford-Jones) is a graduate of the University of Toronto and The Harvard Medical School. He trained in general surgery at the Strong Memorial Hospital, University of Rochester, Montreal General Hospital, McGill University and in gynecology at Harvard. He has also been a general practitioner, ship’s surgeon and hotel doctor. See www.docgiff.com for past columns. For comments: email@example.com.