ARE CORONARY STENTS OVERUSED? A CONTRARIAN VIEW.

I just found time to read this article send to me about 2 weeks ago.
This article was published in THE NEW YORKER.

THE NEW YORKER

October 23, 2013

WHEN IS A MEDICAL TREATMENT UNNECESSARY?

POSTED BY LISA ROSENBAUM

In August, two leading medical societies published a report naming stents, the small mesh tubes that are used to open blocked arteries and restore blood flow to the heart when people have heart attacks, one of the five most overused procedures in medicine. Last month, Bloomberg News ran a report headlined “DEATHS LINKED TO CARDIAC STENTS RISE AS OVERUSE SEEN.” A handful of widely covered scandals, such as one involving a Baltimore cardiologist accused of performing five hundred and eighty-five unnecessary procedures, have given the problem a face, bolstering the national narrative about our “epidemic” of medical waste.

Heart attacks happen when a small plaque in the artery suddenly ruptures and a blood clot rushes to heal it. In many instances, one moment the artery is mostly open and the next moment it is mostly closed. In those cases, using a stent to open an artery before the heart muscle dies is life saving. Because the benefits of stents for patients having heart attacks are so clear, hospitals equipped to perform the procedure are penalized if a stent is not placed within ninety minutes of the patient’s arrival in the emergency room. This is partly why rates of death associated with cardiovascular disease have fallen by about half in the past forty years.

But for stable patients with chronic heart disease, when blockages build up over time, the benefit of opening the artery with a stent is far less certain. These long-standing blockages tend to have hardened exteriors, which can shield the plaque from exposure to the clotting factors in the blood passing by it. Chronic blockages aren’t benign—they give many patients chest pain (often called angina) and also portend a much higher risk of future heart attacks. But when it comes to treating chronic disease, medications, such as statins, aspirin, and beta blockers, are often as effective as stents.

However, this has not stopped clinicians from using stents for patients with chronic heart disease, leading to widespread concern about their overuse. The stories about cardiologists behaving badly validate the conviction, common among both policymakers and the public, that misaligned financial incentives drive doctors to do things that they shouldn’t. This narrative has taken root for a number of reasons, one of which is that, in addition to villains, it has heros—health-care reformers who will swoop in and put an end to unnecessary care, simultaneously saving the economy and improving the health of the population.

I wanted to be one of those heroes. Four years ago, when I was beginning my cardiology training, I was on a mission to get cardiologists to use stents appropriately. A patient of mine, Sun Kim (not his real name), developed chest pain one day, while lifting boxes at the grocery store where he worked. He thought it was indigestion, but that night, when it would not go away, his wife dragged him to the E.R., where doctors quickly found that he was having a heart attack. An hour later, the artery feeding the front wall of his heart had been opened with a stent, saving his life. Like many patients who have acute heart attacks, Sun Kim also had long-standing blockages in other arteries. At the time, the guidelines recommended opening the artery causing the heart attack and leaving the other arteries alone. We followed them: Sun Kim received one stent, medications, and plans for a follow-up appointment. Many patients across the country with similar ailments, however, would have emerged with several stents—to me, a classic example of overuse.

Successful conservative management, however, depends on seeing patients regularly, so that you can titrate their medications and make sure that their cardiovascular risk factors are controlled. But Sun Kim didn’t come back. No English. No answering machine. I feared that he had died. Then, six months after his heart attack, he showed up to my clinic, wasted and sunken, the oversized baseball cap that he had proudly worn out of the hospital hanging over his eyes. Because he had developed shortness of breath and chest pain with movement, he did what many patients do: he simply stopped moving. When we took him back to the catheterization lab, things didn’t look good. The front wall, despite being fed with blood, remained weak, likely because heart muscle had died during the hours he had waited to seek medical care after his heart attack.

The other problem was that the bottom wall of his heart had also stopped moving, and the calcified blockage in the artery feeding that wall was now blocking the artery entirely. Even though it’s counterintuitive that an open artery is not invariably better than a closed one, guidelines say that you’re not supposed to stent an artery feeding a wall of the heart that’s already dead. So we followed the guidelines and provided only the care that seemed necessary: medicine and follow-up. Once again, Sun Kim disappeared.

* * *

Because cardiovascular disease is so common, cardiologists have been able to study millions of patients, leading to what is arguably the most robust evidence base in all of clinical medicine. Yet despite innumerable outstanding clinical trials, we are always held back by what we don’t know.

Consider the claim that medications are as good as stents for treatment of stable coronary artery disease. This is the idea upon which most accusations about the overuse of stents are predicated. Several studies support this assertion, but the seminal one is the COURAGE trial, which randomly assigned patients with stable blockages to either medication or a stent. The study found that those treated with medications lived just as long as those with stents. COURAGE is a super-star trial, the best of its kind. So why can’t we say, once and for all, that it’s inappropriate to use stents for patients with stable coronary disease?

The answer is that it’s because such a statement is a colossal oversimplification. The fundamental challenge of translating data into practice is what we call generalizability: Can we extrapolate the findings from a trial to real life? If you are a doctor who is trying to practice evidence-based care, the first thing you want to ask yourself is, Would my patient have been enrolled in the trial? Sun Kim would not have been eligible for the COURAGE trial, which excluded all patients with high-risk features—or nine out of ten otherwise eligible patients.

But let’s say that your patient is among the ten per cent who would have been enrolled in COURAGE. Can’t you say now, with certainty, that your patient should not get a stent? Still no. Real life rarely resembles clinical trials, which are, by definition, rarefied environments—well-oiled machines with incredible depth of resources and a staff to orchestrate patient care.

If, as in the case of COURAGE, you set out to show that medications are as effective as stents in treating chronic disease, you want to make sure that the patients in the trial are actually taking those medications. In reality, the rate of adherence to medications is about fifty per cent, but COURAGE not only provided medications for free—it also hired nurse managers who saw patients regularly and adjusted dosages. Not only did these patients adhere to medications at a far higher rate than patients usually do—this adherence also translated to excellent blood pressure and cholesterol control.

If it’s hard to apply the findings from any one trial to the treatment of a particular patient, it’s harder still to use data from many trials to create guidelines that can be applied to any patient. When a group of expert cardiologists were asked to do just that, they recognized that there are many factors to be considered in addition to medication—including the acuity of the disease, the patient’s degree of chest pain, the results of stress tests, and which of four main arteries are blocked. When you account for all of these factors, you come up with over four thousand clinical scenarios for which stenting may or may not be appropriate, many of which can’t be mapped precisely to a clinical trial.

It was in these gaps between data and life where I lost Sun Kim. There is no guideline that says, “This is how you manage an elderly man who asks nothing of anyone, who may or may not be taking his medications, and who has difficulty coming to see you because he vomits every time he gets on the bus.” In a world with infinite resources, we could conduct clinical trials to address every permutation of coronary disease and every circumstance. But that’s not the world we live in. And in our world, I reached a point where I could not keep Sun Kim out of the hospital.

* * *

Few in medicine exude more confidence, or have a greater following, than Dr. Oz, who devoted an entire show to stents. During the episode, entitled, “The Most Unnecessary Heart Procedure: The Danger of Stents,” he implies that only half of stents placed for chronic disease are appropriate. (Michael Specter wrote about Dr. Oz in February.)

A few months later, cardiovascular experts published a study looking at the appropriateness of over half a million stents. They found that for the seventy per cent of patients who received stents while having a heart attack, ninety-nine per cent of stents were appropriate. But among the thirty per cent of patients with chronic heart disease, only fifty per cent of stents were rated as appropriate. Does that mean, as many people claim, that half of stents placed were inappropriate?

Of course not. What these cardiologists actually found was that, among the smaller subset of patients with stable disease, thirty-eight per cent of stents placed were ranked as uncertain. The label of uncertain is not meant to suggest right or wrong—it simply means that, for that particular clinical situation, we don’t know whether a stent will be beneficial. If you account for this uncertainty in your interpretation of the data, you actually find that, over-all, only 3.5 per cent of the half a million stents placed in the United States during the period studied were found to be inappropriate.

Why might patients with stable disease receive a stent when there is no evidence that it will make them live longer? One big reason is that it often makes them feel better. Though this usually goes unmentioned in descriptions of the COURAGE trial, a separate analysis, published in the New England Journal of Medicine, showed that for the first two to three years of follow-up those patients who received stents had more relief of their chest pain and better quality of life. In this era of shared decision-making, when we are urged to ask our patients what they want, which do you think they choose when you tell them that a stent won’t necessarily make them live longer but might make them feel better?

But no one wants to read a story about doctors putting in stents because they are trying to do the right thing for their patients. For a long time, I didn’t, either. I was furious when, one day, I got a call from an interventional cardiologist at another hospital, closer to Sun Kim’s home. Sun Kim was there, with trouble breathing and worsening heart failure. The interventional cardiologist had performed another cardiac catheterization, where he, too, found the totally blocked artery feeding the dead wall. Except, as he proudly told me, he decided to open the artery with a stent. So much for guidelines, I thought, and spent the next several days telling anyone who cared to listen about my patient getting a stent that he clearly did not need.

“This,” I told them, “is precisely what’s wrong with American medicine.”

* * *

Last month, a study was published in the New England Journal of Medicine which will likely change clinical practice, as well as the constantly updated guidelines that define appropriateness. The study looked at patients, like Sun Kim, who at the time of a heart attack are also found to have chronic blockages. Half of the patients were managed conservatively, as I had managed Sun Kim. Half received stents for both their acute and chronic disease. The results were a surprise: stenting both the acute and chronic disease led to fewer deaths and fewer heart attacks. In fact, the benefit was so pronounced that the trial was stopped early. I have yet to read about this trial in the news.

I did read the article in the New York Times about latest stent-overuse scandal, this time out of Florida. The nurse who alerted the hospital authorities to the scandal is quoted in paragraph three. “It bothered me,” said the nurse. “I care about my patients.”

Of course we should not tolerate inappropriate use—subjecting patients to harm for the sake of a profit is unconscionable. Moreover, given that seventy-five to eighty per cent of patients with chronic disease believe that stents will prevent future heart attacks and prolong their lives, it is our responsibility as physicians to do a better job of explaining when this is not the case.

That said, we must be careful not to let the bad behavior of the few malign the good intentions of the many. Stories in the Times give additional credibility to the assumption, driving many of the payment reforms of the Affordable Care Act, that if you pay doctors for “value,” rather than for volume, we will stop treating patients with care they do not need. If so-called “unnecessary care” were simply the consequence of profit-driven doctors overtreating patients, the reforms are a perfect solution. If, however, we make room for the tremendous uncertainty upon which most of medicine is practiced—an uncertainty that eludes hard and fast rules governing appropriate use—then we are left with a more truthful tale, albeit one that offers a less clear path to a happy ending.

When Sun Kim followed up with me a week after he received the stent that I was certain he didn’t need, I did a double take when I saw him. There was color in his cheeks, and he bounded into the room. He pounded on his chest to demonstrate his new strength, lifting that too-large cap to bow his head in thanks. “Doctor,” his daughter gushed, “you saved his life.”

Lisa Rosenbaum is a cardiologist, a Fellow at the Philadelphia V.A. Medical Center, and a Robert Wood Johnson Foundation Clinical Scholar at the University of Pennsylvania. She served on the writing committee for the Appropriate Use Criteria Multimodality Document for the detection of Ischemic Heart Disease.