As evidence mounts, fewer doctors perform unnecessary angioplasties

When clots block your heart arteries, you have a heart attack. So it only makes sense that an angioplasty to widen your narrowing arteries before you have a heart attack should prevent it from ever happening and even save your life.

Plenty of patients, and even some heart specialists, still think so. But study after study has been showing that the conventional wisdom is wrong — in most cases, the operation won’t protect you from a future heart attack.

The mounting evidence, along with new treatment guidelines, has been causing a quiet revolution in the treatment of coronary heart disease, shifting patients away from angioplasty in favor of medications, exercise and better diets.

A study published this month in the Journal of the American Medical Association finds that the number of elective angioplasties has fallen by a third in just five years. That mean tens of thousands of people are avoiding a procedure that may have done them little or no good but that costs on average $27,000 and may require years of drug therapy to avoid complications.

Meanwhile, a second new study in the New England Journal of Medicine finds that even after 15 years, patients who chose medication and lifestyle changes over angioplasty were no more likely to die than those who chose the procedure.

“This is a good news story,” said John Spertus, a cardiologist and researcher at St. Luke’s Hospital Mid America Heart Institute and a co-author of both studies. “It’s positive for patients and for society at large that is paying for their care.”

It’s also been a long time coming.

Angioplasty was developed in the late 1970s, a time when doctors thought that heart attacks occurred when cholesterol deposits progressively narrowed coronary arteries, the critical vessels that supply blood to the heart muscle, until they shut off blood flow completely.

During angioplasty, a cardiologist snakes a thin tube, called a catheter, into a coronary artery and then inflates a tiny balloon at the catheter’s tip to push back the deposits on the interior wall of the artery. As the technology advanced, tiny metal mesh tubes called stents were added to the procedure. They’re left in the arteries to keep them open.

Angioplasty has been amazingly successful at relieving the chest pains, called angina, caused by reduced blood flow to coronary arteries. When performed during a heart attack, angioplasty quickly clears blockages to prevent damage to heart muscle and potentially saves lives. That’s made it the gold standard for emergency heart attack treatment.

The popularity of angioplasty grew fast. Eventually, cardiologists were performing 600,000 or more per year. Angioplasty became one of the top 10 contributors to health care costs, according to the Blue Cross Blue Shield Association, racking up expenditures of $10 billion last year.

Pimples, not plumbing

But from the start, doctors wrongly assumed that the angioplasty done to relieve angina also would make heart attacks less likely by preventing narrowed arteries from closing off entirely.

“I think the faith in angioplasty comes from thinking of the heart as a plumbing problem,” said Cleveland Clinic researcher and physician Michael Rothberg.

It was persuasive, to both physicians and patients, to liken coronary artery disease to kitchen pipes clogging up with fat, Rothberg said. Angioplasty was the drain-cleaning snake that would clear out the blockage and set things right.

But from 1987 to 2007, a dozen or more studies consistently found that while angioplasty could relieve angina in patients with stable heart disease, it didn’t prevent future heart attacks.

As it turns out, most heart attacks occur at places inside arteries where cholesterol deposits appear so mild they wouldn’t be an obvious target for angioplasty.

These are deposits that become inflamed and then burst, precipitating a heart attack. This inflammatory model represents current thinking among cardiologists. So now, rather than using plumbing analogies to describe what happens, Rothberg said, doctors should be making comparisons to pimples.

When those “pimples” on artery walls pop, they cause blood in the arteries to clot, he said. If the clot closes off the artery completely, it causes a heart attack.

Even as evidence of the limitations of angioplasty grew, cardiologists kept recommending it, even to patients with mild angina that could be relieved with medication.

“It turns out doctors are people and have all the flaws of humans,” Rothberg said.

“They know in an intellectual way that (the studies) are true, but that doesn’t mean they know it in an emotional way. … The fact that they’re paid for (angioplasty) and paid well doesn’t make it easier for them to think the other way.”

And when cardiologists recommend angioplasty, patients have been quick to agree.

“It’s scary to have a blockage in your heart,” Rothberg said. “If someone says they can fix it, it sounds like a good idea.”

Higher cost, little if any benefit

By 2007, the angioplasty wave was about to crest.

The initial report of a landmark study called Courage (an acronym for Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) was published in April that year in the New England Journal of Medicine. Spertus was among the researchers.

The study followed 2,287 patients with stable heart disease at Veterans Affairs and private hospitals in the U.S. and Canada. These patients experienced angina during physical exertion or times of stress. But rest or medications quickly relieved their pain.

Half the patients received medical therapy that included drugs to relieve chest pain and to lower their blood pressure and cholesterol levels. They also were urged to exercise, lose weight and quit smoking. The other half got the same medication and lifestyle counseling plus angioplasty.

In a series of journal articles, the Courage researchers reported:

In the time the patients with stable heart disease were followed — an average of about 4 1/2 years — there was no significant difference in the rates of death, heart attack or stroke among those who received medical therapy alone and those who had an angioplasty and medical therapy.

Angioplasty did a better job than medical therapy alone at reducing angina and improving quality of life, but the differences were very small. A fifth of patients who started on medical therapy alone opted for an angioplasty within three months. But in most cases, for patients who received angioplasty first, most advantages of the operation disappeared after six to 24 months.

The advantages of angioplasty were so slight that the procedure could not be considered cost-effective, the researchers concluded. For every angioplasty patient who experienced a significant reduction in frequency of chest pains, there was an extra $155,000 in health care expenditures.

One of the new studies, published in the New England Journal of Medicine this month, took a further look at about half the Courage patients. It found that over an average of about 12 years, and for as long as 15 years, the two groups of patients have maintained essentially the same death rates.

Slow evolution

After the Courage study came the first set of criteria for using angioplasty appropriately.

A 17-member expert panel convened by the American College of Cardiology, the American Heart Association and other professional societies agreed in 2009 that angioplasty was clearly called for when patients were experiencing heart attacks or unstable heart disease with more frequent or severe episodes of angina.

But the panel was skeptical of performing the procedure on patients who were free of symptoms or had been offered little or no medication for their angina.

Two years after that, a national database of heart procedures began providing its more than 1,000 participating hospitals with information on the appropriateness of their angioplasties, allowing them to compare their rates to those of other hospitals.

Spertus and his St. Luke’s research colleague Paul Chan, who also is a cardiologist, crunched two years of that data in 2011 and found that among patients experiencing heart attacks or unstable angina, nearly 99 percent of the angioplasties were appropriate. But among nonemergency patients, nearly 12 percent of the angioplasties were clearly inappropriate, meaning that the benefits of the procedure were unlikely to outweigh the risks. Their findings made headlines across the country.

At many hospitals, the practice of angioplasty started to change, and fast, the data from the new Journal of the American Medical Association study show. While the number of procedures done for emergency patients remained stable, elective angioplasties started to plummet, dropping every year from 2011 through 2014. The percentage of angioplasties considered inappropriate was cut in half.

“There is a more thoughtful process for doing angioplasty now than five years ago,” said Chan, also a co-author of that study.

Chan thinks a combination of factors precipitated the rapid drop in angioplasties. The Courage study and those that followed played a role. So did the appropriate-use criteria and the data supplied to hospitals. And there was greater scrutiny from insurance companies that didn’t want to pay for unnecessary procedures.

“If you were a hospital administrator and had insurance companies on your back, you darn well didn’t want to be on the bottom” for appropriate angioplasties, he said.

In any case, cardiologists should take pride, Chan said, in having changed their practices so quickly in a positive way.

“I would be very encouraged,” said Patrick O’Gara, immediate past president of the American College of Cardiology and clinical cardiology director at Brigham and Women’s Hospital in Boston. “The field has been evolving in a very positive way. We’re trying to hold ourselves to a higher standard.”

But that evolution has been a very slow process, Spertus said.

“It really frustrates me how long it takes for scientific evidence to reach the bedside,” he said.

Spertus is thrilled that the American College of Cardiology developed the criteria for angioplasties and provided database reports to hospitals, but many cardiologists who perform angioplasties are still skeptical about Courage’s findings.

“I think they want to believe they were saving lives.”

This story was originally published November 28, 2015 at 3:29 PM with the headline "As evidence mounts, fewer doctors perform unnecessary angioplasties."