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Perverse Incentives Lead to Useless Heart Surgeries


The old idea was this:  Coronary disease is akin to sludge building up in a pipe.  Plaque accumulates slowly, over decades, and once it is there it is pretty much there for good.  Every year, the narrowing grows more severe until one day no blood can get through and the patient has a heart attack.  Bypass surgery or angioplasty -- opening arteries by pushing plaque back with a tiny balloon and then, often, holding it there with a stent -- can open up a narrowed artery before it closes completely.  And so, it was assumed, heart attacks could be averted.

But, researchers say, most heart attacks do not occur because an artery is narrowed by plaque.  Instead, they say, heart attacks occur when an area of plaque bursts, a clot forms over the area and blood flow is abruptly blocked.  In 75 to 80 percent of cases, the plaque that erupts was not obstructing an artery and would not be stented or bypassed.  The dangerous plaque is soft and fragile, produces no symptoms and would not be seen as an obstruction to blood flow.

That is why, heart experts say, so many heart attacks are unexpected -- a person will be out jogging one day, feeling fine, and struck with a heart attack the next.  If a narrowed artery were the culprit, exercise would have caused severe chest pain.

Heart patients may have hundreds of vulnerable plaques, so preventing heart attacks means going after all their arteries, not one narrowed section, by attacking the disease itself.  That is what happens when patients take drugs to aggressively lower their cholesterol levels, to get their blood pressure under control and to prevent blood clots.

Yet, researchers say, old notions persist.

''There is just this embedded belief that fixing an artery is a good thing,'' said Dr. Eric Topol, an interventional cardiologist at the Cleveland Clinic in Ohio.

In particular, Dr. Topol said, more and more people with no symptoms are now getting stents.  According to an analysis by Merrill Lynch, based on sales figures, there will be more than a million stent operations this year, nearly double the number performed five years ago.

Some doctors still adhere to the old model.  Others say that they know it no longer holds but that they sometimes end up opening blocked arteries anyway, even when patients have no symptoms.

Dr. David Hillis, an interventional cardiologist at the University of Texas Southwestern Medical Center in Dallas, explained:  ''If you're an invasive cardiologist and Joe Smith, the local internist, is sending you patients, and if you tell them they don't need the procedure, pretty soon Joe Smith doesn't send patients anymore.  Sometimes you can talk yourself into doing it even though in your heart of hearts you don't think it's right.''

Dr. Topol said a patient typically goes to a cardiologist with a vague complaint like indigestion or shortness of breath, or because a scan of the heart indicated calcium deposits -- a sign of atherosclerosis, or buildup of plaque.  The cardiologist puts the patient in the cardiac catheterization room, examining the arteries with an angiogram.  Since most people who are middle-aged and older have atherosclerosis, the angiogram will more often than not show a narrowing.  Inevitably, the patient gets a stent.

''It's this train where you can't get off at any station along the way,'' Dr. Topol said.  ''Once you get on the train, you're getting the stents.  Once you get in the cath lab, it's pretty likely that something will get done.''

 

For the full story, see: 

GINA KOLATA.   "New Heart Studies Question the Value of Opening Arteries."  The New York Times   (Sun., March 21, 2004). 





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