Now they tell us.
Heart specialists who sifted through a registry of more than 600,000 people treated with catheters, inflatable balloons and stents to clear blocked coronary arteries found the procedures were used too often in patients with stable heart trouble.
About 12 percent of the interventions in stable patients, almost all of which involve putting in a stent, were judged to be inappropriate using criteria agreed to by a half-dozen cardiology groups in 2009. The appropriateness of more than a third was uncertain, leaving half of the interventions performed in stable patients in the appropriate column.
Where do doctors go wrong? The most common problem in these patients is using a stent when the patients had no angina, or only very mild symptoms. Previous research has shown that treatment with drugs rather than stents is a reasonable course of action for most of these sorts of patients.
When it comes to emergencies, such as patients with high-risk unstable angina, cardiologists did a better job. A review of the registry data found 98.6 percent of interventions for patients with acute heart problems were in line with the standardized criteria.
The researchers behind this study, published in the latest issue of JAMA, looked at patient data from a 15-month ending last September.
Among other things they found quite a bit of variation among the more than 1,000 hospitals included in the registry. Inappropriate treatment in the stable patients ranged from zero to 55 percent.
The authors of the paper wrote, rather dryly:
Collectively, these findings suggest an important opportunity to examine and improve the selection of patients undergoing [percutaneous coronary intervention] n the nonacute setting.
Cleveland Clinic cardiologist Steven Nissen was more pointed in comments to the Wall Street Journal:
This tends to confirm concerns that many people have expressed—that there are many thousands of patients who undergo coronary interventions for very questionable indications.
In absolute terms, more than 20,000 people of the 500,000 whose cases could be analyzed by the researchers probably got stents when they shouldn't have.
In a statement emailed to Shots, American College of Cardiology President Dr. David Holmes defended the practice of heart specialists, saying the study found "the majority of patients are appropriately selected" for stents. Still, he acknowledged, studies like this one show doctors where improvements can be made.