Seven years ago, Massachusetts mandated that hospitals report on a public database how often they perform minimally invasive heart procedures to open blocked arteries and their death rates from these procedures. It was meant to reduce unnecessary procedures and lower death rates, but new research from the Harvard School of Public Health and two Boston hospitals indicates that the public reporting system might also be leading to fewer angioplasties in patients who need them the most: those in the throes of a heart attack.

A study published last Tuesday in the Journal of the American Medical Association found that stenting procedures were lower in Massachusetts and two other states that have public reporting databases compared with states that don’t have them. About 38 percent of patients having heart attacks in the reporting states received the intervention compared with 43 percent of those in non-reporting states.

There was no difference in overall death rates among heart attack patients from reporting states and those from non-reporting states, but the study did find an increase in death rates among one group of patients — those whose heart attacks were caused by a completely blocked artery. In this group, nearly 14 percent of patients from states with public reporting died within 30 days after entering the hospital compared with 11 percent of those from states that don’t have mandatory reporting.

The researchers also looked at rates in Massachusetts both before and after the public reporting mandate and found that stenting rates in heart attack patients dropped after the mandate was implemented. The biggest drop occurred in patients coming to the hospital in shock triggered by a heart attack or in full cardiac arrest.

“Some of procedures that haven’t been getting done probably were unnecessary, but perhaps some of them could have extended lives,” said study leader Dr. Karen Joynt, a cardiologist at Brigham and Women’s Hospital and the Boston VA Healthcare System. “This shouldn’t be a knock on hospital transparency, but rather that data reporting should be seen as an evolving field.”

Determining when to place a stent in a heart attack patient can be tricky. The latest practice guidelines from cardiology societies recommend stenting to increase survival chances during a heart emergency such as a heart attack or unstable chest pain. But the guidelines advise against the procedure in severely ill patients who may die from the procedure or who won’t be able to tolerate the medications that must be administered for months or years afterward to prevent future heart attacks.

With public reporting, doctors may feel pressure — when faced with gray areas where the benefits of stenting may be dubious — to avoid the procedure and the possibility of a death that will add to their institution’s mortality numbers.

For example, if a patient has an 80 percent chance of dying within 30 days of a heart attack and the stenting procedure will reduce the chances to 75 percent, doctors may be reluctant to perform it, preferring to have a patient’s death attributed to a heart attack rather than the artery-opening intervention.

“The concern is that this may make them risk averse, though we couldn’t measure that in our study,” said Joynt.

Other experts emphasized that this study shouldn’t invalidate the need for more public reporting of hospital data. “The study found that public reporting resulted in fewer procedures with no [significant] difference in patient outcomes,” said Dr. Marty Makary, a surgeon at Johns Hopkins Hospital and author of the new book “Unaccountable,” calling for increased health care transparency. “It supports the recent Institute of Medicine report estimating that up to 30 percent of health care expenditures are unnecessary and do not make us any healthier.”

In an editorial that accompanied the study,
Dr. Maura Moscucci of the University of Miami School of Medicine wrote that while transparency has merits, the study also “confirms the possible unintended consequences of public reporting.”

Perhaps the take-home message should be that public reporting can be done better, added Joynt. “The state has made tweaks to the system in the past few years that didn’t show up in our data,” she said, with attempts to find equitable ways to exclude some of the higher-risk patients from an institution’s data, so doctors aren’t tempted to avoid an intervention simply to make their hospital’s numbers look better.