Criminalizing Stent Cases? The 70/30 Rule Must Go, Experts Say

Putting cardiologists in jail for performing unnecessary coronary stenting procedures based on the so-called 70/30 rule—which hinges on disagreements between treating physicians and outside experts on the degree of stenosis shown on the angiogram—is a practice that must stop, according to a recent perspective in Circulation.

The 70/30 rule is based on the idea that reviewing angiograms can uncover evidence of a crime. The federal government will hire outside cardiologists to review subpoenaed angiograms, and if the independent expert deems the stenosis in the stented area to be less than 30% when the treating cardiologist recorded the blockage as 70% or greater, “the government has probable cause to criminally prosecute the doctor and potentially the hospital and its administrators with federal felonies punishable by decades in prison,” white-collar criminal defense lawyers Andrew George, JD, and Kyle Clark, JD (both of Baker Botts LLP, Washington, DC), and interventional cardiologist Brahmajee Nallamothu, MD (University of Michigan, Ann Arbor), explain in the piece.

First used to secure a healthcare fraud conviction for unnecessary stenting about 11 years ago, the rule has featured prominently in about a dozen “stent cases” since then; the government has yet to lose one. Prison sentences have ranged from several years to as much as 20 years.

The problem is not that the government is rooting out fraudulent use of stents, but that it is using a process—interpretation of angiographic stenosis—that is often a judgment call and has been shown to be variable across physicians, according to George, Clark, and Nallamothu.

They weren’t committing fraud. They just saw the same things differently, which happens in medicine like in many aspects of life. Andrew George

“We need to think about how to be very vigilant about the potential for fraud and abuse,” Nallamothu told TCTMD, stressing that unnecessary stenting remains a critical concern. “I think it’s really important to do this because we need to maintain trust and faith with our patients. Because the reality is that when you go into these procedures you have to have faith in the providers that are there.”

But studies over the years have shown that there can be honest disagreements among cardiologists as to how much stenosis is visible on an angiogram, with sometimes large discrepancies, making use of the 70/30 rule to prove fraud problematic. In fact, George told TCTMD, his and Clark’s research uncovered 93 examples in the medical literature in which two cardiologists disagreed about the degree of stenosis by more than 39% and sometimes by as much as 100%. “They weren’t committing fraud,” George said. “They just saw the same things differently, which happens in medicine like in many aspects of life.”

Thus, Nallamothu said, there is a need to address potential fraud related to unnecessary stenting on a case-by-case basis.

“I think we should individualize our interpretation of these cases and not just have a blanket 70/30 rule to identify something as serious as fraud. I also think that if we are going to use outside interpretations it should probably be more than just one expert against another expert and we should think about things like panel interpretations where we can have a better and more rounded view,” he suggested. “If you have a panel of three cardiologist experts and they discover a great discrepancy in terms of their interpretation for several angiograms compared to what was done, that would be more concerning. But to just bring individual cardiologists in there and say that person says it’s 30% and the other person had said it was 70%, I don’t think that that’s going to make a lot of sense.”

Nallamothu added that it’s not yet clear whether the advent of digital angiography has eliminated the potential for interoperator variability in interpretation. “I don’t know if digital angiography is going to address those kinds of much more important issues, which are: how do we as operators standardize our processes for evaluating and thinking about these images? We have this sense in our own mind when we visually see something that there’s this definitiveness to it, but just like with other types of visual fields . . . there can be some uncertainty there that can be very difficult to clarify.”

Operator dependency on interpretation of imaging has been seen in other areas of medicine as well, Nallamothu pointed out, citing a 1994 paper in the New England Journal of Medicine showing disagreements in the interpretation of mammograms among radiologists.

“I do think the more important thing is just trying to understand a little bit more the subtlety of how our decision-making processes occur and if there are ways in which we can standardize and improve them,” Nallamothu said. “In some ways, I imagine a future where it’s not just having to rely on an individual looking at a video clip of the angiogram and then just making an eyeball estimation of what they think. I think it’s going to take better diagnostic tools within the cath lab to help us.”

In the meantime, the 70/30 rule, which “seems to have originated from a belief among some practitioners that two honest cardiologists, viewing the same angiogram, will not disagree about the extent of a blockage by >10% to 20%,” according to the authors, remains entrenched in the legal system despite a lack of scientific support. It has, in fact, been adopted by three of the 13 US Federal Courts of Appeal, “meaning that it may carry the force of legal precedent in the federal courts of 12 states to have considered the issue so far.”

George, Clark, and Nallamothu stressed that they are not passing judgment on whether any of the stent cases thus far represent true healthcare fraud, but that they are highlighting the weakness of the 70/30 rule as evidence of a crime.

Thinking Beyond Malpractice

There is “the concern of how we set up a threshold for understanding when these things cross over into the space of fraud and abuse,” Nallamothu said. “It’s one thing to say that an individual is a bad cardiologist because they didn’t interpret the study correctly, that they made a mistake. That’s malpractice. But fraud and abuse takes it to another level where there’s this concept that this individual is . . . deliberately misreading stenosis severity and then placing these stents in with the intent of billing for services.”

Reviewing enough angiograms from any high-volume operator will likely uncover at least a few that will run afoul of the 70/30 rule, the authors say. “If you go through thousands of angiograms,” Nallamothu said, “you are going to find ones where two reasonable people can disagree. . . . I don’t think it would be surprising to find for a high-volume operator that there might be a handful where there might be larger disagreements.”

Until research shows that variability in the interpretation of angiograms no longer exists, the 70/30 rule should not be used to prove fraudulent use of stents, the authors argue.

“Doctors who are hired as experts in these cases and asked to review angiograms for the government to detect fraud, those doctors have been passing along a piece of conventional wisdom that is either unfounded or false, or both,” George said. “And we think that that’s dangerous and irresponsible because this isn’t just malpractice where someone might pay some money at the end of the day or their insurance company might pay some money. We’re talking about lengthy prison sentences for people, and if you’re going to put someone through that you really want to be sure that you’re getting it right.”

George, Clark, and Nallamothu hope to raise awareness of this issue.

“One of the big reasons we wanted to write this perspective in Circulation is to hopefully get the attention of the cardiac community,” Clark said, who noted that another article could be written on the need for cardiologists to be diligent in their documentation because of the potential for a criminal—and not just malpractice—investigation.

“But this first article we thought was really important to remind cardiologists to be careful” about determining other cardiologists were perpetrating fraud based on large disagreements in angiographic interpretation, Clark said. “Our hope is that people will take a moment of pause and realize that they may think that’s true but they’ve not studied it or read the other studies about it, because if they did they’d realize it’s not true at all.”

George summed it up by saying: “Doctors need to stop making that claim against other doctors until somebody actually goes out and proves that claim is true.”