Of failure-to-diagnose cases, myocardial infarction (MI) was the most commonly missed diagnosis, according to a recent analysis of 166 cases of cardiology malpractice claims.1

Missed MI occurred in 32 cases. The researchers recommended additional training in reading ECGs and recognizing atypical presentations of MI to reduce missed diagnoses.

“My experience, in looking at claims, is that we do not miss MIs. We miss acute coronary syndrome, or impending MIs,” says Alan Lembitz, MD, chief medical officer at COPIC, a Denver-based medical professional liability insurance provider.

Not too many patients with classically positive ECGs or cardiac troponins are missed. “The biggest issues are the ones where the initial studies look OK, and we did not predict that it was an impending MI in the next few days or weeks,” Lembitz explains.

Most ED patients, relieved to be discharged with no abnormal findings, do not realize their degree of carotid artery plaque or coronary artery disease is completely unknown at the time of the ED visit. “We have only told them whether or not they have damage to the heart. That is a pretty significant difference,” Lembitz notes.

Patients leave thinking ED providers concluded the problem was not their heart. In reality, the ED providers are only saying there was no evidence of an MI. “That is really where the risk is,” Lembitz observes.

The classic example is the patient with a negative ECG and negative troponin test who dies of an MI in the days following the ED visit, and the family sues. “You then have to defend the fact that you didn’t detect it,” Lembitz says.

For patients with normal ECG and troponins, “after that, it becomes a guessing game at them having critical stenosis or significant plaque burden in their coronary arteries,” Lembitz says.

Risk stratification tools are helpful to the ED defense. “You’re still going to miss people after you send them out. But it’s going to be much more defensible,” Lembitz suggests.

The plaintiff’s expert will look to see if this question is answered in the ED chart: Was this truly a low-risk patient who could be sent out with follow-up instructions to see a cardiologist in the next week or two?

Most ED charts show the plaintiff did not experience an MI at the time of the visit. Ideally, the chart also shows there was low risk of significant coronary artery disease that will affect the patient shortly. “The problems we run into are the cases we treated as low risk when we either didn’t get the history or the history is somewhere else,” Lembitz notes.

Documenting the HEART score or other literature-supported tool is helpful. “It will force you to ask and consider all the elements on which you based your decision with the patient about their likely risk of a MACE [major adverse cardiac event] in the near term,” Lembitz explains.

The plaintiff will allege just ruling out an MI was not enough. The argument is the patient should have been admitted due to a high probability of underlying coronary disease. A carefully documented risk stratification tool counters this argument effectively, yet it is often missing from ED charts. Instead, the EP documents subjective statements that the patient was believed to be low risk, but without any evidence to support it. “Sometimes, we get people waxing poetically in the medical decision-making. That doesn’t help the defense,” Lembitz cautions.

Also unhelpful are statements suggesting the EP recommended admission, but the patient wanted to go home. “That’s not truly shared decision-making. You’re going to lose on those,” Lembitz warns.

If the ED provider did not risk-stratify, the patient did not have the data to make an informed decision. “The ED patient really has no idea that they have a high likelihood of having a critical lesion that just hasn’t shown up as myocardial damage yet,” Lembitz adds.

Some malpractice cases happen because the EP ruled out MI perfectly, but missed aortic dissection or pulmonary embolism. “It’s what we call the triple rule-out. It’s not sufficient to rule out one and not consider the others,” Lembitz reports.

It is debatable as to whether the EP should specify in the medical decision-making that each diagnosis was considered. If the ED chart shows a missed diagnosis was considered, the plaintiff attorney could argue it was incumbent on the EP to do something definitive to rule it out.

On the other hand, documentation that specifies aortic dissection was considered, but the history was not consistent and the patient had no family history or other risk factors, probably is going to be helpful. “But some aortic dissections are just going to surprise you because they don’t all have the classic features. I know a lot of very good docs who have gotten surprised,” Lembitz shares.

In one recent malpractice claim, the EP missed aortic dissection in a 29-year-old man who presented without any classic symptoms. “It was so atypical that we can probably defend it by saying there were no features that would have led any reasonable EP to consider aortic dissection,” Lembitz says.


  1. Patel R, Rynecki N, Eidelman E, et al. A qualitative analysis of malpractice litigation in cardiology using case summaries through a national legal database analysis. Cureus 2019;11:e5259.