DNRs Muddy Waters in Acute MI Care as Palliative Services Fall Short

For the one in eight patients with acute MI who have a do-not-resuscitate (DNR) order, the designation makes them less likely to receive invasive management. Yet only one-third receive palliative care, according to new US data.

Moreover, the demographic differences underpinning the decision to specify a DNR in the first place—white patients and women are more likely to do so—may point to deeper issues related to structural racism and sexism, the study authors say.

“One of the problems is how people interpret [DNR], and I think this is where the major issue lies and why many of these patients are much less likely to get guideline-recommended care,” senior author Mamas A. Mamas, BMBCh, DPhil (Keele University/Royal Stoke University Hospital, Stoke-on-Trent, England), told TCTMD. “Many physicians conflate DNR with not receiving invasive care. . . . Of course, these are two very different decisions and are two very different choices that will have an impact on a patient's outcome and following admission to hospital. That belies a problem because DNR is [viewed as] a binary decision. You either resuscitate or you don't resuscitate, whereas end-of-life goals are much more granular and nuanced.”

By definition, a DNR specifies that a patient does not wish to receive cardiopulmonary resuscitation in the event of cardiac arrest. This could be decided as part of an advanced directive, which is often the case for people with dementia or cancer, or indicated during a hospital stay, for example. It does not mean “do not treat.”

Commenting on the study for TCTMD, Penelope Rampersad, MD (Cleveland Clinic, OH), agreed. “There is heterogeneity within the physician population about how physicians interpret a DNR. . . . Some people see that and take on a mindset that ‘I'm just going to do the bare minimum for the patient and potentially just keep them comfortable.’”

The root of this misunderstanding in cardiology, specifically, may stem from the fact that the subspecialty as a whole is focused on intervening to alter the course of disease, she observed. “The idea of not intervening I think creates some disconnect, or maybe some moral injury, for physicians who feel that that's withholding care and then don't know how to navigate that space without being able to offer everything within their armamentarium,” Rampersad said. “So I think there definitely is a role for further education [and] a role for further collaboration with palliative care physicians, so that cardiologists can see that gray area and have open conversations and navigate that with patients and their families.”

DNR Differences

For the study, published in the November 15, 2021, issue of the American Journal of Cardiology, Mamas along with lead author Ofer Kobo, MD, MPH (Hillel Yaffe Medical Center, Hadera, Israel), and colleagues, included data on more than 2.7 million US patients admitted to hospital with acute MI between 2015 and 2018 from the National Inpatient Sample (NIS) database. A total of 12.3% had a DNR order put in place before or during their admission.

Patients who had DNR orders were older and more likely to be female, white, and have Medicare insurance (P < 0.001 for all). The presence of comorbidities like heart failure, dementia, and cancer predicted a greater chance of DNR, while those without a DNR order had a greater likelihood of cardiovascular risk factors like diabetes, dyslipidemia, and smoking.

Ultimately, those with a DNR order were less likely than those without to undergo invasive management including angiography (18.8% vs 61.8%), PCI (10.3% vs 37.7%), CABG (1% vs 7%), and thrombolysis (0.1% vs 0.2%) and less apt to be discharged home (13.5% vs 52.8%; P < 0.001 for all). Despite the thought that DNR orders are meant to preserve dignity in end-of-life care, only one-third of DNR patients received a palliative care consultation. Additionally, both in-hospital mortality (32.7% vs 4.6%; P < 0.001) and MACCE (37.1% vs 8.8%; P < 0.001) were higher for DNR patients.

Notably, independent predictors of death among patients with DNR orders included STEMI (OR 2.90; 95% CI 2.84-2.96) and being Black (OR 1.29; 95% CI 1.26-1.33), Hispanic (OR 1.36; 95% CI 1.32-1.41), Asian/Pacific Islander (OR 1.56; 95% CI 1.49-1.64), or Native American (OR 1.51; 95% CI 1.33-1.7).

Conversations and Palliative Care

At the outset of the study, Mamas said he expected to see a DNR rate of “1 or 2%” so was surprised to see a much higher proportion. “That's really an important finding that this is much more widespread than appreciated and the provision of care differences are quite stark,” he said. “This really does give us pause for thought as to why there are those differences.”

Looking more deeply into who is more likely to have DNR orders, patient preference and care goals definitely come into play, Mamas said, citing research showing that women, for example, tend to want to be less aggressively managed compared with men, especially at the end of life. “But I think part of it may also be related to patient and physician bias,” he said. “You only get a DNR order if you have it discussed with your physician, and one does wonder whether these conversations are being had with women and white patients [but] not with Black patients or Asian patients or other ethnic minorities. So I do wonder whether part of this difference in receipt of DNR orders may be around structural sexism and even structural racism.”

Mamas said he was also struck by the lack of palliative care used within the study, and his team is planning a second study looking more specifically at this.

Rampersad said there is “a huge need” for palliative care within cardiology, especially outside the bounds of chronic conditions like heart failure. “Generally, it's been difficult for us to recognize when the need for palliative care and the introduction of services is warranted, and part of that has to be with prognosis,” she said. “Sometimes we're not great at prognosticating end of life for patients with cardiac conditions versus with a malignancy, where sometimes it can be a little bit more predictable.”

She likes to involve palliative specialists as soon as possible. “It's never wrong to have a conversation early on and to educate them about the natural history of their disease,” Rampersad said. “I usually couch that by saying to patients that things are sometimes unpredictable and I would like to empower them to make decisions on their behalf early in life, or to set that out for them so that their loved ones know what their wishes are ahead of time.”

Bringing palliative specialists into the fold early also allows for more continuity of care for patients, “so that these aren't people that they’re just meeting in the last days of their life but potentially are people who've been there and walking the journey with them for a long period of time,” she added.

These issues are only going to grow more vital as cardiovascular care advances, even though MI outcomes are generally “very good,” Mamas said. “Now that patients are surviving longer and are becoming increasingly more comorbid, I think the whole discussion about DNR is going to become much more relevant, much more important.”

Note: Mamas serves as Senior Clinical Editor for TCTMD.