Neurologic, Psychiatric Risks Linger Among Adult Cardiac Arrest Survivors

Adults who are discharged from the hospital after a cardiac arrest have elevated risks of a variety of neurologic and psychiatric outcomes, a Danish study shows.

Rates of ischemic and hemorrhagic stroke, epilepsy, dementia, depression, and anxiety all were higher among cardiac arrest survivors than among post-MI patients, although that excess risk was greatest early on and lessened over time, lead author Niels Secher, MD, PhD (Aarhus University Hospital, Denmark), and colleagues report.

The findings, from a study published online this week in JAMA Network Open, point to the need to keep closer track of patients after they’ve recovered from a cardiac arrest, the investigators say.

“A follow-up program for cardiac arrest survivors like what they recommend for myocardial infarction patients could be an option,” Secher told TCTMD, saying that close follow-up for the first year or two after discharge to allow for treatment of any lingering conditions, and then subsequent symptom-based management, may be appropriate.

Increasing Numbers of Survivors

Though survival after cardiac arrest remains poor, it has improved in recent years, resulting in a growing number of patients who require post-arrest care. Prior research on cardiac arrest survivors has focused on short-term outcomes, and there’s a need to better understand the longer-term consequences, Secher said.

To explore that issue, he and his colleagues examined 21 years of data from Danish national medical registries on adult survivors of a first-time cardiac arrest (in or out of the hospital). The analysis encompassed 250,838 individuals (median age 67; 69.3% men), including 12,046 with cardiac arrest, 118,332 with a first-time diagnosis of MI, and 120,460 from the general population.

Median follow-up ranged from 3.6 to 5.4 years across groups. One-year postdischarge mortality was highest in cardiac arrest survivors (16.0%), followed by MI patients (4.9%) and individuals from the general population (3.1%).

Compared with the MI cohort, those who had had a cardiac arrest did not have greater risks of stroke over the entire follow-up period, but in the first year, they had elevated risks of both ischemic stroke (adjusted HR 1.30; 95% CI 1.02-1.64) and hemorrhagic stroke (adjusted HR 2.03; 95% CI 1.12-3.67).

For other neurologic and psychiatric outcomes, however, arrest survivors had higher rates over the duration of follow-up:

• Epilepsy (adjusted HR 2.01; 95% CI 1.66-2.44)
• Dementia (adjusted HR 1.23; 95% CI 1.09-1.38)
• Mood disorders including depression (adjusted HR 1.78; 95% CI 1.68-1.89)
• Anxiety (adjusted HR 1.98; 95% CI 1.85-2.12)

The excess risk in the cardiac arrest cohort was greatest in the first year and then fell over time, with rates of the various outcomes becoming comparable to those seen in the MI group at around 5 years. That latter finding is a little surprising, Secher said: “If they get through the first years, they are more comparable to a myocardial infarction patient risk-wise. . . . I think that’s important information for the patients and their relatives.”

Still, risk remained higher after cardiac arrest than in the general population.

Need for Comprehensive Systems of Care

The excess risk of these outcomes compared with the MI population, Secher said, likely is related to the period of circulatory arrest and resulting ischemic damage in the brain. In their paper, he and his colleagues also point to a greater preexisting burden of CVD and a post-cardiac arrest syndrome involving hypotension, inflammation, activated coagulation, and embolism as potential mechanisms to explain the worsened outcomes.

We know that regardless of cardiac arrest status, being intubated, sedated, potentially delirious, and critically ill has profound long-term neurocognitive consequences. Jonathan Elmer

Commenting for TCTMD, Jonathan Elmer, MD (University of Pittsburgh, PA), agreed that hypoxic ischemic injury, particularly in the brain, sustained at the time of pulselessness could have direct neurologic consequences, although that possibility cannot be addressed by the current study.

It’s also possible that arrest survivors have increases in microvascular comorbidities or in the likelihood of previously undiagnosed medical problems—which could not be adequately accounted for with statistical adjustment—that explain the higher rates of adverse outcomes. In addition, from prior research, Elmer noted, “we know that regardless of cardiac arrest status, being intubated, sedated, potentially delirious, and critically ill has profound long-term neurocognitive consequences.”

But the exact reasons ultimately don’t matter when it comes to managing survivors of cardiac arrest, Elmer said: “We know that these patients have these problems, and so there has been a shift in our focus as a community of resuscitation scientists to move beyond just the prehospital care, just the infra-arrest management, just the early critical care, just the in-hospital management, and to start to think more robustly about the arc of survivorship and the post-arrest care that these patients need.”

The current study highlights the need for more research to better understand these problems and to develop interventions addressing them, he said, adding that it also underscores the extensive care these patients require. That includes screening for neurocognitive and psychological problems, interventions and treatment, rehabilitation, psychiatric and social support, and assistance for family members that will be helping them. “In sum, research like this highlights the need for comprehensive systems of care that span the arc of cardiac arrest survival and recovery,” Elmer said.