麻豆传媒

Cardiac arrest during labor and delivery appeared more common than previously seen -- particularly for older, Black, and low-income pregnant patients -- but with better survival rates, according to a national study.

Among women admitted for delivery in the National Inpatient Sample (NIS) from 2017 to 2019, cardiac arrest occurred in about one in 9,000 (13.4 events per 100,000 delivery hospitalizations), reported Nicole D. Ford, PhD, MPH, of the CDC in Atlanta, and colleagues in the .

By comparison, previously reported NIS data showed a rate of one in 12,000 during 1998 to 2011. However, the overall survival rate improved over time, from 58.9% after cardiac arrest during hospital delivery in 1998 to 2011 to 68.6% in the 2017-2019 data.

There was a change from ICD-9 to ICD-10 codes between the two study periods that might have complicated comparisons, but Ford's group noted that a true increase was plausible.

"[T]he higher rate of cardiac arrest may be related to the observed increased prevalence over time of characteristics associated with cardiac arrest, such as hypertensive disorders in pregnancy, heart disease, and hemorrhage," they suggested.

Indeed, in the study, cardiac arrest rates during delivery hospitalization were higher for the following groups, when compared with patients hospitalized without cardiac arrest:

• Older maternal age (median 31.1 vs 28.4 years)
• Black patients (28.6% vs 15.1%)
• Medicare or Medicaid beneficiaries (53.1% vs 43.2%)
• Chronic hypertension (13.7% vs 2.8%)
• Mental health disorders (18.1% vs 7.8%)
• Substance use disorder (9.2% vs 2.7%)
• Acquired heart disease (6.1% vs 0.2%)

"Strategies to address maternal cardiac arrest implemented with an equity lens may reduce disparities in maternal outcomes by addressing upstream factors associated with cardiac arrest incidence and management," Ford and colleagues wrote.

The findings come amid increasing attention to disparities in overall maternal morbidity, including proposed legislation and CMS action to address the threefold higher risk for Black pregnant people.

"For women with underlying medical conditions, prepregnancy counseling and coordinated care with a team of specialists could reduce severe complications," Ford's group suggested. They pointed to clinical tools like the California Maternal Quality Care Collaborative's for symptomatic or high-risk pregnant and postpartum women to boost recognition of cardiovascular complications and improve management.

Their retrospective cohort study included data on 10,921,784 U.S. delivery hospitalizations among women ages 12 to 55 years that were captured from 2017 to 2019 in the NIS, which is a nationally representative sample of 20% of all-payer inpatient healthcare discharges from U.S. community hospitals, excluding rehabilitation and long-term acute care facilities.

In-hospital cardiac arrest was identified using diagnosis codes for cardiac arrest, postprocedural cardiac arrest after cardiac or other surgery, intraoperative cardiac arrest during cardiac or other surgery, cardiac arrest due to anesthesia during pregnancy, ventricular fibrillation, or the procedure code for CPR.

The cardiac arrest rate stayed steady across the study period from 2017 to 2019.

Acute respiratory distress syndrome was the most common co-occurring diagnosis, seen in 56.0% of cases, and mechanical ventilation was the most common intervention or procedure (53.2%).

Chances of survival to hospital discharge after cardiac arrest were somewhat lower with co-occurring disseminated intravascular coagulation (50.0% without transfusion and 54.3% with transfusion).

However, the researchers cautioned that their data couldn't distinguish between a hospitalization for delivery in which a cardiac arrest occurred from a hospitalization for cardiac arrest that necessitated a delivery, nor could they determine the timing of the cardiac arrest relative to the delivery or other maternal complications. "However, we suspect that the cause of the arrest is likely a more important driver of survivability than the sequential order of the delivery versus the cardiac arrest," they wrote.

Also, the claims codes upon which they based the findings are "subject to inherent challenges and coding errors." And, ICD-10 codes for cardiac arrest among pregnant patients have not been validated, they pointed out.

Other limitations were the limited number of deaths in the study population, which precluded analysis of patient- or community-level characteristics associated with survival, and the lack of data on cardiac arrest among pregnant women more broadly outside of delivery hospitalizations.

More information is needed on specific drivers of maternal cardiac arrest during delivery, the researchers acknowledged.

"Implementing clinical guidelines, ensuring that pregnant people receive risk-appropriate care, and addressing potential knowledge deficits in maternal cardiac arrest and cardiopulmonary resuscitation technique for pregnant people may improve maternal outcomes," they concluded.

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