Acute cardiac complications and in-hospital mortality in adults hospitalized with anorexia nervosa: a national analysis, 2016–2022

Anorexia nervosa is among the psychiatric disorders with the highest mortality, second to substance-use disorders, and cardiac complications are commonly invoked as a cause. We determined which acute cardiac and metabolic complications are associated with in-hospital death in a contemporary United States national sample. We performed a serial cross-sectional analysis of the National Inpatient Sample (2016–2022), identifying adults with any-listed anorexia nervosa (ICD-10-CM F50.0x). Survey-weighted logistic regression estimated adjusted odds ratios (aOR), adjusting for age, sex, and Charlson comorbidity. Cause of death was approximated by the principal diagnosis and Major Diagnostic Category. Among 12,188 admissions (weighted about 61,000), 148 in-hospital deaths occurred (1.21%). Severe malnutrition (aOR 3.32, 95% CI 2.34 to 4.70) and hypoglycemia (3.65, 2.33 to 5.73) were independently associated with death; heart failure was associated in the primary model (2.09, 1.24 to 3.53) but attenuated with all complications modelled together (2.01, Holm-adjusted P = 0.07). Neither bradyarrhythmia (0.82, 0.39 to 1.70) nor tachycardia (0.62, 0.19 to 1.96) was associated with death, nor was coronary disease (1.14, 0.65 to 2.00). Men had about twice the odds of death (female aOR 0.42, 0.26 to 0.67). Fatal admissions were led by infection or sepsis (27.0%). Estimates were unchanged after excluding COVID-19-coded admissions (1.1%). In-hospital death was associated with severe malnutrition and hypoglycemia rather than with heart rate in either direction, and fatal admissions were predominantly acute medical events centered on infection. Inpatient vigilance should prioritize malnutrition severity, glycemic and infectious risk, and comorbidity over heart rate alone. Anorexia nervosa has one of the highest death rates of any mental illness. When someone with anorexia nervosa is admitted to hospital, a slow heart rate is the sign clinicians watch most closely, and it often decides whether a person is placed on a heart monitor. We wanted to know which problems are actually linked to dying in hospital. We studied hospital stays across the United States from 2016 to 2022, covering about 61,000 admissions of adults with anorexia nervosa, 148 of which ended in death. Neither a slow nor a fast heart rate was linked to dying; severe malnutrition, low blood sugar, and infection were. Men died about twice as often as women, even though they appeared no more unwell on admission. Most people who died had been admitted for a serious physical illness, usually a severe infection, rather than for treatment of the eating disorder itself. We think hospital teams should attend closely to how malnourished someone is, to their blood sugar, and to signs of infection, rather than judging risk by heart rate alone. Our findings do not mean heart monitoring should be reduced: a slow heart rate may look harmless precisely because it prompts closer monitoring.