PHILADELPHIA — Individuals with preexisting cardiovascular disease (CVD) who are admitted to the emergency department for an anaphylactic reaction have significantly poorer outcomes, including a higher risk for death and heart attack, than those without underlying heart disease, according to a research poster presented at the American Academy of Allergy, Asthma and Immunology 2026 Annual Meeting in Philadelphia.

“These findings highlight the need for integrated cardiovascular risk assessment and multidisciplinary care strategies in the management of severe allergic reactions,” Diala Merheb, MD, of the University of Kansas School of Medicine-Wichita, and her colleagues concluded. 

“We need more research to see what kinds of triggers or medication exposures [might be contributing] to these outcomes because anaphylaxis is very broad, and anything can lead to worse outcomes,” Merheb told Medscape Medical News.

The researchers analyzed data from all 115,395 adult anaphylaxis admissions recorded in the 2016-2022 National Inpatient Sample. A little over half the patients (57.9%) were female, and they were an average 54.5 years old. Those with preexisting CVD made up 60.9% of the patients. Among the 970 patients (4.2%) who died, those with CVD had nearly twice the odds of dying than those without CVD after adjusting for age, sex, and other comorbidities (adjusted odds ratio [aOR], 1.97, P < .001).

Underlying CVD was also linked to a 32% longer hospital stay overall. “Discharge disposition differed by CVD status, with more frequent need for skilled nursing facility placement or home healthcare among CVD patients,” the authors reported.

CVD was also linked to a significantly greater likelihood of various acute complications. Among the 4% of patients who experienced an acute myocardial infarction, odds were nearly four times greater for those with CVD (aOR, 3.85; 95% CI, 2.97-4.98). Those with heart disease were also more likely to experience acute respiratory failure (aOR, 1.33, 95% CI 1.25-1.43), acute kidney injury (aOR, 1.27; 95% CI, 1.17-1.38), and acute bronchospasm (aOR, 1.41; 95% CI, 1.05-1.89).

When the researchers assessed risk based on the type of CVD, the only one not significantly associated with increased mortality was heart failure (P = .11). Individuals with arrhythmias had the highest risk for death (aOR, 5.19, P < .001).

“The strong association between arrhythmias and mortality identifies a high-risk subgroup that may benefit from early monitoring and multidisciplinary inpatient management,” the authors concluded.

The study was limited by its reliance on administrative coding for diagnoses and outcomes, limited data on medication, and no data on anaphylaxis trigger or severity.

Arjun K. Venkatesh, MD, MBA, MHS, chair of the Department of Emergency Medicine at Yale School of Medicine in New Haven, Connecticut, told Medscape Medical News that he was not surprised by the findings.

“Whether a patient is hospitalized for a long-standing chronic condition like COPD [chronic obstructive pulmonary disease] or one of the shortest duration conditions like anaphylaxis, having heart disease is associated with longer hospital stays and more complications,” Venkatesh said.

“I don’t think these findings change how we care for anaphylaxis or milder allergic reactions in the emergency department setting, but I do think that people with heart disease and a risk of allergic reactions, and the doctors who care for them, should be aware of these findings and incorporate this added risk into considerations for treatment,” Venkatesh said. “Knowing that you may be at greater risk of these harms may motivate some patients to be more adherent to medications or motivate some physicians to prescribe more intensive treatment regimens.” 

The study did not receive any external funding. Merheb reported having no disclosures. Venkatesh receives consulting support from Milestone Pharmaceuticals, holds stock options from Hyperfine Inc., and receives contract and grant support from CMS, the National Institutes of Health, the Moore Foundation, Eli Lilly, the FORE Foundation, and the Emergency Medicine Foundation. 

Tara Haelle is a science/health journalist based in Dallas.