Temporal trends and factors associated with emergency department visits and hospitalizations in angina with no obstructive coronary artery disease (ANOCA)

Introduction Angina with no obstructive coronary artery disease (ANOCA) presents diagnostic and treatment challenges, significantly burdening healthcare resources as reported in previous studies. This study assessed temporal changes in emergency department (ED) visits and hospitalizations for ANOCA and factors associated with these outcomes. Methods/Results We assessed a retrospective cohort of 85,573 individuals (26% with ANOCA, 31% female, mean age 62.1±12.0 years) who underwent their first cardiac catheterization for chest pain in Alberta from 2002 to 2017. Temporal trend analysis showed ED visits ranged from 26.3% to 30.7% (β=0.21 [95%CI:-0.28 to 0.70];p=0.33) for ANOCA and from 47.7% to 53.1% (β=-0.15[95%CI:-0.87 to 0.57];p=0.63) for obstructive CAD, with no temporal changes in either. Hospitalizations decreased from 6.5% to 3.8% (β=-0.28 [95%CI:-0.47 to -0.09];p=0.010) for ANOCA and from 24.8% to 15.3% (β=-1.45 [95%CI:-1.77 to -1.12];p<0.001) for obstructive CAD. Multivariable logistic regression analysis factors associated with ED visits in individuals with ANOCA included cerebrovascular disease (CEVD) (OR=1.73 [95%CI:1.40–2.15]), congestive heart failure (CHF) (OR=1.91 [95%CI:1.49–2.44]), peripheral artery disease (PAD) (OR=1.61 [95%CI:1.18–2.19), and unstable angina (UA) (versus (vs) stable angina (SA): OR=1.65 [95%CI:1.51–1.80]). Factors associated with hospitalizations in ANOCA included CEVD (OR=1.39 [95%CI:1.11–1.73]), CHF (OR=2.06 [95%CI:1.66–2.56]), hypertension (OR: 1.26 [95%CI:1.14–1.40]), PAD (OR=1.89 [95%CI:1.43–2.50]), and myocardial infarction (vs SA: OR=1.27 [95%CI:1.12–1.44]), and UA (vs SA: OR=1.36 [95%CI:1.22–1.52]). Conclusions ED visits for ANOCA remained stable, while hospitalizations declined over time. Understanding factors associated with recurrent visits may aid clinicians in treatment strategies. What is new? What are the clinical implications? ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement We are grateful to Leslie Bissett for her generous support of the Libin Cardiovascular Institute Women?s Heart Research program and for supporting this project. We are also thankful to the Holowisky family for supporting the summer research funding for Shubh Patel. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The University of Calgary's Institutional Ethics Review Board provided approval for the research described. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data underlying this study were provided by Alberta Health Services and Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) under the terms of a research agreement. Inquiries regarding access to the data can be made directly to them.