Abstract Body (Do not enter title and authors here): Background: Chronic total occlusion (CTO) of the coronary artery is a complex condition necessitating special care, and the prognosis may vary due to differences in technical and human resources between urban and rural hospitals.

Aim: To evaluate differences in mortality and cardiovascular outcomes in hospitalizations for CTO at urban centers compared to rural centers.

Methods: We queried the National Inpatient Sample (NIS) database from 2016-2021 for hospitalizations related to CTO using the ICD-10 CM code I2582. We compared baseline characteristics and outcomes between urban and rural hospitals using Pearson Chi-Square test and two-sample t-test or Wilcoxon Rank Sum test. We also computed adjusted odds ratios (aORs) using multivariate logistic regression models and conducted a sensitivity analysis using 1:1 propensity score matching.

Results: Out of 562,880 weighted hospitalizations for CTO, patients admitted to urban centers were younger (mean age 67.78 y vs 68.40 y, p<0.001), more likely to be Black American (10.2% vs 6.4%, p<0.001) or Hispanic (10.2% vs 6.4%, p<0.001), had a longer duration of hospital stay (median 4 d vs 3 d, p<0.001), and witnessed higher total charges (median $89,408 vs $55,559, p<0.001) and total cost (median $21,384 vs $17,279, p<0.001) than those in rural hospitals. Multivariate analyses revealed that patients in urban hospitals had higher odds of mortality (aOR 1.28, p=0.010), cardiogenic shock (aOR 1.55, p<0.001), cardiac arrest (aOR 1.31, p<0.001), requiring mechanical circulatory support (aOR 1.52, p<0.001), and acute kidney injury (aOR 1.24, p<0.001) compared to those at rural hospitals. Urban hospitals were also associated with lower odds of myocardial infarction (aOR 0.79, p<0.001) and major adverse cardiovascular and cerebrovascular events (aOR 0.85, p<0.001).

Conclusion: Urban hospitals were associated with increased odds of mortality, cardiogenic shock, cardiac arrest, need for mechanical circulatory support, and acute kidney injury compared to rural hospitals. Despite ample resources at urban hospitals, differential baseline comorbidity burdens may have contributed to these differences thus underscoring the need to conduct prospective studies to better understand the factors responsible for these disparities.