Economic drivers and systemic disparities in invasive coronary angiography: Insights from a national claims database

Background: Despite the prominent economic burden of coronary care, detailed analyses of factors associated with expenditure in developing nations remain sparse. Objectives: This study aimed to provide such analyses using data from a national cohort of patients undergoing invasive coronary angiography (ICA). Methods: Patient data and billable services were retrieved from the Iran Health Insurance Organization (IHIO) database. Data from 158584 hospitalizations were analyzed. A multi-pollutant index was constructed using weighted quantile sum regression. Hospital case volume and provincial ICA rates were modeled using generalized linear models. Three-tier (patient, hospital, and province) generalized linear mixed models were devised for inpatient costs, revascularization odds, and length of stay (LOS). Results: 17.0% of episodes pertained to acute coronary syndrome. Median inpatient cost was PPP$2033. Interventional services accounted for the largest share of costs (37.1%). Out-of-pocket expenditure was 16.6%. Revascularization was performed in 47.2% of hospitalizations. Ambient pollution, lower socioeconomic deprivation, and higher capacity (active beds and angiography devices) were associated with provincial ICA rates. Male sex and older patients had higher revascularization odds, prolonged stays, and incurred higher costs. Procedure complexity (Cost Ratio: 4.37; 95% CI 4.34–4.39) was a major predictor of costs, along with private ownership, heart center status, and weekend hospitalization. Non-cardiac hospitalizations had prolonged LOS. Less deprived provinces had higher revascularization odds for chronic indications. Conclusions: ICA utilization, outcomes, and costs in Iran were found to be significantly associated with clinical complexity, institutional characteristics, regional capacity, and environmental exposures. These findings are critical for identifying future funding and research priorities.