OBJECTIVE: To determine clinical and economic outcomes of primary PTCA and assess the effects of comorbidities (congestive heart failure, diabetes, hypercholesterolemia, hypertension) on outcomes using a national database. METHODS: Data were obtained from MarketScanâ Medstatâ, which contains claims data for 4–5 million people. Patients with a hospital admission for PTCA (CPT codes 92982, 92984) in 1992 and one year of follow-up charge data were identified. A total of 2,663 patients with a single vessel and 331 with a multiple vessel procedure were included. Patients who died or were missing prior to one-year follow-up were excluded (n = 653). Total charges were calculated by summing charges for the index procedure plus all inpatient and outpatient charges incurred during the year following PTCA. Multivariate regression was used to assess effects of comorbidities on outcomes (adjusted for age and other factors). RESULTS: Patients with single vessel versus multiple vessel PTCA did not differ according to comorbid and other characteristics, or most clinical or economic outcomes; therefore combined data are presented. The frequency of clinical outcomes in the year following PTCA was: rehospitalization for angina-41%, myocardial infarction (MI)-33%, repeat PTCA-15%, coronary artery bypass grafting-7%, and stroke-3%. Comorbidities related to clinical outcomes were: congestive heart failure (CHF) for MI (p = 0.0001), diabetes for angina rehospitalization (p = 0.06), and diabetes (p = 0.05) and hypertension (p = 0.004) for repeat PTCA. Total charges per patient at one year after primary PTCA were $35,257, and total charges were strongly related to the presence of diabetes (p = 0.001) and CHF (p = 0.001). There was no association with hypertension or hypercholesterolemia. CONCLUSION: These findings show that the presence of certain comorbid factors does influence clinical and economic outcomes following PTCA.