Abstract 13253: Cost-effectiveness of CABG vs PCI for Treatment of Multivessel Coronary Disease among Unstable Angina Patients---A Secondary Analysis from ASCERT

Abstract

Background: The American College of Cardiology Foundation and The Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategies (ASCERT) has demonstrated that coronary artery bypass graft (CABG) surgery was associated with reduced mortality compared to percutaneous coronary intervention (PCI) at 4 years. In this study, we examined the cost-effectiveness of CABG versus PCI for treatment of multivessel coronary artery disease (CAD) patients among unstable angina patients. Methods: Unstable angina age ≥65 year-old patients with stable 2 and 3-vessel disease undergoing revascularization from 2004 through 2008 were evaluated. Costs were assessed at index, study period from years 2004 to 2008 by Diagnosis Related Group for hospitalizations. The average Medicare participant per capita expenditure in 2004 was used to estimate cost beyond the study period. Effectiveness during the study period was measured via mortality rate. Costs and effectiveness comparisons were adjusted using propensity scores bin bootstrapping (PSBB) method. The incremental cost-effectiveness ratio (ICER) was expressed as cost per quality adjusted life year (QALY) gained. Analyses were also conducted for 1-to-1 matched analytic population. Results: Among unstable angina patients (24,630 of 86,244 in CABG group and 48,261 of 103,549 in PCI group) at least 65 years old with two or three vessel CAD, results from both matched analytic population (16,500 in each group) and PSBB adjusted approach were similar. Costs were higher for CABG by $10,389 (95% CI: $10,269 to $10,509) during the index hospitalization. Over the period from 2004 through 2008, average total costs were $69,476 for CABG versus $57, 037 for PCI, a difference of $12,439 (95% CI: $11,038 to $13,751); patients undergoing CABG gained an average of 0.4066 life-years relative to PCI; the ICER of CABG compared to PCI, was $30, 484 per LYG, with 37%, 100%, and 100% of bootstrap-derived estimates <$30,000/ QALY, <$50,000/ QALY , and <$100,000/ QALY, respectively. Conclusions: Recognizing the limitations of an observational study, this study shows that over a period of 4 years or longer, CABG is associated with better outcomes but at higher cost than PCI in patients with unstable angina.