Shifts in Surgical Revascularization and Valve Procedures Among Medicare Beneficiaries

Abstract

The rapid development of percutaneous coronary intervention (PCI) has reduced the demand for coronary artery bypass grafting (CABG) surgery. We examined whether the previously documented declining demand for CABG and expanding PCI use are associated with changes in performance of valve (aortic or mitral) replacement or repair surgery. We used Medicare Part A administrative data to identify beneficiaries who received PCI, CABG, valve procedures between 1991 and 2005. We used multivariable models to investigate the relationship between CABG and PCI rates and rates of aortic and mitral valve surgery at the hospital referral region level while adjusting for demand and supply factors including heart disease rates. Hospital referral region level rates of valve replacement and repair increased by 0.36 and 0.17 per 1000. A 1 per 1000 change in the isolated CABG rates was positively associated with a 0.0255 and 0.0013 per 1000 change in the concomitant (simultaneous CABG) valve replacement and repair rates. A 1 per 1000 change in the PCI rate was positively associated with 0.0105 and a 0.0051 per 1000 change in the concomitant valve replacement and repair rate. A 1 per 1000 change in the isolated CABG rates was positively associated with a 0.0151 per thousand isolated valve replacement and negatively associated with a 0.0013 per 1000 repair rate. A 1 per 1000 change in the PCI rate was positively associated with a 0.0081 and a 0.0031 per 1000 change in the isolated valve replacement and repair rate. A modest portion of the change in valve replacement and repair use over the period is associated with shifts in revascularization. Future study needs to consider the effects of these trends on patient outcomes and resource use.