Stress imaging use and repeat revascularization among medicare patients with high-risk coronary artery disease

Abstract

The optimal use of stress testing after coronary revascularization remains unclear, and overuse of stress testing might increase the rates of repeat revascularization. We analyzed the association at both the patient and regional level between the use of stress testing and repeat revascularization for a cohort of Medicare beneficiaries receiving revascularization within 30 days of an admission for symptomatic coronary artery disease. The sample consisted of 219,748 Medicare beneficiaries aged >65 years who received percutaneous coronary intervention or cardiac bypass artery grafting after hospital admission for symptomatic coronary artery disease in 2003 to 2004. Medicare claims data through 2008 identified the use of stress testing and repeat revascularization. The associations between the cumulative incidence of stress testing and repeat revascularization were analyzed using linear regression analysis. Within 6 years of the initial revascularization, the cumulative incidence of events was 0.61 for stress testing and 0.23 for repeat revascularization. Most (53.1%) repeat revascularizations were preceded by a stress test. Only 10.3% of repeat revascularization procedures were preceded by myocardial infarction. The 4-year cumulative incidence of repeat revascularization and stress testing varied between the Hospital Referral Regions represented by the sample, and the positive correlation between the rates by the health referral region accounted for only a small portion of the total health referral region variation in revascularization rates. In conclusion, stress testing is commonly performed among Medicare patients after the initial revascularization, and most repeat procedures are performed for stable coronary artery disease. The variation in stress testing patterns only explained a modest fraction of the regional variation in the repeat revascularization rates.

Figure 1

Patient-level cumulative incidence of (A) repeat coronary revascularization and (B) stress testing, stratified by initial revascularization modality.

Figure 2

Histogram of HRR-level cumulative incidence in (A) repeat coronary revascularization and (B) stress testing, both at 48 months after initial revascularization.

Figure 3

Scatter plot illustrating correlation between HRR-level cumulative incidence of repeat revascularization and stress testing