While the costs associated with CABG in diabetic patients with multivessel disease are initially higher by approximately $8,600 compared with PCI using drug-eluting stents (DES), five-year and lifetime calculations show CABG to be more cost effective in a substudy of the FREEDOM trial presented Nov. 4 as a late breaker at the 2012 American Heart Association’s (AHA) scientific sessions in Los Angeles.
For this substudy, Elizabeth A. Magnuson, ScD, director of health economics and technology assessment at Saint Luke’s Mid-America Heart Institute in Kansas City, Mo., and colleagues analyzed economic data from 1,900 participants that compared CABG with PCI using drug-eluting stents (DES) in patients with diabetes with multivessel disease. The study included patients from 16 countries, including 19 percent from the U.S.
The primary endpoint was the incremental cost-effectiveness ratio expressed as cost per quality-adjusted life year (QALY) gained. Costs and QALYs were discounted at 3 percent annually.
The researchers approached the analysis in two stages:
- An in-trial analysis based on observed survival, health state utility (EQ-5D) and costs derived from reported healthcare resource use during the trial period; and
- A lifetime analysis based on projections of survival, quality-adjusted survival and costs beyond the trial period.
To assess expenses, Magnuson et el examined cath lab and CABG-related procedure costs based on measured resource utilization (procedure duration, balloons, stents, wires, etc.) and current unit costs. The costs of DES were evaluated at $1,500 per stent. Also the ancillary hospital costs were based on regression models developed from 2010 MedPAR data for FREEDOM-eligible patients. They used clinical events and complications rather than length of stay “to avoid distortions due to marked differences in length of stay across different countries and healthcare systems.” Additionally, the researchers looked at cardiovascular (CV) and non-CV rehospitalizations, physician fees, outpatient CV care/testing and medications, cardiac rehabilitation and nursing home stays.
For total procedure costs, CABG equaled $9,739, compared with $13,014 for PCI. The cost of PCI was higher mainly due to the DES charges and the amount of stents used in these diabetic patients with multivessel disease, while procedure duration of CABG was an average of 248 minutes—141 minutes longer than PCI.
For the total hospitalization costs, PCI was $8,622 less than CABG, which totaled $34,467. Included in these calculations, physician fees for CABG were $5,170, compared with $2,967 for PCI, but the room and ancillary costs made the biggest difference, with CABG costs totaling $19,521—$9,600 more than PCI costs. However, the index procedure costs were actually $3,212 higher for PCI, at $12,998.
Even though CABG was associated with approximately $8,600 higher initial procedure and hospitalization costs per patient, they were partially offset by lower costs associated with repeat revascularization and to a lesser extent cardiac medications. At five years, CABG improved quality-adjusted life expectancy by approximately 0.03 years while increasing total costs by an approximately $3,600 per patient.
Over a lifetime horizon, CABG was found to have a lifetime cost-effectiveness of $8,132 per quality-adjusted life years (QALY) gained, which is far below the commonly used benchmark of $50,000 per QALY gained for considering a treatment to be cost effective.
For patients with diabetes and multivessel coronary artery disease (CAD), the researchers concluded that CABG provides not only better long-term clinical outcomes than PCI with DES, but these benefits are achieved at an overall cost that represents an attractive use of societal healthcare resources.
“With great concerns about escalating healthcare costs, it’s very important when setting policy to understand the benefits gained from additional expenditures over the long run,” Magnuson said in a release. “This is especially true in cardiovascular disease where many interventions tend to be very costly up front.”
The researchers said that longer follow-up of the patients will be needed to see if the advantages of bypass continue in the years following the initial five years of the study.