Beyond five years, CABG was more cost effective than PCI using drug-eluting stents (DES-PCI) for treating patients with complex coronary artery disease (CAD), according to a study published online Aug. 1 in Circulation.

In prior study findings, researchers of the SYNTAX study (SYNergy between PCI with TAXus and cardiac surgery) found that in the short term to five year period, DES-PCI was more cost effective and offered patients better outcomes. Patients in the SYNTAX study were enrolled between March 2005 and April 2007 and followed for approximately five years.

Cost effectiveness all came down to SYNTAX scores, wrote lead author David J. Cohen, MD, MSc, of St. Luke’s Mid America Heart Institute in Kansas City, Mo. The higher the SYNTAX score, the more complex the degree of coronary artery disease, and the more cost effective CABG became. In patients with lower SYNTAX scores, PCI initial costs proved to be more attractive unless stent price exceeded $4,880 per stent. In patients with higher scores, such as those with a SYNTAX score of 33 or greater, CABG was more attractive no matter what the stent cost.

Initial costs and hospitalizations for CABG and DES-PCI favored DES-PCI by approximately $10,000 per patient. Over the course of five years, the outlay for repeated revascularizations, hospitalizations, outpatient services and medications narrowed the gap to around $5,619 per patient in favor of DES-PCI. Life expectancy at year five and quality-adjusted life expectancy favored CABG at 4.7 years and 3.91 quality-adjusted life years as opposed to DES-PCI at 4.6 years and 3.86 quality-adjusted life years.

In the longer term, Cohen et al found that CABG patients had an incremental cost effectiveness ratio of $12,329 per life-year gained with an increase in life expectancy of 0.412 years. With nonfatal MI or stroke factored into their projections, CABG improved to $15,758 per quality-adjusted life-year gained. CABG, therefore was estimated as having lifetime incremental costs of $5,081.

Cohen et al wrote that “although differences in life expectancy and quality-adjusted life expectancy were small over the 5-year timeframe of the trial (0.100 years and 0.044 [quality-adjusted life-years] QALYs, respectively), the incremental life expectancy and QALY gains with CABG increased considerably when projected over a patient’s lifetime.” Ultimately, they found that the lifetime incremental cost effectiveness ratio for CABG compared with DES-PCI was around $16,500 per quality life year gained and around $12,500 per life-year gained.

The research team found that costs for DES-PCI had reduced over the last four to five years, which widened the rift between initial procedure costs from around $5,000 per patient to around $10,000. Costs for the first-year follow-up changed as well, due to reductions in price of dual antiplatelet therapy and the approval of a generic clopidogrel.

Cohen et al noted that “[b]ased on the results of the SYNTAX trial, for most patients with 3-vessel or left main CAD without recent MI, CABG is a clinically and economically attractive revascularization strategy compared with DES-PCI. However, among patients with less complex disease, DES-PCI may be preferred on both clinical and economic grounds.”

This research was funded by Boston Scientific.