ASCERT: CABG More Cost-Effective Than PCI Over Long Term

LOS ANGELES, CA—While more expensive in the short term, coronary artery bypass graft (CABG) surgery is more cost-effective than percutaneous coronary intervention (PCI) beyond 1 year and over the long term, according to a subanalysis of the ASCERT trial presented November 6, 2012, at the American Heart Association Scientific Sessions.

The main ASCERT (American College of Cardiology [ACC] Foundation - Society of Thoracic Surgeons [STS] Collaboration on the Comparative Effectiveness of Revascularization sTrategies) trial, published in the New England Journal of Medicine, showed a long-term survival advantage with CABG over PCI. For the study, the ACC’s NCDR CathPCI registry and the STS database were linked with claims data from the Centers for Medicare and Medicaid Services to study patients receiving PCI (n = 103,549) or CABG (n = 86,244) from 2004 to 2008. 

Early Cost Advantage for PCI Disappears

In a subanalysis, Zugui Zhang, PhD, of the Christiana Health Care System (Newark, DE), and colleagues looked at resource use and long-term costs in each group to analyze the relative cost-effectiveness of the 2 revascularization strategies. Initial and subsequent hospitalization costs were considered using DRG and Medicare Part A data, as were professional costs using CPT codes.

Early after the procedure, PCI patients were more often free from death/AMI/stroke than CABG patients, but this trend reversed at roughly the 1 year point, with CABG patients showing reduced risk beyond 3 years.

In terms of costs, CABG was more expensive than PCI at every time point measured (table 1).

Table 1. Estimated Costs

In cost-effective analysis, PCI showed gains in quality adjusted life years (QALYs) of 0.14 after the index procedure and 0.13 at 30 days, respectively. At 1 year, however, CABG showed a gain in QALYs of 0.03, with gains of 0.11, 0.14, 0.18, and 0.21 at 2, 3, and 4 years, and lifetime, respectively. In addition, using a threshold of $50,000 per QALY gained, CABG was slightly more cost-effective than PCI at 2 years. This increased to a 10% advantage in cost-effectiveness at 3 years, 50% at 4 years, and 55% over a lifetime.

Using a higher threshold ($100,000 per QALY), CABG was 31% more cost-effective at 2 years, 51% at 3 years, 85% at 4 years, and 90% over a lifetime.

CABG Under the Threshold

Dr. Zhang acknowledged that within the 1-year time frame, CABG was more costly and less effective than PCI. However, despite the continued higher cost, “in the long run (longer than 1 year), CABG offers longer quality adjusted life years,” he said, adding that “using a common threshold ($50,000/QALY, $100,000/QALY), CABG will often be a cost-effective strategy.” 

Dr. Zhang commented that he hopes the results are taken into consideration by the right people. “The main target for our research is policy makers and medical decision makers,” he said.

Session co-moderator Robert W. Yeh, MD, of Massachusetts General Hospital (Boston, MA) commented that the results “are consistent with what we’ve seen with the FREEDOM trial and what we’ve seen previously with SYNTAX and then adding this layer of cost-effectiveness.”

The other co-moderator, Ralph G. Brindis, MD, MPH, of the University of California, San Diego (San Diego, CA), stressed that in today’s practice environment, “as we [care for] the patient, we have to not only think about issues of quality, but accountability, transparency and cost.”

Study Details 

High-risk patients with acute MI, shock, or left main disease were excluded in ASCERT. For lifetime and non-hospital period cost, researchers used the average Medicare participant per capita expenditure of $5,219 in 2004.

  

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Source:
Zhang Z. Cost-effectiveness of revascularization strategies: Results from ASCERT. Presented at: American Heart Association Scientific Sessions; November 6, 2012; Los Angeles, CA.

 

Disclosure:

• The study was funded by a grant from the National Heart, Lung, and Blood Institute.
• Dr. Zhang reports no relevant conflicts of interest.

 

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