Pair of Studies Look at Cost Effectiveness of PCI in Different Populations

LOS ANGELES, CA—A study presented November 4, 2012, at the American Heart Association (AHA) Scientific Sessions demonstrated the long-term cost effectiveness of coronary artery bypass grafting (CABG) compared with percutaneous coronary intervention (PCI) in diabetics with multivessel disease, while results of another study showed the higher costs of PCI in centers without on-site surgery.

The Cost of FREEDOM

In the FREEDOM trial, 1,855 patients with diabetes and multivessel disease were randomized to CABG or PCI with DES and followed for 47 months. The clinical results, also presented November 4 at the AHA meeting, showed that CABG was associated with lower rates of death, MI, or stroke. Elizabeth A. Magnuson, ScD, of Saint Luke’s Mid America Heart Institute (Kansas City, MO), and colleagues looked at the costs and long-term cost effectiveness of the 2 strategies from FREEDOM, measuring quality adjusted life years (QALY) gained.

In FREEDOM, roughly 4.1 DES were used per patient for the index procedure, with a cost estimate of $1,500 per stent. Procedure length was longer for CABG than PCI (248 min vs. 107 min), and total index procedure cost was higher for PCI ($13,014 vs. $9,739). Due to longer recovery times and other ancillary costs, the overall index hospitalization cost was higher with CABG ($34,467 vs. $25,845; P < 0.001).

Cost Difference Narrows With Time

Over time, though, the gap in costs narrowed due to more repeat PCIs (6.8 per 100 person-years vs. 3.3; P < 0.001) and CV hospitalizations (17.2 per 100 person-years vs. 10.8; P < 0.001) in the PCI arm. The difference in costs narrowed from $7,878 at 1 year to $3,641 at 5 years. This translated to a switch from a gain in 0.033 QALYs with PCI at 1 year to a gain of 0.031 QALYs with CABG at 5 years at a cost of $116,699 per QALY gained with CABG.

Using an analysis model projecting the post-trial costs and QALYs from FREEDOM, Dr. Magnuson and colleagues demonstrated a lifetime difference in cost of $5,392 favoring PCI, with 0.663 QALYs gained with CABG. This translated to a cost of $8,132 per QALY gained with CABG, well under the generally accepted threshold of $50,000 per QALY gained.

In a subanalysis by Syntax score, these results remained consistent (table 1).

Table 1. Cost Effectiveness of CABG vs. PCI by Syntax Score

 
“For patients with diabetes and multivessel CAD, 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 health care resources,” Dr. Magnuson concluded. “These findings provide additional support for existing guidelines that recommend CABG for diabetic patients with multivessel CAD.”

Commenting on the results, Mark A. Hlatky, MD, of Stanford University School of Medicine (Stanford, CA), praised the analysis for giving a full accounting of the patients beyond the bounds of the trial. He called the results “quite solid,” adding that “they’re basically saying that the observed differences in survival that were seen in the trial coupled with the cost difference of about $3,600 makes [CABG] look like a very economically attractive therapy for patients who have diabetes [and multivessel disease].”

Surgical Volume Impacts Cost

For the CPORT-E trial, researchers randomized 18,867 patients with stable CAD or ACS to undergo non-emergency PCI at a hospital with (n = 4,718) or without (n = 14,149) on-site cardiac surgery from April 2006 to March 2011. As reported in the New England Journal of Medicine, 9-month data showed that PCI at hospitals without surgical backup was noninferior to PCI at hospitals with on-site surgery with regard to the primary endpoint of MACE, with no differences in all-cause mortality or MI.

In a subanalysis, Eric L. Eisenstein, DBA, of the Duke Clinical Research Institute (Durham, NC), and colleagues looked at the cost differences between the 2 approaches. Overall resource use during the index procedure (diagnostic catheterizations, PCI procedures) was lower without on-site surgery (113.2 per 100 patients vs. 199.5; P < 0.001), while resource use (total revascularizations, ER visits) during follow-up was higher (86.2 per 100 patients vs. 80.0; P < 0.001). Total admissions at 9 months were lower at sites without on-site surgery (199.4 per 100 patients vs. 279.6; P < 0.001).

There was no difference in index procedure medical costs, but there was a trend for higher medical costs at 9 months without on-site surgery, related to higher medical costs during follow-up (table 2).

Table 2. Estimated Medical Costs (Per Patient)

Estimated medical costs during follow-up at low volume sites were higher per patient with no on-site surgery ($6,126 vs. $4,918; P = 0.0002), but this was not the case at high volume sites ($5,529 vs. $5,211; P = 0.18). 

ICU room costs were also higher without on-site surgery, but patients seen at centers without such services were mandated by protocol to receive postprocedural care in the ICU or CCU. Overall costs at 9 months were 15% higher in sites without surgery, 22% higher at low-volume sites and 7% higher in high-volume sites.

“Patients assigned to PCI at sites with versus without on-site cardiac surgery had greater resource use, longer lengths of stay but slightly lower medical costs at 9 months,” Dr. Eisenstein said. “The higher medical costs for patients at sites without on-site cardiac surgery were attributable first of all to the decision in the protocol to use the ICU for post PCI care and second to the slightly higher rates of subsequent revascularizations at sites without on-site cardiac surgery.”

Surgical Capability or Volume?

Dr. Hlatky observed that a key question with the CPORT-E economic analysis is whether the results derive from the presence of on-site cardiac surgery or case volume. “If we have a low volume site, they may have higher costs and higher adverse events,” he said. “Whenever you do something at higher volumes you’re more efficient economically and you might do a little bit of a better job.”

There are also policy implications to consider. “These centers are also doing emergency procedures, so policy may have to take into account the fact that we want to have these sites available, such as for patients with acute MI,” Dr. Hlatky said. “So the policy implications are a little more tricky because they’re providing care for all kinds of patients, not just the kind that were put into the trial.”

 

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Sources:
1. Magnuson EA. Cost-effectiveness of PCI with drug-eluting stents vs. bypass surgery for patients with diabetes and multivessel CAD: Results from the FREEDOM trial. Presented at: American Heart Association Scientific Sessions; November 4, 2012; Los Angeles, CA.

2. Eisenstein EL. Economic outcomes of percutaneous coronary intervention performed at sites with and without on-site cardiac surgery. Presented at: American Heart Association Scientific Sessions; November 4, 2012; Los Angeles, CA.

 

Disclosures:

• FREEDOM was supported by grants from the National Heart, Lung, and Blood Institute.
• CPORT-E economic study was supported by Johns Hopkins University.
• Dr. Magnuson reports receiving research grants from Abbott Vascular, Boston Scientific, Edwards Lifesciences, Eli Lilly, and Medtronic.
• Dr. Eisenstein reports receiving research support from Eli Lilly and Medtronic.

 

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• CPORT-E: PCI Outcomes Similar Regardless of On-Site Cardiac Surgery
• At 1 Year PCI More Cost Effective than CABG for Some SYNTAX Patients