ACC 2009: Quality-of-Life and Cost Analyses for SYNTAX Can Help Hone Treatment Decisions Researchers Say

from <a href="https://www.theheart.org/article/951083.do" target="_blank">Heart<i>wire</i></a> &#151; a professional news service of WebMD

Shelley Wood

March 28, 2009

March 28, 2009 (Orlando, FL) — A new analysis of costs and quality-of-life outcomes in the SYNTAX trial suggests that CABG-treated patients have more angina relief at one year but that PCI is the more cost-effective strategy, at least in low- and moderate-risk patients. During the first month, quality-of-life analyses clearly favor PCI, but these differences evaporate over the first year. In higher-risk patients, CABG was the clear winner when both costs and lifestyle issues are considered.

According to Dr David Cohen (Saint Luke's Mid America Heart Institute, Kansas City, MO), the new information may help physicians weigh the pros and cons of drug-eluting stents (DES) and CABG in patients with complex coronary artery disease. Cohen presented results of the analyses during the opening late-breaking clinical-trial session of the i2 Summit at the American College of Cardiology 2009 Scientific Sessions.

"One of the things that has been the most contentious or confusing about the SYNTAX trial is the different end points going in different directions: an increase in repeat revascularization with PCI, an increase in stroke with bypass surgery, and uncertainty about how patients feel about those things," Cohen told heartwire . "And as a result, there has obviously been confusion in the interpretation of results. This approach really lends itself very nicely to being able to integrate two additional dimensions and the effects of those different outcomes on things that patients and payers care about."

As previously reported by heartwire , SYNTAX was an 1800-patient trial comparing CABG with PCI, using the Taxus (Boston Scientific) DES in patients with either three-vessel or left-main coronary artery disease. One-year results presented at last year's European Society of Cardiology meeting showed that DES were statistically inferior to CABG, at least for the primary composite end point of all-cause death, cerebrovascular events, MI, and repeat revascularization. But the combined rate of "hard" end points--death, MI, and stroke--were no different between the two trial groups, and secondary-end-point findings indicated a statistically lower risk of stroke among PCI-treated patients and a statistically higher risk of revascularization [1].

Quality-of-Life End Points Improve With Time

For the quality-of-life analyses, study participants performed self-administered questionnaires probing CAD-specific quality of life, including angina frequency and physical limitations; general physical and mental health (SF-36); and overall health status and quality-adjusted life-years (QALYs; EQ-5D utility). As Cohen showed here, angina frequency (the primary quality-of-life end point) was slightly but statistically significantly lower in the CABG-treated patients at both six and 12 months and more CABG patients were angina free by 12 months. But roughly the same proportion of CABG and DES patients showed "substantial improvement" in angina frequency (>20 points from baseline score), with no statistical differences between the treatment groups at one, six, or twelve months. For other quality-of-life measures, such as physical limitations and treatment satisfaction, DES-treated patients tended to report feeling significantly better than CABG-treated patients within the first few months, but these differences disappeared by six or 12 months.

"These results tell us that at one year there is very little difference, but the path to that one-year outcome is very different for these patients," Cohen told heartwire . "The bypass patients have a very extended period of disability in the first month or two and eventually make a full recovery. The PCI patients make that recovery much more quickly. Therefore, when we integrate quality of life with duration, you see a benefit in favor of PCI, at least at one year."

Angina Outcomes at One and 12 Months, by Treatment Group

End point PCI CABG p
Angina free, 1 mo 64.4 61.6 NS
Angina free, 12 mo 71.6 76.3 0.05
Substantial improvement in angina frequency, 1 mo 54.7 52.4 NS
Substantial improvement in angina frequency, 12 mo 57.6 58.3 NS

 

Summarizing the quality-of-life results during his presentation, Cohen concluded: "Among patients with left-main and three-vessel coronary disease, angina relief was slightly better with CABG than DES at six and 12 months. The magnitude of benefit was smaller than in previous CABG-vs-PCI comparisons, however, and below the threshold that most patients would find clinically meaningful. All other quality-of-life end points favored PCI at one month, although these differences were transient and largely resolved by six months."

Economic Outcomes Differ by Patient Complexity

For the economic analysis, Cohen and colleagues report that initial hospitalization costs, taking into account physician fees, room costs, and index and repeat procedures, were significantly lower in the DES group: $27 560 per patient vs $33 254, a difference of $5694 (<0.001). Follow-up costs over the year, however, brought the two closer together, at $35 991 and $39 581 (a difference of $3590; p<0.001). But in further analyses, which assessed costs according to baseline SYNTAX score--a measure of patient risk--investigators found that while total costs were substantially and significantly different between treatment groups among low- and moderate-risk patients, the cost difference was negligible ($467) and not statistically significant in patients with the highest SYNTAX scores (>33).

Total One-Year Costs by SYNTAX Score

Risk, by SYNTAX score tertile PCI ($) CABG ($) Cost difference ($)
Low (<22) 32 292 38 446 6154
Moderate (23-32) 36 084 39 973 3889
High (>33) 39 765 40 232 467

Putting the two analyses together, Cohen told heartwire : "There is no single answer to the cost-effectiveness question for this population. These are all very complex patients, but in the least complex of them with the lowest SYNTAX score, the story at least at one year is very clearly in favor of PCI--better overall quality of life and substantially lower cost. However, at the highest end, the top third of the patients based on SYNTAX score, the story is completely flipped--we have actually better quality-adjusted life expectancy for the bypass-surgery patients and neutral cost, meaning that bypass surgery, even at this very admittedly early time point, appears to be the clear winner in that group."

It is definitely too early to tell definitely, but it's not too early to make an educated guess.

Cohen offered some caveats--for one, the cost estimates were done on the basis of US prices and therefore may not apply in Europe and Canada, he noted, where at least in some countries the upfront costs may be lower, particularly where DES are priced substantially lower. He also stressed that as for the primary results of SYNTAX, results for these other analyses may also shift with time. For instance, in the moderate-risk group, he said, "right now the story seems to favor PCI, but I'd say it's a little early to make a final judgment for that group."

Over time, repeat revascularizations will likely increase costs in the DES-treated group, but the price of dual antiplatelet therapy--a significant cost in DES-treated patients--will decline when clopidogrel loses patent protection, he noted.

In the meantime, Cohen believes both the quality-of-life and cost analyses will help patients, physicians, and payers make sense of the main SYNTAX results, which have been hotly debated since they were first presented last fall and published last month. A key point, he told heartwire , is that "we didn't find a big difference in the horrible bad things, like deaths, MIs, and strokes, at least in aggregate, so there we need to look at the more subtle things that will really help patients and doctors to decide.

"For now, this is what we know," he continued. "In four more years, we'll have the five-year data, but until then, this plus intuition is all we can really go on. It is definitely too early to tell definitely, but it's not too early to make an educated guess."

Looking Down the Road

Discussing the results following Cohen's i2 late-breaking presentation, Dr Mark Hlatky (Stanford University School of Medicine, CA) also emphasized the need for longer-term data, admitting he was "a little uncertain as to the long-term cost-effectiveness at this point."

"I do think the gradient of cost-effectiveness [seen in this study] according to SYNTAX score is extremely plausible. But it's important to remember that cost-effectiveness is not a constant thing connected to the treatment; cost-effectiveness derives from the match between the patient and the most appropriate treatment."

Calling the data "very important," Hlatky emphasized that there are inherent limits to one-year follow-up.

"We have not yet seen full costs, and long-term differences and effectiveness may differ, so we will need to do further follow-up. But, overall, this is generally consistent with some of the things we've seen."

Also commenting in a panel discussion, Dr Richard J Shemin (Boston Medical Center, MA), a surgeon, made the point that surgery has the advantage of bypassing lesions entirely, so that some of the problems related to the lesions themselves that crop up over time for PCI simply never become an issue in bypass patients. In most trials, he added, at around the three-year mark, further separation is seen in terms of outcomes between the PCI- and CABG-treated patients. "So I do think that long-term follow-up is going to be key," Shemim stated.

Dr Sanjay Kaul (Cedars Sinai Medical Center, Los Angeles, CA), who did not participate in the panel discussion and was not involved in the trial, offered heartwire some more critical opinions on the SYNTAX analysis. "In my opinion, therapies have to be shown to be effective first before one can make judgments about their cost-effectiveness," he said. "Cost varies according to practice patterns and at different time points of follow-up. Often, the reduced cost at earlier time points can make ineffective therapies appear to be cost-effective. Ask yourself whether you would want the most effective or the most cost-effective therapy?"

Cohen disclosed having no financial conflicts of interest; the study was funded by Boston Scientific. Hlatky receives "significant" consulting fees or honoraria from GE Healthcare, California Pacific Medical Center, and the Blue Cross Blue Shield Association Technology Assessment Committee. Shemim receives "significant" consulting fees/honoraria from Edwards. Kaul has no disclosures.

 

  1. Serruys P, Morice MC, Kappetein AP, et al. Percutaneous coronary intervention versus coronary-artery bypass grafting for severe coronary artery disease. N Engl J Med 2009; 360:961-972. Abstract

 

The complete contents of Heartwire , a professional news service of WebMD, can be found at www.theheart.org, a Web site for cardiovascular healthcare professionals.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.

processing....