Two Trials Explore On-Pump Versus Off-Pump Bypass Surgery Reply

Two large trials presented at the American College of Cardiology meeting in San Francisco and published simultaneously in the New England Journal of Medicine provide important new information about the ongoing debate over whether CABG should be performed with or without cardiopulmonary bypass. The combined results suggest that both techniques can be effective, and that surgeons should choose the technique with which they are most familiar and comfortable.

Previous 30-days results from CORONARY (CABG Off or On Pump Revascularization Study), which randomized 4,752 patients to on-pump or off-pump CABG, showed no significant difference in the primary outcome (death, MI, stroke, or new renal failure requiring dialysis) between the two groups. However, patients in the off-pump group required more repeat revascularization procedures, though they had lower rates of bleeding, acute kidney injury, and respiratory complications.

Now, one-year results from CORONARY have found no significant difference in the primary outcome between the groups at 1 year (12.1% in the off-pump group versus 13.3% in the on-pump group (HR 0.91, CI 0.77-1.07, p=0.24). There were also no significant differences in the individual components of the endpoint. In addition, there were no significant differences in recurrent angina (1% versus 0.9%) or the need for repeat revascularization (1.4% versus 0.8%).

A quality of life substudy found no differences between the two groups at any time point in the first year. A neurocognitive substudy found less deterioration in one assessment of neurocognitive function in the off-pump group at discharge but found no significant differences at 30 days or at 1 year. There were no differences at any time between the two groups in two other tests of neurocognitive function.

“The CORONARY study shows that off-pump bypass is just as good as on-pump. Therefore, surgeons should tailor their surgical approach to their technical expertise and expected technical difficulty,” said Andre Lamy, lead author of the study, in an ACC press release.

In the GOCABE (German Off-Pump Coronary Artery Bypass Grafting in Elderly Patients) study, 2,539 patients 75 years of age or older were randomized to on-pump or off-pump CABG. The primary endpoint was the composite of death, stroke, MI, repeat revascularization, or new renal-replacement therapy at 30 days and one year.

At 30 days there was no significant difference in the primary endpoint: 7.8% for the off-pump group versus 8.2% for the on-pump group (OR 0.95, CI 0.71-1.28, p=0.74). However, there were more repeat revascularizations in the off-pump group at 30 days: 1.3% versus 0.4%, OR 2.42, CI 1.03-5.72, p=0.04. At one year there were no significant differences between the groups in the composite endpoint (13.1% versus 14%, HR 0.93, CI 0.76-1.16, p=0.48) or in any of the individual components of the composite endpoint.

The authors write that their trial “does not support the assumption that off-pump CABG can improve the early outcome in high-risk patients.”

During the discussion section lead investigators for both studies, Anno Diegeler for GOCABE and Andre Lamy for CORONARY, emphasized that their results depended on having expert surgeons highly qualified in both techniques.

Choice of the technique, said Diegeler, should depend on clinical characteristics, patient choice, and surgeon experience.

Chris Cannon, a panel discussant, asked the question:”why would you want to do off-pump since it’s no better and it’s harder to do?” At the ACC news conference, Mark Davies said that “these trials may temper our enthusiasm for off-pump surgery.” In the US, with the advent of publicly reported STS (Society for Thoracic Surgeons) scores for individual hospitals and amateurs, there will no room for amateurs. “If you’re an amateur at it you should give it up.” Neil Kleiman had a recommendation: “if you’re going to do it you damn well better be good at it… there’s no room for sloppiness.”

 

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CABG Highly Cost Effective In Diabetics With Multivessel Disease Reply

In November the main results of the FREEDOM trial showed that diabetics with multivessel disease do better with CABG than PCI. Now the findings of the trial’s cost-effectiveness study, published online in Circulation, demonstrate that CABG is also highly cost-effective when compared with PCI.

Elizabeth Magnuson and colleagues  found that although CABG initially cost nearly $9,000 more than PCI ($34,467 versus $25,845), over the long term it was more cost effective. At five years, greater follow-up costs in the PCI group, in large part due to a greater number of  repeat revascularization procedures, reduced the difference so that CABG cost only $3,600 more than PCI. The researchers calculated that CABG had a lifetime cost-effectiveness of $8,132 per QALY (quality-adjusted life-year) gained, which is considered highly cost effective. The finding was consistent across a broad range of assumptions.

The authors concluded “that CABG provides not only better long-term clinical outcomes than DES-PCI but that these benefits are achieved at an overall cost that represents an attractive use of societal health care resources. These findings suggest that existing guidelines that recommend CABG for diabetic patients with multivessel CAD remain appropriate in current practice and may provide additional support for strengthening those recommendations.”

“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,” said Magnuson, in an AHA press release. “This is especially true in cardiovascular disease where many interventions tend to be very costly up front.”

 

FREEDOM Lends Strong Support To CABG For Diabetics With Multivessel Disease 3

Editor’s note: The embargo on FREEDOM was lifted early after a press release was published by mistake.)

Diabetics with multivessel disease do better with CABG than PCI, according to FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease), a large NIH-sponsored study presented at the American Heart Assocation in Los Angeles and published simultaneously in the New England Journal of Medicine.

The study was designed to evaluate the  relative worth of the two revascularization procedures in diabetics with multivessel disease. Although many studies, including BARI, ARTS, CARDia, and SYNTAX, suggested that CABG was more effective than PCI in this population, PCI has remained a popular procedure in this group. Now, many experts agreed here in Los Angeles, FREEDOM may well dampen enthusiasm for PCI in this group.

In the trial, 1900 patients were randomized to either PCI with a drug-eluting stent or CABG. After followup for at least two years the primary outcome– the composite of death, nonfatal MI, or nonfatal stroke– occurred more often in the PCI group. There were more deaths and MIs in the PCI group but more strokes in the CABG group:

Here are the 5-year event rates:

Composite endpoint: 26.6% in the PCI group versus 18.7% in the CABG group (p=0.005)

  • Deaths: (16.3% versus 10.9%, p=0.049) but more strokes in the CABG group
  • MI: 13.9% versus 6%, p<0.001)
  • Stroke: 2.4% versus 5.2%, (p=0.03)

The results in favor of CABG were consistent across all the prespecified subgroups, including severity of disease as assessed by the SYNTAX score.

In an accompanying editorial, Mark Hltaky discussed the resistance of many cardiologists to accepting that CABG is superior to PCI in this patient population. Previous studies were dismissed because they were outdated, an argument that Hlatky labels “a catch-22, since long-term studies are needed to compare hard outcomes, but evidence from long-term studies may be ignored if therapies are evolving.” In particular, PCI advocates  have proposed that the use of drug-eluting stents would close the gap between PCI and CABG.

Now, he writes, 17 years after the NHLBI issued a clinical alert based on the results of the BARI trial, FREEDOM “provides compelling evidence of the comparative effectivesness of CABG versus PCI.”

He concludes:

“The results of the FREEDOM trial suggest that patients with diabetes ought to be informed about the potential survival benefit from CABG for the treatment of multivessel disease. These discussions should begin before coronary angiography in order to provide enough time for the patient to digest the information, discuss it with family members and members of the heart team, and come to an informed decision.”

At an AHA press conference, David O. Williams said that FREEDOM “provides meaningful information to help” cardiologists choose the best therapy for their patients and that it will cause “a definite change in practice.”

At the same press conference, Alice Jacobs said that FREEDOM might result in CABG receiving a class 1 recommendation in the guidelines. Now, she said, “one would think long and hard” about offering PCI to diabetics with multivessel disease.

Mandatory YouTube Link for this trial:

Click here to read the AHA press release…

No Benefit Found For Exercise Echocardiography In Asymptomatic Patients Following CABG Or PCI 1

Routine exercise echocardiography in asymptomatic patients after revascularization does not lead to better outcomes, according to a new study published in Archives of Internal Medicine. Although guidelines generally discourage the practice, post-revascularization stress tests are still commonly performed.

Serge Harb and colleagues performed exercise echocardiography on 2,105 patients following CABG surgery or PCI and followed them for a mean of 5.7 years. 13% of the subjects were found to have ischemia. One-third of these underwent repeat revascularization. Nearly half (49%) of the patients without ischemia on the initial test underwent further exercise testing. Overall, 17% of patients in the study underwent repeat revascularization. However, revascularization had no significant impact on mortality.

Mortality was higher in patients who had ischemia at any time than in patients with no ischemia (8% versus 4.1%, p=0.03). However, the authors reported that “clinical and stress testing findings, but not echocardiographic features, were associated with both all-cause and cardiac mortality.” This finding, according to the authors, suggests “that risk evaluation could be obtained from a standard exercise test rather than exercise echocardiography.”

The authors write that “careful consideration is warranted before the screening of asymptomatic patients is considered appropriate at any stage after revascularization.”

In an accompanying commentary, Mark Eisenberg writes that the study makes “a compelling argument that routine periodic stress testing in asymptomatic patients following coronary revascularization is of little clinical benefit.”

Click here to read the press release from Archives…

ASCERT Observational Study Finds Long Term Advantage for CABG Over PCI in High Risk Cases Reply

A very large observational study finds that long-term mortality in high risk patients is lower after bypass surgery than after PCI. The results, which were previously revealed in January at the annual meeting of the Society of Thoracic Surgeons (STS), were presented in final form at the American College of Cardiology by William Weintraub and published simultaneously in the New England Journal of Medicine.

ASCERT (ACCF-STS Database Collaboration on the Comparative Effectiveness of Revascularization Strategies) is an NHLBI-funded study based on linked data from the STS, the ACC, and CMS administrative data. The study population included patients 65 or older with 2 or 3 vessel disease who underwent CABG or PCI in the period from 2004 through 2007. 189,793 patients were followed in the study; 103,549 received PCI and 86,244 underwent CABG. Median followup was 2.67 years.

1 year adjusted mortality:

  • 6.2% for CABG versus 6.55% for PCI (RR 0.95, CI 0.90-1.00)

4 year adjusted mortality:

  • 16.4% versus 20.8% (RR 0.79, CI 0.76-0.82)

The findings, the authors said, were consistent with data from both previous observational and randomized trials. But, they acknowledged, “the potential remains for unmeasured confounders to have influenced the findings.”

In an accompanying editorial, Laura Mauri writes that “it is plausible that, in patients with diffuse atherosclerosis, CABG reduces the risk of fatal myocardial infarction more effectively than does focal treatment.” But she expressed skepticism that CABG could be shown to be better in two-vessel disease or in patients with three-vessel disease with focal lesions. ASCERT also does not reflect either the recent advances in PCI technology or the “modern PCI strategies” which reserve PCI for ischemic lesions, she writes.

Observational studies can provide valuable information “but there is no substitution for randomized trials to eliminate selection bias between treatments.” Mauri concludes: “we must … continue to give priority to randomized trials on the most salient questions regarding treatment strategy.”

Has COURAGE been vindicated? Reply

The ACC, the AHA, and a whole alphabet soup worth of other cardiovascular organizations (SCAI, STS, AATS, ASNC, ASE, HFSA SCCT) have published (or in some cases just endorsed) a report, called the ACCF/SCAI/STS/AATS/AHA/ASNC 2009 Appropriateness Criteria for Coronary Revascularization. The report  will probably provide comfort to those who were big supporters of COURAGE. I’m guessing this will only initiate a new round of debate. It seems unlikely that there will be a widespread breakout of peace over this issue in 2009.

You can read a Dow Jones news story about the report.