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Endoscopic vein-graft harvest equals open harvest at 3 years

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REGROUP is not a definitive comparison

The results from the REGROUP trial are interesting and open the field for additional comparisons of endoscopic and open saphenous vein-graft harvesting, but this trial is not the definitive answer regarding whether these two harvesting approaches produce similar results. Greater reassurance of equivalence would come from studies that included more patients and a more diverse patient population; REGROUP largely enrolled male veterans and patients with multiple comorbidities. Longer follow-up is also needed. A median follow-up of 3 years is too brief for complete reassurance that long-term patency is the same with both approaches. It would also help to have follow-up data on graft patency. Many factors besides patency can lead to differences in clinical outcomes following coronary bypass surgery.

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Endoscopic vein harvesting is preferred by patients, and it results in fewer wound infections, as was confirmed in REGROUP. Because of these advantages for endoscopic harvesting, it would be great if we could definitively document that these vein grafts functioned as well as those taken with open harvesting.

Evidence now suggests that the more arterial conduits used during coronary bypass, the better. If I were having triple-vessel bypass surgery, I’d want to get two thoracic-artery bypass grafts and a radial artery graft. But studies like REGROUP are important because a majority of heart surgeons use vein grafts for several reasons including convenience. Surgeons will likely continue to use vein grafts for the foreseeable future, so we need to know whether endoscopic harvesting is an acceptable approach.

Jennifer S. Lawton, MD , is a professor of surgery and chief of cardiac surgery at Johns Hopkins Medicine in Baltimore. She had no disclosures. She made these comments in an interview.


 

REPORTING FROM THE AHA SCIENTIFIC SESSION

CHICAGO – Patients who underwent coronary artery bypass grafting using saphenous veins harvested endoscopically had similar clinical outcomes after nearly 3 years of follow-up as those seen with patients who received vein grafts taken by open harvesting in a multicenter, randomized trial in the United States with 1,150 patients.

Dr. Marco Zenati

As expected, follow-up also showed that endoscopic vein-graft harvesting (EVH) resulted in about half the number of wound infections as did open vein-graft harvesting (OVH). This combination of similar clinical outcomes after a median 2.8 years of follow-up, as well as fewer leg-wound adverse events, makes EVH “the preferred vein-harvesting modality,” Marco A. Zenati, MD, said at the American Heart Association scientific sessions.

Although patients far and away prefer EVH because of the reduced pain and faster healing, questions about its clinical efficacy when compared with that of OVH have lingered. That’s because observational data published almost a decade ago taken from the PREVENT IV (Project of Ex-Vivo Vein Graft Engineering via Transfection IV) trial suggested that patients who underwent coronary artery bypass grafting (CABG) using vein grafts collected by EVH had more vein-graft failures after 12-18 months and a higher rate of death, MI, or need for revascularization after 3 years, compared with patients treated using OVH (N Engl J Med. 2009 July 16;361[3]:235-44).

The results from the prospective, randomized trial reported by Dr. Zenati “take the cloud away from endovascular vein-graft harvesting that PREVENT IV had made,” commented Timothy J. Gardner, MD, a cardiac surgeon who chaired the session.

Dr. Marc Ruel Mitchel L. Zoler/MDedge News

Dr. Marc Ruel

“I think this answers the question,” commented Marc Ruel, MD, a professor of surgery and the chief of cardiac surgery at the University of Ottawa. “The results show that endoscopic harvesting of vein grafts is as good as open harvesting for preventing major adverse cardiac events, which is the goal of CABG. This is a definitive trial, with no trend toward more events with endoscopic harvested vein grafts,” said Dr. Ruel, the designated discussant for Dr. Zenati’s report.

However, the study did have some significant limitations, Dr. Ruel added. The new, randomized trial, run at 16 U.S. VA cardiac surgery centers, exclusively used surgeons who were experts in endovascular vein harvesting, which could have meant that they and their surgical teams were not as expert in open vein harvesting, he said. Also, in the broader context of CABG and conduit selection, new evidence suggests the superiority of pedicled vein grafts (Ann Thoracic Surg. 2017 Oct;104[4]1313-17), and “we could also do better by using the radial artery” rather than a saphenous vein graft, Dr. Ruel said. He cited a meta-analysis published in 2018 that showed the superiority of CABG when it combined an internal thoracic artery graft with a radial artery graft rather than with a vein graft (N Engl J Med. 2018 May 31;378[22]:2069-77).

“The operation of the future is not necessarily what you saw” in Dr. Zenati’s study, Dr. Ruel cautioned.

The results Dr. Zenati reported came from the REGROUP (Randomized End-Vein Graft Prospective) trial, which enrolled patients who underwent CABG during 2014-2017. All patients received an internal thoracic artery graft and were randomized to receive additional saphenous vein grafts with the conduits collected either by the EVH or OVH method. The study’s primary endpoint of all-cause death, nonfatal MI, or need for repeat revascularization after a median follow-up of 2.8 years occurred in 14% of the patients who received vein grafts with EVH and in 16% of the patients who received grafts with OVH, a difference that was not statistically significant, reported Dr. Zenati, a professor of surgery at Harvard Medical School in Boston and the chief of cardiothoracic surgery for the VA Boston Health System. The incidence of wound infection was 3.1% in the OVH patients and 1.4% in the EVH patients, a difference that came close to but did not reach statistical significance. Concurrently with Dr. Zenati’s report, an article with the results appeared online (N Engl J Med. 2018 Nov 11. doi: 0.1056/NEJMoa1812390).

The REGROUP trial did not collect data on vein-graft patency following CABG. The investigators were concerned about having enough patients return for follow-up angiography to produce a meaningful result for this endpoint, and they believed that the clinical endpoint they used sufficed for demonstrating equivalence of the two harvesting methods, Dr. Zenati said during his talk.

Dr. Daniel M. Lloyd-Jones Mitchel L. Zoler/MDedge News

Dr. Donald M. Lloyd-Jones

“The more arterial conduit used in CABG, the better the durability of the grafts, but often surgeons use vein grafts because there is not enough arterial conduit,” commented Donald M. Lloyd-Jones, MD, professor and chair of preventive medicine at Northwestern University in Chicago.* “The recovery from endoscopic vein-graft harvesting is very different from open harvesting. Endoscopic harvesting produces much less pain and infection, and recovery is much easier for patients, so it’s reassuring to see that the quality of the vein is not affected by endoscopic harvesting when done by experts,” he said.

Dr. Zenati, Dr. Gardner, Dr. Ruel, and Dr. Lloyd-Jones had no disclosures.

SOURCE: Zenati M et al. AHA 2018, Abstract 19055.

*Correction, 11/12/18: An earlier version of this article misstated the name of Dr. Donald M. Lloyd-Jones.

This article was updated 11/14/18.

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