Coronary Artery Bypass Grafting (CABG) is performed using arteries and saphenous veins from patients to bypass blocked arteries in the heart. Over 400,000 are performed in the US annually. It is shown to be effective to prolong life and decrease angina. One disadvantage of the use of saphenous vein grafts in CABG procedures is the risk of decrease flow in the vein due to neointimal hyperplasia that could lead to graft failure. To address this issue, a new clinical trial is investigating the use of the VEST device – an external metal sleeve used around the vein graft – that could potentially improve the long-term patency of these common grafts.
Through the VEST Venous Graft External Support Pivotal Study, physicians on the medical staff at Baylor Scott & White The Heart Hospital – Plano will use the VEST device in study participants undergoing CABG for multivessel coronary artery disease. Baylor Scott & White Heart – Plano is one of the first sites to enroll patients and is participating in the study as a part of the Cardiothoracic Surgical Trials Network (CTSN), a group sponsored by the National Institutes of Health.
“We know through years of data that arterial grafts work better and last longer than venous or other grafts,” said Kelley Hutcheson, MD, a cardiothoracic surgeon on the medical staff at Baylor Scott & White Heart – Plano, who is one of the principal investigators for the study. “If we could find a way to make veins work more like arteries, that could be groundbreaking.”
Expanding Graft Options
Currently, neointimal hyperplasia is the most common reason for saphenous vein graft failure, which can result in the need for additional interventions later. As CABG continues to be performed on younger populations, it is becoming increasingly important to find ways to reduce problems like neointimal hyperplasia and make grafts last longer.
“CABG is still the most common operation that heart surgeons perform in the United States,” said J. Michael DiMaio, MD, Medical Director, Public Relations and Post Graduate Cardiovascular Training, and a cardiothoracic surgeon on the medical staff at Baylor Scott & White Heart – Plano, who is the principal investigator for the study. “It’s the only operation proven to extend the life of these patients. Therefore, if we could make it better, that’s what we want to do.”
The VEST trial has the potential to give more patients the option of undergoing CABG by allowing surgeons to use a vein that they otherwise could not use or extending the life of a vein graft that may have otherwise only lasted for a short period of time. It also has potential implications for patients who have had previous arterial grafts and now need additional bypass surgery.
To enroll in the study, patients must be scheduled to undergo CABG with an internal mammary artery (IMA) to left anterior descending (LAD) graft, as well as at least two saphenous vein grafts. One saphenous vein graft – randomized on either the right or left side – will be supported using the VEST device, and the other will be the control.
“The patient’s own vein graft can serve as an internal control, which is also a unique property of this study,” Dr. Hutcheson said. “You’re not comparing vein grafts between two people. You’re comparing the same vein conduit in each person to his or her own veins.”
Potential candidates for the study cannot be undergoing any concomitant procedures, and their primary problem should be blockages in the coronary arteries, not other areas like the neck or legs. They also must have good quality targets or distal vessels. Ejection fraction is not a limitation for the study, so patients with slightly reduced ejection fraction may still qualify.
After the procedure, the study requires only one in-person follow-up appointment, and follow-up will be conducted by phone thereafter. Researchers will follow the patients for a total of five years.
“The addition of the VEST device is very simple; it adds only a few minutes to the procedure,” said Dr. DiMaio. “The patient will be studied in one year by a catheterization to see how the grafts are holding up, and the patient will get extra special care and follow-up as part of the study.”
Comprehensive Approach to CABG
A dedicated team of physicians on the medical staff at Baylor Scott & White Heart – Plano is available for evaluations of patients who may be good candidates for the VEST trial – or one of the many other enrolling clinical trials at the hospital. Because of the hospital’s comprehensive approach to care and commitment to research, numerous options may be considered for patients.
“The belief in quality and in innovative research is in the DNA of the hospital,” Dr. DiMaio said. “We have a very robust research infrastructure, and we try to offer every person that comes to the hospital the potential to be considered for a research trial.”