–National Trial Yields First Scientific Evidence of Who Should Have Surgery–
New York, NY (Aug. 14, 2001) — The National Emphysema Treatment Trial (NETT), in which Columbia Presbyterian Medical Center of NewYork-Presbyterian Hospital is a major participant, has found that certain advanced emphysema patients benefit little from Lung Volume Reduction Surgery (LVRS) and are at unacceptable risk of death from the procedure. The NETT trial — a five-year, multicenter, randomized study designed to evaluate the role of LVRS in the treatment of severe emphysema — indicates that those patients who have severe lung obstruction with either limited ability to exchange gas while breathing or damage that is evenly distributed throughout their lungs should not undergo LVRS.
This is the first time that researchers have identified scientifically based selection criteria for patients seeking LVRS for advanced emphysema. As a result, patients with these high-risk characteristics are no longer being enrolled in NETT. However, the study will continue to recruit other eligible patients until its scheduled completion in 2002.
“Learning when not to perform lung volume reduction surgery is clearly one of the great benefits of NETT,” said Dr. Mark Ginsburg, the principal investigator of NETT, assistant clinical professor of surgery, Columbia University College of Physicians & Surgeons and surgical director of the Center for Chest Disease, Columbia Presbyterian Medical Center of NewYork-Presbyterian Hospital. “We remain guardedly hopeful that for other patients LVRS may prove to be of value.” Dr. Ginsburg is associate director of thoracic surgery at the medical center.
“The NETT hopes to define a role for LVRS in patients with advance emphysema,” said Dr. Byron Thomashow, clinical profesor of medicine at Columbia University College of Physicians and Surgeons and attending physician at Columbia Presbyterian Medical Center. “The preliminary results released by the NHLBI established a subgroup of patients who do not benefit from LVRS Surgery. As the trial moves toward completion, investigators believe that scientifically based selection criteria for the procedure will be established.”
Dr. Claude Lenfant, director of the National Heart, Lung, and Blood Institute (NHLBI), the primary sponsor of the study, said, “This is exactly the kind of insight we hope to gain from NETT. We expect the final results of NETT will guide us further in determining if and when this procedure should be used to treat emphysema.”
The findings are being posted on the Web site of the New England Journal of Medicine (www.nejm.org) on August 14. Because of the importance of the results the NEJM editors agreed to expedite their review of the findings and to publish them on their Internet site prior to printing the investigators’ report within the next few months.
The largest study of its kind, NETT compares the safety and effectiveness of LVRS with medical treatment in patients with end-stage emphysema. The study also aims to define better who benefits from LVRS and who is at excessive risk of complications or death from the procedure. More than 1,000 participants at 17 clinical sites have enrolled in NETT since 1997.
In emphysema, the fine architecture of the lung is destroyed, leading to large holes in the lung, obstruction of the airways, trapping of air, and difficulty exchanging oxygen. Current medical treatments include supportive measures such as medications,
exercise rehabilitation, and nutritional supplementation.
LVRS is an unproven modality to ease symptoms associated with advanced emphysema and to improve overall lung function. The procedure is believed by some to improve the ability to move air in and out of the lungs by surgically removing as much as one-third of each lung, targeting the most damaged regions with the expectation that the
remaining lung will have better air exchange. NETT was developed in response to concerns from both the medical community and the Center for Medicare and Medicaid Services (formerly the Health Care Financing Administration) about the risks and benefits of LVRS compared to medical treatment.
During its quarterly review of the study data in May 2001, the NETT Data and Safety Monitoring Board (DSMB) found that a subgroup of participants undergoing the procedure had a 30-day post-surgery death rate considered unacceptable based on the study’s safety and monitoring guidelines. The DSMB is a group of experts who are unaffiliated with NETT and who are responsible for overseeing participants’ safety and outcomes data. In addition, the NETT DSMB is charged with identifying subgroups of patients who may benefit from or be at high risk of dying from LVRS.
As a result of the DSMB’s findings, NETT is no longer enrolling patients with severe obstruction in the lung as measured by a forced expiratory volume in one second less than or equal to 20 percent of predicted, plus one of the following characteristics: severe loss of lung surface area as measured by a diffusing capacity of less than 20 percent predicted or homogeneous damage to the lung — that is, disease is evenly distributed throughout the lung, rather than being confined to certain areas.
Of the 1,033 current participants, 140 (14%) met these high-risk criteria, 69 of whom underwent surgery as part of the trial. These patients had a 16% 30-day mortality rate. In contrast, no deaths were reported in the medical treatment group 30 days following the start of medical treatment.
Furthermore, compared to similar participants who received only medical treatment, high-risk participants who survived the surgery were found to have only slightly improved functional outcomes and quality-of-life scores six months after enrolling in the study.
In addition to NHLBI, which is part of the National Institutes of Health, NETT is supported by the Center for Medicare and Medicaid Services, which supports clinical services for the study, and the Agency for Healthcare Research and Quality.
Emphysema is a disabling condition that affects approximately 2 million Americans, most of them over age 50. Typically caused by cigarettes, emphysema costs more than $2.5 billion in annual healthcare expenses and kills more than 16,000 people in the U.S. each year.
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