The National Heart, Lung, and Blood Institute convened a Working Group of experts in cardiac surgery on May 7-8, 2004, in Alexandria, Virginia to assess the state of the field and to identify critical gaps in knowledge and areas of opportunity in cardiac surgery research. The Working Group's charge was to develop a list of recommendations for future research directions. Each member of the Working Group gave a short talk describing recent work in one of the following areas: surgical revascularization, novel surgical approaches, valvular research directions, biotechnology and cell based therapy at surgery, heart failure, imaging modalities, and barriers to clinical research. Each session was followed by discussion and recommendations.
The working group provided the following five recommendations to the NHLBI regarding areas of need and opportunity in cardiac surgery research:
1. Create a Cardiovascular Surgery Clinical Research Network.
The working group envisioned this as a network for relatively small, short-term, clinical studies. The group emphasized the importance of including cardiology colleagues in the network since they would play an integral role in screening and referring patients and because results from the trials would impact the medical decisions made not only by surgeons, but by cardiologists as well. The working group indicated that the network would be an important step in developing a culture for clinical trial evaluation within the field of cardiac surgery that would lead to enhanced productivity within the network and improved prospects for larger trials. The working group proposed the following clinical trials as possible candidates for testing in the network:
- A randomized, clinical trial (RCT) comparing minimally invasive surgery to catheter-based ablation approaches for the cure of chronic atrial fibrillation.
- Clinical testing of new valve repair techniques.
- Clinical testing in adults with congenital heart disease of surgery to treat arrhythmia (atrial fibrillation) that is not amenable to minimally invasive approaches.
- A RCT to determine whether it is beneficial to repair mild to moderate mitral regurgitation in patients undergoing clinically indicated coronary artery bypass grafting (CABG).
- An evaluation of the efficacy of CABG with adjunctive left ventricular assist device (VAD) support for shock complicating acute myocardial infarction
- Trials with VADs in conjunction with cell-based or gene-based therapy, including organized human dosing studies.
- Trials of new computer-enhanced modalities for imaging, instrumentation, and robotics.
2. Support a large, multicenter, randomized, clinical trial to compare off-pump coronary artery bypass (OPCAB) surgery with conventional on-pump surgery (ONCAB).
The working group noted that there is a great deal of conflicting information in the literature about the benefits of OPCAB surgery. They agreed that the question of whether OPCAB results in lower mortality or fewer complications than ONCAB surgery is an important one that could be resolved by a carefully designed RCT. They also noted that such a trial would provide the opportunity to conduct ancillary studies of the effects of CABG on neurocognition.
3. Support the development of computer-enhanced imaging and instrumentation, robotics, "next generation" left ventricular assist devices, and prosthetics, with a focus on valves, conduits, vessels, and pacers for the pediatric population.
The working group identified this as a possible area for collaboration with industry partners. As noted above, they also suggested that these new technologies could be tested within a Cardiovascular Surgery Clinical Research Network. The working group recommended the establishment of NIH-supported design cores to allow academic researchers to develop device prototypes and encouraged support for basic research in order to produce biomaterials appropriate for use in making prosthetics. Finally, they noted that advances in imaging, instrumentation, and robotics are integral to a budding field of surgical education using ex vivo training methodologies.
4. Support the use of large animal models for cardiac surgery research.
The need for continued support of large animal models for cardiac surgery research was discussed in many of the sessions. Members agreed that research in large animal models is an important intermediate step in the translation of results from basic science studies into clinical trials. The difficulty researchers face in obtaining funding for such studies was identified as a barrier to clinical research. Large animal models were mentioned in connection with several research areas, for example, studies of myocardial preservation during cardiac surgery and studies of cellular cardiomyoplasty as a therapy for chronic heart failure.
5. Encourage the use of new imaging and instrumentation technology for application in pre-operative planning for pediatric surgery.
The working group recommended the use of new technologies to help pediatric cardiac surgeons quantify the hemodynamic load on vessels and myocardium, assess acute and chronic response to congenital defects, and develop an anatomic "roadmap" for surgical repair of complex lesions.
Working Group Members
- William A. Baumgartner, M.D., Vincent L. Gott Professor of Surgery, The Johns Hopkins Hospital
- Pedro J. del Nido, M.D., Chief of Cardiac Surgery, Children's Hospital Boston
- Timothy Gardner, M.D., Wm. M. Measey Professor of Surgery, Division of Cardiothoracic Surgery, University of Pennsylvania Medical Center
- Robert Gorman, M.D., Assistant Professor of Surgery, University of Pennsylvania
- George V. Letsou, M.D., Associate Professor of Surgery, Director of Heart Failure Center, University of Texas School of Medicine
- Robert E. Michler, M.D., John G. and Jeanne B. McCoy Chair, Professor of Surgery, Chief, Cardiothoracic Surgery and Transplantation, Associate Director, Davis Heart and Lung Institute, Ohio State University
- John D. Puskas, M.D., Associate Professor of Surgery, Emory University
- Eric Rose, M.D., Professor and Chairman, Department of Surgery, Columbia University
- Todd Kenneth Rosengart, M.D., Owen L. Coon Chair, Division of Cardiothoracic Surgery, Evanston Northwestern Healthcare
- Frank Sellke, M.D., Chief, Cardiothoracic Surgery, Johnson and Johnson Professor of Surgery, Beth Israel-Deaconess Medical Center
- Sara J. Shumway, M.D., Professor of Surgery, Division of Cardiovascular and Thoracic Surgery, University of Minnesota
- Norbert Wilke, M.D., Associate Professor of Radiology, Associate Professor of Medicine, Chief, Cardiovascular MR and CT, University of Florida