Current Trials
Completed Trials


Origins of the Network

Cardiac surgery ranks high among the most innovative fields in medicine, with a steady stream of new forms of surgical care that may reduce pain, speed recovery, and decrease morbidity and improve survival. These surgeries include valve replacements, bypass surgeries, heart transplants and other lifesaving procedures. In addition, new surgical procedures, imaging modalities, and medical devices have improved therapy for many patients and made treatment possible for others who have had few options in the past. The percent of heart surgeries performed in the elderly is increasing with new challenges and medical complications unique to this population. While improved survival has been documented for many cardiac surgical practices, stroke and neurological dysfunction have also been observed. This is of particular interest for aging populations where cognitive function declines as a part of normal human aging and exposure to surgical procedures is increasing.

The rapid pace of innovation requires rigorous evaluation that provides timely and ongoing assessments of the value of new treatments as they evolve, and older procedures as modern medical therapy also improves. Despite the lifesaving nature of cardiac surgery and the large number of patients undergoing heart surgery, few patients undergoing heart surgery participate in clinical studies or trials. More importantly, new surgical procedures and devices are often incorporated into clinical practice without objective evaluation of their relative benefit over established therapies. It is particularly important to ensure the safety and efficacy of such treatments compared to less risky and less invasive treatment options.

In recognition of these issues, the National Heart, Lung, and Blood Institute's (NHLBI) Advisory Council in February 2004 proposed that the Institute formally evaluate the status of future directions in cardiac surgery. As a result, on May 7 and 8, 2004, the NHLBI convened a Working Group of cardiac surgeons to assess the state of cardiac surgery research, identify critical gaps in current knowledge, determine areas of opportunity, and obtain specific recommendations for future research activities. The primary recommendation from this working Group was the formation of a Cardiovascular Surgery Clinical Network to develop a culture of systematic scientific evaluation within the field of cardiac surgery in order to inform the use of interventions in surgical practice and improve the scientific basis of care in cardiovascular disease.

The NHLBI, in collaboration with National Institute of Neurologic Disorders and Stroke (NINDS) and Canadian Institutes for Health Research (CIHR), created the Cardiothoracic Surgical Trials Network (CTSN) in 2007. The mission of the Network is to design, conduct, and analyze multiple, collaborative clinical trials that evaluate surgical interventions, and related management approaches, for the treatment of cardiovascular disease in adult patients. The Network trials reflect the scientific collaboration of many the foremost cardiac surgeons, cardiologists and neurologists in North America; and the Network infrastructure increases the efficiency of clinical research by providing a “clinical laboratory” in which multiple clinical questions can be asked without having to create a new infrastructure for each one.

Since its inception, the Network has developed a portfolio of trials that evaluate clinically meaningful questions and address important public health issues. The Network’s studies to date fall into 3 domains: (1) comparative effectiveness research in the areas of mitral regurgitation, atrial fibrillation and coronary artery disease; (2) translational trials of heart muscle recovery for patients with heart failure; and (3) quality improvement studies of infections post-cardiac surgery (see below). Currently, the Network is developing the next set of trials for launch, including trials of neuro-protective agents including embolic protection devices and biological compounds, as well as trials of cardiac stem cells and gene therapy, and functional ischemia-guided revascularization.

Further information regarding the CTSN trials completed, currently being conducted, and in development can be found here. CTSN participating sites can be found here.