Combination Mitral Valve Surgery with Surgical Ablation Frees Patients of Atrial Fibrillation
The Cardiothoracic Surgical Trials Network reports new findings at the American College of Cardiology 64th Annual Scientific Sessions and in the New England Journal of Medicine.
New study results by The Cardiothoracic Surgical Trials Network (CTSN) show the addition of surgical ablation during mitral valve surgery reduces the occurrence of atrial fibrillation in patients.
The findings, presented on March 16 at the American College of Cardiology 64th Annual Scientific Sessions in San Diego and published simultaneously in the New England Journal of Medicine (NEJM), show a significant amount of patients were free from atrial fibrillation after one year when they received an additional surgical ablation procedure instead of mitral valve surgery alone. Also, the study showed no significant increase in mortality, adverse cardiac events, or hospitalizations by adding a surgical ablation procedure to disrupt chaotic electrical signals from atrial fibrillation which can cause abnormal heart rhythms.
Among those patients receiving ablation, 63 percent of patients were free from atrial fibrillation at six and 12 months after surgery. Only 29 percent who received mitral valve surgery alone were free from atrial fibrillation.
"I think what this shows is that, in the mitral valve surgery patient who has persistent atrial fibrillation, you will achieve better rhythm control by performing ablation, without any increase in mortality or other adverse cardiac events," said Marc Gillinov, MD, the Judith Dion Pyle Chair in Heart Valve Research at Cleveland Clinic and the study's lead author who presented the study at ACC 2015.
Approximately 30-50 percent of patients who undergo mitral valve surgery to repair their weak, leaky, or hardened valve experience atrial fibrillation, which is a dangerous heart rhythm disorder linked to increased risk of death and stroke. Currently, evidence regarding the safety and effectiveness of surgical ablation has been limited, leading to considerable variation in its use at the time of mitral valve surgery.
"The good news is that a significant proportion of mitral valve surgery patients with atrial fibrillation are already receiving the additional surgical ablation therapy," says Michael Argenziano, MD, Section Chief of Adult Cardiac Surgery at NewYork- Presbyterian/Columbia University Medical Center, Associate Professor of Surgery at Columbia University Medical Center, and the study's senior author. "Our study's results support this practice and will hopefully lead to even greater adoption of this procedure, allowing more surgical patients to avoid the risks associated with atrial fibrillation."
To assess its effectiveness as an adjunct procedure to mitral valve surgery, 20 institutions in the United States and Canada enrolled 260 patients with persistent or long-standing persistent atrial fibrillation. These patients received mitral valve surgery alone or mitral valve surgery plus surgical ablation. Patients who were randomly assigned to surgical ablation underwent either pulmonary-vein isolation or the bi-atrial maze procedure. All patients underwent standard left atrial appendage closure during mitral valve surgery to further reduce their risk of stroke.
"The only downside associated with surgical ablation was a 2.5 times greater likelihood of needing a pacemaker implant in the year following their surgery," says Annetine C. Gelijns, PhD, Professor and Chair of the Department of Population Health Science and Policy at Icahn School of Medicine at Mount Sinai, who is the corresponding author for the NEJM study and principal investigator for the Data and Clinical Coordinating Center based at Mount Sinai for the NIH-sponsored Cardiothoracic Surgical Trials Network (CTSN). "As such, patients will have to weigh the benefits of a higher probability of being free of atrial fibrillation--with a reduction in its associated complications--versus the higher likelihood of receiving pacemakers."
This CTSN trial was conducted at eight core clinical centers in the U.S. and Canada, including Cleveland Clinic Foundation, NewYork-Presbyterian/Columbia University, Duke University, Emory University, Montefiore Einstein Heart Center, Montreal Heart Institute, University of Virginia, University of Pennsylvania, and 12 consortium sites. The CTSN's Data Coordinating Center, based at the Icahn School of Medicine at Mount Sinai, oversees the design, conduct, and analysis of all CTSN trials.
This study was presented as a Late-Breaking Clinical Trial abstract at ACC 2015 entitled: "Effectiveness of Surgical Ablation of Atrial Fibrillation during Mitral Valve Surgery: A Randomized Clinical Trial from the Cardiothoracic Surgical Trials Network."
The study was funded by the National Heart Lung and Blood Institute, the National Institutes of Neurological Disorders and Stroke of the National Institutes of Health (NIH), Bethesda, MD, and the Canadian Institutes of Health Research.
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The Mount Sinai Health System is an integrated health system committed to providing distinguished care, conducting transformative research, and advancing biomedical education. Structured around seven member hospital campuses and a single medical school, the Health System has an extensive ambulatory network and a range of inpatient and outpatient services—from community‐based facilities to tertiary and quaternary care.
The System includes approximately 6,600 primary and specialty care physicians, 12‐minority‐owned free‐standing ambulatory surgery centers, over 45 ambulatory practices throughout the five boroughs of New York City, Westchester, and Long Island, as well as 31 affiliated community health centers. Physicians are affiliated with the Icahn School of Medicine at Mount Sinai, which is ranked among the top 20 medical schools both in National Institutes of Health funding and by U.S. News & World Report.