Experience backs early heart valve replacement
Results support guidelines for treatment of aortic regurgitation
Patients with leaky aortic heart valves appear to do better when the valves are replaced before significant symptoms develop, as recommended by the American College of Cardiology/American Heart Association guidelines, according to a new study in the Mar. 7, 2006, issue of the Journal of the American College of Cardiology.
"In short, we found that those patients that were operated on early enough following the specific criteria of the guidelines (that is, also assuring that they were not given a too early operation), survived for a longer time and had better health than those patients who were referred for operation in later stages of the disease," said Pilar Tornos, M.D., from the Hospital Universitari Vall dHebron in Barcelona, Spain.
Patients with aortic regurgitation may feel only mild symptoms or no symptoms at all. While some patients never need to have their aortic valves replaced, other patients may already be developing heart failure or other problems by the time their aortic regurgitation symptoms become severe; so the challenge has been to determine the best time to recommend surgery.
Guidelines from the American College of Cardiology and the American Heart Association, as well as recommendations from the European Society of Cardiology and other institutions, describe when surgery may be the best option for patients. This study evaluated the results of following such guidelines in clinical practice.
The researchers analyzed data on a total of 170 patients with chronic severe aortic regurgitation, but who did not have coronary artery disease, when they submitted to aortic valve replacement. Patients were divided in two groups depending on the clinical situation at the time of surgery. Group A were 60 patients who were operated on following guidelines advice of earlier surgery, and group B were 110 patients who were operated on late with regard to guidelines recommendations.
Although many of the patients were operated before current guidelines were published, the clinical practice of the hospital for early surgery was generally similar to the subsequent guidelines.
After an average of 10 years, seven patients (12 percent) from the early surgery group had died compared to 37 deaths (37 percent) in the later surgery group. (p = 0.001) The earliest surgery included the study was done 22 years before the analysis and 16 years before the ACC/AHA guidelines.
Dr. Tornos noted that although it may seem obvious that operating earlier would be better, the risks of surgery and follow-up therapy need to be taken into account.
"While too late means a worse prognosis, too early, that is, operating on patients with a more delayed risk of deterioration, would mean an unnecessary surgical procedure and additional years of anticoagulation therapy, which is in itself somewhat hazardous. So a properly timed waiting period may be needed," she said.
This study was not a randomized controlled trial, but Dr. Tornos says a true clinical trial of aortic regurgitation surgery may not be either practical or ethical.
"Usually, observation in real practice represents a risk of mistakenly attributing a nonexistent effect to a given therapy, or missing a real one, and thus clinical trials are mandatory in many instances of therapeutic research. In our example, the magnitude of the difference in the effects of surgery in the two groups and the statistical adjustment for other factors that might have influenced the results make us very confident of our conclusions. In the present state of our knowledge, we feel that a clinical trial to assess the issue addressed by our study would be unethical, as we are convinced enough of the superiority of the established timing of operation over other options," Dr. Tornos said.
Daniel J. Ullyot, M.D., a consultant and surgeon in Burlingame, California, who was not connected with this study, noted the "happy fact" that the Hospital Universitari Vall dHebron in Barcelona selected patients for surgery in a way very similar to the guidelines that were published years later, thus providing lengthy follow-up data.
"The importance of this study is the indirect validation of the guidelines with respect to the recommendation for early surgical intervention for asymptomatic and moderately symptomatic patients with aortic valvular regurgitation," Dr. Ullyot said.
"Ideally guidelines would be based entirely on randomized controlled trials and would fulfill the desirable goal that clinical practice be exclusively evidence-based. This goal is incompletely achieved in most instances, and data such as provided by the Tornos paper in support of the guidelines is welcome and reassuring," he added.
Amy Murphy | EurekAlert!