The uncommonly used surgical procedure, aortic valve bypass, is an important treatment option for high-risk elderly patients with aortic stenosis, rather than replacing the valve, according to a study in the Sept. 30 issue of Circulation.
The researchers from the University of Maryland Medical Center in Baltimore said the bypass procedure can be performed in a minimally invasive way without stopping the heart for the typical 90 minutes involved with valve replacement. Many of the patients in the study had previously been considered too frail to benefit from surgery.
“Because of the possible risks associated with aortic valve replacement in the elderly, almost 60 percent of patients with symptoms related to aortic stenosis are never referred to surgery,” said the study's principal investigator, James S. Gammie, MD, associate professor of surgery at the University of Maryland School of Medicine and cardiac surgeon at the University of Maryland Medical Center.
Survival for these patients without surgery is poor; only 20 percent live three years after diagnosis. “But our research and five years of experience with the bypass procedure suggests there is a group of patients, typically considered inoperable because they are at the upper level of the risk spectrum, who could benefit from aortic valve bypass,” said Gammie.
Between 2003 and 2007, the surgeons treated 31 high-risk aortic stenosis patients with aortic valve bypass surgery. Many of the patients also had other conditions ranging from chronic obstructive pulmonary disease to kidney disease, or had a history of heart attack or diabetes. The average age was 81, and nearly half had been refused conventional surgery.
Early in the series, Gammie and colleagues said that four of the 31 patients did not survive the procedure, yet there were no deaths among the most recent 16 consecutive patients.
According to researchers, the procedure was as effective as conventional aortic valve replacement surgery at relieving the obstruction of blood leaving the heart. Stroke and kidney problems were uncommon.
Because the impaired aortic valve was left in place, the authors wrote that some blood flow continued through that valve, but postsurgical blood flow measurements indicated that in most patients—approximately 70 percent of cardiac output flowed through the new bypass.
While valve replacement has benefited millions of patients with good outcomes, in elderly patients, particularly those with other health conditions, the death rate can exceed 10 percent, according to the investigators.
The authors wrote that the study results suggest that continued improvements in technology and surgical technique may warrant extending aortic valve bypass surgery to moderate-risk patients with aortic stenosis. In addition to the 31 patients who received an aortic valve bypass, the University of Maryland Medical Center performed 438 other aortic valve procedures during the same time period.