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ATLANTA - Both mitral valve (MV) replacement and MV repair are fairly common surgical procedures that can help patients with faulty heart valves live healthier and longer lives. But what effects do age and coronary artery bypass graft (CABG) surgery have on the outcomes of MV replacement versus MV repair? A new Emory study that will be published next Tuesday, July 22 , in the American Heart Association's peer reviewed medical journal "Circulation" is one of the first to address those issues, according to Emory Heart Center cardiologist William S. Weintraub, MD. The article is currently available on-line at the Circulation website (http://circ.ahajournals.org/).
"We found that MV repair does not provide significant long-term survival benefit over MV replacement in patients older than 60 years of age or those who also require concomitant CABG due to cardiovascular disease," says Dr. Weintraub, principal investigator of the study.
The Emory research team (which also included Vinod H. Thourani, MD; Robert A. Guyton, MD; Ellis L. Jones, MD; Willis H. Williams, MD; Sharif Elkabbani, MD; and Joseph M. Craver, MD) collected information from the Emory cardiovascular database and compared outcomes of 625 MV repair patients with 625 MV replacement patients who had undergone surgery between from 1984 to 1997. Most of the operations were performed electively (96.8 percent) and the subjects in both groups were well matched with the exception that patients who underwent MV replacement were, on average, about a year old than those in the MV repair group. Twenty-five percent in each group also underwent CABG surgery (with a similar number of grafts) at the same time of their heart valve procedures.
Although the number of postoperative neurological events and heart attacks for both groups was the same, the researchers found that patients having MV repair fared better in general . They had less need for anticoagulants, less risk for post-op MV regurgitation, and were able to be released from the hospital three days earlier than the valve replacement group. Overall, the in-hospital mortality rate was also slightly lower (about two percent) for those undergoing repair.
The Emory study also shows that after five years, 89 percent of patients who had undergone MV repair without concomitant CABG were still alive compared to only 77 percent of the patients who had bypass surgery at the same time they had MV repair surgery. "We also found that at five years the survival of patients younger than 60 years of age who underwent MV repair was 90 percent compared with 79 percent for those who underwent valve replacement. However, MV repair didn't offer an improved outcome for patients 60 and older, " says Dr. Weintraub, who is the Director of the Emory Center for Outcomes Research (ECOR).
The lack of benefit of MV repair over MV replacement in older patients can be attributed to the fact many of the older patients were sicker -- they had additional health problems such as diabetes and heart failure more frequently than their younger counterparts. "Older patients also have a shorter life expectancy so their survival is often going to be determined by other things about them rather than what operation they have," Dr. Weintraub explains.
How can the results of the new Emory study be used to help patients who need MV surgery? " Our research shows it should be up to the surgeon to decide whether valve replacement or repair is best for individual , older patients. If valve replacement makes the most medical sense, this study shows there is no harm in valve replacement instead of valve repair in the older patient where technically it can be well performed," Dr. Weintraub concludes.
The study, entitled " Outcomes and Long-Term Survival for Patients Undergoing Mitral Valve Repair Versus Replacement Effect of Age and Concomitant Coronary Artery Bypass Grafting" was supported by a $500,000 American Heart Association Outcomes Award presented to Dr Weintraub to fund research in this area. The Emory scientists are continuing to study other issues involved in MV repair and MV replacement -- including quality of life, costs, and recovery.