April 11, 2008 (Boston) -- Two studies show conflicting data on survival rates for African-Americans who undergo successful heart transplant surgery. Both studies were presented yesterday at the 28th annual meeting and scientific sessions of the International Society for Heart and Lung Transplantation.
A large study involving more than 36,000 U.S. heart transplant patients over a 20-year period found that African-Americans live on average nearly three years shorter than whites and nearly two years shorter than Hispanics who get heart transplants. The reason for the difference in survival rates between the races isn't clear, but it might be because of a mismatch between the races of heart donors and recipients or because of other unidentified differences, says study researcher Ricardo Bello, MD, PhD, a heart surgeon at Montefiore Medical Center/Albert Einstein College of Medicine in the Bronx, N.Y.
Thomas E. MacGillivray, MD, a transplant surgeon at the Massachusetts General Hospital Heart Center in Boston, who commented on the study for WebMD, noted that his research group had found similar results in a study they presented at a transplant meeting in 2007. In that study, they found survival differences related to a mismatch of proteins (antigens) that alert the immune system to the presence of foreign or non-self tissue, which could lead to transplant failure and death.
But a second, much smaller study out of the Henry Ford Hospital in Detroit was also presented at the meeting. That study suggested that survival was similar between African-Americans and white Americans. Ajay Srivastava, MD, and colleagues reviewed follow-up data on 92 patients who underwent heart transplant at their center from January 2001 through June 2006.
They found that after three years of follow-up, survival rates were similar between the groups, at 74% for African-Americans and 76% for whites. There were also no differences between the races in terms of rates of infection after surgery or rates of organ rejection. Furthermore, African-Americans were less likely than white Americans to need a second hospitalization.
This data suggest that "African-Americans are not at higher risk for adverse outcomes after cardiac transplantation," Srivastava says.
While it's difficult to tease out the various risk factors for survival by race, "our attempts to understand how best to improve survival for everybody and to try to understand all the variables we can that are different between different patients will, I think, help everybody get the best results," MacGillivray says.