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.