South Asian ethnicity is a risk factor for cardiovascular events after renal transplantation

Ethnicity is a contributing risk factor of cardiovascular problems in kidney recipients of South Asian origin post-transplant, according to a study appearing in an upcoming issue of the Clinical Journal of the American Society Nephrology (CJASN).

South Asians comprise 25% of all Canadian visible minorities and have a higher risk for cardiovascular disease in the general population. However, the risk of cardiovascular events has never been studied in this minority population.

To investigate, G.V. Ramesh Prasad, MBBS, MSc, FRCPC, FACP, FASN (University of Toronto) and his colleagues studied 864 kidney recipients (139 South Asians, 550 Caucasians, 65 blacks, and 110 East Asians) transplanted from 1998-2007, following them through June 2009. The identified risk factors included ethnicity associated with major cardiac events (MACE, a composite of non-fatal myocardial infarction, coronary intervention, and cardiac death) within and beyond 3 months post-transplant. They found no difference among the patients pre-transplant. However, the post-transplant MACE event rate was more than twice as high in South Asians, as in Caucasians, blacks, and East Asians.

Take home message: "Heart disease is the number one killer in kidney transplant patients. Traditional risk factors (age, high blood pressure, diabetes, smoking, and high cholesterol) do not fully explain the increased risk. This study identifies another risk factor for heart disease in transplant patients and the need for further study," said Dr. Prasad.

This research indicates that South Asians require their own category in all U.S. transplant and dialysis registry studies, along with Caucasians, blacks, Hispanics, East Asians, and Native Americans.

Limitations: This was a single center study. Much of the data was collected retrospectively, and ethnicity was typically assigned by patient self-report.

Study co-authors include Sai Vangala, Michael Huang, Lindita Rapi, and Michelle Nash (St. Michael's Hospital, Renal Transplant Program); Samuel Silver and Steven Wong (University of Toronto, Medicine); and senior author Jeffrey Zaltzman (St. Michael's Hospital, Renal Transplant Program and University of Toronto, Medicine).

This study was previously reported as an oral presentation at the American Transplant Congress 2010 in San Diego, CA, USA.