South Asians at twice the risk of heart attack and death after transplant: study

South Asian men and women have more than twice the risk of suffering a heart attack after a kidney transplant, according to a study led by St. Michael's nephrologist Dr. Ramesh Prasad.

The study, published today in the Clinical Journal of the American Society of Nephrology, studied 864 patients who underwent a transplant between 1998 and 2007. Researchers analyzed and compared the group's risk for a heart attack, angioplasty and bypass surgery rates, and death from heart disease after a kidney transplant with Caucasian, black and East Asian men and women. The findings are the first to report heart disease risk factors for Canadian kidney transplant patients based on ethnicity.

"South Asian patients are having more heart attacks early after kidney transplants and down the road," lead author Dr. Ramesh Prasad says. "The findings signal a need for health-care providers to systematically monitor this group so that heart attacks and death can be prevented."

According to the researchers:

o The overall rate of heart attack, angioplasty, bypass surgery or death was 4.4 in South Asians compared with 1.31, 1.16 and 1.61 per 100 patient-years in Caucasians, blacks and East Asians, respectively.

• By three months after transplant, South Asians had almost twice as many heart attacks than Caucasians, blacks or East Asians.
  
• After 10 years, only 70 per cent of South Asians were free of heart attack, angioplasty or bypass surgery compared with about 90 per cent of Caucasian men and women.

In Canada, South Asians make up 25 per cent of visible minorities and an estimated three per cent of Canadian patients with kidney disease. South Asians have documented higher levels of heart disease and mortality rates than other ethnic groups in the general population. This study extends some of these findings to kidney transplant patients.

The findings are seen despite the fact that all candidates for a kidney transplant are screened for heart disease equally and likely receive equally good health-care overall.

"It did not appear that South Asians had more pre-existing heart disease to explain why they had more heart attacks later," Dr. Prasad said. "Although the risk of diabetes is higher in South Asians, it does not fully explain this increased risk. More research is needed to determine why South Asians are at such an increased risk after their kidney transplants."