Cardiovascular risk factors in renal transplantation--current controversies

Cardiovascular diseases are more common in renal transplant recipients than in the general population, and a number of 'traditional' risk factors, such as smoking, diabetes mellitus and dyslipidaemia, are known to be associated with an increased risk. However, concentrating solely on these risk factors can lead to an underestimation of the true risk in this patient population, because other factors such as C-reactive protein and homocysteine levels are also associated with cardiovascular morbidity and mortality. Renal insufficiency also appears to be a key cardiovascular risk factor in the general population, with increasing proteinuria and decreasing glomerular filtration rate related to increased risk. In renal transplant recipients, a high proportion of whom have some renal insufficiency, the role of graft dysfunction in cardiovascular risk is controversial. While some studies have shown no correlation between graft dysfunction and congestive heart failure or ischaemic heart disease, registry data suggest that increased post-transplant serum creatinine levels are strongly associated with cardiovascular risk. This is believed to be the result of cardiovascular disease developing in the pre-transplantation period, as renal transplantation has been shown significantly to improve cardiovascular risk. As such, renal transplant recipients should be routinely screened for cardiovascular disease pre-transplantation, and immunosuppressive therapy should be tailored to minimize further risk. Different immunosuppressive agents, such as corticosteroids and calcineurin inhibitors, are associated with different exposure to cardiovascular risk, and studies involving withdrawal of these agents have generally shown improvement in parameters such as blood pressure and dyslipidaemia. However, these benefits are often associated with an increased incidence of acute rejection, although overall graft loss and mortality rates are not affected. Further studies are required to determine optimal regimens for minimizing cardiovascular risk in renal transplant recipients.