It is standard practice for kidney transplant candidates, who are asymptomatic but at high risk for major adverse cardiac events (MACE; nonfatal myocardial infarction, hospitalization for unstable angina, coronary revascularization for symptoms and cardiac death), to undergo non-invasive cardiac stress testing and/or coronary angiography. Candidates who are found to have significant coronary disease then undergo preemptive angioplasty or coronary artery bypass grafting to prevent posttransplant MACE. Unfortunately, recent evidence suggests that this strategy may be ineffective, and there may be substantial human and financial costs. Transplants are often delayed. The cardiac screening and intervention procedures themselves may result in morbidity and even mortality. Patients hoping to undergo transplantation without starting maintenance dialysis may need to start dialysis as a result of contrast nephropathy. Finally, the current standard of practice is expensive, and the cost-benefit ratio is unknown. This two-year development proposal will take steps necessary for conducting a randomized controlled trial to determine the efficacy and costs of screening candidates for living donor kidney transplantation who are asymptomatic, but high risk for MACE. The proposed trial will randomly allocate candidates to either standard care or care that does not include routine non-invasive stress testing and/or coronary angiography for asymptomatic patients, but follows American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for noncardiac surgery. All patients will received optimal medical management, including perioperative beta-blockade according to ACC/AHA guidelines. Only candidates for living donor kidney transplants will be included, since the waiting time for deceased donor kidneys is often several years. The primary endpoint will be MACE. The development phase of this proposal will enroll centers that 1) perform adequate numbers of living donor transplants, 2) screen asymptomatic patients with non-invasive stress testing and/or coronary angiography using uniform selection criteria (e.g. history of prior cardiovascular disease, diabetes, and/or age =50 years), and 3) are able to obtain institutional approvals to conduct the proposed randomized trial. The development phase will also include a survey of potential trial participants to assess their willingness to participate in the randomized trial. Finally, the development phase will test statistical methodologies for using Medicare claims data, and data from the United States Renal Data System (USRDS), to conduct a cost-benefit analysis on the subset of patients in the randomized trial for whom Medicare is the primary payer. All of these steps will provide the information needed to proceed with the randomized trial.
If it is determined that screening asymptomatic candidates for kidney transplantation with stress testing and/or coronary angiography does not improve outcomes, there could be a substantial reduction in human and financial costs. Candidates would no longer need to delay transplantation and incur the risk of the procedures that are part of these routine cardiac evaluations. The money spent on these procedures might be better directed to health care measures of proven efficacy. ? ? ?
| Kasiske, Bertram L; Israni, Ajay K; Snyder, Jon J et al. (2011) Design considerations and feasibility for a clinical trial to examine coronary screening before kidney transplantation (COST). Am J Kidney Dis 57:908-16 |
