Preoperative testing for coronary heart disease (CHD) does not reduce the risk of myocardial infarction (MI) or death in the early weeks after kidney transplantation, reports a study in JAMA Internal Medicine.
Using the US Renal Data System, the researchers identified 79,334 adults undergoing first-time kidney transplantation from 2000 through 2014. All were enrolled in Medicare for at least 1 year before and 1 year after transplant. The mean age was 56 years; 62% of patients were men, and 61% were White.
The researchers performed an instrumental variable (IV) analysis, with program-level rates of preoperative CHD testing in the year of transplantation as the IV. Non-urgent CHD testing, invasive or non-invasive, was analyzed for an association with a primary composite outcome of death or MI during the first 30 days after transplantation.
A primary composite outcome event occurred in 5.3% of patients: acute MI in 2.9% of patients and death in 2.6%. From 2012 to 2014, program-level rates of preoperative CHD testing ranged from 56% in the top quintile to 24% in the bottom quintile.
In the main IV analysis, the CHD testing rate was unrelated to the 30-day risk of MI or death: the rate difference of 1.9% was not statistically significant. The findings were consistent across most study periods. The exception was from 2000 to 2003 when CHD testing was associated with higher risk of primary outcome events: rate difference, 6.8%.
Screening for CHD before kidney transplantation is widely recommended and performed—despite a lack of evidence that it affects transplant outcomes. One study has suggested that patients selected for screening are a group at higher risk of MI. Until the results of an ongoing randomized trial are available, IV analysis provides a means of drawing causal inferences from observational data.
Testing for CHD before kidney transplant does not reduce the risk of adverse outcomes during the early posttransplant period, the quasi-experimental study concludes. The results, added to ongoing interventional studies, “may pave the way to deescalating CHD testing before kidney transplantation,” the researchers conclude [Cheng XS, et al. Association of pretransplant coronary heart disease testing with early kidney transplant outcomes. JAMA Intern Med 2023; 183:134–141. doi: 10.1001/jamainternmed.2022.6069].
