Brief Report
Impact of change of ischemic burden on the outcomes of ESRD patients awaiting kidney transplantation

https://doi.org/10.1007/s12350-023-03287-3Get rights and content

Abstract

Background

In asymptomatic patients with end-stage renal disease (ESRD) wait-listed for kidney transplantation (KT), it is unclear whether a change in ischemic burden on serial surveillance SPECT myocardial perfusion imaging (MPI) impacts outcome.

Methods and results

In a retrospective cohort of 700 asymptomatic KT candidates with ≥ 2 sequential SPECT-MPI studies, we defined a significant change in ischemic burden between MPIs as ΔSDS of ≥ 2 points. Patients were followed for mean 19 ± 12 months after MPI2 for cardiac death or myocardial infarction. Between MPIs, 29 (4%) subjects received coronary revascularization which was associated with a greater incidence of reduction in ischemic burden on MPI2 (31% vs. 17%, P = 0.049). Among 514 patients with no ischemia on MPI1 (SDS ≤ 1), 15% had new ischemia on MPI2 which was associated with increased MACE (adjusted HR 1.75; CI 1.02-3.01; P = 0.041). Among 186 patients with ischemia on MPI1 (SDS ≥ 2), 66% had improvement of ischemic burden on MPI2 which was associated with significantly lower MACE (adjusted HR 0.46; CI 0.25-0.82; P = 0.009). There was no significant interaction between coronary revascularization and improvement in ischemic burden impacting outcome (interaction P = 0.845).

Conclusion

Among KT candidates who underwent serial MPI for CAD surveillance, new ischemia was associated with increased MACE risk. Improvement in ischemic burden was associated with lower MACE risk irrespective of coronary revascularization status.

Section snippets

Background

Patients with end-stage renal disease (ESRD) have a high burden of rapidly progressive coronary artery disease (CAD).1 The most common causes of mortality among ESRD patients are cardiovascular events.2,3 While kidney transplantation (KT) has been shown to reduce mortality in this population, potential candidates are subject to medical and imaging evaluation to determine transplant eligibility. CAD surveillance prior to KT is often performed with single-photon emission computed tomography

Patient population

These methods have been described in a previous publication by our group.12 The study population consisted of KT candidates who underwent at least two MPI studies at Rush University Medical Center (Chicago, Illinois). The electronic medical record was queried for all patients with chronic kidney disease or ESRD who underwent SPECT-MPI in the period from June 1, 2005 to May 31, 2015. Patients who received 2 or more MPIs during this period were segregated. Among those, subjects with ESRD

Results

We identified 700 subjects who underwent 2 serial MPIs in the context of KT evaluation. Most patients were asymptomatic. In this cohort, 514 (73%) did not have significant myocardial ischemia (SDS ≤ 1) on MPI1, while 186 (27%) did have ischemia (SDS ≥ 2) on MPI1. Table 1 summarizes the baseline characteristics and Table 2 summarizes the MPI findings of the study subjects. The patients with ischemia on MPI1 had greater sum of AHA/ACC risk factors than those without ischemia (mean 3.6 ± 1.4 vs.

Discussion

This is the only study to date to evaluate the prognostic value of the change in ischemic burden in asymptomatic patients with ESRD awaiting KT. Our data disclose three important findings. First, new or worsening myocardial ischemia defined as ΔSDS ≥ 2 on MPI2 is associated with a significant increase in MACE rate, in keeping with the natural history of accelerated atherosclerosis among subjects with ESRD. Second, patients whose SDS decreased by 2 or more points had a significant decrease in

Limitations

The retrospective, observational, single-center study design is an obvious limitation. Additionally, only those who were sufficiently healthy to be considered for KT and undergo at least two SPECT-MPI studies were included in our cohort. Some patients may have received angiography prior to MPI1, resulting in bias in the patient selection for subsequent angiography. Cause of death in some subjects was ascertained from death certificates, which can be unreliable.

New knowledge gained

Among asymptomatic kidney transplant candidates undergoing serial MPI surveillance for CAD, 15% of subjects were observed to have new or worsening myocardial ischemia on the second MPI, which was associated with an increase in MACE. Patients who had improvement or resolution of myocardial ischemic burden had a significant decrease in MACE. Although coronary revascularization between the 2 serial MPIs was associated with reduction in ischemic burden on the second MPI, improvement in ischemic

Conclusions

Among patients with ESRD waitlisted for KT, new myocardial ischemia on serial surveillance MPI is associated with increased MACE risk. An improvement in ischemic burden is associated with a lower MACE risk, irrespective of whether improvement in myocardial ischemia was derived from coronary revascularization.

Disclosure

None.

Funding

The study was funded, in part, by an investigator-initiated grant from Astellas Pharma Global Development (Northbrook, IL). The funding source had no input into the study design, execution, data analysis, data interpretation, or manuscript preparation and approval.

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