Lung Sestamibi Uptake on Myocardial Perfusion Imaging and Outcomes in Chronic Kidney Disease
<b><i>Background and Objectives:</i></b> In patients with CKD and end-stage kidney disease (ESKD), cardiac stress testing has low sensitivity and specificity for coronary disease. Alternate markers that are derived during the stress testing may enhance the predictive characteristic of stress testing. The objective was to examine the predictive characteristic of lung-to-heart ratio (LHR) in patients with CKD and ESKD. <b><i>Design, Setting, Participants, and Measurements:</i></b> Retrospective parallel cohort of ESKD and CKD not on dialysis (CKD-ND) who underwent stress testing with nuclear myocardial perfusion imaging utilizing sestamibi tracer and regadenoson. Stress LHR was calculated by the processing software and reported. Patients were analyzed by tertile of LHR (≤0.28, 0.29–0.32, ≥0.33). The primary outcome was a composite of all-cause mortality, hospitalization for myocardial infarction or unstable angina, or revascularization. <b><i>Results:</i></b> There were 144 CKD-ND and 145 ESKD patients. Patients with ESKD had greater comorbidity burden than CKD-ND. Stress tests were more often performed for pre-operative risk assessment among ESKD versus CKD-ND (53.8 vs. 5.6%, <i>p</i> < 0.001). ESKD patients more likely had ischemia identified on stress testing (19.3 vs. 8.3%, <i>p</i> = 0.001). Mean LHR was 0.31 (Standard deviation – SD: 0.09) and was similar across CKD-ND stages and ESKD. Primary outcome in the lowest (23%) and highest (33.3%) LHR tertile was higher than the middle tertile (12.8%); <i>p</i> = 0.005. This finding was similar between CKD-ND and ESKD and persisted in multivariable analysis. <b><i>Conclusions:</i></b> LHR ≤0.28 and ≥0.33 are independently associated with higher risk for death in patients with CKD-ND and ESKD. Future studies are warranted to understand the association of extreme LHR values and outcomes in this high-risk population.