Thallium-201 washout rate of stress myocardial perfusion imaging as a predictor of mortality in diabetic kidney disease patients initiating hemodialysis: an observational, follow-up study.

BACKGROUND: Thallium-201 washout rate of stress myocardial perfusion imaging (MPI) has been reported to correlate with coronary flow reserve which is a parameter of myocardial microcirculation. However, the evidence for its use in diabetic kidney disease (DKD) has been lacking, and the association between thallium-201 washout rate and adverse outcomes including death is unknown. Therefore, the present study was conducted to evaluate the predictive ability of thallium-201 washout rate for mortality in DKD patients initiating hemodialysis.

METHODS: A total of 96 patients with type 2 diabetes who had been started on maintenance hemodialysis undergoing stress MPI with thallium-201 within 1 year, 72 men and 24 women, with a median age of 67 years, were studied. The endpoint was defined as all-cause death. The Cox proportional hazards model was used to calculate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS: During the mean follow-up period of 3.4 ± 2.1 years, 18 (18.8%) deaths occurred. Cumulative survival rates during the follow-up period, with thallium-201 washout rate levels in the lowest tertile (3.1-36.2%), the middle tertile (36.5-46.3%), and the highest tertile (46.4-66.2%), were 51.0, 86.5, and 85.3%, respectively. Overall, the multivariate Cox regression analysis revealed that thallium-201 washout rate remained an independent predictor of death after adjusting by confounding variables (HR 0.91, 95% CI 0.85-0.97).

CONCLUSIONS: Among DKD patients initiating hemodialysis, thallium-201 washout rate seems to be useful for predicting death.