Even mild reversible myocardial perfusion defects predict mortality in patients evaluated for kidney transplantation

The value of single-photon emission tomography (SPECT) in patients with severe chronic kidney disease is controversial, and the implications of SPECT finding with lower level of ischaemia are unknown. We assessed the prognostic value of SPECT in patients evaluated for kidney transplantation.

Five hundred and forty-eight patients underwent SPECT as a part of routine evaluation for kidney transplantation. During the median follow-up of 43.7 months (IQR 22.4-68.4 months), 112 patients (20.4%) died, 49 of cardiovascular (CV) causes (8.9%). In comparison to those with no perfusion defects, mild perfusion abnormalities (1%-9.9%) had an adjusted Cox hazard ratio (HR) of 1.80 [95% confidence interval (95% CI) 1.02-3.17, P = 0.041] for all-cause mortality, while large perfusion defects (≥10%) demonstrated an HR of 2.20 (95% CI 1.38-3.50, P = 0.001). A competing risk analysis produced a similar prognostic capacity for CV mortality. SPECT also offered incremental prognostic impact with two reclassification methods. Revascularization was performed clearly more often on patients with severely than mildly abnormal or normal SPECT (28.0%, 4.3%, and 1.3%, respectively, P < 0.001). However, revascularization was not linked with better survival. Patients with a normal SPECT received a kidney transplant more often than patients with a mildly or severely abnormal SPECT (50.5%, 36.2%, and 36.6%, respectively, P = 0.010).

Myocardial ischaemia in SPECT is clearly linked with mortality in patients screened for kidney transplantation. Contrary to populations with coronary artery disease, even a mild perfusion defect in SPECT predicts poor prognosis in this patient population. The finding deserves further attention in forthcoming trials.