The role of myocardial scintigraphy in the assessment of cardiovascular risk in patients with end-stage chronic kidney disease on the waiting list for renal transplantation.

BACKGROUND The usefulness of stress myocardial perfusion scintigraphy for cardiovascular (CV) risk stratification in chronic kidney disease remains controversial. We tested the hypothesis that different clinical risk profiles influence the test. METHODS We assessed the prognostic value of myocardial scintigraphy in 892 consecutive renal transplant candidates classified into four risk groups: very high (aged≥50 years, diabetes and CV disease), high (two factors), intermediate (one factor) and low (no factor). RESULTS The incidence of CV events and death was 20 and 18%, respectively (median follow-up=22 months). Altered stress testing was associated with an increased probability of cardiovascular events only in intermediate-risk (one risk factor) patients [30.3 versus 10%, hazard ratio (HR)=2.37, confidence interval (CI) 1.69-3.33, P<0.0001]. Low-risk patients did well regardless of scan results. In patients with two or three risk factors, an altered stress test did not add to the already increased CV risk. Myocardial scintigraphy was related to overall mortality only in intermediate-risk patients (HR=2.8, CI 1.5-5.1, P=0.007). CONCLUSIONS CV risk stratification based on myocardial stress testing is useful only in patients with just one risk factor. Screening may avoid unnecessary testing in 60% of patients, help stratifying for risk of events and provide an explanation for the inconsistent performance of myocardial scintigraphy.