Dobutamine stress echocardiography and cardiac troponin T for the detection of significant coronary artery disease and predicting outcome in renal transplant candidates.
OBJECTIVE
Ischaemic heart disease is the leading cause of mortality and morbidity in patients with end-stage renal disease (ESRD) and after renal transplantation. However, the optimal non-invasive test for coronary artery disease (CAD) diagnosis in this population has yet to be established. The aim of this study was to assess the diagnostic accuracy of dobutamine stress echocardiography (DSE) and baseline plasma cardiac troponin T (cTnT) for detecting significant CAD and predicting adverse cardiac events in patients referred for renal transplantation.


METHODS
Coronary angiography, DSE, and baseline cTnT measurements were performed in 118 consecutive patients (mean age 52+/-12 years, 75 male) with ESRD (mean creatinine 608+/-272 micromol/L) referred for renal transplantation. The mean follow-up period was 1.32+/-0.48 years. Significant CAD was defined as a reduction in luminal diameter >70% by visual estimation in at least one major epicardial vessel. An abnormal DSE result defined as the development of a new regional wall motion abnormality in one or more normal resting segments or a deterioration of wall motion in one or more resting hypokinetic segments. A baseline cTnT>0.1 microg/L was taken as positive.


RESULTS
Significant CAD in at least one vessel was present in 35 patients (30%). The number of patients with significant 3 vessel and 2 vessel disease was 6 and 7, respectively. An abnormal DSE result was present in 36 (31%) patients. Thirty-one (26%) had cTnT>0.1 microg/L. Sixty-four (54%) patients were on dialysis and 46 (39%) were diabetic. The sensitivity, specificity, positive and negative predictive values for DSE in detecting significant coronary artery disease were 88%, 94%, 86% and 95%, respectively. The same values for a raised cTnT were 54%, 62%, 40% and 74%, respectively. The combination of an abnormal DSE result and raised cTnT gave values of 61%, 91%, 76%, and 80%, respectively. Over the follow-up period, mortality was significantly higher in those with a raised baseline cTnT but not those with an abnormal DSE result or significant CAD.


CONCLUSIONS
DSE is an accurate technique for the detection of significant CAD in renal transplant candidates. An elevated cTnT does not predict significant CAD in this population and when used in conjunction with DSE, reduces the sensitivity of the combined tests. cTnT is an important marker of prognosis in renal transplant candidates.
Department of Cardiology, St George's Hospital, London, UK. rsharma@tinyworld.co.uk
R
R
Sharma
D
D
Pellerin
D C
DC
Gaze
J S
JS
Shah
C P
CP
Streather
P O
PO
Collinson
S J
SJ
Brecker
D000328:Adult; D015415:Biomarkers / Q000097:blood; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging; D025401:Echocardiography, Stress; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000378:metabolism / Q000401:mortality / Q000601:surgery; D013318:Stroke Volume; D016019:Survival Analysis; D016896:Treatment Outcome; D020107:Troponin T / Q000097:blood*; D016277:Ventricular Function, Left
D015415:Biomarkers; D020107:Troponin T