P255
The Role of Myocardial Perfusion Imaging in Determining Suitability for Renal Transplantation
Dr Paul Callan, Prof. Sunil Bhandari, Dr Ann Tweddel, Dr David Eadington, Prof Andrew Clark, Dr Graham
Wright, Mr Manos Papodopolous
Hull and East Yorkshire NHS Trust
Introduction - Renal transplantation is the recommended treatment for patients with end stage renal failure
considered fit enough to undergo major surgery and receive immunosuppression. Pre-transplant cardiac
assessment aims to minimise the risk of perioperative cardiovascular events through the identification of
patients that would benefit from more intensive treatment and monitoring. It may also identify a subset of
patients with a poor cardiovascular prognosis, for whom renal transplantation would be unlikely to confer a
significant survival advantage. Myocardial perfusion imaging (MPI) is a well established non-invasive cardiac
imaging modality, and provides prognostic information beyond clinical risk factors alone in end stage renal
failure patients. Its role as a risk stratification tool prior to renal transplantation remains unclear. Significant
heterogeneity exists among current guidelines regarding the most appropriate screening methods, and few
prior studies have examined the role of pre-operative cardiac imaging in determining suitability for
transplantation.
Methods – We conducted a retrospective review of all patients undergoing MPI as part of a renal transplant
assessment at a tertiary renal unit serving a population of 1.2 million people. A hand search was performed of
all scan reports between January 2005 and July 2012. Details of baseline demographics, co-morbidities,
medication history, dialysis modality, transplant status and outcomes (death, myocardial infarction, stroke,
heart failure hospitalisation) were obtained from clinic and discharge letters stored on Patient Centre
electronic database. Original MPI and ECG data were re-examined, and relevant data from stress testing,
perfusion imaging and gated left ventricular function assessment were recorded. Chi-squared tests were used
to test for differences in clinical characteristics between transplanted and non-transplanted patients. Kaplan
Meier curves were constructed to compare survival, and differences were formally assessed by log-rank test.
Results -138 scans were identified that had complete follow up data. 130 (94%) received dobutamine stress,
all were imaged with Technetium 99m sestamibi. 46 (33.3%) underwent renal transplantation, 49 (35.5%)
were active or currently suspended on the transplant waiting list , 43 (31.2%) were deemed unsuitable for
renal transplantation. 12 out of the 43 patients deemed unsuitable were primarily due to significant cardiac
disease. Compared to patients considered suitable for renal transplantation, this group were significantly older
57.3 vs 50.7 years (p=0.004), but were otherwise similar in terms of co-morbidities, dialysis modality, renal
failure aetiology, and medication use. Mortality and cardiovascular event rates were significantly higher in
those deemed unsuitable for renal transplantation, compared to those that were considered suitable. There was
no significant difference in mortality and CV event rates between those considered unsuitable primarily due to
cardiac disease, and those unsuitable for other reasons. Abnormal MPI led to coronary angiography for 34
patients, with 5 subsequently undergoing percutaneous coronary angioplasty and 3 referred for coronary artery
bypass grafting (1 patient died prior to surgery).
Conclusion- One third of patients undergoing MPI as part of a renal transplant assessment were ultimately
considered not suitable for transplantation. Major cardiac disease was the most common reason for
determining that a patient was unsuitable, with perfusion imaging playing a key role in identifying this group.
Furthermore abnormal perfusion imaging led to the identification of high risk coronary disease and
subsequent revascularisation in 7 patients. The higher mortality and CV event rates amongst those deemed
unsuitable would suggest that current screening methods within our department are appropriately selecting
those that are likely to benefit most from renal transplantation.