Predictive value of myocardial and coronary imaging in the long-term outcome of potential renal transplant recipients

Background: Coronary artery disease is a major cause of morbidity and mortality in renal transplant recipients, but there is no agreed screening protocol. The value of myocardial perfusion imaging (MPI) and coronary angiography (CA) in predicting future cardiovascular events and mortality in unselected dialysis patients was studied. Methods: Forty seven patients (mean age 51 ± 14 years, 37 males), underwent both CA and MPI as part of pre-renal transplant assessment between 1995 and 1999. Follow-up period was 75 ± 132 (range 3 to 143) months. Results: Twenty-two (46.8%) patients had > 50% stenosis of at least one major coronary artery (CAD), only 10 patients had abnormal MPI. Positive CA was found in all patients with angina and in 80% of diabetics. During follow-up 18 (38.3%) patients received a transplant and 28 (59.6%) patients died, of which 16 were proven or suspected cardiac deaths. Survival was significantly longer in patients with negative MPI or CA (92 and 96 versus 29 and 54 months for positive studies, respectively). CA had PPV of 95.7% and NPV of 54.2% for predicting the combined outcome of death and cardiovascular events whereas for MPI and MUGA, PPVs were 90.9% and 73.3% and NPVs 37.8% and 30%, respectively. Conclusions: Although MPI had a high specificity for CAD detection, its sensitivity appears limited in dialysis patients. The study suggests that those with angina and/or diabetes should undergo CA because of the high incidence of CAD in these groups, but MPI was at least as important as CA in overall mortality prediction over a long follow-up.