Predictive value of thallium stress testing for coronary and cardiovascular events in uremic diabetic patients before renal transplantation

Abstract

Coronary artery disease and the ability of noninvasive exercise perfusion imaging with thalium-201 to predict future coronary and cardiovascular events was prospectively evaluated in a group of 85 insulin-dependent diabetic renal transplantation candidates. Sixty patients received renal allografts (36 living related donors, 24 cadaver donors) after a thallium stress test; the actuarial 2 year patient survival rate after transplantation was 84 percent. Twenty-five patients remained on dialysis, and the 2 year actuarial survival rate from onset of dialysis was 41 percent, significantly lower than the actuarial survival rate of transplanted patients (p < 0.01). Thirteen transplanted patients had positive thallium stress test results, and 6 (46 percent) had cardiovascular events (two fatal). In contrast, of 47 transplant patients with negative thallium stress test results, only 13 (28 percent) had cardiovascular events (four fatal). Five patients treated by hemodialysis only had positive test results and three (60 percent) had cardiovascular events (two fatal), whereas of 20 hemodialysis patients with negative test results, 9 (45 percent) suffered cardiovascular events (four fatal). In this study, cardiovascular events included arrhythmia, stroke, and pulmonary embolism. Within the total group, 4 of 18 patients (22 percent) with a positive test result (22 percent) had a fatal myocardial infarction, whereas only 3 of 67 patients (4 percent) with a negative result had a fatal myocardial infarction (p < 0.05). In comparison, 24 of 85 patients had a history or electrocardiographic evidence of preexisting cardiovascular disease, and 13 (54 percent) had subsequent cardiovascular events (5 of 11 patients with positive test results and 8 of 13 patients with negative results). In summary, renal transplant candidates with positive thallium stress test results appear to be at increased risk compared with those with negative results for the development of fatal myocardial infarction, but thallium stress testing is no more predictive for future coronary and cardiovascular events than is a history or an abnormal electrocardiogram.