The predictive value of noninvasive cardiac test remains unclear in the kidney transplant(KT) population. We evaluated the performance of noninvasive tests and clinical risk stratification in predicting a post-KT cardiac ischemic event or the need for coronary artery intervention(CAI).

We reviewed the charts of 254 adult KT recipients, transplanted between October 2007 and December 2011 at Brigham and Women’s Hospital. The primary cardiovascular(CV) outcomes were: 1)post-transplant acute coronary syndrome(unstable angina[UA], STEMI and non-STEMI), 2)the need for CAI pre-transplant and 3)cardiac arrest. We created a clinical algorithm for the determination of CV risks and assessed its performance in predicting CV outcomes.

68(26.8%) underwent exercise stress(ES)-testing(ES-ECG or ES-echocardiogram), while 117(46%) had pharmacologic stress tests(adenosine, dipyridamole,or dobutamine stress imaging) as the initial screening test. Only 44.7% of subjects who underwent an ES-test achieved an adequate increase in heart rate, whereas, pharmacologic based tests were adequate in 97.4% of patients. 12 patients(4.7%) developed CV events (2 UA, 3 MI, and 7 cardiac arrest) post-transplantation, and 4 patients required a pre-transplant CAI. The algorithm for risk determination is presented in Figure1.

No patients in the low-risk group suffered post-transplant CV events. The sensitivity(53% vs 44%), specificity(90% vs 91%), positive predictive value(30% vs 29%), and negative predictive value(96% vs 95%) of the non-invasive cardiac testing and the risk stratification algorithm to predict CV outcomes(respectively shown) are comparable.

ES-tests have high rates of inadequacy in pre-KT patients. CV risk stratification can guide pre-transplant cardiac evaluation. Using the devised clinical risk stratification presented here, low-risk patients do not need further cardiac evaluation, high-risk group would benefit from a pre-transplant coronary angiogram. Non-invasive cardiac testing may be most beneficial in the intermediate-risk group.

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