Prognostic value of myocardial perfusion imaging performed pre-renal transplantation: post-transplantation follow-up and outcomes

Christopher W. Ives, Wael A. AlJaroudi, Vineeta Kumar, Ayman Farag, Dana V. Rizk, Suzanne Oparil, Ami E. Iskandrian, Fadi G. Hage

Noninvasive stress testing is commonly performed as part of pre-renal transplantation (RT) evaluation. We evaluated the prognostic value of myocardial perfusion imaging (MPI)-myocardial perfusion, left ventricular ejection fraction (LVEF) and heart rate response (HRR)-post-RT. Consecutive RT recipients were identified at our institution. MPI was considered abnormal when there was a perfusion defect or reduced ejection fraction. HRR to vasodilator stress was calculated as percentage change from baseline. The primary outcome was a composite of cardiovascular (CV) death, myocardial infarction (MI) and coronary revascularization (CR) post-RT; all-cause mortality was the secondary endpoint. Among 1189 RT recipients, 819 (69%) underwent MPI. Of those, 182 (22%) had abnormal MPI, and 31 (4%) underwent CR pre-RT. During a median follow-up of 56 months post-RT, the annual CV event and mortality rates for patients who had no MPI, normal MPI and abnormal MPI were 1.5%, 3.1% and 4.3% (p < 0.001), and 1.8%, 2.6% and 3.6% (p = 0.016), respectively. After multivariate adjustment, compared to patients without MPI, the hazard ratios (HRs) for CV events for normal and abnormal MPI were 1.47 ([0.93-2.33], p = 0.1) and 1.78 ([1.03-3.06], p = 0.04). Blunted HRR was an independent predictor of CV events (HR = 1.73 [1.04-2.86], p = 0.034) and all-cause death (HR = 2.26 [1.28-3.98], p = 0.005) after adjusting for abnormal MPI. Patients with abnormal MPI who underwent CR pre-RT had annual mortality rates similar to those with no or normal MPI (1.9% vs. 1.7-2.6%, p = 0.2), while those who did not undergo CR had higher annual mortality (4% vs. 1.7-2.6%, p = 0.003). One in five RT recipients who underwent screening MPI had an abnormal study, an independent predictor of CV events. A blunted HRR to vasodilator stress was associated with increased risk of CV events and death, even after adjusting for abnormal MPI. Patients with abnormal MPI who underwent CR were at low risk of mortality following RT. MPI is a useful tool to aid in risk stratification pre-RT.