Reduced myocardial perfusion in renal transplant patients is not associated with aortic stiffness

Background: Renal transplant recipients are at increased risk of cardiovascular (CV) disease. The cardiac phenotype in post-transplant recipients is not well defined. We hypothesised that post transplant patients have persistently increased aortic stiffness. Methods: Twenty-five asymptomatic renal transplant patients (RT) and ten hypertensive controls (HT) underwent CMR scanning at 1.5 T. Myocardial function, late enhancement, aortic pulse wave velocity and first-pass perfusion at rest and stress was performed. Myocardial Perfusion Reserve Index (MPRI) was calculated as the ratio of hyperaemic to resting myocardial blood flow by dividing the myocardial perfusion at stress by rest perfusion (corrected to rate pressure product). Pulse wave velocity (PWV) was calculated as the ratio between the distance and time from ascending aorta to descending aorta at the level of main pulmonary artery. Results: Mean inter-ventricular septal thickness and LV mass indexed to body surface area were similar in both RT cases and HT controls. MPRI was significantly lower in the RT group compared to the HT group (1.24 ± 0.48 vs 2.04 ± 0.32, p<0.0001), globally and in all three coronary artery territories. Aortic Pulse Wave Velocity (PWV) is not significantly different between RT and HT group (4.38 ± 1.87 vs 4.65 ± 2.45, p= 0.76). There is no correlation between aortic pulse wave velocity and MPRI (β= -0.04, 95% confidence interval -0.16 to 0.07, p = 0.46). Conclusions: In our cohort population, there is no evidence of increased aortic stiffness in post renal transplant patients compared to hypertensive patients. Although these patients demonstrate impaired myocardial perfusion reserve, this is not correlated with increased aortic stiffness.