Ferumoxytol-Enhanced Coronary Magnetic Resonance Angiography Compared to Invasive Coronary Angiography for Detection of Epicardial Coronary Artery Disease

Abstract

The prevalence of cardiac disease in patients with estimated glomerular filtration rates (eGFRs) < 30 mL/min/ 1.73 m is estimated between 40% and 55%. The incidence of coronary artery stenosis > 50% in proximal segments amenable to intervention was identified using invasive coronary angiography (ICA) in 28.5% of asymptomatic patients with chronic kidney disease (CKD) stage 5 requiring dialysis. Use of iodinated contrast agents in patients with eGFRs < 30 mL/min/1.73 m, including dialysis-dependent patients with residual kidney function, is limited by the risks for contrast-induced acute kidney injury (CI-AKI). It has recently been suggested that exposure to <20 g of elemental iodine may place patients at lower risk for CI-AKI. Ferumoxytol is a feasible contrast agent for cardiac magnetic resonance angiography (cMRA) based on preliminary studies visualizing cardiac anatomy in patients with CKD. If offered in coordination with targeted percutaneous intervention, rather than computed tomographic coronary angiography, the risk for CI-AKI may be reduced. The performance of ferumoxytolenhanced cMRA (fcMRA) compared with standard intraluminal imaging of the coronary arteries has not been studied. The primary objective of the study was to assess the sensitivity and specificity of fcMRA using ICA as the reference standard in asymptomatic patients with CKD stage 4-5 at high risk for coronary artery disease. Clinical characteristics and radiologic imaging data from 13 patients who completed fcMRA were then analyzed (Fig S1; Tables S1 and S2). No women were enrolled. One patient was of African American ethnicity. Mean age of enrolled patients was 67 ± 6 years. Five patients had diabetes mellitus diagnosed. Mean weight was 88.4 ± 15.4 kg. All patients had maintained urine output, while 30.8% were receiving maintenance hemodialysis. The eGFR of patients not requiring dialysis was 14 ± 3 mL/min/1.73 m. The mean dose of ferumoxytol was 264 ± 46 mg. No anaphylactic reaction was reported during the imaging protocol, immediately afterward, or within 30 days following fcMRA. The mean absolute time between ICA and fcMRA was 90 ± 35 days. A total of 144 vessel segments were evaluated among 13 patients to calculate the test accuracy of fcMRA using ICA as the reference standard (Figs 1, 2, S2, and S3). The prevalence of 1 or more stenotic sites per patient identified using fcMRA or ICA was 100% (Table S3), and 25.0% of all segments (36/144) contained a stenosis identified using ICA. Mean percentages of stenosis using fcMRA and