P5252Can functional MR imaging supersede angiography? An audit of stress cardiac MRI outcomes compared those seen in the CE-MARC trials

Abstract

Abstract Background Recent studies have compared the performance of cardiac MRI (CMR) with coronary angiography. The CE-MARC trial established CMR's high diagnostic accuracy for coronary artery disease (CAD). Following these results, and those of CE-MARC 2, which showed reduced unnecessary angiography rates with CMR-guided care, we increased our adoption of CMR as an investigation of choice for CAD at our centre. Purpose In patients who have a CMR for stable angina, what is the outcome after detection of CAD, how do findings compare with angiography, and do those without CAD identified go on to have a major adverse cardiovascular event (MACE)? Method We performed a retrospective audit of all stress CMR performed from August 2016 to March 2017 at our hospital in North England. All patients were followed up for a minimum of 12 months. NICE guideline care was used during the study period. The CE-MARC trial was used for quality standards and to compare results. Results 91 stress CMRs were performed. 13 were excluded as they were performed on out-of-area patients. Median follow up was 14.5 months. Of the remaining 78 patients, 34 (43%) had a positive CMR. 20/34 (59%) proceeded to angiogram. In 16/20 of patients, CMR findings correlated with angiogram findings. A PPV of 80%. The PPV in CE-MARC was 77.2% (72.1–81.6). Of those who did not proceed to angiography, 8/14 had non-viable myocardium, 3 continued with medical management, in two it was unclear. 3/34 (8.8%) with positive CMR had a MACE. 44 patients had a negative CMR. Three had an angiogram during follow up. All were negative. There was a MACE in 1/44 (2.3%). Conclusion The audit population has a similar PPV to that of CE-MARC. MACE rates at 12 months were similar to CE-MARC which suggests that the trial results are reproducible in our setting. The wider use of CMR can therefore improve investigation and management for patients with stable angina. The audit is limited by the small number of patients proceeding to angiogram and the ability to confirm negative CMR results.