P707 Positive rest and negative adenosine stress perfusion in typical angina

Abstract Clinical Presentation A 45 year old gentleman seen in Rapid Access Chest Pain Clinic with typical angina (exertional chest pain). No risk factors for CAD. Normal ECG. Pre-test probability of significant CAD 51% . Diagnostic techniques and findings The patient was referred for adenosine stress CMR. CMR was performed on a 1.5 Tesla scanner. Cine was performed first, followed by stress perfusion, gadolinium enhance images and finally rest perfusion images. LV systolic function was normal. A significant perfusion defect of the LAD territory was noted on the rest but not on the stress perfusion images. The radiographers confirmed that stress and rest perfusion images were performed normally (stress first). A good physiological response was obtained during the assumed vasodilator stress with > 20% in the HR (from 65-75bpm to 91-107bpm respectively). During the presumed rest perfusion acquisition, HR was similar to the previously recorded resting HR. The spleen was not adequately visible to comment on splenic switch off. This type of perfusion defect (normal stress/abnormal rest) had not been described before, and there is no evidence that it was due to acquisition error. A coronary CT was advised to assess the LAD. CT coronary angiogram showed mild coronary calcification. A severe (80%), focal, non-calcified mid LAD stenosis was identified. A mild proximal OM1 stenosis was also noted. The patient subsequently underwent an invasive angiogram which confirmed the presence of a severe mid LAD stenosis. PCI was performed in the same setting with deployment of a single 4x18mm XIENCE drug eluting stent. The successful procedure was optimised with OCT guidance. Learning points Resting perfusion is often considered an integral part of adenosine perfusion imaging in order to overcome dark ring artefact, but it requires an additional contrast injection, prolongs imaging time and adds to cost. Some experts suggest that resting perfusion does not add to clinical interpretation and is not required. Our case is interesting, showing a previously unreported phenomenon. We cannot explain the reason for it but do not believe that the stress/rest order was reversed (as this would require two radiographers to go off protocol, and they and the supervising physician to be lying) and the physiological response is as expected. It therefore suggests that a rest study may occasionally provide helpful diagnostic information. Abstract P707 Figure.