Descending aortic strain quantification by intra‐operative transesophageal echocardiography: Multimodality validation via cardiovascular magnetic resonance

Background Whereas cardiac magnetic resonance (CMR) imaging provides high temporal resolution imaging of aortic distensibility (strain), transesophageal echocardiography (TEE) is widely used for intra‐operative aortic imaging and provides a clinical alternative for aortic assessment. We tested intra‐operative global circumferential aortic strain (GCS) measured on TEE in relation to the reference of CMR‐derived strain among patients undergoing surgical graft repair of ascending aortic aneurysms. Methods CMR (3T) was prospectively performed in patients scheduled for aortic repair. TEE was performed intra‐operatively; images were co‐localized with MRI. GCS on CMR and TEE was quantified independently, blinded to results of the other modality. Results 25 patients (54 ± 10 year‐old, 88% male) were studied, inclusive of 13 genetically mediated and 12 degenerative aneurysms: CMR and TEE were performed within 12 ± 9 days. Pulse pressure (PP)–adjusted descending aortic TEE‐derived GCS strongly correlated with cine‐CMR‐derived GCS (r = .75, P = .002) though absolute GCS and PP‐adjusted values were slightly lower (5.40 ± 1.11 vs 6.49 ± 1.43% and 11.55 ± 3.04 vs 13.99 ± 4.53%, respectively). Similarly, TEE yielded slightly lower end‐diastolic area (EDA [5.1 ± 1.7 cm2 vs 5.8 ± 1.3 cm2, P = .004]) and end‐systolic area (ESA [6.1 ± 1.9 cm2 vs 6.5 ± 1.7 cm2, P = .10]), with significant correlations between the two modalities (r = .73, .76, P < .05 for all). Conclusions This exploratory study supports feasibility of TEE for assessing aortic GCS in a surgical at‐risk population, as well as magnitude of agreement between intra‐operative TEE and preoperative CMR. We found that there is a significant correlation between GCS and EDA and ESA aortic areas, but that TEE‐derived parameters underestimated CMR values by a small but significant amount.