Abstract 15225: Delayed Hyper-Enhancement on Cardiac MRI in Patients with Severe Aortic Stenosis is Related with Attenuated Improvement of Left Ventricle Geometry and Diastolic Function

Abstract

Background Severe aortic stenosis (AS) causes myocardial fibrosis (MF), presented by delayed hyperenhancement (DHE) on magnetic resonance imaging (MRI). The presence of MF is known to be strongly related with outcome after aortic valve replacement (AVR), however, there are some limitations inhibiting routine use of MRI to detect DHE. So we investigated echocardiographic predictors of DHE in patients with severe AS and followed up their change during 1year after AVR.

Methods We analyzed 47 patients (27 males, 63 ± 10 years) to undergo AVR due to severe AS and to be examined by concurrent transthoracic echocardiography (TTE) and cardiac MRI prior to AVR. On the analysis of DHE on MRI and TTE, left ventricle (LV) was divided by 16 segment model. The amount of DHE was represented by absolute area and percent ratio per every segment area. All patients performed serial TTE on post AVR, 6month and 12months after AVR, which were analyzed according to the presence of DHE on MRI.

Results DHE was detected in one-thirds of patients (DHE+, 17/47, 34%). The DHE+ group had increased relative wall thickness (RWT; 0.53 ± 0.14 vs 0.45 ± 0.07, p=0.033), reduced TDI-S’ (4.2 ± 1.3 vs 5.5 ± 1.5 cm/sec, p=0.013), TDI-E’ (3.4 ± 0.9 vs 5.0 ± 1.6 cm/sec, p<0.001), and also increased E/E’ (23.6 ± 11.1 vs 16.8 ± 8.0, p=0.05) than those without DHE (DHE-). On multiple regression analysis, E/E’ was an independent predictor of DHE in patients with severe AS, after adjusting clinical and echocardiographic parameters. On 6months follow-up, DHE- group represented reduced LV end-diastolic diameter (LVEDD; 46 ± 3.8 vs 49 ± 5.6mm, p=0.027), LV mass index (LVMI; 104.8 ± 24.7 vs 132.2 ± 43.0 g/m2, p=0.001), increased deceleration time (DT; 243.8 ± 55.1 vs 207.2 ± 57.9ms, p=0.033), TDI-S’ (6.1 ± 1.2 vs 4.9 ± 1.1 cm/sec, p=0.001), TDI-E’ (6.1 ± 1.7 vs 4.7 ± 1.6 cm/sec, p=0.007) and reduced E/E’ (13.8 ± 1.0 vs 17.4 ± 8.0, p=0.013). But, DHE+ group did not show significant improvement except reduced LVMI (128.2 ± 30.1 vs 158.7 ± 24.7, p=0.029). These findings were also consistent on 1-year follow-up.

Conclusion DHE of cardiac MRI in patients with severe AS is frequently noted. E/E’ is an independent predictor of DHE in patient with severe AS. The absence of DHE is associated with favorable improvement of LV geometry and diastolic dysfunction