Layer-specific longitudinal strain detects transmural dysfunction in chronic severe aortic regurgitation before and after aortic valve surgery.

To assess if layer-specific longitudinal strain (LS) provides incremental diagnostic and prognostic value compared to global longitudinal strain (GLS) in patients with chronic severe aortic regurgitation (AR) scheduled for aortic valve surgery. Forty-one patients were examined with speckle tracking echocardiography before surgery along with 15 healthy age-matched controls. Paired strain analyses before and after surgery were available in 31 patients. Layer-specific LS analysis enabled assessment of epicardial GLS (GLSepi), endocardial GLS (GLSendo), and conventional GLS. Strain parameters were indexed to end-diastolic volume (EDV; GLS/EDV) to account for increased preload. The prognostic value of layer-specific LS was evaluated using the primary outcome of persistent LV dilatation (LVEDV ≥ 175 mL) three months after surgery. Absolute (GLS, GLSepi, GLSendo) and EDV-indexed layer-specific LS (GLS/EDV, GLSepi/EDV, GLSendo/EDV) were impaired in severe AR compared to controls at baseline (GLS:17.0 ± 3.2 vs. 20.6 ± 2.0; GLSepi:14.6 ± 2.8 vs. 18.1 ± 1.9; GLSendo:20.2 ± 3.7 vs. 23.8 ± 2.2%; GLS/EDV:0.09 ± 0.05 vs. 0.21 ± 0.05; GLSepi/EDV:0.08 ± 0.04 vs. 0.18 ± 0.04; GLSendo/EDV:0.11 ± 0.06 vs. 0.24 ± 0.05%/mL; all p < 0.001). In severe AR, GLS, GLSepi and GLSendo decreased after surgery whereas GLS/EDV, GLSepi/EDV and GLSendo/EDV increased (all p < 0.001). Impaired absolute and EDV-indexed layer-specific LS were all associated with the primary outcome (all p ≤ 0.01). Area under the curve analysis revealed similar prognostic value of GLSepi, GLSendo and GLS (GLS:0.86; GLSepi:0.87; GLSendo:0.86; p = n.s.). EDV-indexed LS did not improve the predictive value significantly (GLS/EDV:0.93; GLSepi/EDV: 0.93; GLSendo/EDV:0.92; p = n.s.). Layer-specific LS detects transmural dysfunction in chronic severe AR and predicts persistent LV dilation after surgery. Layer-specific LS or EDV-indexed LS does not provide incremental prognostic value compared to conventional GLS.