Latent myopathy is more pronounced in patients with low flow versus normal flow aortic stenosis with normal left ventricular ejection fraction who are undergoing surgical aortic valve replacement: Multicenter study with a brief review of the literature

Background Midwall fibrosis and low stroke volume are independent predictors of mortality in severe aortic stenosis (AS) with preserved LV ejection fraction ( LVEF ). The role of speckle tracking echocardiography ( STE ) to identify latent myopathy pre‐ and post‐ aortic valve replacement ( AVR ) in high risk AS patients with normal LVEF is limited. Methods Demographic, 2D echocardiographic, and STE data were analyzed in patients with severe AS and preserved LVEF who underwent tissue AVR . Velocity vector imaging ( VVI ) was used to assess regional and global peak systolic longitudinal strain ( GLS ). Low flow ( LF ) was defined as an indexed LV stroke volume <35 mL/m 2 . Results Between December 2008 and May 2011, 37 patients (75 ± 9 years, 51% male) had both pre‐ and post‐ AVR echos within 6.6 ± 6.5 months (median = 4 months; range = 2.5–9.5) of surgery. Compared with pre‐ AVR , GLS (−6.9 ± 4.9% vs −11.1 ± 4.1%; P  < .001) and strain rate (−0.72 ± 0.3s ‐1 vs −0.87 ± 0.3s ‐1 ; P  = .01) improved post‐ AVR . Pre‐ AVR mid‐segments showed a similar myopathy as the basal segments (−9.5 ± 4.3% vs −9.0 ± 4.2%; P  = .3). The 16 (43%) LF patients in this study had lower pre‐ and post‐ AVR strain compared to NF patients (GLS Pre‐ AVR : LF vs NF : −5.1 ± 4.1% vs −8.4 ± 4.9% ( P  = .04) and GLS Post‐ AVR : LF vs NF : −9.2 ± 3.7% vs −12.5 ± 3.9% ( P  = .01)). However, there was no difference in absolute and %change improvement in GLS post‐ AVR ( LF vs NF :∆ −4.2 ± 3.5% vs ∆−4.1 ± 5.3% ( P  = .90) and 193 ± 214% vs 143 ± 230% change ( P  = .5)). The lowest GLS was seen in LF / HG AS followed by LF / LG , NF / LG and NF / HG AS ; P  = .03. Conclusions Latent myopathy is more pronounced in LF AS both pre‐ and post‐ AVR . Our study provides evidence of improvement in myopathy in LF AS despite a persistent worse myopathy compared to NF patients post‐ AVR .