Abstract 14140: The Weight of the Evidence: Comparison of Operatively Excised Aortic Valve Weights in Patients With High Gradient versus Low Gradient Aortic Stenosis and Overall Survival Following Aortic Valve Replacement
Introduction: Excised aortic valve weight (AVW) correlates with severity of AS. There is some debate about the true severity of AS in low gradient AS (LGAS) compared to high gradient AS (HGAS). We sought to compare patient characteristics and operatively excised AVW in patients with LGAS vs HGAS vs moderate AS.
Methods: 916 patients with EF ≥50% undergoing surgical aortic valve replacement for AS between 2010-2012 were included. Clinical and echocardiographic characteristics of LGAS patients (AVA≤1cm2, MnG<40mmHg; N=68) were compared to HGAS patients (AVA≤1cm2, MnG≥40mmHg; N=745) and operatively excised AVW were compared to moderate AS (AVA>1cm2, MnG<40mmHg; N=102).
Results: Compared to HGAS, LGAS patients were older (mean age 77 ± 10 vs 73 ± 10 years; p=0.001), often female (56% vs 38%; p=0.006), but without differences in diabetes (26% vs 29%; p=0.78), hyperlipidemia (85% vs 86%, p=0.86), coronary artery disease (49% vs 44%; p=0.53), or hypertension (81% vs 76%; p=0.38). LGAS patients predominantly had trileaflet aortic valves (91% vs 71%; p<0.001), smaller LVOT diameter (2.16 ± 0.15 vs 2.25 ± 0.20 cm; p=0.002), lower stroke volume index (42.1 ± 7.3 vs 49.0 ± 8.8 cc/m2; p<0.001), lower systemic compliance (0.77 ± 0.30 vs 0.93 ± 0.33 ; p<0.001), but no difference in valvulo-arterial impedance (3.96 ± 0.76 vs. 3.84 ± 0.80, p=0.24) compared to HGAS. Excised AVW were lower in patients with LGAS vs HGAS (1.77 ± 0.76 vs 2.69 ± 1.26 g, p<0.001), but not different from moderate AS (1.77 ± 0.76 vs 2.04 ± 0.94 g; p=0.1). This relationship held true when AVW was indexed to body surface area. Three-year mortality post-valve replacement was significantly higher in LGAS compared to HGAS (22% vs 11%, p=0.02).
Conclusions: LGAS occurs mostly in older female patients with trileaflet aortic valves. Excised AVW in LGAS is similar to moderate AS but lower than HGAS. However, systemic compliance is higher in LGAS vs HGAS contributing to increased afterload. Poorer outcomes after surgery in LGAS patients may be attributed to noncompliant vasculature which is not corrected with valve replacement and evaluation of patients with LGAS should include assessment of peripheral resistance.
Author Disclosures: S.M. Negrotto: None. J.J. Thaden: None. R.M. Suri: None. J.J. Maleszewski: None. S.V. Pislaru: None. M.F. Eleid: None. V.T. Nkomo: None.
- © 2015 by American Heart Association, Inc.