1039 The impact of using different measures of relative wall thickness on assessment of left ventricular geometry in asymptomatic aortic stenosis. A SEAS substudy

Abstract

in men/women), RWT and midwall shortening were evaluated in 1728 patients (39% women, aged 67±10 years) with asymptomatic AS, re- cruited in the Simvastatin Ezetimibe in Aortic Stenosis (SEAS) study. RWT was defined as the ratio of either posterior wall thickness (RWTp, concentric geometry if ≥0.43), or the average of posterior and septal wall thickness (RWTm, concentric geometry if ≥0.45) to LV radius. Both variables were also normalized for age using previously published regression coefficients (RWTpa and RWTma, concentric geometry if ≥0.40 and 0.41, respectively). Results: Average peak transaortic velocity was 3.09±0.54 m/sec. Compared to RWTp and RWTm, use of RWTpa and RWTma reclassified LV geometry in 2.8% and 3.5% of patients (Table 1). Compared to RWTp, use of RWTm reclassified LV geometry in 11.2% of patients (183 from eccentric to concen- tric and 11 from concentric to eccentric geometry) (p<0.01). Compared to those who maintained eccentric or concentric geometry, respectively, pa- tients reclassified to concentric geometry by RWTm included more hyper- tensive patients, had larger LV mass and wall thicknesses and lower midwall shortening (all p<0.05), while patients reclassified to eccentric geometry did not differ in clinical characteristics, but had lower LV septal thickness and higher midwall shortening (both p<0.01). Conclusions: Use of age-normalized RWT modestly reclassified LV geom- etry in this elderly population. However, in patients with asymptomatic AS, defining RWT from average septal and posterior wall thickness compared to posterior wall thickness alone, considerably increased both prevalence of concentric geometry and associated midwall dysfunction. ), with low gradient-low EF (LVEF £35%, GDT £30 mm Hg) and who had aortic valvular replacement (AVR) were prospectively enrolled. Preoperative contractile reserve (CR) during dobutamine infusion was defined by an increase in stroke volume of ≥20% compared with baseline values. CR was present in 35 patients (Group I, 76%) and absent in 11 patients (Group II, 24%). In the overall sample, operative mortality was 17%. Operative mortality was 8.5% in group I compared with 45% in group II (p=0.013). In univariate analysis, lack of CR (p=0.013), three-vessel coronary artery disease (p=0.02) and GDT £20 mm Hg (p=0.02) were associated with operative mortality. In- dependent predictors of operative mortality were GDT £20 mmHg (odds ra- tio=11; 95% CI, 1.2 to 107.6; p=0.03), lack of contractile reserve (odds ratio =10; 95% CI, 1.2 to 81.6; p=0.034) and three vessels coronary artery disease (odds ratio =11; 95% CI, 1.2 to 107.6; p=0.034). All patients without CR and with GDT £20 mmHg (n=3) died in the perioperative period. Conclusions: These data further support in patients with low GDT-low EF AS the value of very low gradient (±20 mm Hg) at rest and of CR on DSH for preoperative risk stratification. Patients with GDT £20 mm Hg and lack of CR have an extremely high operative mortality.