0434: Impact of low flow on long-term survival in patients with severe aortic stenosis and preserved left ventricular ejection fraction: a cardiac catheterization study

Abstract

Previous studies suggested that a low flow defined as an indexed stroke volume (SVi) < 35 ml/m 2 may be an important determinant of outcome in patients with severe aortic stenosis (AS). However, its quantification using echocardiography may be subject to error measurement. The aim of this study is to determine the impact of low SVi determined during cardiac catheterization on long-term survivalamong patients with severe aortic stenosis and preserved LV ejection fraction. Between 2000 and 2010, 768 patients with preserved LVEF (>50%) and severe AS (valve area ≤1cm²) without other valvular heart disease underwent cardiac catheterization. SVi was derived from catheterization data. Mean age was 74±8 years, 42% were female, 46% had coronary artery disease and mean LVEF was 72±10%. Overall, low SVi was found in 27% (n=...) of AS patients. As compared to patients with normal SVi, those with decreased SVi were significantly older (p<0.0001) and had more frequently atrial fibrillation (p<0.0001) in addition, they had lower LVEF (p=0.04),; aortic valve area (p<0.0001), mean pressure gradient (p= 0.001), systemic arterial compliance (p<0.0001) and higher-systemic vascular and pulmonary resistances (p<0.0001). Ten-year survival was significantly reduced in patients with lower SVi as compared to those with normal SVi (41±5% vs. 63±3%; p=0.0007, Figure). After adjustment for all other risk factors, SVi was independently associated with long-term survival (hazard ratio =0.97, 95%CI: 0.95-0.99; p=0.01). Low SVi measured invasively is frequent in patients with severe AS and preserved LVEF and is a powerful and independent predictor of survival. SVi should be systematically measured and used as an additional parameter for risk stratification of patients with severe AS.