P927Long-term mortality in patients with paradoxical low-flow low-gradient versus normal-flow high-gradient aortic stenosis undergoing transcatheter aortic valve implantation

Abstract Background Controversial data exist on clinical outcomes of patients with paradoxical low-flow, low-gradient aortic stenosis (PLF-LG) undergoing valve replacement. This entity is a combination of a small aortic valve area (AVA<1cm2), a preserved left ventricular ejection fraction (LVEF≥50%), and a “paradoxical” low mean gradient due to the presence of low LV stroke volume (≤35 mL/m2). The low flow state is explained by the presence of a high afterload and pronounced LV concentric remodeling, with impaired LV filling. Currently, poorer outcomes have been reported after surgical aortic valve replacement in patients with PLF-LG AS compared with the normal-flow high-gradient (NF-HG) AS. Purpose The aim of this study was to determine the clinical outcomes in patients with PLF-LG AS undergoing transcatheter aortic valve implantation (TAVI) compare to NF-HG patients. Methods A total of 609 patients (age 81±6 years) with symptomatic severe AS and preserved LVEF who underwent TAVI, was enrolled and divided in two groups: group A included patients with NF-HG (542 patients) and group B including those with PLF-LG (66 patients). At 1-year follow-up, death and clinical events were reported. Results TAVI was feasible in all patients. A significant reduction in mean aortic pressure gradient was observed after TAVI both in PLF-LG (baseline, 30±5 mmHg; 1-year, 11±4 mmHg; p<0.001) and in NF-HG (baseline, 53±11 mmHg; 1-year, 12±4 mmHg; p<0.001) together with an increase in AVA (PLF-LG: baseline, 0.74±0.16 cm2, 1-year: 1.83±0.41 cm2, p<0.001; NF-HG: baseline, 0.65±0.16 cm2, 1-year: 1.84±0.35cm2, p<0.001). Perioperative mortality at 30-days was similar in group A (17/542, 3%) and in group B (2/66, 3%). Figure shows the survival curves up to 5 years follow-up according to the two groups. PLF-LG and HG-AS had similar survival rate throughout the long-term follow-up. Similarly, rehospitalization rate was not different in the two groups (PLF-LG: 12% vs NF-HG: 7%, p=0.121). Kaplan-Meier analysis Conclusions Differently from surgical series, TAVI patients with PLF-LG AS had showed similar mortality and rehospitalization rates compared to NF-HG.