'Paradoxical' Low-Flow, Low-Gradient Severe Aortic' Valve Stenosis: An Entity with Limited Improvement Following Transcatheter Aortic Valve Implantation

Background and aim of the study: The aim of this single-center observational study was to determine the outcome of patients with 'paradoxical' low-flow, low-gradient aortic valve stenosis (PLF-LG-AS) after transcatheter aortic valve implantation (TAVI). Methods: Based on pre-procedural echocardiographic data, a total of 150 patients with severe aortic valve stenosis (AS) (indexed aortic valve area (AVA) <= 0.6 cm(2)/m(2)) who underwent TAVI at the authors' institution were allocated retrospectively to three groups: Group 1: PLF-LG-AS (ejection fraction (EF) >= 50%, indexed stroke volume (SV) <= 35 ml/m(2), mean AV gradient <40 mmHg; n = 30); Group 2: Classical low-flow, low-gradient AS (CLF-LG-AS: EF <50%, SV 535 ml/m(2), mean AV gradient <40 mmHg; n = 21); and Group 3: High-gradient AS (HG-AS: EF < or >= 50%, mean AV gradient >= 40 mmHg; n = 99). Results: PLF-LG-AS was associated with an increased relative wall thickness (RWT) and a higher post-procedural systolic blood pressure (sBP) and pulse pressure (PP) (RWT 60.6 +/- 15.3%, sBP 144 +/- 14 mmHg, PP 79 +/- 15 mmHg) compared to patients with HG-AS or CLF-LG-AS: (RWT 52 +/- 13% and 40 +/- 9%, p <0.001; sBP 138 +/- 15 mmHg and 125 +/- 25 mmHg, p = 0.006; PP 68 +/- 16 mmHg and 60 +/- 21 mmHg, p = 0.01). These patients experienced less improvement in a 6-min walk test (improvement for PLF-LG-AS 14 +/- 84 m, for CLF-LG-AS 86 +/- 83 m, for HG-AS 87 +/- 66 m; intergroup p <0.007). PLF-LG-AS and CLF-LG-AS were also associated with significantly increased one-year overall mortality (PLF-LG-AS 31%, CLF-LG-AS 19%, HG-AS 6%; p = 0.001) and cardiovascular mortality (PLF-LG-AS 20%, CLF-LG-AS 19%, HG-AS 3%; p = 0.002). Conclusion: Patients with PLF-LG-AS may represent a subgroup with a worse clinical outcome after TAVI.