'Paradoxical' low-flow, low-gradient severe aortic valve stenosis: an entity with limited improvement following transcatheter aortic valve implantation.

ABSTRACT

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 cm2/m2) 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/m2, mean AV gradient < 40 mmHg; n = 30); Group 2 Classical low-flow, low-gradient AS (CLF-LG-AS EF < 50%, SV ≤ 35 ml/m2, 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.