Prognostic value of paradoxical low-gradient severe aortic stenosis in Japan: Japanese Multicenter Aortic Stenosis Study, Retrospective (JUST-R) Registry.

Background: Whether the prognosis of paradoxical low-gradient severe aortic stenosis (PLG-SAS), especially due to paradoxical low-flow low-gradient SAS (PLFLG-SAS), is malignant in any specific ethnicity, including Japanese, remains unclear.

Methods: We retrospectively enrolled 385 consecutive Japanese patients (age, 76±8 years; 148 men) with moderate AS [MAS: 0.6≤indexed aortic valve area (iAVA)<0.85cm(2)/m(2)] or SAS (iAVA <0.6cm(2)/m(2)) with preserved left ventricular ejection fraction (≥50%). SAS patients were divided into PLG-SAS and high-gradient (HG)-SAS according to the transvalvular mean gradient (40mmHg). PLG-SAS was categorized into 2 groups: normal-flow (NF) LG-SAS [stroke volume index (SVi) ≥35mL/m(2)] and PLFLG-SAS (SVi <35mL/m(2)). Endpoints were all-cause death and major adverse cardio-cerebrovascular events (MACE).

Results: During a median follow-up of 15 months, 31 patients died and 48 suffered MACE. All-cause death and MACE rates in PLG-SAS and PLFLG-SAS were significantly lower than those in HG-SAS and similar to those in MAS. On multivariate analysis, neither PLG-SAS nor PLFLG-SAS were independent determinants for all-cause death compared with MAS [MAS as reference, PLG-SAS: hazard ratio (HR) 0.47, p=0.32; PLFLG-SAS: HR 0.01, p=0.20; HG-SAS: HR 3.37, 95% confidence interval 1.24-9.74, p=0.02].

Conclusions: In Japanese patients, the prognoses of PLG-SAS and PLFLG-SAS were better than that of HG-SAS and similar to that of MAS, being better than that in Western populations.