Impact of sex-specific thresholds for low flow in assessment of prognosis in concordantly and discordantly graded aortic valve stenosis.

Aims: Sex-specific low flow was recently defined as stroke volume index (SVi) ≤ 40 mL/m² in men and ≤32 mL/m² in women. We tested the prognostic association of these cut-offs in patients with aortic stenosis (AS) with concordantly and discordantly graded AS [concordantly graded AS by energy loss (CGASEL) and discordantly graded AS by energy loss (DGASEL)] based on pressure recovery adjusted aortic valve area [energy loss (EL)].

Methods And Results: Data from 1351 patients with asymptomatic AS, peak jet velocity <4 m/s, and preserved left ventricular ejection fraction enrolled in the Simvastatin and Ezetimibe in Aortic Stenosis study were used. DGASEL was defined as EL <1.0 cm² with mean aortic gradient <40 mmHg and CGASEL as EL ≥1.0 cm² with mean aortic gradient <40 mmHg. Patients were further grouped into normal and low flow. The outcome was combined all-cause death and hospitalization for heart failure (HF). CGASEL with normal/low flow was present in 915/253 patients, and DGASEL with normal/low flow was present in 57/126 patients. During a median follow-up of 4.3 years, event-free survival was lower in patients with DGASEL irrespective of flow compared to CGASEL with normal flow (P < 0.05). In Cox regression analysis, DGASEL with normal or low flow were both associated with increased risk of all-cause death and hospitalization for HF after adjustment for age, sex, heart rate, randomized study treatment, hypertension, aortic valve replacement, and aortic valve calcification (P < 0.05). No survival difference was found between patients with normal vs. low flow within groups of DGASEL or CGASEL.

Conclusion: Identification of low flow by the proposed sex-specific thresholds of SVi needs more prognostic validation before application in clinical practice.

Clinicaltrials.gov Identifier: NCT00092677.