UCSF

Aims

There is uncertainty in identifying patients with severe aortic stenosis (AS) with preserved left ventricular (LV) ejection fraction, low flow, and low gradients (LFLG). Prior studies propose that these patients demonstrate significant concentric remodelling and decreased survival, while others suggest that they have features and survival similar to moderate AS.

Methods and results

We compared the clinical characteristics, echocardiographic features, and overall survival of LFLG AS patients (n = 38) to those with normal-flow, low-gradient (NFLG) severe AS (n = 75) and moderate AS (n = 70). Low-flow, low-gradient patients had the lowest end-diastolic volume index (43 vs. 54 vs. 54 mL/m², P < 0.001), highest relative wall thickness (RWT) (60 vs. 49 vs. 48%, P < 0.001), and lowest septal mitral annular displacement (1.0 vs. 1.5 vs. 1.5 cm, P < 0.001). New York Heart Association (NYHA) class III/IV symptoms were the most frequent in the LFLG group (29 vs. 11 vs. 3%, P < 0.001). Survival at 3 years was significantly lower in LFLG compared with NFLG (P = 0.006) and moderate AS (P = 0.002), but not different between NFLG and moderate AS (P = 0.49). Higher NYHA classification (HR 1.77, 95% CI 1.22-2.57), RWT > 50% (HR 3.28, 95% CI 1.33-8.1), and septal displacement <1.1 cm (HR 3.93, 95% CI 1.96-7.82) but not low flow were independent predictors of survival in Cox proportional hazards analysis.

Conclusion

Preserved ejection fraction, LFLG AS patients exhibit marked concentric remodelling and impaired longitudinal functional-features that predict their poor long-term survival. Normal-flow, low-gradient AS patients have outcomes similar to moderate AS.