Abstract 2659: Predictors And Outcomes Of Low Gradient Severe Aortic Stenosis: Results From A Cohort Of 168 Patients
The transvalvular gradient in aortic stenosis (AS) is a function of aortic valve area and stroke volume. We investigated the predictors of low transvalvular gradient in patients with severe AS, its prognostic implications and outcome with aortic valve replacement (AVR).
Methods: Our echocardiographic data base for the period of 1993 to 2003 was screened for severe AS (AVA ≤0.8 cm2) and mean aortic transvalvular gradient of ≤30 mmHg. Chart reviews were performed for clinical, pharmacological and surgical details. Survival data was obtained from social security death index.
Results: Of the 740 patients with severe AS, 168 (23%) had a mean transaortic gradient of ≤30 mmHg. The mean age was 76 years and 53% men. Compared to those with a higher gradient, they had a lower LVEF (41±20 vs. 58±18%, p<0.0001), lower stroke volume (p<0.0001), greater prevalence of 3 or 4+ MR (34 vs. 20%, p=0.0002), greater prevalence of CAD (53 vs. 29%, p=0.002) and a slightly larger AV area (0.76 vs. 0.69 cm2, p<0.0001). They were also less likely to receive AVR (28 vs. 44%, p=0.0003). Only 49% of these had an EF ≤35% and 31% had an EF ≥55% indicating that low EF is not a prerequisite for low gradient as commonly thought. AVR was the strongest predictor of survival in these patients (adjusted RR 0.22, 95% CI 0.11– 0.45, p<0.0001, figure⇓). Other independent predictors of mortality were EF (0.03) and renal insufficiency (p=0.01).
A large number of patients with severe AS with low gradient are not offered AVR despite a huge survival benefit.
Low EF is not a prerequisite for low transvalvular gradient in severe AS.