Low gradient aortic stenosis - is survival that different between types and strategies
Authors: Dias Claudio F , Santos M , Custodio P , Ferreira B , Quadrado M , Manuel A , Francisco AR , Neves B , Cruz I , Almeida AR , Fazendas P , Joao I , Pereira H 
Published: February 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Severe aortic stenosis is characterized for a high mean gradient (&gt;40mmHg) and an aortic valve area (AVA ≤1cm2). There is a population of patients with discordant findings. These patients present with a lower mean gradient (&lt;40mmHg) and a small area (AVA ≤1cm2). They encompass a population with specific characteristics and rather heterogeneous treatment approach and different prognosis

Purpose
This paper aims to enlighten to the prognosis of the different subpopulation of low gradient aortic stenosis, alone and according to the treatment strategies in a center without surgical ou percutaneous valvular intervention.

Methods
We present a retrospective study from all consecutive patients to whom an echocardiogram was performed in our hospital during the years 2017 and 2018 which meet the criteria for low gradient aortic stenosis. Comorbidities were analysed for each subgroup as well as echocardiographic variables to properly characterize aortic stenosis and employed strategy and death.

Results
A total of 135 patients met the criteria for severe aortic stenosis with a valvular area ≤1cm2. This population was made up of 19 patients with severe aortic stenosis low flow, low gradient with depressed ejection fraction and 36 patients with preserved ejection fraction. The other 80 patients represented patients with a normal flow, low gradient aortic stenosis. Groups were similar in terms of age, sex, BMI, hypertension, dyslipidaemia, atrial fibrillation, chronic obstructive pulmonary disease, chronic kidney disease and chronic coronary syndrome. In terms of diabetes there was a statistically significant difference (p = 0.019) with a lower prevalence in the group with low flow, low gradient and preserved ejection fraction. There was a statistically significant difference in survival at 24 months between groups (p = 0,004), with a mean survival of 13.6 months, 17.6months and 21 months for low flow low gradient with depressed ejection fraction, low flow low gradient with preserved ejection fraction and normal flow, low gradient patients, respectively. When analysing the treatment strategies, there were also statistically significant differences between the whole population of patients (p = 0.001) and each subgroup (low flow, low gradient with depressed ejection fraction – p &lt;0,001; and normal flow low gradient – p = 0,005), with exception of patients with low flow low gradient and preserved ejection fraction (p = 0,081).

Conclusion
Our analyses brings to our attention a clear difference in prognosis between the subgroups analysed with a worse mean survival at 24 months in patients with low flow, low gradient and depressed ejection fraction. Furthermore, there seems to be a clear impact of treatment strategies in each group of patients and still some margin of improvement especially in patients without a clearly defined treatment strategy. Abstract Figure. Abstract Figure.