What drives mortality in paradoxical low-flow, low-gradient aortic stenosis?
M L Moura, F L Sousa, R Teixeira, I A Rodrigues, F M Nunes, A Goncalves, M C Almeida, A Lobo, M Leite, A I Neves, R Faria, R Fontes-CarvalhoAbstract
Background
Paradoxical low flow, low gradient aortic stenosis (PLFLGAS) is a frequent subtype of severe aortic stenosis, characterized by preserved ejection fraction despite reduced stroke volume and low transvalvular gradients. Its prognostic determinants remain incompletely defined.
Purpose
To evaluate three-year mortality in patients with PLFLGAS and identify associated and predictive factors.
Methods
We performed a retrospective study including patients diagnosed with PLFLGAS between 2012 and 2020. PLFLGAS was defined as: aortic valve area ≤1.0 cm², mean gradient <40 mmHg, stroke volume index <35 mL/m² and left ventricular ejection fraction (LVEF) ≥50%. Demographic data, clinical comorbidities, echocardiographic parameters and mortality outcomes were collected. Statistical analyses were performed using IBM SPSS Statistics v30. Mann–Whitney and Chi-square tests were used to group comparisons. Univariate logistic regression was used to identify predictors of three-year mortality.
Results
Ninety patients were diagnosed with PLFLGAS and included. At three-year follow-up, 24% (n=22) had died. The deceased group was predominantly female (64%) with a median age of 83 years (IQR 8). Mean LVEF was 56%. Mortality was significantly associated with older age (p=0.010) and lower LVEF (p=0.002). Patients who died exhibited prolonged aortic valve ejection time and lower LVOT peak gradient (p=0.010 and p=0.048, respectively). Markers of right ventricular dysfunction were also associated with mortality: although TAPSE did not differ significantly, pulmonary artery systolic pressure was higher in non-survivors (p=0.019), who also had a larger right atrial area (p=0.003) and impaired right ventricular–arterial coupling (p=0.033). Concomitant valvular disease was relevant, particularly the presence and severity of mitral regurgitation (p=0.023) and aortic regurgitation (p=0.036). In univariate analysis, three-year mortality was predicted by age (OR 1.13; 95% CI 1.04–1.23; p=0.004), LVEF (OR 0.86; 95% CI 0.76–0.97; p=0.011), right atrial area (OR 1.15; 95% CI 1.05–1.26; p=0.003) and mitral regurgitation severity (Omnibus Wald=7.053, p=0.029).
Conclusion
Three-year mortality in this subtype of aortic stenosis was influenced by age, left ventricular systolic function, associated valvular disease and markers of right ventricular dysfunction. Evaluation of these factors may improve risk stratification and guide management in this population.