1044 CHARACTERISTIC AND OUTCOME IN PATIENTS WITH LOW FLOW, LOW GRADIENT AORTIC STENOSIS

Abstract

Abstract Aim The aim of this study was to assess the prevalence and outcome in patients with severe low flow, low gradient aortic stenosis (LFLG-AS) undergoing transcatheter aortic valve intervention (TAVI). Methods Patients with LFLG AS undergoing TAVI from 2013 to 2022 were prospectively collected. Clinical, imaging data and procedural parameters were collected. LFLG-AS was defined as indexed aortic valve area (iAVA) ≤0.6 cm2/m2, mean transaortic gradient <40 mmHg and stroke volume index <36 ml/m2. Overall population was classified in due subgroups: classical LFLG AS if left ventricular ejection fraction (LVEF) was <50%, and paradoxical in patients with preserved LVEF. The major comorbidities and primary outcome defined as a composite of all-cause mortality and rehospitalization for worsening heart failure (HF) up to 1 year in the different subtypes of severe LFLG AS undergoing TAVI were evaluated. Results The study included 268 patients [81±6 years; 142 (53%) females]; of these, 155 patients (58%) had paradoxical LFLG AS and 113 patients (42%) had LFLG AS with low LVEF. Regarding echocardiography parameters, in the overall population the mean transaortic gradient was 31±6 mmHg, the mean iAVA 0.38±0.08 cm/m2, and the median LVEF 50% (IQR 38-55). Compared with paradoxical LFLG AS, the patients with classical form were characterized by a lower percentage of women (43% vs. 60% p 0.07), worse renal function (46% vs. 30%, p 0.012), and a significantly higher number of cardiovascular disease as coronary artery disease (52% vs. 29%, p <0.001) and atrial fibrillation (37% vs. 23%, p 0.018), resulting in higher Society of Thoracic Surgeons scores [7,34% (IQR: 4.96 to 13,25) versus 5,36% (IQR: 3,22 to 11); p value 0.037]. Higher percentage of patients of New York Heart Association functional class III or IV (61% vs. 27%; p 0.037) was observed in classical LFLG AS. At one-year follow-up, the composite outcome was reported in 49 patients (18%), 21 patients (13%) had paradoxical LFLG AS and 28 patients (24%) had classical form. Kaplan-Meier survival free from the composite outcome was significantly lower in patients with classical LFLG AS compared to those paradoxical LFLG AS (Log-Rank 0,022, Figure 1). Conclusion LFLG AS is a complex population with significant incidence of adverse event at one years. Patients with classical LFLG AS have higher number of risk factor and cardiovascular disease and lower survival compared paradoxical form. Figure 1