Prognostic Relevance of Gradient and Flow Status in Severe Aortic Stenosis

Background: Severe aortic stenosis (AS) may present with different flow, gradient and left ventricular ejection fraction (LVEF) patterns. Paradoxical low-flow low-gradient (PLF-LG) severe AS has a specific clinical profile, but its prognosis and management remain controversial. Our aim is to evaluate the impact of different AS patterns in the incidence of major clinical events. Methods: A retrospective observational study was carried out on all the consecutive patients diagnosed with severe AS at our tertiary hospital centre in 2021. Echocardiographic measurements were carefully reviewed, and patients were classified following current guidelines into four categories: high gradient (HG), concordant low-flow low-gradient (CLF-LG), paradoxical low-flow low-gradient (PLF-LG) and normal-flow low-gradient (NF-LG). The baseline characteristics and clinical events (heart failure admission, intervention and death) at 1-year follow-up were collected from medical records. The association between categories and events was established using Student's t test or ANOVA as required. Results: 205 patients with severe AS were included in the study (81 ± 10 years old, 52.7% female). Category distribution was as follows: HG (138, 67.3%), PLF-LG (34, 19.8%), CLF-LG (21, 10.2%) and NF-LG (12, 5.9%). During the follow-up, 24.8% were admitted due to heart failure, 68.3% received valve replacement (51.7% TAVR) and 22% died. Severe tricuspid regurgitation was more frequent in patients with PLF-LG than in HG AS (14.7% vs. 2.2%; p < 0.01). Despite no differences in intervention rate, more patients with PLF-LG (32.4% vs. 15.9%; p = 0.049) died during the evolution. Conclusions: The PLF-LG pattern was the second most common pattern of severe AS in our cohort, and it was related to a higher mortality with no differences in intervention rate. Thus, this controversial category, rather than being underestimated, should be followed closely and considered for early intervention.