TAVI patients with very low gradient (≤20 mmHg) had higher 2-year mortality (74%) vs high gradient (83%), with HR 1.6; STS score and LVEF predicted mortality best in VLG.
Does baseline mean gradient (high, low, very low) affect 2-year survival and the predictive value of risk scores in patients undergoing TAVI?
In TAVI patients, lower baseline gradients (especially ≤ 20 mmHg) are associated with increased 2-year mortality, though survival remains acceptable and conventional risk scores maintain their predictive value.
Abstract Background Studies investigating the effect of TAVI have consistently shown worse outcomes in patients presenting with low-flow low-gradient aortic stenosis (LG) as compared to those with high gradient (HG). Nevertheless, some patients show a very low mean gradient (VLG), ≤ 20 mmHg. It is not clear the extent to which the degree of decrease in gradient affects clinical outcomes and what is the predictive value of risk scores and LVEF in these distinct subsets. Purpose The study aimed at analyzing the profile of patients with HG, LG and VLG, the effect of LG and VLG on outcomes, and to evaluate the performance of predictive survival factors into these categories. Methods We analyzed the database of the Spanish TAVI registry, which has been conducted since 2010 and includes 46 participating centers. Patients with a full dataset were divided into groups according to the mean baseline gradient: VLG (grad. ≤ 20 mmHg), LG (20 grad. 40 mmHg) and HG (grad. ≥ 40 mmHg). Baseline characteristics, all-cause mortality, and independent survival predictors were obtained and compared between groups. Results Among 17,421 patients undergoing TAVI between 2010 and 2024, 12,800 (73.4%) showed HG, 4,126 (23.7%) showed LG and 495 (2.8%) showed VLG. The mean age was 81.3±6.2 yrs, 80.4±6.7 yrs, 78.9±8.8 yrs (p0.001), female sex 55%, 43%, 39% (p0.001) and LVEF 59±11%, 51±12%, 49±13% (p0.001), respectively. Survival at 2 years was 83 ± 0.5%, 79 ± 0.9% and 74 ± 2.5% in HG, LG and VLG respectively (p0.001). Noteworthy, the survival in VLG, being lower, was reasonably acceptable. The risk of death was significantly higher in the LG (HR 1.18, 95% CI 1.07-1.30) and VLG (HR 1.6, 95% CI 1.2-2.1) as compared to the HG group. Both EuroSCORE II and STS scores were independent predictors of mortality in LG group, HR 1.03, CI95% 1.02-1.04 and HR 1.04, CI95% 1.03-1.05 respectively and in VLG group, HR 1.03, CI95% 1.02-1.04 and HR 1.07, CI95% 1.05 -1.08 respectively, but STS score performed better in the VLG group. LVEF was predictor in both groups but showed greater effect in the VLG than in LG, with HR 1.009, CI95% 1.0035-1.015 and HR 1.004, CI95% 1.0006-1.008 respectively. Conclusions In the Spanish TAVI registry, patients with VLG represent a small minority of well-selected patients. We observed an increase in mortality during follow-up according to the baseline gradient, yet survival in the VLG group was acceptable at 2 years. Conventional risk scores and LVEF maintain their predictive value in all these groups, but STS score and LVEF performed better in the VLG group.
Hernandez et al. (2025) studied this question. TAVI patients with very low gradient (≤20 mmHg) had higher 2-year mortality (74%) vs high gradient (83%), with HR 1.6; STS score and LVEF predicted mortality best in VLG.