TAVI for low-flow, low-gradient severe aortic stenosis with preserved or reduced ejection fraction: a subgroup analysis from the German Aortic Valve Registry (GARY)

Abstract

Low-EF, low-gradient (LEF-LGAS: EF ≤40%, MPG <40 mmHg), paradoxical low-gradient (PLF-LGAS: EF ≥50%, MPG <40 mmHg) and high-gradient AS (HGAS: MPG ≥40 mmHg) were observed in 11.7% (n=359), 20.8% (n=640) and 60.6% (n=1,864) of the study population, respectively. EuroSCORE I (36.7±20.9 vs. 22.6±15.7 vs. 24.3±17.4; p<0.001) differed significantly among subgroups. In-hospital and one-year mortality were higher in patients with LEF-LGAS compared to HGAS (in-hospital: 7.8% vs. 4.9%; p=0.029; one-year: 32.3% vs. 19.8%; p=0.001). In contrast, mortality in patients with PLF-LGAS was comparable to patients with HGAS (in-hospital: PLF-LGAS: 5.3%; p=0.67; one-year: 22.3%; p=0.192). The rate of TAVI-associated complications was not significantly different among groups. However, postoperative low cardiac output occurred significantly more frequently in patients with LEF-LGAS Conclusions: Severe AS with a reduced transaortic flow and gradient is a common finding and is present in >30% of patients undergoing TAVI. Patients with low flow and impaired LV function have a significantly higher mortality within the first year after TAVI. In contrast, the outcome of patients with low flow and preserved EF is comparable to those with a high transvalvular aortic gradient.

Predictors of Mortality and Symptomatic Outcome of Patients With Low‐Flow Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

“…These data support the above mentioned thesis that flow, rather than the mechanism for reduced flow, is the key prognostic factor1 and that an LF state might be a sign for an advanced disease. The divergence compared with the analysis derived from the German Aortic Valve Registry9 might be caused by the definition of pLF‐LG, including only LV‐EF ≥50% and MPG <40 mm Hg but not SVI, which may have led to the inclusion of nonsevere AS in this group. Despite the higher mortality in pLF‐LG and cLF‐LG after TAVR, those patients derive a mortality benefit from valve replacement compared with medical therapy, which seems to be comparable between TAVR and surgical aortic valve replacement 1, 17…”

“…For instance, an analysis of 2535 patients from the UK‐TAVR registry found reduced midterm survival in patients with LG and EF <50%, whereas patients with normal MPG or preserved EF did not exhibit increased mortality at 2 years 10. A study with 3908 patients from the German Aortic Valve Registry yielded similar results 9. A meta‐analysis of 12 589 patients found transvalvular gradient to be an independent predictor of 1‐year mortality but not LV‐EF 20.…”

“…Studies show comparable outcomes to NF‐HG,9 a higher mortality in pLF‐LG compared with NF‐HG but lower compared with cLF‐LG,23 and those with equal mortality rates in pLF‐LG and cLF‐LG but higher compared with NF‐HG 19. Our findings confirm the high prevalence of pLF‐LG and similar worse prognosis of those patients compared with cLF‐LG, which is in line with those studies integrating SVI as an essential parameter for group definition 1, 19, 22, 23.…”

“…LV ejection fraction (LV‐EF) has affected survival after surgical aortic valve replacement2, 3, 4 and has consequently been incorporated in statistical models for assessment of operative risk 5. Conversely, in transcatheter aortic valve replacement (TAVR), which has been a safe and effective treatment for patients at intermediate6 and high surgical risk,7 the relationship is less clear 8, 9, 10, 11, 12…”

“…LF states are associated with either poor prognosis, if treated medically,16 or with increased operative mortality, if treated by surgical aortic valve replacement16, 17, 18 or TAVR 19. Data in TAVR cohorts are characterized by different definitions of AS entities and missing information on SVI, leading to an inconclusive assessment on the impact of LV‐EF, mean pressure gradient (MPG), and SVI on outcome 1, 9, 10, 19, 20, 21, 22, 23. Beyond survival, it is also recognized that some patients fail to experience a benefit in functional capacity or morbidity after TAVR 24.…”