September 9, 2026Journal of the American College of Cardiology215 citations
Transcatheter Aortic Valve Replacement in Patients With Low-Flow, Low-Gradient Aortic Stenosis
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Key Result
TAVR in patients with low-flow, low-gradient aortic stenosis was associated with a 32.3% mortality rate at 2 years and an 8.3% increase in LVEF at 1 year, which was not predicted by baseline DSE.
Key Points
- To assess clinical outcomes and left ventricular ejection fraction recovery after transcatheter aortic valve replacement, and to evaluate the prognostic value of pre-procedural dobutamine stress echocardiography in classical low-flow, low-gradient aortic stenosis.
- Interventional multicenter study (TOPAS, NCT01835028) evaluating 287 patients with low-flow, low-gradient aortic stenosis undergoing transcatheter aortic valve replacement.
- Dobutamine stress echocardiography was performed before the procedure in 234 patients, defining contractile reserve as an increase of ≥20% in stroke volume.
- Transthoracic echocardiography was evaluated at discharge and 1 year, alongside clinical follow-up at 1 month, 12 months, and yearly thereafter.
- All-cause mortality was 3.8% at 30 days, 20.1% at 1 year, and 32.3% at 2 years, with chronic obstructive pulmonary disease (p=0.022) and lower hemoglobin (p<0.001) independently predicting mortality.
- Left ventricular ejection fraction increased by 8.3% (95% CI: 6% to 11%) at 1-year follow-up, with larger gains associated with lower baseline ejection fraction (p<0.001) and absence of prior bypass surgery (p=0.004).
- Contractile reserve was present in 45% of patients on dobutamine stress echocardiography, but its absence was not associated with adverse clinical outcomes or lack of ejection fraction improvement.
Study Design
Type
Cohort (n=287)
Multicenter
Yes
Structured PICO
Does TAVR improve clinical outcomes and LVEF in patients with classical low-flow, low-gradient aortic stenosis?
P
Population
287 patients with classical low-flow, low-gradient aortic stenosis undergoing transcatheter aortic valve replacement, followed for up to 2 years.
E
Exposure
Transcatheter aortic valve replacement (TAVR), with dobutamine stress echocardiography (DSE) performed before TAVR in 234 patients.
O
Outcome
Clinical outcomes (mortality) and changes in left ventricular ejection fraction (LVEF) at 1-year and 2-year follow-up.hard clinical
TAVR in patients with low-flow, low-gradient aortic stenosis improves LVEF, but 2-year mortality is high and baseline dobutamine stress echocardiography fails to predict clinical outcomes or LVEF changes.
Abstract
BACKGROUND: Few data exist on patients with low-flow, low-gradient aortic stenosis (LFLG-AS) undergoing transcatheter aortic valve replacement (TAVR). Also, very scarce data exist on the usefulness of dobutamine stress echocardiography (DSE) before TAVR in these patients. OBJECTIVES: The authors sought to evaluate clinical outcomes and changes in left ventricular ejection fraction (LVEF) following TAVR in patients with classical LFLG-AS. METHODS: This multicenter registry included 287 patients with LFLG-AS undergoing TAVR. DSE was performed before TAVR in 234 patients and the presence of contractile reserve was defined as an increase of ≥20% in stroke volume. Transthoracic echocardiography was repeated at hospital discharge and at 1-year follow-up. Clinical follow-up was obtained at 1 and 12 months, and yearly thereafter. RESULTS: The median Society of Thoracic Surgeons score of the study population was 7.7% (interquartile range 5.3% to 12.0%), and the mean LVEF and transvalvular gradient were 30.1 ± 9.7% and 25.4 ± 6.6 mm Hg, respectively. The presence of contractile reserve was observed in 45% of patients at DSE. Mortality rates were 3.8%, 20.1%, and 32.3% at 30 days, 1 year, and 2 years, respectively. On multivariable analysis, chronic obstructive pulmonary disease (p = 0.022) and lower hemoglobin values (p < 0.001) were associated with all-cause mortality. Lower hemoglobin values (p = 0.004) and moderate-to-severe aortic regurgitation post-TAVR (p = 0.018) were predictors of the composite of mortality and rehospitalization due to heart failure. LVEF increased by 8.3% (95% confidence interval: 6% to 11%) at 1-year follow-up, and the lack of prior coronary artery bypass graft (p = 0.004), a lower LVEF at baseline (p < 0.001), and a lower stroke volume index at baseline (p = 0.019) were associated with greater increase in LVEF. The absence of contractile reserve at baseline DSE was not associated with any negative effect on clinical outcomes or LVEF changes at follow-up. CONCLUSIONS: TAVR was associated with good periprocedural outcomes in patients with LFLG-AS. However, approximately one-third of LFLG-AS TAVR recipients died at 2-year follow-up, with pulmonary disease, anemia, and residual paravalvular leaks associated with poorer outcomes. LVEF improved following TAVR, but DSE failed to predict clinical outcomes or LVEF changes over time. (Multicenter Prospective Study of Low-Flow Low-Gradient Aortic Stenosis TOPAS Study; NCT01835028).
Cite This Study
Ribeiro et al. (2018) conducted a cohort in Low-flow, low-gradient aortic stenosis (LFLG-AS) (n=287). Transcatheter aortic valve replacement (TAVR) was evaluated on Mortality at 2 years. TAVR in patients with low-flow, low-gradient aortic stenosis was associated with a 32.3% mortality rate at 2 years and an 8.3% increase in LVEF at 1 year, which was not predicted by baseline DSE.