Related Experiment Video
Updated: Dec 14, 2025
Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section
Published on: July 19, 2016
Outcome of Flow-Gradient Patterns of Aortic Stenosis After Aortic Valve Replacement: An Analysis of the PARTNER 2
Erwan Salaun1, Marie-Annick Clavel1, Rebecca T Hahn2,3
1Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Canada (E.S., M.-A.C., A.D., M.-S.A., O.T., M.B., J.B., C.R., G.O., J.R.-C., P.P.).
Insights
Low-gradient aortic stenosis (AS) is common and classical low-flow AS is linked to worse outcomes after aortic valve replacement. Outcomes for other low-gradient AS types were similar to high-gradient AS.
Area of Science:
- Cardiology
- Interventional Cardiology
- Cardiac Surgery
Background:
- Severe aortic stenosis (AS) management benefits from aortic valve replacement (AVR), but outcomes in low-gradient (LG) AS are debated.
- LG AS is categorized into classical low-flow (CLF-LG), paradoxical low-flow, and normal-flow subtypes.
- Understanding AVR outcomes across these LG AS subgroups is crucial for treatment decisions.
Purpose of the Study:
- To evaluate the outcomes of AVR in four distinct flow-gradient groups within the PARTNER 2 trial and registry.
- To compare the efficacy of transcatheter aortic valve replacement (TAVR) versus surgical AVR (SAVR) across these groups.
Main Methods:
- Analysis of 3511 patients from the PARTNER 2 trial and SAPIEN 3 registry.
- Classification of patients into high-gradient (HG), CLF-LG, paradoxical low-flow-LG, and normal-flow-LG based on baseline echocardiography.
- Primary endpoint: composite of death, rehospitalization for heart failure/valve complications, or stroke at 2 years.
Main Results:
- LG AS represented 36.5% of the study population.
- CLF-LG patients had significantly higher 2-year event rates compared to HG patients (38.8% vs. 31.8%, P=0.002).
- No significant differences in 2-year outcomes between TAVR and SAVR were observed within any flow-gradient group.
Conclusions:
- Classical low-flow LG AS is associated with poorer outcomes post-AVR compared to HG AS.
- LG AS with preserved ejection fraction (paradoxical and normal-flow) showed outcomes comparable to HG AS.
- AVR, both TAVR and SAVR, demonstrated similar clinical effectiveness across all flow-gradient patterns.
Background:
Although aortic valve replacement is associated with a major benefit in high-gradient (HG) severe aortic stenosis (AS), the results in low-gradient (LG, mean gradient <40 mm Hg) AS are conflicting. LG severe AS may be subdivided in classical low-flow (left ventricular ejection fraction <50%) and LG (CLF-LG); paradoxical low-flow (left ventricular ejection fraction ≥50% but stroke volume index <35 mL/m2) and LG; and normal-flow (left ventricular ejection fraction ≥50% and stroke volume index ≥35 mL/m2) and LG. The primary objective is to determine in the PARTNER 2 trial (The Placement of Aortic Transcatheter Valves) and registry the outcomes after aortic valve replacement of the 4 flow-gradient groups.
Methods:
A total of 3511 patients from the PARTNER 2 Cohort A randomized trial (n=1910) and SAPIEN 3 registry (n=1601) were included. The flow-gradient pattern was determined at baseline transthoracic echocardiography and classified as follows: (1) HG; (2) CLF-LG; (3) paradoxical low-flow-LG; and (4) normal-flow-LG. The primary end point for this analysis was the composite of (1) death; (2) rehospitalization for heart failure symptoms and valve prosthesis complication; or (3) stroke.
Results:
The distribution was HG, 2229 patients (63.5%); CLF-LG, 689 patients (19.6%); paradoxical low-flow-LG, 247 patients (7.0%); and normal-flow-LG, 346 patients (9.9%). The 2-year rate of primary end point was higher in CLF-LG (38.8%) versus HG: 31.8% (P=0.002) and normal-flow-LG: 32.1% (P=0.05) but was not statistically different from paradoxical low-flow-LG: 33.6% (P=0.18). There was no significant difference in the 2-year rates of clinical events between transcatheter aortic valve replacement versus surgical aortic valve replacement in the whole cohort and within each flow-gradient group.
Conclusions:
The LG AS pattern was highly prevalent (36.5%) in the PARTNER 2 trial and registry. CLF-LG was the most common pattern of LG AS and was associated with higher rates of death, rehospitalization, or stroke at 2 years compared with the HG group. Clinical outcomes were as good in the LG AS groups with preserved left ventricular ejection fraction compared with the HG group.
Related Concept Videos
01:22Aortic Regurgitation II: Clinical Features and Diagnostic Tests
01:15Aortic Regurgitation I: Introduction
01:17Aortic Regurgitation IV: Nursing Management
01:25Aortic Regurgitation III: Medical Management
01:23Mitral Stenosis II: Clinical features and Diagnostic Tests
01:22Mitral Stenosis I: Introduction