Low-flow Low-gradient Severe Aortic Stenosis Research Articles

Low gradient severe aortic stenosis with preserved ejection fraction: reclassification of severity by fusion of Doppler and computed tomographic data.

Low gradient severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) may be attributed to aortic valve area index (AVAi) underestimation due to the assumption of a circular shape of the left ventricular outflow tract (LVOT) with 2-dimensional echocardiography. The current study evaluated whether fusing Doppler and multidetector computed tomography (MDCT) data to calculate AVAi results in significant reclassification of inconsistently graded severe AS. In total, 191 patients with AVAi < 0.6 cm2/m2 and LVEF ≥ 50% (mean age 80 ± 7 years, 48% male) were included in the current analysis. Patients were classified according to flow (stroke volume index <35 or ≥35 mL/m2) and gradient (mean transaortic pressure gradient ≤40 or >40 mmHg) into four groups: normal flow-high gradient (n = 72), low flow-high gradient (n = 31), normal flow-low gradient (n = 46), and low flow-low gradient (n = 42). Left ventricular outflow tract area was measured by planimetry on MDCT and combined with Doppler haemodynamics on continuity equation to obtain the fusion AVAi. The group of patients with normal flow-low gradient had significantly larger AVAi and LVOT area index compared with the other groups. Although MDCT-derived LVOT area index was comparable among the four groups, the fusion AVAi was significantly larger in the normal flow-low gradient group. By using the fusion AVAi, 52% (n = 24) of patients with normal flow-low gradient and 12% (n = 5) of patients with low flow-low gradient would have been reclassified into moderate AS due to AVAi ≥ 0.6 cm2/m2. The fusion AVAi reclassifies 52% of normal flow-low gradient and 12% of low flow-low gradient severe AS into true moderate AS, by providing true cross-sectional LVOT area.

Calcification Characteristics of Low-Flow Low-Gradient Severe Aortic Stenosis in Patients Undergoing Transcatheter Aortic Valve Replacement.

Low-flow low-gradient severe aortic stenosis (LFLGAS) is associated with worse outcomes. Aortic valve calcification patterns of LFLGAS as compared to non-LFLGAS have not yet been thoroughly assessed. 137 patients undergoing transcatheter aortic valve replacement (TAVR) with preprocedural multidetector computed tomography (MDCT) and postprocedural transthoracic echocardiography were enrolled. Calcification characteristics were assessed by MDCT both for the total aortic valve and separately for each leaflet. 34 patients had LFLGAS and 103 non-LFLGAS. Total aortic valve calcification volume (p < 0.001), mass (p < 0.001), and density (p = 0.004) were lower in LFLGAS as compared to non-LFLGAS patients. At 30-day follow-up, mean transaortic pressure gradients and more than mild paravalvular regurgitation did not differ between groups. In conclusion, LFLGAS and non-LFLGAS express different calcification patterns which, however, did not impact on device success after TAVR.

Left Ventricular Functional Recovery and Remodeling in Low-Flow Low-Gradient Severe Aortic Stenosis after Transcatheter Aortic Valve Implantation

Speckle-tracking-derived global longitudinal strain (GLS) is a more sensitive method of detecting left ventricular (LV) functional recovery after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis. However, it remains unknown whether LV function improves in patients with low-flow, low-gradient severe aortic stenosis (LFLGSAS) after TAVI. The aim of the present was to evaluate LV functional recovery and remodeling after TAVI in patients with LFLGSAS. Sixty-eight patients (57% men; mean age, 79.1 ± 7.1 years) with LFLGSAS treated with TAVI were evaluated. LV function and remodeling were investigated before TAVI and at 6 and 12 months after TAVI. All echocardiographic data were prospectively collected, and GLS was retrospectively analyzed. Among patients with LFLGSAS, 35 (52%) had low LV ejection fraction (LVEF) (<50%), and 33 (48%) had preserved LVEF (≥50%). The low-LVEF group had significantly more impaired GLS than the group with preserved LVEF (-8.3 ± 2.6% vs -13.3 ± 3.5%, P < .001). LV systolic function improved after TAVI in both groups. Although in the group of patients with low LVEF, all functional parameters improved, in the group of patients with preserved LVEF, only strain-derived parameters significantly improved. There were significant decreases in absolute LV wall thickness and relative wall thickness and a trend toward decreased LV mass index in both LVEF groups. LV volumes decreased significantly in those with low LVEF but not in those with preserved LVEF. Baseline GLS but not LVEF group was independently associated to GLS improvement at 12 months after TAVI. Patients with LFLGSAS with low and preserved LVEF had a significant improvement in LV function after TAVI, as assessed by GLS. Absolute and relative LV wall thickness decreased in both groups of patients, but only those with low LVEF had reductions in LV volumes.

TCT-710 Difference of Short Term Outcome in Low, Intermediate and High risk Patient in TAVI

Withdrawn TCT-712 Clinical Outcomes of Patients With Low Flow, Low Gradient Severe Aortic Stenosis According To Treatment Modality Crochan J. O'Sullivan, Lars Englberger 1 , Stefan Stortecky 1 , Christoph Huber 1 , Nicola Hosek 1 , Ahmed Khattab 1 , Lutz Buellesfeld 1 , Thomas Pilgrim 1 , Bernhard Meier 2 , Peter Wenaweser 2 , Stephan Windecker 1 Bern University Hospital, Bern, Switzerland, University Hospital Bern, Bern, Switzerland Background: The aim of this study was to assess the role of transcatheter aortic valve implantation (TAVI) compared with medical treatment (MT) and surgical aortic valve replacement (SAVR) in patients presenting with low-flow, low-gradient (LFLG) severe aortic stenosis (AS). Methods: Between 2006 and 2012, 142 patients with LFLG severe AS (indexed aortic valve area [AVAi] 0.6cm2.m-2, ejection fraction [EF] <50% and mean gradient [MG] <40mmHg) and a complete pre-TAVI right and left heart catheterization underwent treatment allocation to MT (n1⁄428) SAVR (n1⁄441) or TAVI (n1⁄473). Results: Baseline characteristics were similar among patients allocated to MT and TAVI, whereas patients allocated to SAVR were younger (MT 82.0 5.2 vs SAVR 75.7 5.6 vs TAVI 82.2 4.8 years, p<0.0001) and were at lower predicted surgical risk (Logistic EuroSCORE MT 39.1 14.1 vs SAVR 20.7 13.6 vs TAVI 35.7 15.2%). Pre-procedural invasive hemodynamic indices were similar among MT and TAVI patients, whereas patients allocated to SAVR had a higher MG (p1⁄40.03) and EF (p1⁄40.008) and lower pulmonary artery (PA) systolic (p<0.0001) pressures. OverallMG was 26.4 8.4 mmHg, mean AVAi was 0.33 0.12, mean systemic vascular resistance was 2071.9 701.0 dyne.s.cm-2,mean PApressurewas 36.7 10.8mmHg andmean EF was 33.0 8.8 %. All-cause mortality at 30-days was similar among SAVR (4.9%) and TAVI (5.5%) patients, but was non-significantly higher among MT patients (17.9%, p1⁄40.08). Unadjusted rates of all-cause mortality at 12 months were significantly lower for SAVR (17.1%) and TAVI (17.8%) as comparedwithMT (42.9%, p1⁄40.02). Adjusted hazard ratios for death were 0.39 (95% confidence interval: 0.16 to 0.94) for SAVR compared withMT and 0.35 (95% confidence interval: 0.17 to 0.70) for TAVI compared with MT. Medical treatment (p1⁄40.02) and pulmonary hypertension (p1⁄40.03) were significantly associated with all-cause mortality at 12 months on multivariate analysis. Conclusions: Among patients with low-flow, low-gradient severe AS, SAVR and TAVI improved survival compared with MT. Clinical outcomes of TAVI and SAVR appeared similar among appropriately selected patients with LFLG severe AS.

TCT-724 Low-Flow Low-Gradient Severe Aortic Stenosis by Echocardiography Does Not Reliably Predict Aortic Stenosis Classification by Invasive Hemodynamics

It may be challenging to distinguish low-flow low-gradient (LFLG) severe aortic stenosis (AS) from pseudo-severe AS, underestimation normal-flow high-gradient (NFHG) AS, or inaccurate effective orifice area (EOA) on transthoracic echocardiography (TTE). We evaluated changes in classification of AS

Low-flow, low-gradient severe aortic stenosis in patients with normal ejection fraction

The occurrence of low-flow low-gradient severe aortic stenosis in patients with normal left ventricle (LV) ejection fraction has only been recently described. The purpose of this review is to highlight the diagnostic and management specificities of this entity. In the American College of Cardiology/American Heart Association guidelines, the criteria for severe aortic stenosis are an effective orifice area less than1.0 cm or less than 0.6 cm/m, a transvalvular mean gradient greater than 40 mmHg and a peak aortic jet velocity greater than 4.0 m/s. The guidelines also acknowledge that lower gradients may be observed in patients with depressed ejection fraction, with the implication that such an occurrence is not expected in patients with normal ejection fraction. However, recent studies confirm that a bona fide low-flow, low-gradient (LFLG) state may nonetheless be observed in 10-25% of patients with severe aortic stenosis and normal left ventricular ejection fraction (LVEF). This entity bears analogy with normal LVEF heart failure and is due to a restrictive physiology in relation with more pronounced LV concentric remodeling, a smaller LV cavity size and reductions in LV compliance and filling. The clinical relevance of LFLG severe aortic stenosis is now recognized in the most recent European (European Society of Cardiology/European Association for Cardio-Thoracic Surgery) guidelines, which also emphasize that it should be confirmed as being due to low-flow conditions. In particular, patients with bona fide paradoxical LFLG aortic stenosis should be distinguished from patients with normal flow and low gradient because of inconsistent cutoff criteria because, among patients with severe aortic stenosis, the former have the worst prognosis, whereas the latter have the best.

Projected aortic valve area reflects true severity in patients with paradoxical low-flow low-gradient severe aortic stenosis: a Multicenter Aortic Stenosis Assessment (MASA) study

Projected aortic valve area reflects true severity in patients with paradoxical low-flow low-gradient severe aortic stenosis: a Multicenter Aortic Stenosis Assessment (MASA) study

Abstract 5773: Reduced Left Ventricular Vortex Formation Ability Despite Preserved Ejection Fraction in Low-Flow, Low-Gradient Severe Aortic Stenosis

Background and Aim : Low-flow, low-gradient (LFLG) severe aortic stenosis (AS) despite preserved left ventricular (LV) ejection fraction (EF) has been associated with more advanced stage of the disease, lower cardiac output (CO) and higher systemic afterload. We aim to characterize the LV performance determinants, including its vortex formation (VF) ability. Methods : Echocardiography was performed in 61 consecutive patients with severe AS (aortic valve area index (AVAI) ≤ 0.6 cm 2 /m 2 ) and preserved LVEF (≥ 50%). In addition to biplane LV measurements, AS severity indices and Tei index were measured. Hemodynamic indices (including systemic vascular resistance (SVR) and valvulo-arterial impedance (VAI)) were calculated. VF index (VFI) was obtained from 4 X (1-β)/πX α 3 X LVEF where β is the fraction of total transmitral diastolic stroke volume (SVol) contributed by atrial contraction (assessed by time velocity integral of the mitral E and A waves) and α is the end diastolic volume (EDV) 1/3 divided by mitral annular diameter during early diastole. Patients were categorized by their LV SVol index (SVI). LFLG group consisted of SVI &lt; 45ml/m 2 . Results : Mean VFI was 2.67±1.1; AVAI, 0.50±0.09 cm 2 /m 2 . Though AVAI was slightly lower in LFLG, dimensionless index and aortic valve resistance were similar and associated with no difference in LV mass and volume between the 2 groups. VFI was significantly reduced in the LFLG, 2.37±0.9 vs 3.12±1.3 ( P =0.01), However other LV functional parameters including Tei index and LVEF were similar (Table ). LFLG was associated with higher SVR and VAI (Table ). In LFLG, the only significant correlates of VFI were SVR (r=0.38), VAI (0.37) and stroke work index (0.36); all P s&lt;0.05. VFI did not correlate to these parameters in the non-LFLG group. Conclusion : In LFLG severe AS, increased afterload and suboptimal LV vortex formation ability contribute to lower CO/SV. VFI provides useful insights in understanding this relatively new entity. Comparison of echocardiographic and haemodynamic data in LFLG and non-LFLG groups