Dobutamine Stress Echocardiography in Low-Flow, Low-Gradient Aortic Stenosis: Flow Reserve Does Not Matter Anymore.
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SUBMITTER: Annabi MS
PROVIDER: S-EPMC6475035 | biostudies-literature | 2019 Mar
REPOSITORIES: biostudies-literature
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Dobutamine Stress Echocardiography in Low-Flow, Low-Gradient Aortic Stenosis: Flow Reserve Does Not Matter Anymore.
Annabi Mohamed-Salah MS Clavel Marie-Annick MA Pibarot Philippe P
Journal of the American Heart Association 20190301 6
See Article by Sato et al. ...[more]
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Project description:BackgroundDobutamine stress echocardiography (DSE) in classical low-flow, low-gradient (LFLG) aortic stenosis (AS) is recommended in recent guidelines to differentiate true-severe AS from pseudo-severe AS. However, DSE for patients with concomitant significant mitral regurgitation (MR) is often inaccurate or inconclusive.Case summaryA 73-year-old man with a history of coronary artery bypass grafting was referred to our institution with congestive heart failure. Transthoracic echocardiogram showed severe functional MR and LFLG AS. The results of DSE to determine the severity of AS were inconclusive owing to the absence of flow reserve, usually defined as stroke volume increase of ≥20%. In addition, calcium score by computed tomography scan was also inconclusive. Our heart team decided to reassess the severity of AS after percutaneous edge-to-edge mitral valve repair (PMVR), considering the patient's high surgical risk. Percutaneous edge-to-edge mitral valve repair was uneventful, resulting in marked reduction of MR from severe to trivial. Dobutamine stress echocardiography after PMVR revealed true-severe AS with the presence of flow reserve. Transcatheter aortic valve implantation (TAVI) was performed, and the patient ambulatorily discharged.DiscussionThe coexistence of significant AS may lead to overestimation of the severity of MR, and reportedly, concomitant MR improves in the majority of patients after TAVI, especially MR of functional aetiology. However, the coexistence of significant MR often leads to inconclusive DSE results because dobutamine stress may worsen MR and fail to increase the stroke volume. In our case, DSE after PMVR was useful to diagnose the true-severe AS for the patient with LFLG AS and severe functional MR.
| S-EPMC8189303 | biostudies-literature
Project description:Background Detection of flow reserve ( FR ) by dobutamine stress echocardiography is used for risk stratification in low-gradient aortic stenosis ( AS ). Prognostic significance of dobutamine stress echocardiography in the transcatheter aortic valve replacement era is unclear. We aimed to assess the current relevance of FR . Methods and Results We studied 235 patients with low-gradient severe AS (rest aortic valve area ≤1.0 cm2 or indexed aortic valve area ≤0.60 cm2/m2; mean aortic valve gradient <40 mm Hg) and left ventricular ejection fraction <50%) with dobutamine stress echocardiography done September 2010 through July 2016. FR was defined by ≥20% stroke volume increase. We diagnosed "true-severe AS " if peak aortic valve velocity ≥4 m/s occurred with aortic valve area ≤1.0 cm2 (or indexed aortic valve area ≤0.6 cm2/m2). At a median time of 51 days, 128 patients underwent aortic valve replacement,either surgical aortic valve replacement (n=42) or transcatheter aortic valve replacement (n=86). FR was observed in 138 patients, while 86 patients had true-severe AS . During median follow-up of 2.3 years, 138 patients died. In a multivariable model, aortic valve replacement (hazard ratio 0.41, 95% CI : 0.29-0.58, P <0.001) and lower Society of Thoracic Surgeons score (hazard ratio 1.06, 95% CI : 1.04-1.09, P<0.001) were associated with better survival, while FR was not predictive. aortic valve replacement was associated with survival regardless of the presence or absence of FR or AS severity stratification. Conclusions In low-gradient AS with reduced ejection fraction, FR or AS severity stratification by dobutamine stress echocardiography was not associated with survival. Aortic valve replacement was associated with better survival in low-gradient AS independent of FR .
| S-EPMC6475055 | biostudies-literature
Project description:Low-dose dobutamine stress echocardiography (DSE) is a valuable tool to distinguish true-severe (TS) from pseudo-severe (PS) low gradient aortic valve stenosis (LGAS) in patients with reduced left ventricular ejection fraction (LVEF). However, only scanty studies reported the clinical utility of DSE in differentiating TS-LGAS patients with preserved LVEF. We investigated the clinical utility of DSE in LGAS patients with preserved LVEF and the echocardiographic determinants suggestive of TS-LGAS. 130 consecutive LGAS patients [indexed aortic valve area (AVA) ≤ 0.6cm2/m2 and mean trans-aortic pressure gradient (PGmean) < 40mmHg] with preserved (≥ 50%, n = 63) and reduced (< 50%, n = 67) LVEF were included. DSE defined TS-LGAS (projected AVA ≤ 1 cm2) in 61.2% patients with reduced LVEF and in 68.3% patients with preserved LVEF. Multivariate logistic regression analysis showed that baseline AVA was an independent determinant of TS-LGAS both in LVEF ≥ 50% (OR 0.45, P = 0.004) and LVEF < 50% groups (OR 0.55, P = 0.005). Reduced septal and lateral mitral annular plane systolic excursion (MAPSE, OR 0.72 and 0.75, P = 0.013 and 0.016) and septal TDI-s´ were significantly associated with TS-LGAS in patients with LVEF ≥ 50%. Higher systolic pulmonary artery pressure (SPAP, OR 1.43, P = 0.045) was associated with TS-LGAS in patients with LVEF < 50%. DSE is useful to define TS-LGAS also in patients with preserved LVEF. Lower baseline AVA values are linked with TS-LGAS in both patients with reduced and preserved LVEF. Reduced MAPSE and septal TDI-s´ are suggestive of TS-LGAS in patients with preserved LVEF, while higher SPAP is associated with TS-LGAS in patients with reduced LVEF.
| S-EPMC6245091 | biostudies-literature
Project description:An important proportion of patients with aortic stenosis (AS) have a 'low-gradient' AS, i.e. a small aortic valve area (AVA <1.0 cm(2)) consistent with severe AS but a low mean transvalvular gradient (<40 mmHg) consistent with non-severe AS. The management of this subset of patients is particularly challenging because the AVA-gradient discrepancy raises uncertainty about the actual stenosis severity and thus about the indication for aortic valve replacement (AVR) if the patient has symptoms and/or left ventricular (LV) systolic dysfunction. The most frequent cause of low-gradient (LG) AS is the presence of a low LV outflow state, which may occur with reduced left ventricular ejection fraction (LVEF), i.e. classical low-flow, low-gradient (LF-LG), or preserved LVEF, i.e. paradoxical LF-LG. Furthermore, a substantial proportion of patients with AS may have a normal-flow, low-gradient (NF-LG) AS: i.e. a small AVA-low-gradient combination but with a normal flow. One of the most important clinical challenges in these three categories of patients with LG AS (classical LF-LG, paradoxical LF-LG, and NF-LG) is to differentiate a true-severe AS that generally benefits from AVR vs. a pseudo-severe AS that should be managed conservatively. A low-dose dobutamine stress echocardiography may be used for this purpose in patients with classical LF-LG AS, whereas aortic valve calcium scoring by multi-detector computed tomography is the preferred modality in those with paradoxical LF-LG or NF-LG AS. Although patients with LF-LG severe AS have worse outcomes than those with high-gradient AS following AVR, they nonetheless display an important survival benefit with this intervention. Some studies suggest that transcatheter AVR may be superior to surgical AVR in patients with LF-LG AS.
| S-EPMC5030681 | biostudies-literature
Project description:BackgroundDiscordance between small aortic valve area (AVA; < 1.0 cm(2)) and low mean pressure gradient (MPG; < 40 mm Hg) affects a third of patients with moderate or severe aortic stenosis (AS). We hypothesized that this is largely due to inaccurate echocardiographic measurements of the left ventricular outflow tract area (LVOTarea) and stroke volume alongside inconsistencies in recommended thresholds.MethodsOne hundred thirty-three patients with mild to severe AS and 33 control individuals underwent comprehensive echocardiography and cardiovascular magnetic resonance imaging (MRI). Stroke volume and LVOTarea were calculated using echocardiography and MRI, and the effects on AVA estimation were assessed. The relationship between AVA and MPG measurements was then modelled with nonlinear regression and consistent thresholds for these parameters calculated. Finally the effect of these modified AVA measurements and novel thresholds on the number of patients with small-area low-gradient AS was investigated.ResultsCompared with MRI, echocardiography underestimated LVOTarea (n = 40; -0.7 cm(2); 95% confidence interval [CI], -2.6 to 1.3), stroke volumes (-6.5 mL/m(2); 95% CI, -28.9 to 16.0) and consequently, AVA (-0.23 cm(2); 95% CI, -1.01 to 0.59). Moreover, an AVA of 1.0 cm(2) corresponded to MPG of 24 mm Hg based on echocardiographic measurements and 37 mm Hg after correction with MRI-derived stroke volumes. Based on conventional measures, 56 patients had discordant small-area low-gradient AS. Using MRI-derived stroke volumes and the revised thresholds, a 48% reduction in discordance was observed (n = 29).ConclusionsEchocardiography underestimated LVOTarea, stroke volume, and therefore AVA, compared with MRI. The thresholds based on current guidelines were also inconsistent. In combination, these factors explain > 40% of patients with discordant small-area low-gradient AS.
| S-EPMC4161727 | biostudies-literature
Project description:ObjectivePatients with low-flow, low-gradient aortic stenosis (LFLG AS) and reduced left ventricular ejection fraction (LVEF) are known to suffer from poor prognosis after transcatheter aortic valve implantation (TAVI). This study aimed to develop a simple score system for risk prediction in this vulnerable subset of patients.MethodsAll patients with LFLG AS with reduced EF and sufficient CT data for aortic valve calcification (AVC) quantification, who underwent TAVI at five German centres, were retrospectively included. The Risk prEdiction in patients with Low Ejection Fraction low gradient aortic stenosis undergoing TAVI (RELiEF TAVI) score was developed based on multivariable Cox regression for all-cause mortality.ResultsAmong all included patients (n=718), RELiEF TAVI score variables were defined as independent predictors of mortality: male sex (HR 1.34 (1.06, 1.68), p=0.013), underweight (HR 3.10 (1.50, 6.40), p=0.0022), chronic obstructive pulmonary disease (HR 1.55 (1.21, 1.99), p=0.001), pulmonary hypertension (HR 1.51 (1.17, 1.94), p=0.0015), atrial fibrillation (HR 1.28 (1.03, 1.60), p=0.028), stroke volume index (HR 0.96 (0.95, 0.98), p<0.001), non-transfemoral access (HR 1.36 (1.05, 1.76), p=0.021) and low AVC density (HR 1.44 (1.15, 1.79), p=0.0012). A score system was developed ranging from 0 to 12 points (risk of 1-year mortality: 13%-99%). Kaplan-Meier analysis for low (0-1 points), moderate (2-4 points) and high RELiEF TAVI score (>4 points) demonstrated rates of 18.0%, 29.0% and 46.1% (p<0.001) for all-cause mortality and 23.8%, 35.9% and 53.4% (p<0.001) for the combined endpoint of all-cause mortality or heart failure rehospitalisation after 1 year, respectively.ConclusionsThe RELiEF TAVI score is based on simple clinical, echocardiographic and CT parameters and might serve as a helpful tool for risk prediction in patients with LFLG AS and reduced LVEF scheduled for TAVI.
| S-EPMC8734034 | biostudies-literature
Project description:ObjectivesThe association between extracellular volume (ECV) measured by computed tomography angiography (CTA) and clinical outcomes was evaluated in low-flow low-gradient (LFLG) aortic stenosis (AS) patients undergoing transcatheter aortic valve replacement (TAVR).BackgroundPatients with LFLG AS comprise a high-risk group with respect to clinical outcomes. Although ECV, a marker of myocardial fibrosis, is traditionally measured with cardiac magnetic resonance, it can also be measured using cardiac CTA. The authors hypothesized that in LFLG AS, increased ECV may be associated with adverse clinical outcomes.MethodsIn 150 LFLG patients with AS who underwent TAVR, ECV was quantified using pre-TAVR CTA. Echocardiographic and clinical information including all-cause death and heart failure rehospitalization (HFH) was obtained from electronic medical records. A Cox proportional hazards model was used to evaluate the association between ECV and death+HFH.ResultsDuring a median follow-up of 13.9 months (range 0.07 to 28.9 months), there were 31 death+HFH events (21%). Patients who experienced death+HFH had a greater median Society of Thoracic Surgery score (9.9 vs. 4.7; p < 0.01), lower left ventricular ejection fraction (42.3 ± 20.2% vs. 52.7 ± 17.2%; p < 0.01), lower mean transvalvular gradient (24.9 ± 8.9 mm Hg vs. 28.1 ± 7.3 mm Hg; p = 0.04) and increased mean ECV (35.5 ± 9.6% vs. 29.9 ± 8.2%; p < 0.01) compared with patients who did not experience death+HFH. In a multivariable Cox proportional hazards model, increase in ECV was associated with increase in death+HFH, (hazard ratio per 1% increase: 1.04, 95% confidence interval: 1.01 to 1.09; p < 0.01).ConclusionsIn patients with LFLG AS, CTA measured increase in ECV is associated with increased risk of adverse clinical outcomes post-TAVR and may thus serve as a useful noninvasive marker for prognostication.
| S-EPMC7850162 | biostudies-literature
Project description:AimsWe reported that patients with small aortic valve area (AVA) and low flow despite preserved left ventricular ejection fraction (LVEF), i.e. 'paradoxical' low flow (PLF), have worse outcomes compared with patients with normal flow (NF), although they generally have a lower mean gradient (MG). The aortic valve weight (AVW) excised at the time of valve replacement is a flow-independent marker of stenosis severity. The objective of this study was to compare the AVW of patients with PLF and MG<40 mmHg with the AVW of patients with NF and MG≥40 mmHg.Methods and resultsWe recruited 250 consecutive patients undergoing valve replacement (Cohort A) for severe stenosis. Among them, 33 (13%) were in PLF [LVEF > 50% but stroke volume index (SVi) ≤ 35 mL/m(2)] with MG < 40 mmHg (PLF-LG group) and 105 (42%) were in NF (LVEF > 50% and SVi > 35 mL/m(2)) with MG ≥ 40 mmHg (NF-HG group). Despite a much lower MG (29 ± 7 vs. 53 ± 10 mmHg; P < 0.0001), patients in the PLF-LG group had a similar AVA (0.73 ± 0.12 vs. 0.69 ± 0.13; P = 0.19) compared with those in the NF-HG group. The AVW [median (interquartile): 1.90 (1.63-2.50) vs. 2.60 (1.66-3.32)] and prevalence of bicuspid phenotype (15 vs. 42%) were lower in the PLF-LG group than in the NF-HG group. However, AVWs analysed separately in the tricuspid and bicuspid valves were similar in both groups [tricuspid valves: 1.80 (1.63-2.50) vs. 2.30 (1.58-3.00) g; P = 0.26 and bicuspid valves: 2.72 (1.73-3.61) vs. 2.60 (2.10-3.55) g; P = 0.93]. When using cut-point values of AVW established in another series of non-consecutive patients (n = 150, Cohort B) with NF and concordant Doppler-echocardiographic findings, we found that the percentage of patients with evidence of severe stenosis in Cohort A was 70% in patients with PLF-LG and 86% in patients with NF-HG.ConclusionThe aortic valve weight data reported in this study provide evidence that a large proportion of patients with PLF and low-gradient have a severe stenosis and that the gradient may substantially underestimate stenosis severity in these patients. A multi-parametric approach including all Doppler-echocardiographic parameters of valve function as well as other complementary diagnostic tests may help correctly identify these patients.
| S-EPMC4187204 | biostudies-literature
Project description:Background Normal-flow, low-gradient severe aortic stenosis (NF-LG-SAS), defined by aortic valve area <1 cm2, mean gradient <40 mm Hg, and indexed stroke volume >35 mL/m2, is the most prevalent form of low-gradient aortic stenosis (AS). However, the true severity of AS and the management of NF-LG-SAS are controversial. The aim of this study was to evaluate the outcome of patients with NF-LG-SAS compared with moderate AS (MAS) and with high-gradient severe-AS (HG-SAS). Methods and Results A total of 154 patients with NF-LG-SAS, 366 with MAS (aortic valve area between 1.0 and 1.3 cm2), and 1055 with HG-SAS were included. On multivariate analysis, after adjustment for covariates of prognostic importance, NF-LG-SAS patients did not exhibit an excess risk of mortality compared with MAS patients under medical management (hazard ratio=1.13 [95% CI, 0.82-1.56]; P=0.45) and under medical and surgical management (hazard ratio 1.06 [95% CI, 0.79-1.43]; P=0.70), even after further adjustment for aortic valve replacement (hazard ratio=1.09 [95% CI, 0.81-1.48]; P=0.56). The 6-year cumulative incidence of aortic valve replacement (performed in accordance with guidelines) was comparable between the 2 groups (39±4% for NF-LG-SAS and 35±3% for MAS, P=0.10). After propensity score matching (n=226), NF-LG-SAS and MAS patients also had comparable outcomes under medical (P=0.41) and under medical and surgical management (P=0.52). NF-LG-SAS had better outcomes than HG-SAS patients (adjusted hazard ratio 1.84 [95% CI, 1.18-2.88]; P<0.001). Conclusions This study shows that patients with NF-LG-SAS have a comparable outcome to those with MAS when aortic valve replacement is performed during follow-up according to guidelines, mostly at the stage of HG-SAS. Rigorous echocardiographic assessment to rule out measurement errors and close follow-up are essential to detect progression to true severe AS in NF-LG-SAS.
| S-EPMC6806034 | biostudies-literature
Project description:BackgroundImpaired coronary flow reserve (CFR) portends a poor prognosis in patients with aortic stenosis. The present study aims to investigate how CFR changes over one year after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis, and to explore factors related to the changes.MethodsConsecutive patients undergoing TAVI were registered. CFR in the left anterior descending artery was measured by transthoracic echocardiography on three occasions pre-TAVI, one-day post-TAVI, and one-year post-TAVI.ResultsA total of 59 patients were enrolled, 46 of whom completed one-year follow-up. CFR was impaired in 35 (59.3%) patients pre-TAVI, but the impairment was only seen in 2 patients (4%) one-year post-TAVI. CFR value improved from 1.75 (1.50-2.10) cm/s pre-TAVI, to 2.00 (1.70-2.30) one-day post-TAVI, and further to 2.60 (2.30-3.10) one-year post-TAVI (P < 0.001). The median difference in CFR between pre-TAVI and one-year post-TAVI was 0.90 (0.53-1.20). Patients with significant improvement of CFR (more than the median value of 0.9) had larger aortic valve area (1.55 [1.38-1.92] vs. 1.36 cm2 [1.26-1.69], P = 0.042) and greater improvement in left ventricular ejection fraction (3.10 [-1.67-4.24] vs. -1.46 [-3.42-1.48] percentage points, P = 0.019) than those without.ConclusionsCFR is impaired in a considerable proportion of patients with severe aortic stenosis, but improvement is seen immediately after TAVI, and one year later. Patients with significant improvement of CFR had larger aortic valve area and greater increase in left ventricular ejection fraction after TAVI.
| S-EPMC9304717 | biostudies-literature