Non-severe Aortic Stenosis Research Articles

Abstract 11588: Variation in Reader-Reported Severity of Paradoxical Low-Flow Low Gradient Aortic Stenosis: Observations from AaLarge Academic Health System

Introduction: Paradoxical low-flow low-gradient (PLFLG) aortic stenosis (AS) is frequently reported as non-severe AS on transthoracic echocardiogram (TTE) in clinical practice. It is uncertain how reader characteristics are associated with reporting of AS severity in patients with PLFLG AS. Methods: We identified all adults ≥ 18 years old from 9/2015-11/2019 with PLFLG AS on TTE within a large academic health system, and included only readers with ≥10 TTEs in this cohort. We determined the proportion of TTEs reported as either severe or moderate-severe and non-severe, and evaluated differences in reporting based on years of experience, volume of PLFLG AS studies interpreted per year, and quaternary vs. non-quaternary care site. We performed unadjusted and adjusted analyses using multivariable logistic regression. Results: Among 1329 patients meeting TTE criteria for PLFLG AS, only 37.3% were reported as severe/moderate-severe AS. Among 53 readers, the median proportion of patients reported as having severe/moderate-severe AS was 31.6% (25 th -75 th percentile 20.0%-50.0%, range 0.0-91.7%). There were differences in reporting between quartiles based on reader years of experience (33.3-40.9% across Q1-Q4 for proportion of patients reported with severe/moderate-severe AS; p = 0.01) but not volume (34.3-43.1% across Q1-Q4; p = 0.10). Quaternary care readers reported severe/moderate-severe AS for a much higher proportion of patients than non-quaternary care readers (64.3% [reader median 55.2%] vs. 30.9% [reader median 27.3%]; p < 0.001) (Figure), and this was the strongest reader-associated predictor of reporting severe-range AS (adjusted OR 7.6, 95% CI 5.1-11.5). Conclusions: Among patients with PLFLG AS, quaternary care TTE readers report severe AS much more commonly than non-quaternary care readers. Greater focus on TTE reporting of PLFLG AS at non-quaternary sites is likely needed to address underreporting of severe AS in this population.

Diagnostic and Prognostic Performance of Aortic Valve Calcium Score with Cardiac CT for Aortic Stenosis: A Meta-Analysis.

To evaluate the diagnostic and prognostic performance of the aortic valve calcium score (AVCS) with the Agatston method using CT in aortic stenosis (AS) and to assess mean AVCS according to AS severity. In this meta-analysis, PubMed, Embase, and Cochrane were searched from January 1, 1980, to December 31, 2020, for studies reporting sensitivity and specificity of AVCS using CT for severe AS, mean AVCS in severe and nonsevere AS, and/or hazard ratios for all-cause mortality in AS. Data were pooled using random effect models and meta-analysis software. Twelve studies (six diagnostic, three prognostic, and 10 reporting mean AVCS by AS severity) were included for analysis. A total of 4101 patients (2255 with severe AS) were described in these 12 studies. Pooled sensitivity and specificity were 82% (95% CI: 80, 84) and 78% (95% CI: 75, 81), respectively. Pooled mean AVCS were 3219 (95% CI: 2795, 3643) for severe AS, compared with 1252 (95% CI: 863, 1640) for nonsevere AS, 1808 (95% CI: 1163, 2452) for moderate AS, and 584 (95% CI: 309, 859) for mild AS. Pooled hazard ratio for AVCS as a binary threshold to predict mortality was 2.11 (95% CI: 1.11, 4.12). AVCS had moderate to high sensitivity and specificity for identifying severe AS and was also a useful prognostic imaging marker in AS. Mean AVCS categorized by AS severity may help guide clinical management.Keywords CT, Aortic Valve, Valves, Meta-Analysis© RSNA, 2021.

A Novel Two-Dimensional Echocardiography Method to Objectively Quantify Aortic Valve Calcium and Predict Aortic Stenosis Severity

Aortic valve calcium (AVC) is a strong predictor of aortic stenosis (AS) severity and is typically calculated by multidetector computed tomography (MDCT). We propose a novel method using pixel density quantification software to objectively quantify AVC by two-dimensional (2D) transthoracic echocardiography (TTE) and distinguish severe from non-severe AS. A total of 90 patients (mean age 76 ± 10 years, 75% male, mean AV gradient 32 ± 11 mmHg, peak AV velocity 3.6 ± 0.6 m/s, AV area (AVA) 1.0 ± 0.3 cm2, dimensionless index (DI) 0.27 ± 0.08) with suspected severe aortic stenosis undergoing 2D echocardiography were retrospectively evaluated. Parasternal short axis aortic valve views were used to calculate a gain-independent ratio between the average pixel density of the entire aortic valve in short axis at end diastole and the average pixel density of the aortic annulus in short axis (2D-AVC ratio). The 2D-AVC ratio was compared to echocardiographic hemodynamic parameters associated with AS, MDCT AVC quantification, and expert reader interpretation of AS severity based on echocardiographic AVC interpretation. The 2D-AVC ratio exhibited strong correlations with mean AV gradient (r=0.72, p < 0.001), peak AV velocity (r=0.74, p < 0.001), AVC quantified by MDCT (r=0.71, p <0.001) and excellent accuracy in distinguishing severe from non-severe AS (area under the curve=0.93). Conversely, expert reader interpretation of AS severity based on echocardiographic AVC was not significantly related to AV mean gradient (t=0.23, p=0.64), AVA (t=2.94, p=0.11), peak velocity (t=0.59, p=0.46), or DI (t=0.02, p=0.89). In conclusion, these data suggest that the 2D-AVC ratio may be a complementary method for AS severity adjudication that is readily quantifiable at time of TTE.

Value of non-apical echocardiographic views in the up-grading of patients with aortic stenosis

Purpose. Echocardiography assessment from apical five-chamber view (A5CV) is the standard technique for aortic stenosis (AS) grading. Data on non-apical views, such as right parasternal (RPV), subcostal (SCV) and suprasternal notch (SSNV), is scarce and constitutes the aim of our study. Methods. We designed an observational study that included patients with AS recruited prospectively in whom the stenosis was graded by echocardiography from A5CV and non-apical view. The value of non-apical views in up-grading the stenosis severity (primary objective), the prognostic relevance of such reclassification and the feasibility and reproducibility of non-apical views assessment (secondary objectives) was evaluated. Results. Feasibility of AS appraisal from RPV, SCV and SSNV was 78%, 81% and 56%, respectively (SCV vs SSNV, p = .009). AS were up-graded from non-apical views according to peak gradient, mean gradient, area and indexed area by 24%, 17%, 24% and 22%, respectively (p < .0001). Non-apical views reclassified from non-severe to severe AS, from low gradient severe to high gradient severe AS and from non-critical to critical AS 19%, 23% and 3% of cases (p < .0001). The 4-years hard cardiac events rate was 41% in patients with non-severe AS, 67% in patients with severe AS from non-apical views, 68% in patients with severe AS from A5CV and 80% in patients with severe AS from A5CV and non-apical views (p < .001). Reproducibility of AS evaluation from non-apical views was fair to excellent (intraclass correlation coefficients: SSNV = 0.44, RPV = 0.61, SCV = 0.92). Conclusion. Assessment of AS from non-apical views is feasible, reproducible and valuable over A5CV; its use is encouraged.

Spectrum bias in algorithms derived by artificial intelligence: a case study in detecting aortic stenosis using electrocardiograms.

Spectrum bias can arise when a diagnostic test is derived from study populations with different disease spectra than the target population, resulting in poor generalizability. We used a real-world artificial intelligence (AI)-derived algorithm to detect severe aortic stenosis (AS) to experimentally assess the effect of spectrum bias on test performance. All adult patients at the Mayo Clinic between 1 January 1989 and 30 September 2019 with transthoracic echocardiograms within 180 days after electrocardiogram (ECG) were identified. Two models were developed from two distinct patient cohorts: a whole-spectrum cohort comparing severe AS to any non-severe AS and an extreme-spectrum cohort comparing severe AS to no AS at all. Model performance was assessed. Overall, 258 607 patients had valid ECG and echocardiograms pairs. The area under the receiver operator curve was 0.87 and 0.91 for the whole-spectrum and extreme-spectrum models, respectively. Sensitivity and specificity for the whole-spectrum model was 80% and 81%, respectively, while for the extreme-spectrum model it was 84% and 84%, respectively. When applying the AI-ECG derived from the extreme-spectrum cohort to patients in the whole-spectrum cohort, the sensitivity, specificity, and area under the curve dropped to 83%, 73%, and 0.86, respectively. While the algorithm performed robustly in identifying severe AS, this study shows that limiting datasets to clearly positive or negative labels leads to overestimation of test performance when testing an AI algorithm in the setting of classifying severe AS using ECG data. While the effect of the bias may be modest in this example, clinicians should be aware of the existence of such a bias in AI-derived algorithms.

A Machine-Learning Framework to Identify Distinct Phenotypes of Aortic Stenosis Severity

ObjectivesThe authors explored the development and validation of machine-learning models for augmenting the echocardiographic grading of aortic stenosis (AS) severity. BackgroundIn AS, symptoms and adverse events develop secondarily to valvular obstruction and left ventricular decompensation. The current echocardiographic grading of AS severity focuses on the valve and is limited by diagnostic uncertainty. MethodsUsing echocardiography (ECHO) measurements (ECHO cohort, n = 1,052), we performed patient similarity analysis to derive high-severity and low-severity phenogroups of AS. We subsequently developed a supervised machine-learning classifier and validated its performance with independent markers of disease severity obtained using computed tomography (CT) (CT cohort, n = 752) and cardiovascular magnetic resonance (CMR) imaging (CMR cohort, n = 160). The classifier’s prognostic value was further validated using clinical outcomes (aortic valve replacement [AVR] and death) observed in the ECHO and CMR cohorts. ResultsIn 1,964 patients from the 3 multi-institutional cohorts, 1,346 (68%) subjects had either nonsevere or discordant AS severity. Machine learning identified 1,117 (57%) patients as having high-severity and 847 (43%) as having low-severity AS. High-severity patients in CT and CMR cohorts had higher valve calcium scores and left ventricular mass and fibrosis, respectively than the low-severity group. In the ECHO cohort, progression to AVR and progression to death in patients who did not receive AVR was faster in the high-severity group. Compared with the conventional classification of disease severity, machine-learning–based severity classification improved discrimination (integrated discrimination improvement: 0.07; 95% confidence interval: 0.02 to 0.12) and reclassification (net reclassification improvement: 0.17; 95% confidence interval: 0.11 to 0.23) for the outcome of AVR at 5 years. For both ECHO and CMR cohorts, we observed prognostic value of the machine-learning classifications for subgroups with asymptomatic, nonsevere or discordant AS. ConclusionsMachine learning can integrate ECHO measurements to augment the classification of disease severity in most patients with AS, with major potential to optimize the timing of AVR.

Management of aortic stenosis: a systematic review of clinical practice guidelines and recommendations.

Multiple guidelines exist for the management of aortic stenosis (AS). We systematically reviewed current guidelines and recommendations, developed by national or international medical organizations, on management of AS to aid clinical decision-making. Publications in MEDLINE and EMBASE between 1 June 2010 and 15 January 2021 were identified. Additionally, the International Guideline Library, National Guideline Clearinghouse, National Library for Health Guidelines Finder, Canadian Medical Association Clinical Practice Guidelines Infobase, and websites of relevant organizations were searched. Two reviewers independently screened titles and abstracts. Two reviewers assessed rigour of guideline development and extracted the recommendations. Of the seven guidelines and recommendations retrieved, five showed considerable rigour of development. Those rigourously developed, agreed on the definition of severe AS and diverse haemodynamic phenotypes, indications and contraindications for intervention in symptomatic severe AS, surveillance intervals in asymptomatic severe AS, and the importance of multidisciplinary teams (MDTs) and shared decision-making. Discrepancies exist in age and surgical risk cut-offs for recommending surgical aortic valve replacement (SAVR) vs. transcatheter aortic valve implantation (TAVI), the use of biomarkers and complementary multimodality imaging for decision-making in asymptomatic patients and surveillance intervals for non-severe AS. Contemporary guidelines for AS management agree on the importance of MDT involvement and shared decision-making for individualized treatment and unanimously indicate valve replacement in severe, symptomatic AS. Discrepancies exist in thresholds for age and procedural risk used in choosing between SAVR and TAVI, role of biomarkers and complementary imaging modalities to define AS severity and risk of progression in asymptomatic patients.

Calcium score of the aortic valve as a predictor of aortic stenosis severity

Abstract Funding Acknowledgements Type of funding sources: None. Background The calcium score of the aortic valve (CaScAoV) is now recommended as a supporting tool to assist in the grading of aortic stenosis (AS) severity when echocardiographic assessment is inconclusive. However, the proposed CaScAoV cut-offs for considering severe AS "unlikely", "likely", or "very likely" have never been validated in Portuguese cohorts. Aim The purpose of this study was to assess the performance of the proposed CaScAoV cut-offs in identifying patients with severe aortic stenosis. Methods A total of 513 consecutive patients (median age 83 years [IQR 79–87], 38% males) evaluated at a single-centre TAVI-programme between Jan/2016 and Nov/2019 were retrospectively identified. Only patients with an ECG-gated cardiac computed tomography (CT) and a transthoracic echocardiography performed within a 6-month time-frame were included. Main exclusion criteria were left ventricular ejection fraction &amp;lt; 50%, indexed stroke volume &amp;lt; 35 ml/m2, previous valve surgery and bicuspid aortic disease. CaScAoV was measured according to the Agatston method (Agatston units – AU). As previously reported, the likelihood of aortic stenosis as assessed by CT was categorized as: "very likely" (&amp;gt;3000 AU for men, &amp;gt;1600 AU for women); "likely" (&amp;gt;2000 AU for men, &amp;gt;1200 AU for women) ; or unlikely (&amp;lt;1600 AU for men, &amp;lt;800 AU for women). Diagnostic tests performance measures were calculated for each category. Separate analyses were performed for each gender. Results Severe AS (mean gradient ≥ 40 mmHg) was present in 422 patients (overall 82.3%: 83.1% in females and 80.8% in males), with a median transvalvular gradient of 49 mmHg (IQR 42 – 60). Overall, the discriminative ability of the CaScAoV to distinguish severe from non-severe AS was higher in men when compared with women (c-statistic 0.86 [95%CI 0.80 – 0.93] vs. 0.72 [95%CI 0.64 – 0.80], p for comparison &amp;lt; 0.001). In males, the "very likely" cut-off had a sensitivity of 71% (95%CI 63 – 78%), a specificity of 81% (95%CI 65 – 92%), a positive predictive value (PPV) of 94% (95%CI 89 – 97%) and a negative predictive value (NPV) of 40% (95%CI 33 – 46%) for the diagnosis of severe AS. Conversely, in women the sensitivity was 75% (95%CI 69 – 80%), specificity was 57% (95%CI 43 – 71%), PPV was 90% (95%CI 86 – 92%) and NPV was 32% (95%CI 25 – 39%). On the other end of the spectrum, the "unlikely" cut-off showed poor performance in dismissing severe AS, particularly in females – NPV of 43% (95%CI 25-63%) in women vs. 83% (95%CI 63-93%) in men. Conclusion In our population, the discriminative power of CaScAoV for identifying patients with severe AS was lower than in previously published cohorts, particularly in females. While very high CaScAoV is strongly supportive of severe AS, caution should be employed when interpreting low CaScAoV values in women, since the recommended cut-off value does not allow the safe exclusion of severe aortic stenosis. Abstract Figure. Waterfall chart of individuals CaScAoV

Markers of Elevated Left Ventricular Filling Pressure Are Associated with Increased Mortality in Nonsevere Aortic Stenosis

Echocardiographic measures of elevated left ventricular filling pressures are associated with an adverse prognosis. The aim of this study was to determine the relationship between acute (ratio of early transmitral flow to mitral annular velocity [E/e']) and chronic (indexed left atrial volume) markers of left ventricular filling pressure and mortality in patients with nonsevere aortic stenosis (AS), within the National Echo Database Australia cohort, testing the hypothesis that they would reflect the early hemodynamic consequences of AS and be associated with increased mortality in this setting. The first record for patients ≥18years of age showing hemodynamically significant but nonsevere (mild or moderate) AS (mean pressure gradient≥10 to <40mm Hg and aortic valve area > 1cm2) was analyzed. Baseline demographics and echocardiographic variables were compared with those among patients without AS (mean pressure gradient<10mm Hg). Mortality linkage data were available for all patients. Of 78,886 patients with aortic valve mean pressure gradients < 40mm Hg and aortic valve areas > 1cm2, 13,768 (17%) were identified with nonsevere AS (aortic valve mean pressure gradient 10-40mm Hg), of whom 57% were men (mean age, 73±13.4years) with a median follow-up of 3.4years (interquartile range, 1.7-6.1years). In unadjusted time-varying coefficient models, nonsevere AS and indexed left atrial volume > 34mL/m2 (hazard ratio [HR], 2.29; 95% CI, 2.03-2.58), E/e' ratio>14 (HR, 2.27; 95% CI, 2.08-2.49), left ventricular ejection fraction<50% (HR, 2.82; 95% CI, 2.50-3.19), and tricuspid regurgitation peak velocity>280cm/sec (HR, 2.54; 95% CI, 2.30-2.80) were associated with increased mortality hazard at the time of echocardiography. All markers were significant when combined in a multivariate model. Indices of elevated left ventricular filling pressure are independently associated with death in patients with nonsevere AS. Risk stratification models incorporating these variables may identify patients at risk for complications, warranting closer surveillance and possibly earlier intervention.

High-sensitive Troponin T in asymptomatic aortic stenosis

Abstract Background High-sensitive cardiac Troponin T (hsTnT) is the most frequently used biomarker for the detection of cardiomyocyte injury. Severe aortic stenosis (AS) leads to an increased left ventricular load, with the potential of myocardial injury reflected by increased TnT levels. However, there is a lack of studies showing the prevalence and prognostic role of elevated hsTnT in patients with asymptomatic AS. Purpose To examine the association between the hsTnT levels and AS severity in asymptomatic AS patients. We hypothesized that patients with more severe AS will have elevated hsTnT levels and that hsTnT levels are associated with a higher risk for aortic valve events (AVE) and all-cause mortality (ACM). Methods We performed a post-hoc analysis in 1739 asymptomatic patients with mild to moderate-severe AS, enrolled in the randomized, double-blinded SEAS-study (Simvastatin and Ezetimibe in Aortic Stenosis). All patients had available hsTnT blood samples measured at baseline (Year 0) and Year 1. We defined moderate to severe (mod-severe) AS as a transaortic maximal outflow velocity (Vmax)&amp;gt;3.5 m/s combined with aortic valve area (AVA)&amp;lt;1.0 cm2, otherwise non-severe AS. An hsTnT&amp;gt;14 ng/L was high according to assay (Roche, Elecsys Troponin T hs on cobas e 601). Linear multivariable regression model examined the association of hsTnT levels to clinical and echocardiographic variables. Cox multivariable regression model evaluated competing risks and hazard ratios (HR) of outcomes while adjusting for relevant variables, including a Framingham 10-years risk score of cardiovascular diseases. The competing risks were either ACM or AVE, i.e. the first of AVR, cardiovascular death and heart failure due to AS progression. Results At baseline, hsTnT was high in 26% (453/1739) patients; 25% (380/1529) in non-severe and 35% (73/210) in mod-severe AS. Relative TnT change over one year was 17% (mean 1.17, SD 1.01); 15% in non-severe vs. 32% in mod-severe AS, and neither associated to AS severity, hsTnT at baseline or lipid-lowering treatment. In multivariable linear regression analysis, there were significant correlations between hsTnT at baseline and age, male gender, creatinine, left ventricular mass index and BMI (all p&amp;lt;0.001, R-square=0.42), but not with AS severity. In multivariable Cox regression analyses, a high hsTnT at baseline was associated with AVE 1.61 [95% CI 1.29–1.99]. In contrast, hsTnT at baseline was not associated to all-cause mortality (see figure). Conclusions In asymptomatic AS patients without severe AS, high-sensitive Troponin T is not associated with AS severity in cross-sectional analyses, and its levels do not change substantially during one year of follow-up. However, patients with hsTnT &amp;gt;14 ng/l had a sixty percent higher independent risk of subsequent aortic valve events. Multivariable Cox regression Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Acknowledgements: Main sponsor (SEAS): MSD Singapore Company, LLC, partnership between Merck &amp; Co. Inc. and Schering-Plough Corporation. Blood analysis sponsor: Roche

Aortic Acceleration Time and the Intraoperative Assessment of Aortic Stenosis

Aortic acceleration time (AAT) and the ratio of AAT to ejection time (AAT/ET) are relatively new echocardiographic measures of the severity of aortic stenosis (AS). This study investigated the utility of transesophageal echocardiography (TEE) measurements of AAT and AAT/ET to predict the severity of AS under intraoperative conditions. Retrospective diagnostic accuracy study. St. Vincent's Hospital, Melbourne, Australia, from July 2007 to February 2017. The study comprised 199 patients who underwent aortic valve replacement (AVR) and whose aortic valves were evaluated with spectral Doppler analysis in both preoperative transthoracic echocardiography (TTE) and intraoperative TEE studies fewer than three months apart. Exclusion criteria included AVR for only aortic regurgitation, AVR of prosthetic aortic valves, and known left ventricular outflow tract obstruction. Standard echocardiography assessment of AS and the AAT and AAT/ET measurements was performed using preoperative TTE and intraoperative TEE. The intraoperative AAT and AAT/ET were increased significantly in patients with both high- and low-gradient severe AS compared with patients without severe AS (p < 0.01). Comparing preoperative TTE and intraoperative TEE measurements showed that the AAT was significantly prolonged during general anesthesia (mean difference 9.67 msec [95% confidence interval -13.54 to -5.81]), whereas the AAT/ET was preserved (mean difference -0.0018 [95% confidence interval -0.013 to 0.0091]). An intraoperative TEE cutoff of 109 msec for AAT and 0.35 for AAT/ET had a 74% and 67% sensitivity and 72% and 78% specificity, respectively, to differentiate severe from non-severe AS. The AAT and AAT/ET may be useful adjuncts for the intraoperative measurement of AS. The agreement between intraoperative TEE and preoperative TTE was better with AAT/ET compared with AAT alone.

Does the severity of low-gradient aortic stenosis classified by computed tomography-derived aortic valve calcification determine the outcome of patients after transcatheter aortic valve implantation (TAVI)?

Aortic valve calcification (AVC) determined by computed tomography has emerged as a complementary measure of aortic stenosis (AS) severity and as a predictor of adverse events. Thus, AVC can guide further treatment decisions in patients with low-gradient AS (LG-AS). We compared the symptomatic and prognostic outcome of patients with low vs. high AVC after transcatheter aortic valve implantation (TAVI). Patients with an aortic valve area index ≤ 0.6cm2/m2 and a mean pressure gradient (MPG) < 40mmHg were classified as low-flow, low-gradient AS (LFLG-AS; stroke volume index [SVI] ≤ 35ml/m2, left ventricular ejection fraction [LVEF] < 50%, n = 173), paradoxical LFLG-AS (pLFLG-AS, SVI ≤ 35ml/m2, LVEF ≥ 50%, n = 233), or normal-flow, low-gradient AS (NFLG-AS, SVI > 35ml/m2, LVEF ≥ 50%, n = 244); patients with MPG ≥ 40mmHg (n = 1142) served as controls. Patients were further categorized according to published AVC thresholds. Demographic characteristics and cardiovascular risk were not different between patients with high vs. low AVC in any of the subgroups. Patients with low AVC had a lower MPG. Symptom improvement at 30days was observed in the majority of patients but was less pronounced in LFLG-AS patients with low vs. those with high AVC. Kaplan-Meier 1-year survival curves were identical between patients with low and high AVC in all three LG-AS groups. The severity of LG-AS based on AVC has no impact on 1-year prognosis once TAVI has been performed. • Aortic valve calcification (AVC) determined by computed tomography has emerged as a complementary measure of aortic stenosis (AS) severity and is of prognostic value in selected patients. • Patients with inconsistent echocardiographic measures can be classified as having severe or nonsevere AS by the computed tomography-derived AVC score. • The prognostic value of AVC in patients with low-gradient AS is abrogated after correction of afterload by TAVI.

What Is New in Low Gradient Aortic Stenosis: Surgery, TAVR, or Medical Therapy?

A significant proportion of patients with aortic stenosis (AS) have discordance in severity by mean gradient/peak velocity and aortic valve area. Low gradient aortic stenosis (LG-AS) is defined when the aortic valve area is < 1cm2 consistent with severe AS and mean aortic gradient is < 40mmHg consistent with non-severe AS. LG-AS represents a diagnostic and therapeutic challenge. To summarize the different categories, diagnosis, management, and prognosis of LG-AS. LG-AS is classified as classical (ejection fraction (EF) < 50%, indexed stroke volume (SVi) < 35ml/m2), paradoxical (EF > 50%, SVi < 35ml/m2), pseudo-severe (moderate AS with reduced EF), or normal flow low gradient AS. Recent findings emphasize the importance of low-dose dobutamine stress echocardiography and CT calcium score in the assessment of aortic valve. In addition, flow reserve (increase in SV > 50%) can be evaluated during dobutamine stress echocardiography and helps predict perioperative prognosis. Patients with LG-AS have better survival with aortic valve replacement (AVR) compared to medical therapy, irrespective of presence or absence of flow reserve. Some recent studies suggest that transcatheter aortic valve replacement (TAVR) may be superior to surgical AVR for patients with a lack of contractile flow reserve or those with paradoxical LG-AS, but further investigation is needed to clarify optimal treatment. The role of TAVR in patients with moderate AS and reduced EF is also under investigation.

Severe aortic stenosis is associated with perioperative mortality in proximal femur fracture patients.

Objectives:Evaluate the correlation between aortic stenosis and perioperative mortality in patients following surgical fixation of proximal femur fractures.Design:Retrospectively reviewed case series.Setting:Two Academic, Level 1 Trauma Centers.Patients/Participants:One hundred fifty-eight patients, definitively diagnosed with aortic stenosis by means of echocardiogram, who underwent surgical fixation for an isolated proximal femur fracture (OTA/AO 31-A, 31-B, 32-A, 32-B, and 32-C fractures) between January 2000 and June 2015. The severity of the aortic stenosis was based upon accepted echocardiographic hemodynamic parameters designated by the 2014 American Heart Association guidelines.Main Outcome Measures:Post Injury mortality, 30-day mortality, and 1-year mortality.Secondary Outcome Measures:Postoperative mortality stratified by severity of aortic stenosis based on aortic valve area (AVA) and ejection fracture (EF) as determined by preoperative echocardiography.Results:One hundred fifty-eight patients were available for final analysis. Kaplan–Meier survival analysis revealed a significantly longer time to mortality among Non-severe aortic stenosis patients compared to Severe aortic stenosis patients, P value .006. Twenty-three percent of patients with Severe aortic stenosis and 10% of patients with Non-severe aortic stenosis died within 30 days of surgery. No significant difference was observed in mean survival among AS patients who underwent surgery within 48 hours of injury (34.5 months) and those delayed more than 48 hours after injury (25.0 months), P value .116. Among the commonly measured hemodynamic parameters of aortic stenosis, only AVA and EF were significantly associated with mortality, P value .015, and P value < .001, respectively. There were no significant effects for Aortic Vmax, Peak ΔP, and Mean ΔP. An AVA of 0.8 cm2 or less is associated with a significantly shorter (22 months) postinjury mortality than patients with an AVA > 0.8 cm2. (37 months), P value .009.Conclusions:Severe aortic stenosis is associated with a shorter postoperative time to mortality after surgical fixation of hip fractures compared to patients with Non-severe stenosis. Aortic valve area and Ejection Fraction are the only hemodynamic parameters significantly associated with postoperative mortality.Level of Evidence: Prognostic Level III

Characteristics and usefulness of unintended premature ventricular contraction during invasive assessment of aortic stenosis

BackgroundPostextrasystolic potentiation (PESP)-associated augmentation in left ventricular-aorta pressure gradient (LVAoG) observed after incidental premature ventricular contraction (PVC) during resting echocardiography is similar to dobutamine stress echocardiography (DSE)-associated augmentation in LVAoG in patients with low-flow, low-gradient (LF-LG) aortic stenosis (AS). What is not known is whether a similar relationship exists when unintended PVC causes PESP during cardiac catheterization in patients with AS. MethodsWe retrospectively reviewed all catheterizations performed for patients with at least moderate AS who had LVAoG assessment. Univariate and multivariate analyses were conducted to determine the predictors of pre- and post-PVC mean LVAoG ≥ 40 mmHg. ResultsBetween September 2015 to September 2017, of 140 individuals undergoing cardiac catheterization, 34 met study criteria. Mean pre-PVC gradient was 38.9 ± 22.8 mmHg. All patients exhibited PESP-associated augmentation of LVAoG by an average of 28 ± 12%. In multivariate analysis, the only significant predictor of post-PVC mean LVAoG ≥ 40 mmHg was preserved LV function (OR 6.81; 95% CI 1.41–32.82, p = 0.02). Inability to generate ≥ 40 mmHg of mean LVAoG post-PVC had 100% specificity for nonsevere AS in our observational cohort. ConclusionsUnintended but interpretable PVCs occurred in one in four patients with AS undergoing cardiac catheterization with measurable hemodynamics. All of our patients with PVCs, regardless of underlying LVEF, exhibited PESP-associated augmentation of LVAoG. Our exploratory analysis suggests that inability to generate ≥40 mmHg of mean LVAoG post-PVC is highly specific for nonsevere AS.

Physical examination in aortic stenosis. Correlation with echocardiographic and peripheral Doppler echocardiography findings

Introduction and objectivesPhysical examination is useful for detecting cardiac murmurs in patients with suspected aortic stenosis (AS). Our aim was to evaluate the correlation between physical findings, peripheral artery Doppler, and the echocardiographic parameters of severity in patients with AS. MethodsBetween August 2017 and January 2018, patients diagnosed with AS (peak velocity >2.5m/s) were prospectively included, and classified into severe (effective orifice area [EOA] <1cm2) and non-severe AS (EOA ≥1cm2). A cardiologist, blinded to the echocardiographic findings, performed a complete physical examination, and then another cardiologist, blinded to previous data, examined the patients to evaluate interobserver variability. A brachial artery Doppler was also performed. ResultsEighty-six patients were included (mean age 76±9 years, 48% women), of which 49 (57%) had non-severe, and 37 (43%) severe AS. Murmur intensity (r=−0.32; P=.003) and duration (r=−0.54; P<.001) correlated with EOA. Absence of second heart sound was the parameter with higher AUC=0.85; P<.001), late-systole murmur duration (AUC=0.79, P<.001) and pulsus tardus ≥2 (AUC=0.77, P<.001) for severe AS. A cut-off value of 84ms in acceleration time in brachial artery had a sensitivity of 46%, specificity of 87% for severe AS. ConclusionsPhysical examination findings have an acceptable diagnostic accuracy for assessing AS severity. Prolongation of acceleration time in brachial artery could help assessing AS severity.

Quantitative analysis of spectral Doppler clicks in assessment of aortic stenosis.

This study was performed to evaluate an additional echocardiographic spectral Doppler marker, which would identify severe aortic stenosis (AS). Echocardiography is most commonly utilized to assess AS and has been validated against invasive measurements. However, the data obtained are not always in agreement, leaving a conundrum regarding the true severity of AS and can lead to other diagnostic procedures. This highlights the importance of improved noninvasive diagnostic techniques. Forty-eight indeterminate cases of calcific AS that had been previously evaluated by both echocardiography and cardiac catheterization were included in the study, using cardiac catheterization as the gold standard for calculation of aortic valve area (AVA). The intensity of opening and closing of the aortic valve, represented by bright vertical deflections on the CW spectral waveform, was quantified using ImageJ software to generate pixel intensity histograms to create opening and closing click (OC and CC) ratios. These ratios were compared with echocardiographic variables and catheterization AVA. Thirty-five patients were found to have severe AS and 13 patients were found to have nonsevere AS, as assessed by cardiac catheterization. CC ratio was found to be a significant predictor of severe AS with an OR 0.024 (95% CI: 0.002-0.378, P=.0079). Adding CC to a model using standard echocardiographic parameters resulted in significant improvement in the C-statistic (0.693 to 0.835, P=.0134). An additional Doppler marker measuring the aortic valve CC ratio has been found to improve detection of severe AS.

Predictors of aortic stenosis severity reclassification using an imaging data fusion method in patients referred for transcatheter aortic valve implantation

The use of imaging data fusion method (IDFM) with multislice computed tomography (MSCT) and two-dimensional transthoracic echocardiography (2D-TTE) in patients with aortic stenosis (AS) may result in reclassification of AS severity from severe to non-severe. We sought to establish potential predictors of AS severity reclassification using the IDFM method. A total of 54 high-risk patients (mean age 79 ± 7.9 years; 40.7% male) with severe AS by 2D-TTE (indexed aortic valve area [AVAi] < 0.6 cm2/m2), referred for transcatheter aortic valve implantation, were included in the analysis. AVAi was subsequently recalculated using IDFM by replacing 2D-TTE left ventricular outflow tract (LVOT) measurements with MSCT LVOT parameters. Imaging data fusion method reclassified 20.4% patients into the potentially non-severe AS group. In a multivariable model including clinical variables, reclassification to non-severe AS by IDFM was independently associated with younger age and diabetes mellitus (DM), (odds ratio [OR] 0.864; 95% confidence interval [CI] 0.76-0.99; p < 0.035 and OR 19.259; 95% CI 2.28-162.41; p < 0.007, respectively). In a multivariable analysis of echocardiographic variables, reclassification was associ-ated with higher LVOT velocity time integral and lower aortic mean gradient (OR 1.402; 95% CI 1.07-1.84; p < 0.014 and OR 0.858; 95%: CI 0.760-0.968; p < 0.013, respectively). In addition, 24.1% of patients were reallocated from low-flow (< 35 mL/m2) to normal-flow AS. Imaging data fusion method reclassified a substantial proportion of patients with severe AS into a potentially moderate AS group and from a low-flow to a normal-flow AS group. Such regrouping calls for increased diagnostic prudence in AS patients, especially those with specific clinical and echocardiographic predictors of reclassification, such as DM or low aortic mean gradient.

Effect of Asymptomatic Severe Aortic Stenosis on Outcomes of Individuals Aged 80 and Older.

To examine the effect of asymptomatic severe aortic stenosis (AS) on mortality late in life. Retrospective cohort study. Large medical center. Asymptomatic adults aged 80 and older (mean age 86 ± 4; N=1,060, n=569 women) with preserved left ventricular ejection fraction (LVEF; > 50%); 927 (87.5%) with no AS, 70 (6.6%) with nonsevere AS, and 63 (5.9%) with severe AS. Information was collected on demographic characteristics, comorbidities, and laboratory and echocardiographic data. Survival was assessed according to longest follow-up available. During a mean follow-up of 2.2 ± 2.3 years, there were 203 (19%) deaths, 51 of which were from cardiovascular causes. Four-year estimates of survival were 72% for no AS, 58% for nonsevere AS, and 23% for severe AS (p<.001). Univariable analysis showed that asymptomatic severe AS was significantly associated with greater risk of all-cause mortality (hazard ratio (HR)=3.06, 95% confidence interval (CI)=1.96-4.58, p<.001). After adjustment for age, sex, LVEF, hypertension, dyslipidemia, diabetes, atrial fibrillation, chronic kidney disease, and coronary artery disease, asymptomatic severe AS was an independent predictor of all-cause mortality (HR=3.16, 95% CI=1.97-4.88, p<.001). Asymptomatic severe AS has a major effect on prognosis even in very old adults.

Assessment of aortic valve calcium load by multidetector computed tomography. Anatomical validation, impact of scanner settings and incremental diagnostic value

ObjectivesTo validate aortic valve calcium (AVC) load measurements by multidetector row computed tomography (MDCT), to evaluate the impact of tube potential and slice thickness on AVC scores, to examine the accuracy of AVC load in distinguishing severe from nonsevere aortic stenosis (AS) and to investigate its effectiveness as an alternative diagnosis method when echocardiography remains inconclusive. MethodsWe prospectively studied 266 consecutive patients with moderate to severe AS who underwent MDCT to measure AVC load and a comprehensive echocardiographic examination to assess AS severity. AVC load was validated against valve weight in 57 patients undergoing aortic valve replacement. The dependence of AVC scores on tube potential and slice thickness was also tested, as well as the relationship between AVC load and echocardiographic criteria of AS severity. ResultsMDCT Agatston score correlated well with valve weight (r = 0.82, p < 0.001) and hemodynamic indices of AS severity (all p < 0.001). Ex-vivo Agatston scores decreased significantly with increasing tube potential and slice thickness (repeated measures ANOVA p < 0.001). Multivariate analysis identified mean gradient, the indexed effective orifice area, male gender and left ventricular outflow tract cross-sectional area as independent correlates of the in-vivo AVC load. ConclusionsMDCT-derived AVC load correlated well with valve weight and hemodynamic indices of AS severity. It also depends on tube potential and slice thickness, thus suggesting that these parameters should be standardized to optimize reproducibility and accuracy.