Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve Stenosis.

After 15 years of successive randomized, controlled trials, indications for transcatheter aortic valve replacement (TAVR) are rapidly expanding. In the coming years, this procedure could become the first line treatment for patients with a symptomatic severe aortic stenosis and a tricuspid aortic valve anatomy. However, randomized, controlled trials have excluded bicuspid aortic valve (BAV), which is the most frequent congenital heart disease occurring in 1% to 2% of the total population and representing at least 25% of patients 80 years of age or older referred for aortic valve replacement. The use of a less invasive transcatheter therapy in this elderly population became rapidly attractive, and approximately 10% of patients currently undergoing TAVR have a BAV. The U.S. Food and Drug Administration and the "European Conformity" have approved TAVR for low-risk patients regardless of the aortic valve anatomy whereas international guidelines recommend surgical replacement in BAV populations. Given this progressive expansion of TAVR toward younger and lower-risk patients, heart teams are encountering BAV patients more frequently, while the ability of this therapy to treat such a challenging anatomy remains uncertain. This review will address the singularity of BAV anatomy and associated technical challenges for the TAVR procedure. We will examine and summarize available clinical evidence and highlight critical knowledge gaps regarding TAVR utilization in BAV patients. We will provide a comprehensive overview of the role of computed tomography scans in the diagnosis, and classification of BAV and TAVR procedure planning. Overall, we will offer an integrated framework for understanding the current role of TAVR in the treatment of bicuspid aortic stenosis and for guiding physicians in clinical decision-making.

Accuracy of stroke volume measurement with phase-contrast cardiovascular magnetic resonance in patients with aortic stenosis.

BACKGROUND: Phase contrast (PC) cardiovascular magnetic resonance (CMR) in the ascending aorta (AAo) is widely used to calculate left ventricular (LV) stroke volume (SV). The accuracy of PC CMR may be altered by turbulent flow. Measurement of SV at another site is suggested in the presence of aortic stenosis, but very few data validates the accuracy or inaccuracy of PC in that setting. Our objective is to compare flow measurements obtained in the AAo and LV outflow tract (LVOT) in patients with aortic stenosis. METHODS: Retrospective analysis of patients with aortic stenosis who had CMR and echocardiography. Patients with mitral regurgitation were excluded. PC in the AAo and LVOT were acquired to derive SV. LV SV from end-systolic and end-diastolic tracings was used as the reference measure. A difference ≥ 10% between the volumetric method and PC derived SVs was considered discordant. Metrics of turbulence and jet eccentricity were assessed to explore the predictors of discordant measurements. RESULTS: We included 88 patients, 41% with bicuspid aortic valve. LVOT SV was concordant with the volumetric method in 79 (90%) patients vs 52 (59%) patients for AAo SV (p = 0.015). In multivariate analysis, aortic stenosis flow jet angle was a strong predictor of discordant measurement in the AAo (p = 0.003). Mathematical correction for the jet angle improved the concordance from 59 to 91%. Concordance was comparable in patients with bicuspid and trileaflet valves (57% and 62% concordance respectively; p = 0.11). Accuracy of SV measured in the LVOT was not influenced by jet eccentricity. For aortic regurgitation quantification, PC in the AAo had better correlation to volumetric assessments than LVOT PC. CONCLUSION: LVOT PC SV in patients with aortic stenosis and eccentric jet might be more accurate compared to the AAo SV. Mathematical correction for the jet angle in the AAo might be another alternative to improve accuracy.

Blood, tissue and imaging biomarkers in calcific aortic valve stenosis: past, present and future.

PURPOSE OF REVIEW: Calcific aortic valve stenosis is the most prevalent valvular heart disease in the high-income countries. To this date, no medical therapy has been proven to prevent or to stop the progression of aortic valve stenosis. The physiopathology of aortic valve stenosis is highly complex and involves several signalling pathways, as well as genetic related factors, which delay the elaboration of effective pharmacotherapies. Moreover, it is difficult to predict accurately the progression of the valve stenosis and finding the optimal timing for aortic valve replacement remains challenging. Therefore, the present review makes an inventory of the most recent and promising circulating and imaging biomarkers related to the underlying mechanisms involved in the physiopathology of aortic valve stenosis, as well as the biomarkers associated with the left ventricular (LV) remodelling and subsequent dysfunction in patients with aortic valve stenosis. RECENT FINDINGS: Over the last decade, several blood, tissue and imaging biomarkers have been investigated in aortic valve stenosis patients. At the aortic valve level, these biomarkers are mostly associated and/or involved with processes such as lipid infiltration and oxidation, chronic inflammation and fibrocalcific remodelling of the valve. Moreover, recent findings suggest that aging and sex hormones might interact with these multiple processes. Several studies demonstrated the usefulness of circulating biomarkers such as lipoprotein(a), brain natriuretic peptides and high-sensitivity cardiac troponin, which are very close to clinical routine. Furthermore, noninvasive imaging biomarkers including positron emission tomography and cardiac magnetic resonance, which provide a detailed view of the disease activity within the aortic valve and its repercussion on the left ventricle, may help to improve the understanding of aortic valve stenosis physiopathology and enhance the risk stratification. Other biomarkers such as von Willebrand factor and microRNAs are promising but further studies are needed to prove their additive value in aortic valve stenosis. SUMMARY: Most of the biomarkers are used in research and thus, are still being investigated. However, some biomarkers including plasma level of lipoprotein(a), F-sodium fluoride, brain natriuretic peptides and high-sensitivity cardiac troponin can be or are very close to be used for the clinical management of patients with aortic valve stenosis. Moreover, a multibiomarker approach might provide a more global view of the disease activity and improve the management strategies of these patients.

Effect of race on pressure recovery adjustment for prevention of aortic stenosis grading discordance.

OBJECTIVE: We sought to evaluate the potential impact of racial difference (Asians vs Caucasians) on the clinical usefulness of pressure recovery (PR) adjustment for preventing discordant aortic stenosis (AS) grading in patients with severe AS. METHODS: Data from 1450 patients (mean age, 70.2±10.6 years; 290 (20%) Caucasians; aortic valve area (AVA), 0.77±0.26 cm2) were retrospectively analysed. PR-adjusted AVA was calculated using a validated equation. Discordant grading of severe AS was defined as AVA of <1.0 cm2 and mean gradient of <40 mm Hg. The frequency of discordant grading was assessed in the overall cohort and the propensity score-matched cohort. RESULTS: Before PR adjustment, 1186 patients showed AVA values of <1.0 cm2; after PR adjustment, 170 (14.3%) were reclassified as having moderate AS. PR adjustment decreased the frequency of discordant grading from 31.4% to 14.1% in Caucasians and from 13.8% to 7.9% in Asians. Patients with reclassification to moderate AS after PR adjustment had a significantly lower risk of a composite of aortic valve replacement or all-cause death than did those with severe AS after PR adjustment (HR 0.38; 95% CI 0.31-0.46; p<0.001). In propensity score-matched cohorts (173 pairs), the frequency of discordant grading before PR adjustment was 42.2% and 43.9% in the Caucasian and Asian patients, respectively, which decreased to 21.4% and 20.2%, respectively, after PR adjustment. CONCLUSIONS: Clinically relevant PR occurred, regardless of race in patients with moderate to severe AS. Routine PR adjustment may be useful for reconciling discordant AS grading.

Prevalence and Prognostic Implications of Moderate or Severe Mitral Regurgitation in Patients with Bicuspid Aortic Valve.

BACKGROUND: Significant (moderate or greater) mitral regurgitation (MR) could augment the hemodynamic effects of aortic valvular disease in patients with bicuspid aortic valve (BAV), imposing a greater hemodynamic burden on the left ventricle and atrium, possibly culminating in a faster onset of left ventricular dilation and/or symptoms. The aim of this study was to determine the prevalence and prognostic implications of significant MR in patients with BAV. METHODS: In this large, multicenter, international registry, a total of 2,932 patients (mean age, 48 ± 18 years; 71% men) with BAV were identified. All patients were evaluated for the presence of significant primary or secondary MR by transthoracic echocardiography and were followed up for the end points of all-cause mortality and event-free survival. RESULTS: Overall, 147 patients (5.0%) had significant primary (1.5%) or secondary (3.5%) MR. Significant MR was associated with all-cause mortality (hazard ratio [HR], 2.80; 95% CI, 1.91-4.11; P < .001) and reduced event-free survival (HR, 1.97; 95% CI, 1.58-2.46; P < .001) on univariable analysis. MR was not associated with all-cause mortality (adjusted HR, 1.33; 95% CI, 0.85-2.07; P = .21) or event-free survival (adjusted HR, 1.10; 95% CI, 0.85-1.42; P = .49) after multivariable adjustment. However, sensitivity analyses demonstrated that significant MR not due to aortic valve disease retained an independent association with mortality (adjusted HR, 1.81; 95% CI, 1.04-3.15; P = .037). Subgroup analyses demonstrated an independent association between significant MR and all-cause mortality for individuals with significant aortic regurgitation (HR, 2.037; 95% CI, 1.025-4.049; P = .042), although this association was not observed for subgroups with significant aortic stenosis or without significant aortic valve dysfunction. CONCLUSIONS: Significant MR is uncommon in patients with BAV. Following adjustment for important confounding variables, significant MR was not associated with adverse prognosis in this large study of patients with BAV, except for the patient subgroup with moderate to severe aortic regurgitation. In addition, significant MR not due to aortic valve disease demonstrated an independent association with all-cause mortality.

Determinants of Aortic Stenosis Progression in Bicuspid and Tricuspid Aortic Valves.

Background: Bicuspid aortic valve (BAV) is associated with a faster progression of aortic stenosis (AS). Whether the determinants of AS progression are the same or different in patients with BAV vs tricuspid aortic valve (TAV) is unknown. The aim of this study was to identify the factors associated with the progression of AS in patients with BAV vs patients with TAV. Methods: Patients with AS were prospectively recruited in the Metabolic Determinants of the Progression of Aortic Stenosis (PROGRESSA) study (ClinicalTrials.gov Identifier: NCT01679431). The haemodynamic progression rate of AS was assessed by the annualized progression rate of peak aortic jet velocity (Vpeak). Univariable and multivariable linear regression analyses were used to identify the factors associated with a faster progression of AS in patients with BAV vs patients with TAV. Results: There were 79 patients with BAV and 208 patients with TAV. The baseline severity of AS was similar between the 2 groups of patients as well as the annualized progression rate of AS. In patients with BAV, obesity (ß = 0.25, P = 0.04), diabetes (ß = 0.26, P = 0.02), and BAV with right-noncoronary cusp fusion (ß = 0.29, P = 0.01) were found to be independently associated with a faster progression of AS, whereas in patients with TAV, AS baseline severity (baseline Vpeak, ß = 0.14, P = 0.04) and chronic kidney disease (ß = 0.16, P = 0.02) were significantly associated with AS progression. Conclusion: Factors associated with progression rate of AS are different in BAV and TAV. The main factors associated with a faster progression of AS appear to be obesity, diabetes, right-noncoronary cusp fusion in patients with BAV vs chronic kidney disease in patients with TAV.

Contexte: La bicuspidie valvulaire aortique (BVA) est associée à une progression plus rapide de la sténose aortique (SA). On ignore toutefois si les facteurs en cause dans la progression de la SA sont les mêmes chez les patients qui présentent une BVA et chez ceux qui présentent une valve aortique tricuspide. Le but de cette étude était de déterminer les facteurs associés à la progression de la SA chez les patients présentant une BVA par rapport à ceux ayant une valve aortique tricuspide. Méthodologie: Des patients présentant une SA ont été recrutés dans l'étude PROGRESSA (Metabolic Determinants of the Progression of Aortic Stenosis), une étude prospective sur les déterminants métaboliques de la progression de la SA (ClinicalTrials.gov : NCT01679431). Pour calculer le taux de progression hémodynamique de la SA, on a utilisé les mesures annualisées de la vélocité maximale du jet transaortique (Vmax). Des analyses de régression linéaire univariées et multivariées ont permis de mettre en évidence les facteurs associés à une progression plus rapide de la SA en présence d'une BVA par rapport à une valve aortique tricuspide. Résultats: Parmi les patients évalués, 79 présentaient une BVA et 208, une valve aortique tricuspide. La gravité de la SA au départ était comparable entre les deux groupes de patients, tout comme le taux de progression annualisé de la SA. Chez les patients avec BVA, l'obésité (ß = 0,25, P = 0,04), le diabète (ß = 0,26, P = 0,02) et la BVA avec fusion des feuillets coronaire droit et non coronaire (ß = 0,29, P = 0,01) ont été associés de manière indépendante à une progression plus rapide de la SA, tandis que chez les patients ayant une valve tricuspide, la gravité de la SA au départ (Vmax initiale, ß = 0,14, P = 0,04) et la présence d'une néphropathie chronique (ß = 0,16, P = 0,02) ont été significativement associées à une progression de la SA. Conclusion: Les facteurs associés au taux de progression de la SA sont différents selon qu'il y a ou non présence d'une BVA. Les principaux facteurs associés à une progression plus rapide de la SA semblent être l'obésité, le diabète et la fusion des feuillets coronaire droit et non coronaire pour la BVA, tandis que la néphropathie chronique serait le facteur aggravant chez les patients présentant une valve aortique tricuspide.

Impact of sex and sex hormones on pathophysiology and progression of aortic stenosis in a murine model.

The lesions observed in AS have been shown to be sex specific, with women presenting extensive fibrotic remodeling while men developing more calcification deposit. We thus aimed to evaluate the influence of sex and sex hormones on the pathophysiology of aortic valve stenosis (AS) in our mouse model of AS. LDLr-/- ApoB100/100 IGF-II+/- mice (n = 210) were separated in six different groups: (1) intact male (IM), (2) intact female (IF), (3) castrated male (CM), (4) ovariectomized females (OF), (5) CM with testosterone supplementation (CMT), and (6) OF with 17ß-estradiol supplementation (OFE). Mice were fed a high-fat/high-sucrose/high-cholesterol diet for 6 months. Hemodynamic progression of AS was followed by transthoracic echocardiography (at 12 and 36 weeks) and analyzed in all mice alive at 36 weeks. Aortic valves were collected for histological and digital droplet PCR* analysis. Increases in peak velocity were comparable in IF and IM (24.2 ± 5.7 vs. 25.8 ± 5.3 cm/s; p = 0.68), but IF presented with less severe AS. Between the three groups of male mice, AS progression was more important in IM (increase in peak velocity: 24.2 ± 5.7 cm/s; p < 0.001) compared to CM (6.2 ± 1.4; p = 0.42), and CMT (15.1 ± 3.5; p = 0.002). In the three groups of female mice, there were no statistical differences in AS progression. Digital PCR analysis revealed an important upregulation of the osteogenic gene RunX2 in IM (p < 0.0001) and downregulation of the pro-calcifying gene ALPL in IF (p < 0.05). Male sex and testosterone play an important role in upregulation of pro-calcifying genes and hemodynamic progression of AS. However, female mice appeared to be protected against calcification, characterized by downregulation of pro-osteogenic genes, but presented a similar AS hemodynamic progression.

Validation of aortic valve calcium quantification thresholds measured by computed tomography in Asian patients with calcific aortic stenosis.

AIMS: Sex-specific thresholds of aortic valve calcification (AVC) have been proposed and validated in Caucasians. Thus, we aimed to validate their accuracy in Asians. METHODS AND RESULTS: Patients with calcific aortic stenosis (AS) from seven international centres were included. Exclusion criteria were ≥moderate aortic/mitral regurgitation and bicuspid valve. Optimal AVC and AVC-density sex-specific thresholds for severe AS were obtained in concordant grading and normal flow patients (CG/NF). We included 1263 patients [728 (57%) Asians, 573 (45%) women, 837 (66%) with CG/NF]. Mean gradient was 48 (26-64) mmHg and peak aortic velocity 4.5 (3.4-5.1) m/s. Optimal AVC thresholds were: 2145 Agatston Units (AU) in men and 1301 AU in women for Asians; and 1885 AU in men and 1129 AU in women for Caucasians. Overall, accuracy (% correctly classified) was high and comparable either using optimal or guidelines' thresholds (2000 AU in men, 1200 AU in women). However, accuracy was lower in Asian women vs. Caucasian women (76-78% vs. 94-95%; P < 0.001). Accuracy of AVC-density (476 AU/cm2 in men and 292 AU/cm2 in women) was comparable to absolute AVC in Caucasians (91% vs. 91%, respectively, P = 0.74), but higher than absolute AVC in Asians (87% vs. 81%, P < 0.001). There was no interaction between AVC/AVC-density and ethnicity (all P > 0.41) with regards to AS haemodynamic severity. CONCLUSION: AVC thresholds defining severe AS are comparable in Asian and Caucasian populations, and similar to those proposed in the guidelines. However, accuracy of AVC to identify severe AS in Asians (especially women) is sub-optimal. Therefore, the use of AVC-density is preferable in Asians.

Computed Tomography Aortic Valve Calcium Scoring in Patients With Bicuspid Aortic Valve Stenosis.

Background: Sex-specific thresholds of computed tomography (CT)-derived aortic valve calcification (AVC) or AVC density (AVCd) to identify severe aortic stenosis (AS) have been established in populations that consisted mainly of Caucasians with a tricuspid aortic valve. The objective of this study was to evaluate the accuracy (i.e., sensitivity and specificity) of previously established thresholds to identify severe AS in patients with bicuspid aortic valve (BAV) and according to ethnicity: Caucasian vs. Asian. Methods: We built a multicenter registry of echocardiographic and CT data collected in BAV patients with at least mild AS and preserved left ventricular ejection fraction from 7 different centers. Anatomic severity of AS obtained by CT-derived AVC and AVCd was compared to hemodynamic severity of AS obtained by echocardiography. Results: Among 485 BAV patients (60% men, 73% Asians), the best thresholds of AVC and AVCd to identify severe AS in BAV patients were 2315 arbitrary units (AU) (sensitivity [Se]/specificity [Spe] = 82/78%) in men, 1103 AU (Se/Spe = 80/82%) in women, and 561 AU/cm2 (Se/Spe = 86/91%) in men, and 301 AU/cm2 (Se/Spe = 83/82%) in women, respectively. According to ethnicity, thresholds for severe AS in Caucasian patients were, respectively, in men and women: 2208 AU (Se/Spe = 83/83%) and 1230 AU (Se/Spe = 87/82%) for AVC and 474 AU/cm2 (Se/Spe = 88/83%) and 358 AU/cm2 (Se/Spe = 80/82%) for AVCd. In Asian patients, they were 2582 AU (Se/Spe = 76/78%) and 924 AU (Se/Spe = 84/80%) for AVC and 640 AU/cm2 (Se/Spe = 82/89%) and 255 AU/cm2 (Se/Spe = 86/80%) for AVCd. Conclusions: The optimal thresholds to identify hemodynamically severe AS in BAV patients are similar in Caucasians but appear to be higher in Asian men, compared with thresholds previously reported in tricuspid aortic valve patients. Nonetheless, the thresholds currently proposed in the guidelines have good accuracy and can be applied in BAV patients to confirm AS severity.

Left ventricular remodelling in bicuspid aortic valve disease.

AIMS: Characterization of left ventricular (LV) geometric pattern and LV mass could provide an important insight into the pathophysiological adaptations of the LV to pressure and/or volume overload in patients with bicuspid aortic valve (BAV) and significant (≥moderate) aortic valve (AV) disease. This study aimed to characterize LV remodelling and its prognostic impact in patients with BAV according to the predominant type of valvular dysfunction. METHODS AND RESULTS: In this international, multicentre BAV registry, 1345 patients [51.0 (37.0-63.0) years, 71% male] with significant AV disease were identified. Patients were classified as having isolated aortic stenosis (AS) (n = 669), isolated aortic regurgitation (AR) (n = 499) or mixed aortic valve disease (MAVD) (n = 177). LV hypertrophy was defined as a LV mass index >115 g/m2 in males and >95 g/m2 in females. LV geometric pattern was classified as (i) normal geometry: no LV hypertrophy, relative wall thickness (RWT) ≤0.42, (ii) concentric remodelling: no LV hypertrophy, RWT >0.42, (iii) concentric hypertrophy: LV hypertrophy, RWT >0.42, and (iv) eccentric hypertrophy: LV hypertrophy, RWT ≤0.42. Patients were followed-up for the endpoints of event-free survival (defined as a composite of AV repair/replacement and all-cause mortality) and all-cause mortality. Type of AV dysfunction was related to significant variations in LV remodelling. Higher LV mass index, i.e. LV hypertrophy, was independently associated with the composite endpoint for patients with isolated AS [hazard ratio (HR) 1.08 per 25 g/m2, 95% confidence interval (CI) 1.00-1.17, P = 0.046] and AR (HR 1.19 per 25 g/m2, 95% CI 1.11-1.29, P < 0.001), but not for those with MAVD. The presence of concentric remodelling, concentric hypertrophy and eccentric hypertrophy were independently related to the composite endpoint in patients with isolated AS (HR 1.54, 95% CI 1.06-2.23, P = 0.024; HR 1.68, 95% CI 1.17-2.42, P = 0.005; HR 1.59, 95% CI 1.03-2.45, P = 0.038, respectively), while concentric hypertrophy and eccentric hypertrophy were independently associated with the combined endpoint for those with isolated AR (HR 2.49, 95% CI 1.35-4.60, P = 0.004 and HR 3.05, 95% CI 1.71-5.45, P < 0.001, respectively). There was no independent association observed between LV remodelling and the combined endpoint for patients with MAVD. CONCLUSIONS: LV hypertrophy or remodelling were independently associated with the composite endpoint of AV repair/replacement and all-cause mortality for patients with isolated AS and isolated AR, although not for patients with MAVD.

Prognostic implications of left atrial dilation in aortic regurgitation due to bicuspid aortic valve.

OBJECTIVE: To investigate the prognostic value of left atrial volume index (LAVI) in patients with moderate to severe aortic regurgitation (AR) and bicuspid aortic valve (BAV). METHODS: 554 individuals (45 (IQR 33-57) years, 80% male) with BAV and moderate or severe AR were selected from an international, multicentre registry. The association between LAVI and the combined endpoint of all-cause mortality or aortic valve surgery was investigated with Cox proportional hazard regression analyses. RESULTS: Dilated LAVI was observed in 181 (32.7%) patients. The mean indexed aortic annulus, sinus of Valsalva, sinotubular junction and ascending aorta diameters were 13.0±2.0 mm/m2, 19.4±3.7 mm/m2, 16.5±3.8 mm/m2 and 20.4±4.5 mm/m2, respectively. After a median follow-up of 23 (4-82) months, 272 patients underwent aortic valve surgery (89%) or died (11%). When compared with patients with normal LAVI (<35 mL/m2), those with a dilated LAVI (≥35 mL/m2) had significantly higher rates of aortic valve surgery or mortality (43% and 60% vs 23% and 36%, at 1 and 5 years of follow-up, respectively, p<0.001). Dilated LAVI was independently associated with reduced event-free survival (HR=1.450, 95% CI 1.085 to 1.938, p=0.012) after adjustment for LV ejection fraction, aortic root diameter, LV end-diastolic diameter and LV end-systolic diameter. CONCLUSIONS: In this large, multicentre registry of patients with BAV and moderate to severe AR, left atrial dilation was independently associated with reduced event-free survival. The role of this parameter for the risk stratification of individuals with significant AR merits further investigation.

Impact of Left Ventricular Ejection Fraction on Clinical Outcomes in Bicuspid Aortic Valve Disease.

BACKGROUND: The prognostic impact of left ventricular ejection fraction (LVEF) in patients with bicuspid aortic valve (BAV) disease has not been previously studied. OBJECTIVES: The purpose of this study was to determine the prognostic impact of LVEF in BAV patients according to the type of aortic valve dysfunction. METHODS: We retrospectively analyzed the data collected in 2,672 patients included in an international registry of patients with BAV. Patients were classified according to the type of aortic valve dysfunction: isolated aortic stenosis (AS) (n = 749), isolated aortic regurgitation (AR) (n = 554), mixed aortic valve disease (MAVD) (n = 190), or no significant aortic valve dysfunction (n = 1,179; excluded from this analysis). The study population was divided according to LVEF strata to investigate its impact on clinical outcomes. RESULTS: The risk of all-cause mortality and the composite endpoint of aortic valve replacement or repair (AVR) and all-cause mortality increased when LVEF was <60% in the whole cohort as well as in the AS and AR groups, and when LVEF was <55% in MAVD group. In multivariable analysis, LVEF strata were significantly associated with increased rate of mortality (LVEF 50%-59%: HR: 1.83 [95% CI: 1.09-3.07]; P = 0.022; LVEF 30%-49%: HR: 1.97 [95% CI: 1.13-3.41]; P = 0.016; LVEF <30%: HR: 4.20 [95% CI: 2.01-8.75]; P < 0.001; vs LVEF 60%-70%, reference group). CONCLUSIONS: In BAV patients, the risk of adverse clinical outcomes increases significantly when the LVEF is <60%. These findings suggest that LVEF cutoff values proposed in the guidelines to indicate intervention should be raised from 50% to 60% in AS or AR and 55% in MAVD.

Left ventricular asymmetric remodeling and subclinical left ventricular dysfunction in patients with calcific aortic valve stenosis - Results from a subanalysis of the PROGRESSA study.

BACKGROUND: LV asymmetric remodeling (LVAR) is a feature commonly found in AS patients and it is presumed to be mainly related to the severity of valve stenosis. The aim of this study was to determine the associated factors and impact on left ventricular (LV) systolic function of LVAR in patients with mild and moderate aortic valve stenosis (AS). METHODS: Clinical, Doppler-echocardiographic and computed-tomographic data of 155 AS patients with preserved LV ejection fraction (≥50%) prospectively recruited in the PROGRESSA study (NCT01679431) were analyzed. LVAR was defined as a septal wall thickness ≥ 13 mm and a ratio of septal/posterior wall thickness > 1.5. LV global longitudinal strain (LV-GLS) was available in 129 patients. Plasma levels of N-terminal natriuretic B-type peptides (Nt-proBNP) were also measured. RESULTS: Mean age was 63 ± 15 years (70% men). LVAR was present in 21% (n = 33) of patients. A series of nested multivariate analysis revealed that age was the only factor associated with LVAR (all p ≤ 0.03). Additionally, these patients had higher baseline Nt-proBNP ratio (median [25-75 percentiles]: 1.04 [0.66-2.41] vs. 0.65 [0.33-1.19], p = 0.02), and significantly reduced LV-GLS (17.9[16.6-19.5] vs. 19.3[17.4-20.7] |%|, p = 0.04). A 1:1 matched analysis showed a significant association of LVAR with reduced LV-GLS (17.9[16.6-19.5] vs. 19.8[18.1-20.7] |%|, p = 0.02) and elevated Nt-proBNP (134[86-348] vs. 83[50-179]pg/ml, p = 0.03). Multivariable analysis also revealed that LVAR remains significantly associated with reduced LV-GLS (p = 0.03) and elevated Nt-proBNP (p = 0.001). LVAR was significantly associated with increased risk of major adverse cardiac events and death (Hazard ratio [95% confidence interval]: 2.32[1.28-4.22], p = 0.006). CONCLUSIONS: LVAR was found in ~20% of patients with mild or moderate AS and was not related to the degree of AS severity or concomitant comorbidities, but rather to older age. LVAR was significantly associated with reduced LV longitudinal systolic function, increased Nt-proBNP levels, and higher risk of major adverse events and death. These findings provide support for closer clinical and echocardiographic surveillance of patients harboring this adverse LV remodeling feature.

Effect of Regional Upper Septal Hypertrophy on Echocardiographic Assessment of Left Ventricular Mass and Remodeling in Aortic Stenosis.

BACKGROUND: Transthoracic echocardiography (TTE) is the reference method for evaluation of aortic stenosis (AS), and it is extensively used to quantitate left ventricular (LV) mass and volumes. Regional upper septal hypertrophy (USH) or septal bulge is a frequent finding in patients with AS and may lead to overestimation of LV mass when using linear measurements. The objective of this study was to compare estimates of LV mass obtained by two-dimensional transthoracic echocardiographic LV dimensions measured at different levels of the LV cavity with those obtained by cardiovascular magnetic resonance (CMR). METHODS: One hundred six patients (mean age, 63 ± 15 years; 68% men) with AS were included in this subanalysis of the PROGRESSA study. Two-dimensional transthoracic echocardiographic measurements of LV dimensions were obtained at the basal level (BL; as recommended in guidelines), immediately below the septal bulge (BSB), and at a midventricular level (ML). Regional USH was defined as a basal interventricular septal thickness ≥ 13 mm and >1.3 times the thickness of the septal wall at the ML. Agreement between transthoracic echocardiographic and CMR measures was evaluated using Bland-Altman analysis. RESULTS: The distribution of AS severity was mild in 23%, moderate in 57%, and severe in 20% of patients. Regional USH was present in 28 patients (26%). In the whole cohort, two-dimensional TTE overestimated LV mass (bias: BL, +60 ± 31 g; BSB, +59 ± 32 g; ML, +54 ± 32 g; P = .02). The biplane Simpson method slightly but significantly underestimated LV end-diastolic volume (bias -10 ± 20 mL, P < .001) compared with CMR. Overestimation of LV mass was more marked in patients with USH when measuring at the BL and was significantly lower when measuring LV dimensions at the ML (P < .025 vs BL and BSB). CONCLUSIONS: Two-dimensional TTE systematically overestimated LV mass and underestimated LV volumes compared with CMR. However, the bias between TTE and CMR was less important when measuring at the ML. Measurements at the BL as suggested in guidelines should be avoided, and measurements at the ML should be preferred in patients with AS, especially in those with USH.

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

OBJECTIVES: The authors explored the development and validation of machine-learning models for augmenting the echocardiographic grading of aortic stenosis (AS) severity. BACKGROUND: In 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. METHODS: Using 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. RESULTS: In 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. CONCLUSIONS: Machine 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.

Effect of bicuspid aortic valve phenotype on progression of aortic stenosis.

AIMS: To compare the progression of aortic stenosis (AS) in patients with bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV). METHODS AND RESULTS: One hundred and forty-one patients with mild-to-moderate AS, recruited prospectively in the PROGRESSA study, were included in this sub-analysis. Baseline clinical, Doppler echocardiography and multidetector computed tomography characteristics were compared between BAV (n = 32) and TAV (n = 109) patients. The 2-year haemodynamic [i.e. peak aortic jet velocity (Vpeak) and mean transvalvular gradient (MG)] and anatomic [i.e. aortic valve calcification density (AVCd) and aortic valve calcification density ratio (AVCd ratio)] progression of AS were compared between the two valve phenotypes. The 2-year progression rate of Vpeak was: 16 (-0 to 40) vs. 17 (3-35) cm/s, P = 0.95; of MG was: 1.8 (-0.7 to 5.8) vs. 2.6 (0.4-4.8) mmHg, P = 0.56; of AVCd was 32 (2-109) vs. 52 (25-85) AU/cm2, P = 0.15; and of AVCd ratio was: 0.08 (0.01-0.23) vs. 0.12 (0.06-0.18), P = 0.16 in patients with BAV vs. TAV. In univariable analyses, BAV was not associated with AS progression (all, P ≥ 0.26). However, with further adjustment for age, AS baseline severity, and several risk factors (i.e. sex, history of hypertension, creatinine level, diabetes, metabolic syndrome), BAV was independently associated with faster haemodynamic (Vpeak: ß = 0.31, P = 0.02) and anatomic (AVCd: ß = 0.26, P = 0.03 and AVCd ratio: ß = 0.26, P = 0.03) progression of AS. CONCLUSION: In patients with mild-to-moderate AS, patients with BAV have faster haemodynamic and anatomic progression of AS when compared to TAV patients with similar age and risk profile. This study highlights the importance and necessity to closely monitor patients with BAV and to adequately control and treat their risk factors. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov Unique identifier: NCT01679431.

Age, Sex, and Valve Phenotype Differences in Fibro-Calcific Remodeling of Calcified Aortic Valve.

Background In calcific aortic valve disease on tricuspid aortic valves (TAVs), men have higher aortic valve calcification and less fibrosis than women. However, little is known in bicuspid aortic valves (BAV). We thus aimed to investigate the impact of age, sex, and valve phenotype (TAVs versus BAVs) on fibro-calcific remodeling in calcific aortic valve disease. Methods and Results We included 2 cohorts: 411 patients who underwent multidetector computed tomography (37% women) for aortic valve calcification density assessment and 138 explanted aortic valves (histological cohort; 50% women). The cohorts were divided in younger (<60 years old) or older patients with BAV (≥60 years old), and TAV patients. In each group, women and men were matched. Women presented less aortic valve calcification density than men in each group of the multidetector computed tomography cohort (all P≤0.01). Moreover, in women, younger patients with BAV had the lowest aortic valve calcification density (both P=0.02). In multivariate analysis, aortic valve calcification density correlated with age (ß estimate±standard error: 6.5±1.8; P=0.0004) and male sex (109.2±18.4; P<0.0001), and there was a trend with TAVs (41.5±23.0; P=0.07). Women presented a higher collagen content than men (77.8±10.8 versus 69.9±12.9%; P<0.001) in the entire cohort. In women, younger patients with BAV had denser connective tissue than TAV and older patients with BAV (both P≤0.05), while no difference was observed between men. Conclusions In calcific aortic valve disease, women had less calcification and more fibrotic remodeling than men, regardless of the phenotype of the valve or age of the patient. Moreover, younger women with BAVs had less valve calcification. Thus, mineralization/fibrosis of the aortic valve is likely to have sex/age-specific mechanisms and be influenced by the valve morphology.

Sex-differences in echocardiographic assessment of aortic valve in young adult LDLr-/-/ApoB100/100/IGF-II+/- mice.

BACKGROUND: LDLr-/-/ApoB100/100/IGF-II+/- mice are used as a calcific aortic valve disease (CAVD) model. However, normal aortic valve hemodynamics i.e. remotely from CAVD onset and the sex-related differences are poorly known. METHODS AND RESULTS: Four groups of mice, intact males (IM, n = 49) and females (IF, n = 50), castrated males (CxM, n = 79) and ovariectomized females (OxF: 73), underwent a Doppler-echocardiography at 12 weeks of age. Gonadectomy was performed at 8 weeks. Aortic valve assessment using effective orifice area (EOA, using the continuity equation) and peak aortic transvalvular velocity (VPeak) was feasible in 89% of the mice with good to excellent reliability (intraclass correlation coefficients ranging from 0.90 to 0.98, p < 0.001). Mean VPeak was 104 ± 17 cm/s and mean EOA was 1.18*10-2 ± 0.22*10-2 cm2. EOA indexed to body surface area was 1.5 ± 0.3 cm2/m2. The 95th percentile of Vpeak was 132 cm/s and the 5th percentile of indexed EOA was 1.0 cm2/m2. Interestingly, IM had the highest VPeak (114 ± 14 cm/s) vs each of the other groups (CxM: 106 ± 19 cm/s, OxF: 97 ± 13 cm/s and IF: 96 ± 12 cm/s, ANOVA and corrected p < 0.001). This was mostly explained by a higher stroke volume (ANOVA and corrected p < 0.001) in IM compared to other groups. There were no major sex-differences in ventricular systolic function parameters. CONCLUSION: In LDLr-/-/ApoB100/100/IGF-II CAVD mice model, an aortic EOA <0.8*10-2 cm2 (or indexed EOA <1.0cm2/m2), and a peak aortic valve velocity > 132 cm/s may be proposed as thresholds to define CAVD. Intact male mice appear to have higher velocities.

Sex-Related Differences in the Extent of Myocardial Fibrosis in Patients With Aortic Valve Stenosis.

OBJECTIVES: The aim of this study was to assess the effect of sex on myocardial fibrosis as assessed by using cardiac magnetic resonance (CMR) imaging in aortic stenosis (AS). BACKGROUND: Previous studies reported sex-related differences in the left ventricular (LV) remodeling response to pressure overload in AS. However, there are very few data regarding the effect of sex on myocardial fibrosis, a key marker of LV decompensation and adverse cardiac events in AS. METHODS: A total of 249 patients (mean age 66 ± 13 years; 30% women) with at least mild AS were recruited from 2 prospective observational cohort studies and underwent comprehensive Doppler echocardiography and CMR examinations. On CMR, T1 mapping was used to quantify extracellular volume (ECV) fraction as a marker of diffuse fibrosis, and late gadolinium enhancement (LGE) was used to assess focal fibrosis. RESULTS: There was no difference in age between women and men (age 66 ± 15 years vs 66 ± 12 years; p = 0.78). However, women presented with a better cardiovascular risk profile than men with less hypertension, dyslipidemia, diabetes, and coronary artery disease (all, p ≤ 0.10). As expected, LV mass index measured by CMR imaging was smaller in women than in men (p < 0.0001). Despite fewer comorbidities, women presented with larger ECV fraction (median: 29.0% [25th to 75th percentiles: 27.4% to 30.6%] vs. 26.8% [25th to 75th percentiles: 25.1% to 28.7%]; p < 0.0001) and similar LGE (median: 4.5% [25th-75th percentiles: 2.3% to 7.0%] vs. 2.8% [25th-75th percentiles: 0.6% to 6.8%]; p = 0.20) than men. In multivariable analysis, female sex remained an independent determinant of higher ECV fraction and LGE (all, p ≤ 0.05). CONCLUSIONS: Women have greater diffuse and focal myocardial fibrosis independent of the degree of AS severity. These findings further emphasize the sex-related differences in LV remodeling response to pressure overload.

Prognostic implications of left ventricular global longitudinal strain in patients with bicuspid aortic valve disease and preserved left ventricular ejection fraction.

AIMS: In patients with bicuspid aortic valve (BAV) and preserved left ventricular (LV) ejection fraction (EF), the frequency of impaired LV global longitudinal strain (GLS) and its prognostic implications are unknown. The present study evaluated the proportion and prognostic value of impaired LV GLS in patients with BAV and preserved LVEF. METHODS AND RESULTS: Five hundred and thirteen patients (68% men; mean age 44 ± 18 years) with BAV and preserved LVEF (>50%) were divided into five groups according to the type of BAV dysfunction: (i) normal function BAV, (ii) mild aortic stenosis (AS) or aortic regurgitation (AR), (iii) ≥moderate isolated AS, (iv) ≥moderate isolated AR, and (v) ≥moderate mixed AS and AR. LV systolic dysfunction based on 2D speckle-tracking echocardiography was defined as a cut-off value of LVGLS (-13.6%). The primary outcome was aortic valve intervention or all-cause mortality. The proportion of patients with LVGLS ≤-13.6% was the highest in the normal BAV group (97%) and the lowest in the group with moderate and severe mixed AS and AR (79%). During a median follow-up of 10 years, 210 (41%) patients underwent aortic valve replacement and 17 (3%) died. Patients with preserved LV systolic function (LVGLS ≤ -13.6%) had significantly better event-free survival compared to those with impaired LV systolic function (LVGLS > -13.6%). LVGLS was independently associated with increased risk of events (mainly aortic valve replacement): hazard ratio 1.09; P < 0.001. CONCLUSION: Impaired LVGLS in BAV with preserved LVEF is not infrequent and was independently associated with increased risk of events (mainly aortic valve replacement events).