Why and How to Measure Aortic Valve Calcification in Patients With Aortic Stenosis

Grading of Aortic Valve Calcification Severity and Risk Stratification in Aortic Stenosis

BACKGROUND

Thresholds of aortic valve calcification (AVC) to define hemodynamically moderate aortic stenosis (AS) from mild are lacking. We aimed to establish a novel grading classification of AVC as quantified by computed tomography and determine its prognostic value.

METHODS AND RESULTS

This study included 915 patients with at least mild AS (mean age 70±12 years, 30% women) from a multicenter prospective registry. All patients underwent Doppler-echocardiography and noncontrast computed tomography within 3 months. Primary end point was the occurrence of all-cause death. Receiver operating characteristic curves analyses were used to determine the sensitivity and specificity of sex-specific thresholds of AVC to identify hemodynamically moderate AS. Optimal thresholds (ie, with best sensitivity/specificity) of AVC to distinguish moderate (aortic valve area 1.0-1.5 cm2 and mean gradient 20-39 mm Hg) from mild AS (aortic valve area >1.5 cm2 and mean gradient <20 mm Hg) were AVC ≥360 arbitrary units in women and ≥1037 arbitrary units in men. Based on the guidelines' thresholds for severe AS and the new thresholds in our study for moderate AS, 312 (34%) patients had mild, 253 (28%) moderate, and 350 (38%) severe AVC. During a mean follow-up of 5.6±3.9 years, 183 (27%) deaths occurred. In Cox multivariable models, AVC remained associated with an increased risk of death (adjusted hazard ratio per grade increase, 1.94 [95% CI, 1.53-2.56]; P<0.001).

CONCLUSIONS

A novel grading classification of anatomic AS severity based on sex-specific thresholds of AVC provides significant prognostic value for predicting mortality. These findings support the complementarity of computed tomography-calcium scoring to Doppler-echocardiography to corroborate AS severity and enhance risk stratification in patients with AS.

Clinical impact of cardiovascular calcifications on stroke incidence in primary prevention: analysis in NADESICO study

The utility of assessment of cardiovascular calcifications for predicting stroke incidence remains unclear. This study assessed the relationship between cardiovascular calcifications including coronary artery calcification (CAC), aortic valve (AVC), and aortic root (ARC) assessed by coronary computed tomography (CT) and stroke incidence in patients with suspected CAD. In this multicenter prospective cohort study, 1187 patients suspected of CAD who underwent coronary CT were enrolled. Cardiovascular events including stroke were documented. Hazard ratio (HR) and confidence interval (CI) were assessed by Cox proportional hazard model adjusted for the Framingham risk score. C statistics for stroke incidence were also examined by models including cardiovascular calcifications. A total of 980 patients (mean age, 65 ± 7 years; females, 45.8%) were assessed by the CAC, AVC, and ARC Agatston scores. During a median follow-up of 4.0 years, 19 patients developed stroke. Cox proportional hazard model showed severe CAC (Agatston score ≥ 90th percentile [580.0 value]) and presence of AVC and ARC were associated with stroke incidence (HR; 10.33 [95% CI; 2.08-51.26], 3.08 [1.19-7.98], and 2.75 [1.03-7.30], respectively). C statistic in the model with CAC and AVC severity for predicting stroke incidence was 0.841 (95% CI; 0.761-0.920), which was superior to the model with CAC alone (0.762 [95% CI; 0.665-0.859], P < 0.01). CAC, AVC, and ARC were associated with stroke incidence in patients suspected of CAD. Assessment of both CAC and AVC may be useful for prediction of stroke incidence.

Multimodality Imaging in Aortic Stenosis: Beyond the Valve - Focusing on the Myocardium

Current guidelines of aortic stenosis (AS) management focus on valve parameters, LV systolic dysfunction, and symptoms; however, emerging data suggest that there may be benefit of aortic valve replacement before it becomes severe by present criteria. Myocardial assessment using novel multimodality imaging techniques exhibits subclinical myocardial injury and remodeling at various stages before guideline-directed interventions, which predicts adverse outcomes. This raises the question of whether implementing serial myocardial assessment should become part of the standard appraisal, thereby identifying high-risk patients aiming to minimize adverse outcomes.

Sex Differences in Aortic Stenosis: From the Pathophysiology to the Intervention, Current Challenges, and Future Perspectives

Calcific aortic stenosis (AS) is a major cause of morbidity and mortality in high-income countries. AS presents sex-specific features impacting pathophysiology, outcomes, and management strategies. In women, AS often manifests with a high valvular fibrotic burden, small valvular annuli, concentric left ventricular (LV) remodeling/hypertrophy, and, frequently, supernormal LV ejection fraction coupled with diastolic dysfunction. Paradoxical low-flow low-gradient AS epitomizes these traits, posing significant challenges post-aortic valve replacement due to limited positive remodeling and significant risk of patient-prosthesis mismatch. Conversely, men present more commonly with LV dilatation and dysfunction, indicating the phenotype of classical low-flow low-gradient AS, i.e., with decreased LV ejection fraction. However, these distinctions have not been fully incorporated into guidelines for AS management. The only treatment for AS is aortic valve replacement; women are frequently referred late, leading to increased heart damage caused by AS. Therefore, it is important to reassess surgical planning and timing to minimize irreversible cardiac damage in women. The integrity and the consideration of sex differences in the management of AS is critical. Further research, including sufficient representation of women, is needed to investigate these differences and to develop individualized, sex-specific management strategies.

Aortic Valve Calcium Score: Applications in Clinical Practice and Scientific Research-A Narrative Review

In this narrative review, we investigate the essential role played by the computed tomography Aortic Valve Calcium Score (AVCS) in the cardiovascular diagnostic landscape, with a special focus on its implications for clinical practice and scientific research. Calcific aortic valve stenosis is the most prevalent type of aortic stenosis (AS) in industrialized countries, and due to the aging population, its prevalence is increasing. While transthoracic echocardiography (TTE) remains the gold standard, AVCS stands out as an essential complementary tool in evaluating patients with AS. The advantage of AVCS is its independence from flow; this allows for a more precise evaluation of patients with discordant findings in TTE. Further clinical applications of AVCS include in the assessment of patients before transcatheter aortic valve replacement (TAVR), as it helps in predicting outcomes and provides prognostic information post-TAVR. Additionally, we describe different AVCS thresholds regarding gender and the anatomical variations of the aortic valve. Finally, we discuss various scientific studies where AVCS was applied. As AVCS has some limitations, due to the pathophysiologies of AS extending beyond calcification and gender differences, scientists strive to validate contrast-enhanced AVCS. Furthermore, research on developing radiation-free methods of measuring calcium content is ongoing.

The importance of MDCT in the evaluation of risk factors before the TAVI procedure and its complications after implantation

Transcatheter aortic valve implantation (TAVI) is the alternative to surgical valve replacement, expanding its indications in the latest guidelines. Multimodal CT (MDCT) is essential in patient selection and detection of complications. Vascular complications are frequent, so it is important to analyse the anatomy of the vessels before the procedure. Regarding annular ruptures and ventricular perforations, the volume and distribution of calcium and the ventricular diameter play an important role. Finally, valve migration is a rare complication that can occur both during and after TAVI. Proper planning of the MDCT procedure reduces the risk of complications and gives the interventional cardiologist security both before and during the procedure.

Reproducibility of semi-quantitative assessment of aortic valve calcification and valve motion on echocardiography: a small-scale study

BACKGROUND

Aortic stenosis (AS) is the most common degenerative valve disease in high income countries. While hemodynamic metrics are commonly used to assess severity of stenosis, they are impacted by loading conditions and stroke volume and are often discordant. Anatomic valve assessments such as aortic valve calcification (AVC) and valve motion (VM) during transthoracic echocardiography (TTE) can offer clues to disease severity. The reliability of these semi-quantitatively assessed anatomic imaging parameters is unknown.

METHODS

This is a retrospective study of semi-quantitative assessment of AVC and valve VM on TTE. TTEs representing a range of AS severities were identified. The degree of calcification of the aortic valve and the degree of restricted VM were assessed in standard fashion. AVC scores and valve motion were assessed by readers with varied training levels blinded to the severity of AS. Correlation and inter-reader reliability between readers were assessed.

RESULTS

420 assessments (210 each for AVC and VM) were collected for 35 TTEs. Correlation of AVC for imaging trainees (fellows and students, respectively), ranged from 0.49 (95% CI 0.18-0.70) to 0.62 (95% CI 0.36-0.79) and 0.58 (95% CI 0.30-0.76) to 0.54 (95% CI 0.25-0.74) for VM. Correlation of anatomic assessments between echocardiographer-assigned AVC grades was r = 0.76 (95% CI 0.57-0.87)). The correlation between echocardiographer-assigned assessment of VM was r = 0.73 (95% CI 0.53-0.86), p < 0.00001 for both. For echocardiographer AVC assessment, weighted kappa was 0.52 (0.32-0.72), valve motion weighted kappa was 0.60 (0.42-0.78).

CONCLUSION

There was good inter-reader correlation between TTE-based semi-quantitative assessment of AVC and VM when assessed by board certified echocardiographers. There was modest inter-reader reliability of semi-quantitative assessments of AVC and VM between board certified echocardiographers. Inter-reader correlation and reliability between imaging trainees was lower. More reliable methods to assess TTE based anatomic assessments are needed in order to accurately track disease progression.

CLINICAL TRIAL NUMBER

STUDY00003100.

Predominant determinants for evaluation of right parasternal approach in transthoracic echocardiography in aortic stenosis: a study based on three-dimensional cardiac computed tomography analysis

The maximum blood flow velocity through the aortic valve (AVmax) using Doppler transthoracic echocardiography (TTE) is important in assessing the severity of aortic stenosis (AS). The right parasternal (RP) approach has been reported to be more useful than the apical approach, but the anatomical rationale has not been studied. We aimed to clarify the influence of the angle formed by the ascending aorta and left ventricle on Doppler analysis by TTE (Sep-Ao angle) and three-dimensional multidetector computed tomography (3D-MDCT) in patients with AS. A total of 151 patients evaluated using the RP approach and 3D-MDCT were included in this study. The Sep-Ao angle determined using TTE was compared with that determined using 3D-MDCT analysis. In MDCT analysis, the left ventricular (LV) axis was measured in two ways and the calcification score was calculated simultaneously. The Sep-Ao angle on TTE was consistent with that measured using 3D-MDCT. In patients with an acute Sep-Ao angle, the Doppler angle in the apical approach was larger, potentially underestimating AVmax. Multivariate analysis revealed that an acute Sep-Ao angle, large Doppler angle in the apical approach, smaller Doppler angle in the RP approach, and low aortic valve calcification were independently associated with a higher AVmax in the RP approach than in the apical approach. The Sep-Ao angle measured using TTE reflected the 3D anatomical angle. In addition to measurements using the RP approach, technical adjustments to minimize the Doppler angle to avoid bulky calcification should always be noted for accurate assessment.

Moderate aortic stenosis: Navigating the uncharted

Aortic stenosis (AS) stands as the most common valvular heart disease in developed countries and is characterized by progressive narrowing of the aortic valve orifice resulting in elevated transvalvular flow resistance, left ventricular hypertrophy, and progressive increased risk of heart failure and sudden death. This narrative review explores clinical challenges and evolving perspectives in moderate AS, where discrepancies between aortic valve area and pressure gradient measurements may pose diagnostic and therapeutic quandaries. Transthoracic echocardiography is the first-line imaging modality for AS evaluation, yet cases of discordance may require the application of ancillary noninvasive diagnostic modalities. This review underscores the importance of accurate grading of AS severity, especially in low-gradient phenotypes, emphasizing the need for vigilant follow-up. Current clinical guidelines primarily recommend aortic valve replacement for severe AS, potentially overlooking latent risks in moderate disease stages. The noninvasive multimodality imaging approach-including echocardiography, cardiac magnetic resonance, computed tomography, and nuclear techniques-provides unique insights into adaptive and maladaptive cardiac remodeling in AS and offers a promising avenue to deliver precise indications and exact timing for intervention in moderate AS phenotypes and asymptomatic patients, potentially improving long-term outcomes. Nevertheless, what we may have gleaned from a large amount of observational data is still insufficient to build a robust framework for clinical decision-making in moderate AS. Future research will prioritize randomized clinical trials designed to weigh the benefits and risks of preemptive aortic valve replacement in the management of moderate AS, as directed by specific imaging and nonimaging biomarkers.

Insights into calcific aortic valve stenosis: a comprehensive overview of the disease and advancing treatment strategies

Aortic valve stenosis is a disease characterized by thickening and narrowing of the aortic valve (AV), most commonly due to calcification, which leads to left ventricular outflow obstruction called calcific aortic valve disease (CAVD). CAVD presents as a progressive clinical syndrome with cardiorespiratory symptoms, often with rapid deterioration. The modern-day pathophysiology of CAVD involves a complex interplay of genetic factors, chronic inflammation, lipid deposition, and valve calcification, with early CAVD stages resembling atherosclerosis. Various imaging modalities have been used to evaluate CAVD, with a recent trend of using advanced imaging to measure numerous AV parameters, such as peak jet velocity. Significant improvements in mortality have been achieved with transcatheter AV repair, but numerous therapeutics and modalities are being researched to delay the progression of CAVD. This article aims to provide a comprehensive review of CAVD, explore recent developments, and provide insights into future treatments with various novel modalities.

Diagnostic Value of Aortic Valve Calcification Levels in the Assessment of Low-Gradient Aortic Stenosis

BACKGROUND

In patients with low-gradient aortic stenosis (AS) and low transvalvular flow, dobutamine stress echocardiography (DSE) is recommended to determine AS severity, whereas the degree of aortic valve calcification (AVC) supposedly correlates with AS severity according to current European and American guidelines.

OBJECTIVES

The purpose of this study was to assess the relationship between AVC and AS severity as determined using echocardiography and DSE in patients with aortic valve area <1 cm2 and peak aortic valve velocity <4.0 m/s.

METHODS

All patients underwent DSE to determine AS severity and multislice computed tomography to quantify AVC. Receiver-operating characteristics curve analysis was used to assess the diagnostic value of AVC for AS severity grading as determined using echocardiography and DSE in men and women.

RESULTS

A total of 214 patients were included. Median age was 78 years (25th-75th percentile: 71-84 years) and 25% were women. Left ventricular ejection fraction was reduced (<50%) in 197 (92.1%) patients. Severe AS was diagnosed in 106 patients (49.5%). Moderate AS was diagnosed in 108 patients (50.5%; in 77 based on resting transthoracic echocardiography, in 31 confirmed using DSE). AVC score was high (≥2,000 for men or ≥1,200 for women) in 47 (44.3%) patients with severe AS and in 47 (43.5%) patients with moderate AS. AVC sensitivity was 44.3%, specificity was 56.5%, and positive and negative predictive values for severe AS were 50.0% and 50.8%, respectively. Area under the receiver-operating characteristics curve was 0.508 for men and 0.524 for women.

CONCLUSIONS

Multi-slice computed tomography-derived AVC scores showed poor discrimination between grades of AS severity using DSE and cannot replace DSE in the diagnostic work-up of low-gradient severe AS.

Asymptomatic Aortic Stenosis: From Risk Stratification to Treatment

Our understanding of the natural history of aortic stenosis has significantly increased over the last decade. There have been considerable advances in the diagnosis and risk stratification of patients with aortic stenosis and in surgical and anesthetic techniques. In addition, transcatheter aortic valve replacement has established itself as a viable alternative to surgical management. Inevitably, these developments have raised questions regarding the merits of waiting for symptom onset in asymptomatic patients with severe aortic stenosis before offering treatment. Recent observational and randomized trial data suggest that early intervention in asymptomatic patients with severe aortic stenosis and normal left ventricular function may confer a prognostic advantage to a watchful waiting strategy. In this review, we highlight advances in the management and risk stratification of patients with asymptomatic severe aortic stenosis with particular consideration of recent findings supporting early valvular intervention.

Aortic Valve Calcification Density Measured by MDCT in the Assessment of Aortic Stenosis Severity

BACKGROUND

Aortic valve calcification (AVC) indexation to the aortic annulus (AA) area measured by Doppler echocardiography (AVCdEcho) provides powerful prognostic information in patients with aortic stenosis (AS). However, the indexation by AA measured by multidetector computed tomography (AVCdCT) has never been evaluated. The aim of this study was to compare AVC, AVCdCT, and AVCdEcho with regard to hemodynamic correlations and clinical outcomes in patients with AS.

METHODS

Data from 889 patients, mainly White, with calcific AS who underwent Doppler echocardiography and multidetector computed tomography within the same episode of care were retrospectively analyzed. AA was measured both by Doppler echocardiography and multidetector computed tomography. AVCdCT severity thresholds were established using receiver operating characteristic curve analyses in men and women separately. The primary end point was the occurrence of all-cause mortality.

RESULTS

Correlations between gradient/velocity and AVCd were stronger (both P≤0.005) using AVCdCT (r=0.68, P<0.001 and r=0.66, P<0.001) than AVC (r=0.61, P<0.001 and r=0.60, P<0.001) or AVCdEcho (r=0.61, P<0.001 and r=0.59, P<0.001). AVCdCT thresholds for the identification of severe AS were 334 Agatston units (AU)/cm2 for women and 467 AU/cm2 for men. On a median follow-up of 6.62 (6.19-9.69) years, AVCdCT ratio was superior to AVC ratio and AVCdEcho ratio to predict all-cause mortality in multivariate analyses (hazard ratio [HR], 1.59 [95% CI, 1.26-2.00]; P<0.001 versus HR, 1.53 [95% CI, 1.11-1.65]; P=0.003 versus HR, 1.27 [95% CI, 1.11-1.46]; P<0.001; all likelihood test P≤0.004). AVCdCT ratio was superior to AVC ratio and AVCdEcho ratio to predict survival under medical treatment in multivariate analyses (HR, 1.80 [95% CI, 1.27-1.58]; P<0.001 compared with HR, 1.55 [95% CI, 1.13-2.10]; P=0.007; HR, 1.28 [95% CI, 1.03-1.57]; P=0.01; all likelihood test P<0.03). AVCdCT ratio predicts mortality in all subgroups of patients with AS.

CONCLUSIONS

AVCdCT appears to be equivalent or superior to AVC and AVCdEcho to assess AS severity and predict all-cause mortality. Thus, it should be used to evaluate AS severity in patients with nonconclusive echocardiographic evaluations with or without low-flow status. AVCdCT thresholds of 300 AU/cm2 for women and 500 AU/cm2 for men seem to be appropriate to identify severe AS. Further studies are needed to validate these thresholds, especially in diverse populations.

Quantification of Aortic Valve Calcification in Contrast-Enhanced Computed Tomography

Background: The goal of our study is to evaluate a method to quantify aortic valve calcification (AVC) in contrast-enhanced computed tomography for patients with suspected severe aortic stenosis pre-interventionally. Methods: A total of sixty-five patients with aortic stenosis underwent both a native and a contrast-enhanced computed tomography (CECT) scan of the aortic valve (45 in the training cohort and 20 in the validation cohort) using a standardized protocol. Aortic valve calcification was semi-automatically quantified via the Agatston score method for the native scans and was used as a reference. For contrast-enhanced computed tomography, a calcium threshold of the Hounsfield units of the aorta plus four times the standard deviation was used. Results: For the quantification of aortic valve calcification in contrast-enhanced computed tomography, a conversion formula (691 + 1.83 x AVCCECT) was derived via a linear regression model in the training cohort. The validation in the second cohort showed high agreement for this conversion formula with no significant proportional bias (Bland-Altman, p = 0.055) and with an intraclass correlation coefficient in the validation cohort of 0.915 (confidence interval 95% 0.786-0.966) p < 0.001. Conclusions: Calcium scoring in patients with aortic valve stenosis can be performed using contrast-enhanced computed tomography with high validity. Using a conversion factor led to an excellent agreement, thereby obviating an additional native computed tomography scan. This might contribute to a decrease in radiation exposure.

Aortic valve perivascular adipose tissue computed tomography attenuation in patients with aortic stenosis

OBJECTIVE

Aortic stenosis (AS) shares pathophysiological similarities with atherosclerosis including active inflammation. CT attenuation of perivascular adipose tissue provides a measure of vascular inflammation that is linked to prognosis and has the potential to be applied to the aortic valve. We investigated perivascular adipose tissue attenuation around the aortic valve in patients with AS.

METHODS

CT attenuation was measured in the perivascular adipose tissue extending 3 mm radially and 10 mm longitudinally around the aortic valve in patients with and without AS. Associations between perivascular adipose tissue attenuation and AS disease severity, activity and progression were investigated.

RESULTS

Perivascular adipose tissue attenuation around the aortic valve demonstrated good intraobserver and interobserver repeatability (interobserver: intraclass correlation coefficient 0.977 (95% CI: 0.94, 0.99)) but was similar between patients with AS (n=120) and control subjects (n=80) (-62.4 (-68.7, -56.5) Hounsfield units (HU) vs -61.2 (-65.3, -55.6) HU, p=0.099). There were no differences between perivascular adipose tissue attenuation in patients with mild (-60.2 (-66.9, -55.1) HU), moderate (-62.8 (-69.6, -56.80) HU) or severe (-62.3 (-69.3, -55.4) HU) AS (all p>0.05), and perivascular adipose tissue attenuation did not demonstrate an association with AS severity as assessed by echocardiography or CT calcium scoring, nor with disease activity assessed by 18F-sodium fluoride positron emission tomography. Moreover, there was no association between baseline aortic valve perivascular adipose tissue attenuation and subsequent AS progression (annualised change in peak velocity: r=0.072, p=0.458). Similar results were found using five other image analysis methods.

CONCLUSIONS

CT-derived aortic valve perivascular adipose tissue attenuation is not associated with AS disease severity, activity or progression suggesting that it has no value in the investigation and management of patients with AS.

Atorvastatin reduces calcification in valve interstitial cells via the NF-κB signalling pathway by promoting Atg5-mediated autophagy

Aortic valve calcification (AVC) is a common cardiovascular disease and a risk factor for sudden death. However, the potential mechanisms and effective therapeutic drugs need to be explored. Atorvastatin is a statin that can effectively prevent cardiovascular events by lowering cholesterol levels. However, whether atorvastatin can inhibit AVC by reducing low-density lipoprotein (LDL) and its possible mechanism of action require further exploration. In the current study, we constructed an in vitro AVC model by inducing calcification of the valve interstitial cells. We found that atorvastatin significantly inhibited osteogenic differentiation, reduced the deposition of calcium nodules in valve interstitial cells, and enhanced autophagy in calcified valve interstitial cells, manifested by increased expression levels of the autophagy proteins Atg5 and LC3B-II/I and the formation of smooth autophagic flow. Atorvastatin inhibited the NF-κB signalling pathway and the expression of inflammatory factors mediated by NF-κB in calcified valve interstitial cells. The activation of the NF-κB signalling pathway led to the reversal of atorvastatin's effect on enhancing autophagy and alleviating valve interstitial cell calcification. In conclusion, atorvastatin inhibited the NF-κB signalling pathway by upregulating autophagy, thereby alleviating valve interstitial cell calcification, which was conducive to improving AVC.

Contemporary experience with the Commando procedure for anterior mitral anular calcification

Objective

Anterior mitral anular calcification, particularly in radiation heart disease, and previous valve replacement with destroyed intervalvular fibrosa are challenging for prosthesis sizing and placement. The Commando procedure with intervalvular fibrosa reconstruction permits double-valve replacement in these challenging conditions. We referenced outcomes after Commando procedures to standard double-valve replacements.

Methods

From January 2011 to January 2022, 129 Commando procedures and 1191 aortic and mitral double-valve replacements were performed at the Cleveland Clinic, excluding endocarditis. Reasons for the Commando were severe calcification after radiation (n = 67), without radiation (n = 43), and others (n = 19). Commando procedures were referenced to a subset of double-valve replacements using balancing-score methods (109 pairs).

Results

Between balanced groups, Commando versus double-valve replacement had higher total calcium scores (median 6140 vs 2680 HU, P = .03). Hospital outcomes were similar, including operative mortality (12/11% vs 8/7.3%, P = .35) and reoperation for bleeding (9/8.3% vs 5/4.6%, P = .28). Survival and freedom from reoperation at 5 years were 54% versus 67% (P = .33) and 87% versus 100% (P = .04), respectively. Higher calcium score was associated with lower survival after double-valve replacement but not after the Commando. The Commando procedure had lower aortic valve mean gradients at 4 years (9.4 vs 11 mm Hg, P = .04). After Commando procedures for calcification, 5-year survival was 60% and 59% with and without radiation, respectively (P = .47).

Conclusions

The Commando procedure with reconstruction of the intervalvular fibrosa destroyed by mitral anular calcification, radiation, or previous surgery demonstrates acceptable outcomes similar to standard double-valve replacement. More experience and long-term outcomes are required to refine patient selection for and application of the Commando approach.

Coronary Artery Disease Assessment via On-Site CT Fractional Flow Reserve in Patients Undergoing Transcatheter Aortic Valve Replacement

Purpose To examine the clinical feasibility of workstation-based CT fractional flow reserve (CT-FFR) for coronary artery disease (CAD) evaluation during preprocedural planning in patients undergoing transcatheter aortic valve replacement (TAVR). Materials and Methods In this retrospective single-center study, 434 patients scheduled for TAVR between 2018 and 2020 were screened for study inclusion; a relevant proportion of patients (35.0% [152 of 434]) was not suitable for evaluation due to insufficient imaging properties. A total of 112 patients (mean age, 82.1 years ± 6.7 [SD]; 58 [52%] men) were included in the study. Invasive angiography findings, coronary CT angiography results, and Agatston score were acquired and compared with on-site CT-FFR computation for evaluation of CAD and prediction of major adverse cardiovascular events (MACE) within a 24-month follow-up. Results Hemodynamic relevant CAD, as suggested by CT-FFR of 0.80 or less, was found in 41 of 70 (59%) patients with stenosis of 50% or more. MACE occurred in 23 of 112 (20.5%) patients, from which 14 of 23 had stenoses with CT-FFR of 0.80 or less (hazard ratio [HR], 3.33; 95% CI: 1.56, 7.10; P = .002). CT-FFR remained a significant predictor of MACE after inclusion in a multivariable model with relevant covariables (HR, 2.89; 95% CI: 1.22, 6.86; P = .02). An Agatston score of 1000 Agatston units or more (HR, 2.25; 95% CI: 0.98, 5.21; P = .06) and stenoses of 50% or more determined via invasive angiography (HR, 0.94; 95% CI: 0.41, 2.17; P = .88) were not significant predictors of MACE. Conclusion Compared with conventional CAD markers, CT-FFR better predicted adverse outcomes after TAVR. A relevant portion of the screened cohort, however, was not suitable for CT-based CAD evaluation. Keywords: CT, Transcatheter Aortic Valve Implantation/Replacement (TAVI/TAVR), Cardiac, Coronary Arteries, Outcomes Analysis © RSNA, 2024 See also the commentary by Weir-McCall and Pugliese in this issue.

Prevalence and Outcomes of Patients With Discordant High-Gradient Aortic Stenosis

BACKGROUND

Conflicting prognostic results have been reported in patients with discordant high-gradient aortic stenosis ([DHG-AS] the combination of a mean pressure gradient ≥40 mm Hg and an aortic valve area [AVA] >1 cm2). Moreover, existing studies only included selected patients without concomitant aortic regurgitation.

OBJECTIVES

The authors assessed the prevalence and survival of patients presenting with DHG-AS in an unselected group of consecutive patients presenting to the echocardiography laboratory of a tertiary referral center.

METHODS

A total of 3,547 adult patients with AVA ≤1.5 cm2 and peak aortic jet velocity ≥2.5 m/s or mean gradient ≥25 mm Hg who presented between 2005 and 2015 were included. Baseline clinical and echocardiographic data, and, when available, aortic valve calcium (AVC) score were collected in an institutional database, with subsequent retrospective analysis. The primary endpoint was all-cause mortality during follow-up.

RESULTS

DHG-AS was observed in 163 patients (11.6% of patients with a high gradient). After adjustment for potential confounders, overall mortality rate of patients with DHG-AS was similar to that of patients with concordant severe aortic stenosis (HR: 0.98 [95% CI: 0.66-1.44]; P = 0.91), and patients with discordant low-gradient aortic stenosis (HR: 0.85 [95% CI: 0.58-1.26]; P = 0.42), and higher than concordant moderate aortic stenosis (HR: 0.54 [95% CI: 0.36-0.81]; P = 0.003). After adjustment for aortic velocities, aortic regurgitation had no significant impact on survival. AVC was higher than in patients with concordant moderate aortic stenosis and discordant low-gradient aortic stenosis, and not significantly different from that of concordant severe aortic stenosis.

CONCLUSIONS

DHG-AS is not uncommon. Whereas AVA >1.0 cm2 is often seen as moderate aortic stenosis, a high-pressure gradient conveys a poor prognosis, whatever the AVA and the severity of concomitant aortic regurgitation.

Association Between Aortic Valve Calcification and Severity of Concomitant Aortic Regurgitation in Patients With Severe Aortic Stenosis

BACKGROUND

Patients with severe aortic stenosis (AS) frequently have concomitant aortic regurgitation (AR), but the association between aortic valvular calcification (AVC) and the severity of AR remains unclear.Methods and Results: We retrospectively reviewed patients with severe AS who underwent transthoracic echocardiography and multidetector computed tomography (MDCT) within 1 month. The patients were divided into 3 groups according to the degree of concomitant AR. The association between AVC and the severity of concomitant AR was assessed in patients with severe AS. The study population consisted of 95 patients: 43 men and 52 women with a mean age of 82±7 years. Of the 95 patients with severe AS, 27 had no or trivial AR, 53 had mild AR, and 15 had moderate AR. The AVC score (AVCS) and AVC volume (AVCV) significantly increased as the severity of concomitant AR increased (P=0.014 for both), and similar findings were obtained for the AVCS and AVCV indexes (P=0.004 for both).

CONCLUSIONS

The severity of AR correlated with AVCS and AVCV measured by MDCT in patients with severe AS. AVC may cause concomitant AR, leading to worsening of disease condition.

Computed tomography calcium scoring in aortic stenosis: bicuspid versus tricuspid morphology

OBJECTIVE

CT aortic valve calcium score (AVCscore) and density (AVCdensity) thresholds have been recommended for aortic stenosis (AS) severity assessment in tricuspid aortic valve (TAV). We aimed to compare AVCscore and AVCdensity in bicuspid aortic valve (BAV) versus TAV.

METHODS

Retrospective single-centre study of patients with echocardiographic AS-severity and CT-AVC assessments within 6 months, and left ventricular ejection fraction ≥50%, all referred for clinical AS evaluation.Severe AS was defined as aortic valve area (AVA) ≤1 cm2 or indexed AVA ≤0.6cm2/m2 plus mean gradient ≥40 mm Hg or peak velocity ≥4 m/s. AVC was assessed by Agatston method.

RESULTS

Of the 1957 patients, 328 had BAV and 1629 had TAV, age 65±11 vs 80±9 years (p<0.001), men 65% vs 56% (p=0.006), respectively. BAV morphology was associated with higher AVCscore and AVCdensity independent of age, comorbidities and AS severity (p<0.001) in men only (sex and BAV interaction p<0.001). In patients with severe AS, mean AVCscore and AVCdensity were higher in BAV-men than that in TAV-men (both p<0.001), but similar in BAV-women and TAV-women (both p≥0.4). Such patterns remained the same after adjustment for clinical covariates and AS severity. Best thresholds for severe AS diagnosis in BAV-men were 2916 AU by AVCscore and 600 AU/cm2 by AVCdensity which were higher than the guideline-recommended thresholds, while thresholds in BAV-women (1036 AU and 282 AU/cm2) were similar to guideline-recommended ones.

CONCLUSION

Valve calcification in AS differs according to valve morphology and sex. BAV-men with severe AS exhibit greater AVCscore and AVCdensity than TAV-men. This presents a diagnostic challenge to the current guidelines, which needs confirmation in larger studies.

Virtual non-iodine photon-counting CT-angiography for aortic valve calcification scoring

Photon-counting detector (PCD)-CT allows for reconstruction of virtual non-iodine (VNI) images from contrast-enhanced datasets. This study assesses the diagnostic performance of aortic valve calcification scoring (AVCS) derived from VNI datasets generated with a 1st generation clinical dual-source PCD-CT. AVCS was evaluated in 123 patients (statistical analysis only comprising patients with aortic valve calcifications [n = 56; 63.2 ± 11.6 years]), who underwent contrast enhanced electrocardiogram-gated (either prospective or retrospective or both) cardiac CT on a clinical PCD system. Patient data was reconstructed at 70 keV employing a VNI reconstruction algorithm. True non-contrast (TNC) scans at 70 keV without quantum iterative reconstruction served as reference in all individuals. Subgroup analysis was performed in 17 patients who received both, prospectively and retrospectively gated contrast enhanced scans (n = 8 with aortic valve calcifications). VNI images with prospective/retrospective gating had an overall sensitivity of 69.2%/56.0%, specificity of 100%/100%, accuracy of 85.4%/81.0%, positive predictive value of 100%/100%, and a negative predictive value of 78.2%/75.0%. VNI images with retrospective gating achieved similar results. For both gating approaches, AVCSVNI showed high correlation (r = 0.983, P < 0.001 for prospective; r = 0.986, P < 0.001 for retrospective) with AVCSTNC. Subgroup analyses demonstrated excellent intra-individual correlation between different acquisition modes (r = 0.986, P < 0.001). Thus, VNI images derived from cardiac PCD-CT allow for excellent diagnostic performance in the assessment of AVCS, suggesting potential for the omission of true non-contrast scans in the clinical workup of patients with aortic calcifications.

Mitral Annulus Calcium Score in Patients With Calcific Mitral Stenosis Undergoing Invasive Hemodynamic Assessment

BACKGROUND

Aortic valve calcium score is associated with hemodynamic severity of aortic stenosis. Whether this association is present in calcific mitral stenosis remains unknown.

METHODS AND RESULTS

This study was a retrospective analysis of consecutive patients with mitral stenosis secondary to mitral annular calcification (MAC) undergoing transseptal catheterization. All patients underwent invasive mitral valve assessment via direct left atrial and left ventricular pressure measurement. Computed tomography within 1 year of cardiac catheterization and with adequate visualization of the mitral annulus was included. MAC calcium score quantification by Agatston method was obtained offline using dedicated software (Aquarius, TeraRecon, V.4). Median patient age was 66.9±11.2 years, 47% of patients were women, 50% had coronary artery disease, 40% had atrial fibrillation, 47% had prior cardiac surgery, and 33% had prior chest radiation. Median diastolic mitral valve gradient was 9.4±3.4 mm Hg on echocardiography and 8.5±4 mm Hg invasively. Invasive median mitral valve area using the Gorlin formula was 1.87±0.9 cm2. Median MAC calcium score for the cohort was 7280±7937 Hounsfield units. MAC calcium score correlated with the presence of atrial fibrillation (P=0.02) but was not associated with other comorbidities. There was no correlation between MAC calcium score and mitral valve area (r=0.07; P=0.6) or mitral valve gradient (r=-0.03; P=0.8).

CONCLUSIONS

MAC calcium score did not correlate with invasively measured mitral valve gradient and mitral valve area in patients with MAC-related mitral stenosis, suggesting that calcium score should not be used as a surrogate for invasive hemodynamic parameters.

Combined Significant Aortic Stenosis and Mitral Regurgitation: Challenges in Timing and Type of Intervention

In this narrative review, we aim to summarize the literature surrounding the assessment and management of the common, yet understudied combination of aortic stenosis (AS) and mitral regurgitation (MR), the components of which are complexly inter-related and interdependent from diagnostic, prognostic, and therapeutic perspectives. The hemodynamic interdependency of AS and MR confounds the assessment of the severity of each valve disease, thus underscoring the importance of a multimodal approach integrating valvular and extravalvular indicators of severity. A large body of literature suggests that baseline MR is associated with reduced survival post aortic valve (AV) intervention and that regression of MR post-AV intervention confers a mortality benefit. Functional MR is more likely to regress after AV intervention than primary MR. The respective natural courses of the 2 valve diseases are not synchronized; therefore, significant AS and MR at or above the respective threshold for intervention might not coincide. Surgery is primarily a 1-stop-shop procedure because of a considerable perioperative risk of repeat interventions, whereas transcatheter treatment modalities allow for a more tailored timing of intervention with reassessment of concomitant MR after AV replacement and a potential staged intervention in the absence of MR regression. In summary, AS and MR, when combined, are interlaced into a complex hemodynamic, diagnostic, and prognostic synergy, with important therapeutic implications. Contemporary approaches should consider stepwise intervention by exploiting the advantage of transcatheter options. However, evidence is needed to demonstrate the efficacy of different timing and therapeutic options.

Remnant cholesterol and the risk of aortic valve calcium progression: insights from the MESA study

BACKGROUND

Remnant cholesterol (RC) is implicated in the risk of cardiovascular disease. However, comprehensive population-based studies elucidating its association with aortic valve calcium (AVC) progression are limited, rendering its precise role in AVC ambiguous.

METHODS

From the Multi-Ethnic Study of Atherosclerosis database, we included 5597 individuals (61.8 ± 10.1 years and 47.5% men) without atherosclerotic cardiovascular disease at baseline for analysis. RC was calculated as total cholesterol minus high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), as estimated by the Martin/Hopkins equation. Using the adjusted Cox regression analyses, we examined the relationships between RC levels and AVC progression. Furthermore, we conducted discordance analyses to evaluate the relative AVC risk in RC versus LDL-C discordant/concordant groups.

RESULTS

During a median follow-up of 2.4 ± 0.9 years, 568 (10.1%) participants exhibited AVC progression. After adjusting for traditional cardiovascular risk factors, the HRs (95% CIs) for AVC progression comparing the second, third, and fourth quartiles of RC levels with the first quartile were 1.195 (0.925-1.545), 1.322 (1.028-1.701) and 1.546 (1.188-2.012), respectively. Notably, the discordant high RC/low LDL-C group demonstrated a significantly elevated risk of AVC progression compared to the concordant low RC/LDL-C group based on their medians (HR, 1.528 [95% CI 1.201-1.943]). This pattern persisted when clinical LDL-C threshold was set at 100 and 130 mg/dL. The association was consistently observed across various sensitivity analyses.

CONCLUSIONS

In atherosclerotic cardiovascular disease-free individuals, elevated RC is identified as a residual risk for AVC progression, independent of traditional cardiovascular risk factors. The causal relationship of RC to AVC and the potential for targeted RC reduction in primary prevention require deeper exploration.

Transcatheter aortic valve durability, predictors of bioprosthetic valve dysfunction, longer-term outcomes - a review

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is one of the most significant inventions in cardiology, as it provides a viable minimally invasive treatment option for patients with aortic stenosis, the most common valvular disease in the developed world and one with a poor prognosis when left untreated. Using data available to date, this review aims to discuss and identify possible predictors of TAVI valve durability - an essential requirement for the device's wide-spread use, especially in younger patients.

AREAS COVERED

This article explores the main causes of bioprosthetic valve dysfunction (BVD) based on pathophysiology and available data, and reviews possible predictors of BVD including prosthesis-related, procedure-related, and patient-related factors. An emphasis is made on affectable predictors, which could potentially be targeted with prevention management and improve valve durability. A literature search of online medical databases was conducted using relevant key words and dates; significant clinical trials were identified. A brief overview of important randomized controlled trials with mid to long-term follow-up is included in this article.

EXPERT OPINION

Identifying modifiable predictors of valve dysfunction presents an opportunity to enhance and predict valve durability - a necessity as patients with longer life-expectancies are being considered for the procedure.

DLFFNet: A new dynamical local feature fusion network for automatic aortic valve calcification recognition using echocardiography

BACKGROUND AND OBJECTIVE

Aortic valve calcification (AVC) is a strong predictor of adverse cardiovascular events and is correlated with the degree of coronary artery stenosis. Generally, AVC is identified by echocardiography using visual "eyeballing", which results in huge differences between observers and requires a long time to learn. Therefore, accurately identifying AVC from echocardiographic images is a challenging task due to the interference of various factors.

METHOD

In this paper, we built a dynamical local feature fusion net capable of processing echocardiography to recognize AVC automatically. We proposed high-echo area which were segmented by a U-Net. Meanwhile, we fine-tuned the segmentation results by adding brightness in the mask tuning module in order to dynamically adjust the selection of local features. To better fuse multi-level and multi-scale information, we designed a pyramid-based two-branch feature fusion module in classification, which enables the network to better integrate global and local semantic representations. In addition, for the echocardiographic data collected by different devices and doctors, inconsistent aortic valve position with a small occupied area, a unified preprocessing algorithm was designed.

RESULTS

To highlight the effectiveness of the proposed approach, we compared several state-of-the-art methods on the same ultrasound dataset. The 231 patients with short-axis views of the aortic valve images were collected and labeled (masked) by experienced ultrasound doctors from The First Hospital of China Medical University. The accuracy, precision, sensitivity, specificity, and F1 score, micro-AUC, and macro-AUC of the model for the test dataset were, 82.40%, 82.50%, 82.50%, 91.23%, 82.47%, 92.39%, and 92.25%, respectively.

CONCLUSIONS

The results showed the possibility of using echocardiography to examine AVC automatically and verified by visualization methods that the Region of Interest of the model is consistent with the observed region of the experts.

Diagnostic accuracy of virtual non-contrast CT for aortic valve stenosis severity evaluation

BACKGROUND

Computed tomography aortic valve calcium (AVC) score has accepted value for diagnosing and predicting outcomes in aortic stenosis (AS). Multi-energy CT (MECT) allows virtual non-contrast (VNC) reconstructions from contrast scans. We aim to compare the VNC-AVC score to the true non-contrast (TNC)-AVC score for assessing AS severity.

METHODS

We prospectively included patients undergoing a MECT for transcatheter aortic valve replacement (TAVR) planning. TNC-AVC was acquired before contrast, and VNC-AVC was derived from a retrospectively gated contrast-enhanced scan. The Agatston scoring method was used for quantification, and linear regression analysis to derive adjusted-VNC values.

RESULTS

Among 109 patients (55% female) included, 43% had concordant severe and 14% concordant moderate AS. TNC scan median dose-length product was 116 ​mGy∗cm. The median TNC-AVC was 2,107 AU (1,093-3,372), while VNC-AVC was 1,835 AU (1293-2,972) after applying the coefficient (1.46) and constant (743) terms. A strong correlation was demonstrated between methods (r ​= ​0.93; p ​< ​0.001). Using accepted thresholds (>1,300 AU for women and >2,000 AU for men), 65% (n ​= ​71) of patients had severe AS by TNC-AVC and 67% (n ​= ​73) by adjusted-VNC-AVC. After estimating thresholds for adjusted-VNC (>1,564 AU for women and >2,375 AU for men), 56% (n ​= ​61) had severe AS, demonstrating substantial agreement with TNC-AVC (κ ​= ​0.77).

CONCLUSIONS

MECT-derived VNC-AVC showed a strong correlation with TNC-AVC. After adjustment, VNC-AVC demonstrated substantial agreement with TNC-AVC, potentially eliminating the requirement for an additional scan and enabling reductions in both radiation exposure and acquisition time.

Multimodality Imaging in Aortic Stenosis: Beyond the Valve - Focusing on the Myocardium

Current guidelines of aortic stenosis (AS) management focus on valve parameters, LV systolic dysfunction, and symptoms; however, emerging data suggest that there may be benefit of aortic valve replacement before it becomes severe by present criteria. Myocardial assessment using novel multimodality imaging techniques exhibits subclinical myocardial injury and remodeling at various stages before guideline-directed interventions, which predicts adverse outcomes. This raises the question of whether implementing serial myocardial assessment should become part of the standard appraisal, thereby identifying high-risk patients aiming to minimize adverse outcomes.

Value of Post-/Pre-Procedural Aortic Regurgitation Ratio vs. Pre-Procedural Aortic Valve Calcium Score to Predict Moderate to Severe Paravalvular Leak Requiring Post-Dilation after Transcatheter Aortic Valve Implantation

BACKGROUND AND AIM

Tools that assist interventionists in selecting patients for post-dilation (PD) are needed. We aimed to assess whether pre-interventional aortic valve calcium (AVC) or the peri-interventional aortic regurgitation (ARI) ratio is a better predictor for a more than mild paravalvular leak (PVL) requiring PD after TAVI.

METHODS

Patients undergoing TAVI with available data on AVC derived from MSCTs and the ARI ratio derived from peri-interventional hemodynamic curves were studied. The main outcome was moderate-to-severe PVL requiring PD.

RESULTS

In 237 patients, more than mild PVL after valve deployment was present in 25.7%. PD was performed in 65 patients. The median (IQR) total AVC was 390.5 (211.5-665.4) mm3. All calcification values were significantly higher in patients who underwent PD. The median (IQR) individual threshold was 600 (550-685) Hus. The overall ARI ratio was 0.78 (0.61-0.96), with values being significantly lower in patients who underwent PD: 0.61 (0.49-0.80) vs. 0.82 (0.69-0.99) (p < 0.001). Both the ARI ratio (OR [95%CI] 0.053 [0.014-0.203]; p < 0.001) and AVC (1.01 [1.000-1.002]; p = 0.015) predicted PD need. ROC curves showed higher discrimination for the ARI ratio (AUC 0.73) than for any calcification parameter (all AUCs ≤ 0.62).

CONCLUSIONS

The ARI ratio provides interventionists with a powerful predictive tool for PVL requiring PD after TAVI that is beyond the predictive value of pre-procedural valve calcification derived from MSCT.

Coronary and Extra-coronary Subclinical Atherosclerosis to Guide Lipid-Lowering Therapy

PURPOSE OF REVIEW

To discuss and review the technical considerations, fundamentals, and guideline-based indications for coronary artery calcium scoring, and the use of other non-invasive imaging modalities, such as extra-coronary calcification in cardiovascular risk prediction.

RECENT FINDINGS

The most robust evidence for the use of CAC scoring is in select individuals, 40-75 years of age, at borderline to intermediate 10-year ASCVD risk. Recent US recommendations support the use of CAC scoring in varying clinical scenarios. First, in adults with very high CAC scores (CAC ≥ 1000), the use of high-intensity statin therapy and, if necessary, guideline-based add-on LDL-C lowering therapies (ezetimibe, PCSK9-inhibitors) to achieve a ≥ 50% reduction in LDL-C and optimally an LDL-C < 70 mg/dL is recommended. In patients with a CAC score ≥ 100 at low risk of bleeding, the benefits of aspirin use may outweigh the risk of bleeding. Other applications of CAC scoring include risk estimation on non-contrast CT scans of the chest, risk prediction in younger patients (< 40 years of age), its value as a gatekeeper for the decision to perform nuclear stress testing, and to aid in risk stratification in patients presenting with low-risk chest pain. There is a correlation between extra-coronary calcification (e.g., breast arterial calcification, aortic calcification, and aortic valve calcification) and incident ASCVD events. However, its role in informing lipid management remains unclear. Identification of coronary calcium in selected patients is the single best non-invasive imaging modality to identify future ASCVD risk and inform lipid-lowering therapy decision-making.

Influence of cusp morphology and sex on quantitative valve composition in severe aortic stenosis

AIMS

Aortic stenosis is characterized by fibrosis and calcification of the valve, with a higher proportion of fibrosis observed in women. Stenotic bicuspid aortic valves progress more rapidly than tricuspid valves, which may also influence the relative composition of the valve. We aimed to investigate the influence of cusp morphology on quantitative aortic valve composition quantified from contrast-enhanced computed tomography angiography in severe aortic stenosis.

METHODS AND RESULTS

Patients undergoing transcatheter aortic valve implantation with bicuspid and tricuspid valves were propensity matched 1:1 by age, sex, and comorbidities. Computed tomography angiograms were analysed using semi-automated software to quantify the fibrotic and calcific scores (volume/valve annular area) and the fibro-calcific ratio (fibrotic score/calcific score). The study population (n = 140) was elderly (76 ± 10 years, 62% male) and had a peak aortic jet velocity of 4.1 ± 0.7 m/s. Compared with those with tricuspid valves (n = 70), patients with bicuspid valves (n = 70) had higher fibrotic scores [204 (interquartile range 118-267) vs. 144 (99-208) mm3/cm2, P = 0.006] with similar calcific scores (P = 0.614). Women had greater fibrotic scores than men in bicuspid [224 (181-307) vs. 169 (109-247) mm3/cm2, P = 0.042] but not tricuspid valves (P = 0.232). Men had greater calcific scores than women in both bicuspid [203 (124-355) vs. 130 (70-182) mm3/cm2, P = 0.008] and tricuspid [177 (136-249) vs. 100 (62-150) mm3/cm2, P = 0.004] valves. Among both valve types, women had a greater fibro-calcific ratio compared with men [tricuspid 1.86 (0.94-2.56) vs. 0.86 (0.54-1.24), P = 0.001 and bicuspid 1.78 (1.21-2.90) vs. 0.74 (0.44-1.53), P = 0.001].

CONCLUSIONS

In severe aortic stenosis, bicuspid valves have proportionately more fibrosis than tricuspid valves, especially in women.

Aortic Valve Calcium Score by Computed Tomography as an Adjunct to Echocardiographic Assessment-A Review of Clinical Utility and Applications

Aortic valve stenosis (AS) is increasing in prevalence due to the aging population, and severe AS is associated with significant morbidity and mortality. Echocardiography remains the mainstay for the initial detection and diagnosis of AS, as well as for grading of severity. However, there are important subgroups of patients, for example, patients with low-flow low-gradient or paradoxical low-gradient AS, where quantification of severity of AS is challenging by echocardiography and underestimation of severity may delay appropriate management and impart a worse prognosis. Aortic valve calcium score by computed tomography has emerged as a useful clinical diagnostic test that is complimentary to echocardiography, particularly in cases where there may be conflicting data or clinical uncertainty about the degree of AS. In these situations, aortic valve calcium scoring may help re-stratify grading of severity and, therefore, further direct clinical management. This review presents the evolution of aortic valve calcium score by computed tomography, its diagnostic and prognostic value, as well as its utility in clinical care.

Noncontrast cardiac computed tomography-derived mitral annular calcification scores in mitral valve disease

BACKGROUND AND AIMS

Mitral annular calcification (MAC) by computed tomography (CT) is reported as an independent predictor of poor outcomes. However, it currently remains unclear if quantitative MAC parameters provide more value for mitral valve disease (MVD) management, therefore, we examined the prognostic value of MAC scores using noncontrast cardiac-CT in MVD patients.

METHODS

Between January 2020 and December 2021, we prospectively enrolled 300 consecutive patients with MVD (MAC-present = 80 and MAC-absent = 220) undergoing preoperative cardiac-CT and mitral valve (MV) surgery. Noncontrast cardiac-CT images were used to qualitatively detect MAC (present or absent) and evaluate MAC scores. For analyses, we also collected baseline clinical data, intraoperative conversion (from MV repair to MV replacement), and follow-up arrhythmia data.

RESULTS

Compared with the MAC-absent group, MAC-present patients were older (62 ± 7 vs. 58 ± 9 years, p < .001), mostly women (55% vs. 39.5%, p = .017), and also had aortic valve calcification (57.5% vs. 23.2%, p < .001), mitral stenosis (82.5% vs. 61.8%, p < .001), atrial fibrillation (30% vs. 11.8%, p < .001), and larger left atrial end-diastolic dimension (LADD, 49 [44-56] versus 46 [41-50], p = .001]. Furthermore, MAC-present patients underwent more MV replacements (61.8% vs. 82.5%, p = .001) and experienced a higher intraoperative conversion prevalence (11.8% vs. 61.3%, p < .001). Multiple logistic regression analyses showed that the female gender (odds ratio [OR]/95% confidence interval [CI]/p = 2.001/1.042-3.841/0.037) and MAC scores (OR/95% CI/p = 10.153/4.434-23.253/p < .001) were independent predictors of intraoperative conversion. During a follow-up of 263 ± 134 days, MAC-present patients had more arrhythmias (42.5% vs. 9.5%, p < .001). Also, MAC-scores (hazard ratio [HR]/95% CI/p = 6.841/3.322-14.089/p < .001) and LADD (HR/95% CI/p = 1.039/1.018-1.060/p < .001) were independently associated with arrhythmias by Cox regression analyses.

CONCLUSIONS

Noncontrast cardiac CT-derived MAC-scores showed a high risk for intraoperative conversion and follow-up arrhythmias in MVD-patients.

A systematic review of contrast-enhanced computed tomography calcium scoring methodologies and impact of aortic valve calcium burden on TAVI clinical outcomes

Different methodologies have been used to assess the role of AV calcification (AVC) on TAVI outcomes. This systematic review aims to describe the burden of AVC, synthesize the different methods of calcium score quantification, and evaluate the impact of AVC on outcomes after TAVI. We included studies of TAVI patients who had reported AV calcium scoring by contrast-enhanced multidetector CT and the Agatston method. The impact of calcification on TAVI outcomes without restrictions on follow-up time or outcome type was evaluated. Results were reported descriptively, and a meta-analysis was conducted when feasible. Sixty-eight articles were included, with sample sizes ranging from 23 to 1425 patients. Contrast-enhanced calcium scoring was reported in 30 studies, calcium volume score in 28 studies, and unique scoring methods in two. All studies with calcium volume scores had variable protocols, but most utilized a modified Agatston method with variable attenuation threshold values of 300-850 HU. Eight studies used the Agatston method, with the overall mean AV calcium score in studies published from 2010 to 2012 of 3342.9 AU [95%CI: 3150.4; 3535.4, I2 ​= ​0%]. The overall mean score was lower and heterogenous in studies published from 2014 to 2020 (2658.9 AU [95% CI: 2517.3; 2800.5, I2 ​= ​79%]. Most studies reported a positive association between calcium burden and increased risk of adverse outcomes, including implantation of permanent pacemaker (7/8 studies), paravalvular leak (13/13 studies), and risk of aortic rupture (2/2 studies). AVC quantification methodology with contrast-enhanced CT is still variable. AVC negatively impacts TAVI outcomes independently of the quantification method.

Diagnostic Performance of Cardiac CT and Transthoracic Echocardiography for Detection of Surgically Confirmed Bicuspid Aortic Valve: Effect of Calcium Extent and Valve Subtypes

Purpose

This study aimed to compare the diagnostic performance of cardiac CT and transthoracic echocardiogram (TTE) depending on the degree of valvular calcification and bicuspid aortic valve (BAV) subtype.

Materials and Methods

This retrospective study included 266 consecutive patients (106 with BAV and 160 with tricuspid aortic valve) who underwent cardiac CT and TTE before aortic valve replacement. Cardiac CT was used to evaluate the morphology of the aortic valve, and a calcium scoring scan was used to quantify valve calcium. The aortic valves were classified into fused and two-sinus types. The diagnostic accuracy of cardiac CT and TTE was calculated using a reference standard for intraoperative inspection.

Results

CT demonstrated significantly higher sensitivity, negative predictive value, and accuracy than TTE in detecting BAV (p < 0.001, p < 0.001, and p = 0.003, respectively). The TTE sensitivity tended to decrease as valvular calcification increased. The error rate of TTE for CT was 10.9% for the two-sinus type of BAV and 28.3% for the fused type (p = 0.044).

Conclusion

Cardiac CT had a higher diagnostic performance in detecting BAV than TTE and may help diagnose BAV, particularly in patients with severe valvular calcification.

Multi-modality imaging in aortic stenosis: an EACVI clinical consensus document

In this EACVI clinical scientific update, we will explore the current use of multi-modality imaging in the diagnosis, risk stratification, and follow-up of patients with aortic stenosis, with a particular focus on recent developments and future directions. Echocardiography is and will likely remain the key method of diagnosis and surveillance of aortic stenosis providing detailed assessments of valve haemodynamics and the cardiac remodelling response. Computed tomography (CT) is already widely used in the planning of transcutaneous aortic valve implantation. We anticipate its increased use as an anatomical adjudicator to clarify disease severity in patients with discordant echocardiographic measurements. CT calcium scoring is currently used for this purpose; however, contrast CT techniques are emerging that allow identification of both calcific and fibrotic valve thickening. Additionally, improved assessments of myocardial decompensation with echocardiography, cardiac magnetic resonance, and CT will become more commonplace in our routine assessment of aortic stenosis. Underpinning all of this will be widespread application of artificial intelligence. In combination, we believe this new era of multi-modality imaging in aortic stenosis will improve the diagnosis, follow-up, and timing of intervention in aortic stenosis as well as potentially accelerate the development of the novel pharmacological treatments required for this disease.

Computed Tomography and Magnetic Resonance Imaging Findings of Bicuspid Aortic Valve and Related Abnormalities of the Heart and Thoracic Aorta

The bicuspid aortic valve (BAV) is the most common congenital cardiovascular malformation. Patients with BAV are at higher risk of other congenital cardiovascular malformations and valvular dysfunction, including aortic stenosis/regurgitation and infective endocarditis. BAV may also be related to aortic wall abnormalities such as aortic dilatation, aneurysm, and dissection. The morphology of the BAV varies with the presence and position of the raphe and is associated with the type of valvular dysfunction and aortopathy. Therefore, accurate diagnosis and effective treatment at an early stage are essential to prevent complications in patients with BAV. This pictorial essay highlights the characteristics of BAV and its related congenital cardiovascular malformations, valvular dysfunction, aortopathy, and other rare cardiac complications using multimodal imaging.

CardioVision: A fully automated deep learning package for medical image segmentation and reconstruction generating digital twins for patients with aortic stenosis

Aortic stenosis (AS) is the most prevalent heart valve disease in western countries that poses a significant public health challenge due to the lack of a medical treatment to prevent valve calcification. Given the aging population demographic, the prevalence of AS is projected to rise, resulting in a progressively significant healthcare and economic burden. While surgical aortic valve replacement (SAVR) has been the gold standard approach, the less invasive transcatheter aortic valve replacement (TAVR) is poised to become the dominant method for high- and medium-risk interventions. Computational simulations using patient-specific models, have opened new research avenues for optimizing emerging devices and predicting clinical outcomes. The traditional techniques of generating digital replicas of patients' aortic root, native valve, and calcification are time-consuming and labor-intensive processes requiring specialized tools and expertise in anatomy. Alternatively, deep learning models, such as the U-Net architecture, have emerged as reliable and fully automated methods for medical image segmentation. Two-dimensional U-Nets have been shown to produce comparable or more accurate results than trained clinicians' manual segmentation while significantly reducing computational costs. In this study, we have developed a fully automatic AI tool capable of reconstructing the digital twin geometry and analyzing the calcification distribution on the aortic valve. The developed automatic segmentation package enables the modeling of patient-specific anatomies, which can then be used to simulate virtual interventional procedures, optimize emerging prosthetic devices, and predict clinical outcomes.

Development and validation of a deep learning-based fully automated algorithm for pre-TAVR CT assessment of the aortic valvular complex and detection of anatomical risk factors: a retrospective, multicentre study

BACKGROUND

Pre-procedural computed tomography (CT) imaging assessment of the aortic valvular complex (AVC) is essential for the success of transcatheter aortic valve replacement (TAVR). However, pre-TAVR assessment is a time-intensive process, and the visual assessment of anatomical structures at the AVC shows interobserver variability. This study aimed to develop and validate a deep learning-based algorithm for pre-TAVR CT assessment and anatomical risk factor detection.

METHODS

This retrospective, multicentre study used AVC CT scans to develop a deep learning-based, fully automated algorithm, which was then internally and externally validated. After loading CT scans into the algorithm, it automatically assessed the essential anatomical structure data required for TAVR planning. CT scans of 1252 TAVR candidates continuously enrolled from Fuwai Hospital were used to establish training and internal validation datasets, while CT scans of 100 patients with aortic valve disease across 19 Chinese hospitals served as an external validation dataset. The validation focused on segmentation performance, localisation and measurement accuracy of key anatomical structures, detection ability of specific anatomical risk factors, and improvement in assessment efficiency.

FINDINGS

Relative to senior observers, our algorithm achieved significant consistent performance with remarkable accuracy, efficiency and ease in segmentation, localisation, and the assessment of the aortic annulus perimeter-derived diameter, and other basic planes, coronary ostia height, calcification volume, and aortic angle. The intraclass correlation coefficient values for the algorithm in the internal and external validation datasets were up to 0.998 (95% confidence interval 0.998-0.998), respectively. Furthermore, the algorithm demonstrated high alignment in detecting specific anatomical risk factors, with accuracy, sensitivity, and specificity up to 0.989 (95% CI 0.973-0.996), 0.979 (95% CI 0.936-0.995), 0.986 (95% CI 0.945-0.998), respectively.

INTERPRETATION

Our algorithm efficiently performs pre-TAVR assessments by using AVC CT imaging with accuracy comparable to senior observers, potentially improving TAVR planning in clinical practice.

FUNDING

National Key R&D Program of China (2020YFC2008100), CAMS Innovation Fund for Medical Sciences (2022-I2M-C&T-B-044).

Multimodality Imaging in Aortic Stenosis: Beyond the Valve - Focusing on the Myocardium

Current guidelines of aortic stenosis (AS) management focus on valve parameters, LV systolic dysfunction, and symptoms; however, emerging data suggest that there may be benefit of aortic valve replacement before it becomes severe by present criteria. Myocardial assessment using novel multimodality imaging techniques exhibits subclinical myocardial injury and remodeling at various stages before guideline-directed interventions, which predicts adverse outcomes. This raises the question of whether implementing serial myocardial assessment should become part of the standard appraisal, thereby identifying high-risk patients aiming to minimize adverse outcomes.

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.

Incremental prognostic value of intensity-weighted regional calcification scoring using contrast CT imaging in TAVR

Aims

Aortic valve calcification scoring plays an important role in predicting outcomes of transcatheter aortic valve replacement (TAVR). However, the impact of relative calcific density and its causal effect on peri-procedural complications due to sub-optimal valve expansion remains limited. This study aims to investigate the prognostic power of quantifying regional calcification in the device landing zone in the context of peri-procedural events and post-procedural complications based on pre-operative contrast computed tomography angiography (CCTA) images. Assess the effect of calcification on post-procedural device expansion and final configuration.

Methods and results

We introduce a novel patient invariant topographic scheme for quantifying the location and relative density of landing zone calcification. The calcification was detected on CCTA images based on a recently developed method using automatic minimization of the false positive rate between aortic lumen and calcific segments. Multinomial logistic regression model evaluation and ROC curve analysis showed excellent classification power for predicting paravalvular leakage [area under the curve (AUC) = 0.8; P < 0.001] and balloon pre-dilation (AUC = 0.907; P < 0.001). The model exhibited an acceptable classification ability for left bundle branch block (AUC = 0.748; P < 0.001) and balloon post-dilation (AUC = 0.75; P < 0.001). Notably, all evaluated models were significantly superior to alternative models that did not include intensity-weighted regional volume scoring.

Conclusions

TAVR planning based on contrast computed tomography images can benefit from detailed location, quantity, and density contribution of calcific deposits in the device landing zone. Those parameters could be employed to stratify patients who need a more personalized approach during TAVR planning, predict peri-procedural complications, and indicate patients for follow-up monitoring.

Calcium Scoring to Classify Aortic Valve Stenosis Severity: What Is the Current Data?

PURPOSE OF REVIEW

This review explores current clinical value of aortic valve calcification (AVC) in classifying aortic valve stenosis (AS) severity, refining patient's follow-up, as well as novel and potential applications of this highly accurate marker in improving outcomes for AS patients. AVC limitations and important particularities regarding sex, valve phenotype, and ethnicity will also be addressed.

RECENT FINDINGS

Sex-specific AVC cut-offs have been included in current guidelines to identify severe AS when echocardiography is inconclusive. AVC is also associated with AS progression and could help refine the timing for patient's follow-up. In patients with AS, Doppler echocardiography is the gold standard for the assessment of AS severity. However, in more than one-third of patients, echocardiographic parameters are discordant, casting shadow on the true severity of the disease. Considering active leaflet calcification is the driving mechanism of AS, quantification of AVC has been shown to be of great interest for distinguishing true-severe from pseudo-severe AS. Moreover, AVC is closely associated with AS progression and outcomes.