Predicting the outcome of transcatheter mitral valve implantation using image-based computational models

BackgroundThe appropriate placement and size selection of mitral prostheses in transcatheter mitral valve implantation (TMVI) is critical, as encroachment on the left ventricular outflow tract (LVOT) may lead to flow obstruction. Recent advances in computed tomography (CT) can be employed for pre-procedural planning of mitral prosthetic valve placement. This study aims to develop patient-specific computational fluid dynamics models of the left ventricle (LV) in the presence of a mitral valve prosthesis to investigate blood flow and LVOT pressure gradient during systole.MethodsPatient-specific computational fluid dynamics simulations of TMVI with varied cardiac anatomy and insertion angles were performed (n = 30). Wide-volume full cycle cardiovascular CT images prior to TMVI were used as source anatomical data (n = 6 patients). Blood movement was governed by Navier-Stokes equations and the LV endocardial wall deformation was derived from each patient's CT images.ResultsThe computed pressure gradients in the presence of the mitral prosthesis compared well with clinically measured gradients. Analysis of the effects of prosthetic valve angulation, aorto-mitral annular angle, ejection fraction, LV size and new LVOT area (neo-LVOT) after TMVI in silico revealed that the neo-LVOT area (p < 0.001) was the most significant factor affecting LVOT pressure gradient. Angulation of the mitral valve can substantially mitigate LVOT gradient.ConclusionsComputational fluid dynamics simulation is a promising method to aid in pre-TMVI planning and understanding the factors underlying LVOT obstruction.     

Predicting paravalvular leak after transcatheter mitral valve replacement using commercially available software modeling

BackgroundThere is limited data identifying patients at risk for significant mitral regurgitation (MR) after transcatheter mitral valve replacement (TMVR). We hypothesized that software modeling based on computed tomography angiography (CTA) can predict the risk of moderate or severe MR after TMVR.Methods58 consecutive patients underwent TMVR at two institutions, including 31 valve-in-valve, 16 valve-in-ring, and 11 valve-in-mitral annular calcification. 12 (20%) patients developed moderate or severe MR due to paravalvular leak (PVL).ResultsThe software model correctly predicted 8 (67%) patients with significant PVL, resulting in sensitivity of 67%, specificity 96%, positive predictive value 89%, and negative predictive value 86%. There was excellent agreement between CTA readers using software modeling to predict PVL (kappa 0.92; p < 0.01). On univariate analysis, CTA predictors of moderate or severe PVL included presence of a gap between the virtual valve and mitral annulus on the software model (OR 48; p < 0.01), mitral annular area (OR 1.02; p 0.01), and % valve oversizing (OR 0.9; p 0.01). On multivariate analysis, only presence of a gap on the software model remained significant (OR 36.8; p < 0.01).ConclusionsSoftware modeling using pre-procedural CTA is a straightforward method for predicting the risk of moderate and severe MR due to PVL after TMVR.     

A simplified D-shaped model of the mitral annulus to facilitate CT-based sizing before transcatheter mitral valve implantation

BackgroundThe nonplanar, saddle-shaped structure of the mitral annulus has been well established through decades of anatomic and echocardiographic study. Its relevance for mitral annular assessment for transcatheter mitral valve implantation is uncertain.ObjectiveOur objectives are to define the methodology for CT-based simplified “D-shaped” mitral annular assessment for transcatheter mitral valve implantation and compare these measurements to traditional “saddle-shaped” mitral annular assessment.MethodsThe annular contour was manually segmented, and fibrous trigones were identified using electrocardiogram-gated diastolic CT data sets of 28 patients with severe functional mitral regurgitation, yielding annular perimeter, projected area, trigone-to-trigone (TT) distance, and septal-lateral distance. In contrast to the traditional saddle-shaped annulus, the D-shaped annulus was defined as being limited anteriorly by the TT distance, excluding the aortomitral continuity. Hypothetical left ventricular outflow tract (LVOT) clearance was assessed.ResultsProjected area, perimeter, and septal-lateral distance were found to be significantly smaller for the D-shaped annulus (11.2 ± 2.7 vs 13.0 ± 3.0 cm²; 124.1 ± 15.1 vs 136.0 ± 15.5 mm; and 32.1 ± 4.0 vs 40.1 ± 4.9 mm, respectively; P < .001). TT distances were identical (32.7 ± 4.1 mm). Hypothetical LVOT clearance was significantly lower for the saddle-shaped annulus than for the D-shaped annulus (10.7 ± 2.2 vs 17.5 ± 3.0 mm; P < .001).ConclusionBy truncating the anterior horn of the saddle-shaped annular contour at the TT distance, the resulting more planar and smaller D-shaped annulus projects less onto the LVOT, yielding a significantly larger hypothetical LVOT clearance than the saddle-shaped approach. CT-based mitral annular assessment may aid preprocedural sizing, ensuring appropriate patient and device selection.     

Tricuspid valve anatomy of massive to torrential tricuspid regurgitation: Computed tomography analysis

BackgroundWe aimed to comprehensively assess tricuspid valve anatomy and to determine factors associated with the more advanced stages beyond severe TR (i.e., massive to torrential).MethodsWe retrospectively analyzed the pre-procedural cardiac CT images in patients with ≥severe TR using 3mensio software. The tricuspid valve annulus size, right-atrial and right-ventricular dimensions, tenting height, and leaflet angles were measured.ResultsA total of 103 patients were analyzed. The mean effective regurgitant orifice area was 61.7 ​± ​31.5 ​mm², vena contracta was 13.1 ​± ​4.6 ​mm, and massive/torrential TR was observed in 62 patients. Compared to patients with severe TR, patients with massive/torrential TR had a larger tricuspid annulus area (18.6 ​± ​3.4 ​cm² vs. 20.6 ​± ​5.3 ​cm², p ​= ​0.037), right atrial short-axis diameter (66.1 ​± ​9.1 ​mm vs. 70.6 ​± ​9.9 ​mm, p ​= ​0.022), increased tenting height (8.8 ​± ​3.6 ​mm vs. 10.7 ​± ​3.7 ​mm, p ​= ​0.014), and greater leaflet angles (anterior leaflet: 22 ​± ​9° vs. 32 ​± ​13°, p ​< ​0.001; posterior leaflet: 22 ​± ​11° vs. 30 ​± ​11°, p ​= ​0.003). In the multivariable logistic regression model, the angle of anterior leaflet (OR 1.08, 95%CI 1.03–1.14, p ​= ​0.004) and posterior leaflet (OR 1.07, 95%CI 1.02–1.13, p ​= ​0.007) were associated with massive/torrential TR. Additionally, patients with massive/torrential TR more often had TR jets from non-central/non-anteroseptal commissure (34% vs. 76%, p ​< ​0.001). In the multivariable model, a greater angle of the leaflets and a more elliptical annulus were associated with non-central/non-anteroseptal TR jets.ConclusionsAnterior and posterior leaflet angles are significant factors associated with massive/torrential TR. Furthermore, leaflet angles and ellipticity of the tricuspid valve are associated with the location of TR jets.     

Mitral annular calcification in the elderly – Quantitative assessment

PurposeTo determine the reliability of subjective and objective quantification of mitral annular calcification (MAC) in elderly patients with severe aortic stenosis, to define quantitative sex- and age-related reference values of MAC, and to correlate quantitative MAC with mitral valve disease.MethodsIn this retrospective, IRB-approved study, we included 559 patients (268 females, median age 81 years, inter-quartile range 77–85 years) with severe aortic stenosis undergoing CT. Four independent readers performed subjective MAC categorization as follows: no, mild, moderate, and severe MAC. Two independent readers performed quantitative evaluation of MAC using the Agatston score method (Agatston_MAC). Mitral valve disease was determined by echocardiography.ResultsSubjective MAC categorization showed high inter-reader agreement for no (k ?= ?0.88) and severe MAC (k ?= ?0.75), whereas agreement for moderate (k ?= ?0.59) and mild (k ?= ?0.45) MAC was moderate. Intra-reader agreement for subjective MAC categorization was substantial (k ?= ?0.69 and 0.62). Inter- and intra-reader agreement for Agatston_MAC were excellent (ICC ?= ?0.998 and 0.999, respectively), with minor inconsistencies in MAC involving the left ventricular outflow tract/aortic valve. There were significantly more women than men with MAC (n ?= ?227, 85% versus n ?= ?209, 72%; p ?< ?0.001), with a significantly higher Agatston_MAC (median 597, range 81–2055 versus median 244; range 0–1565; p ?< ?0.001), particularly in patients ≥85 years of age. Agatston_MAC showed an area-under-the-curve of 0.84 to diagnose mitral stenosis, whereas there was no association of Agatston_MAC with mitral regurgitation (p ?> ?0.05).ConclusionsOur study in elderly patients with severe aortic stenosis shows that quantitative MAC scoring is more reliable than subjective MAC assessment. Women show higher Agatston_MAC scores than men, particularly in the elderly population. Agatston_MAC shows high accuracy to diagnose mitral stenosis.     

Left ventricular and atrial strain imaging with cardiac computed tomography: Validation against echocardiography

BackgroundData on left ventricular (LV) deformation imaging using CT angiography (CTA) are scarce and the feasibility of atrial deformation analysis by CT has not been addressed. We aimed to compare 2D echocardiographic and CT derived LV and left atrial (LA) global longitudinal strain (GLS) obtained by using a novel feature tracking algorithm in patients following transcatheter aortic valve implantation.MethodsTwenty-eight patients were included who underwent retrospectively-gated 256-slice CTA and speckle-tracking echocardiography (STE) on the same day. CT datasets in 10% increments were reconstructed throughout the cardiac cycle. LV GLS and LA global peak reservoir strain (LA GS) was measured.ResultsMedian absolute values for LV GLS were 19.9 [14.8–22.4] vs. 19.9 [16.8–24.7], as measured by CT vs STE, respectively (p = 0.017). We found good inter-modality correlation for LV GLS (ρ = 0.78, p < 0.05) with a mean bias of −1.6. Regarding atrial measurements, the median LA GS was 19.0 [13.5–27.3] for CT vs. 28.0 [17.5–32.6] for STE (p < 0.001) with a mean bias of −5.6 between CT and STE and a correlation coefficient of ρ = 0.87, p < 0.001. CT measurements were highly reproducible: intra-observer intra-class correlation coefficient was 0.96 for LV GLS and 0.95 for LA GS.ConclusionWe detected good correlation between CTA and echocardiography-based LV and LA longitudinal strain parameters. CTA provides accurate strain measurements with high reproducibility. Feature tracking-based deformation analysis could provide a clinically important addition to CT examinations by complementing anatomical information with functional data.     

Dynamic computed tomographic assessment of the mitral annulus in patients with and without mitral prolapse

ObjectivesTo obtain 3D CT measurements of mitral annulus throughout cardiac cycle using prototype mitral modeling software, assess interobserver agreement, and compare among patients with mitral prolapse (MP) and control group.BackgroundPre-procedural imaging is critical for planning of transcatheter mitral valve (MV) replacement. However, there is limited data regarding reliable CT-based measurements to accurately characterize the dynamic geometry of the mitral annulus in patients with MV disease.MethodsPatients with MP and control subjects without any MV disease who underwent ECG-gated cardiac CT were retrospectively identified. Multiphasic CT data was loaded into a prototype mitral modeling software. Multiple anatomical parameters in 3D space were recorded throughout the cardiac cycle (0–95%): annular circumference, planar-surface-area (PSA), anterior-posterior (A-P) distance, and anterolateral-posteromedial (AL-PM) distance. Comparisons were made among the two groups, with p < 0.05 considered statistically significant. Interobserver agreement was assessed on ten patients using intraclass correlation coefficient (ICC) among 4 experienced readers.ResultsA total of 100 subjects were included: 50 with MP and 50 control. Annular dimensions were significantly higher in the MP group than control group, with circumference (144 ± 11 vs. 117±8 mm), PSA (1533 ± 247 vs. 1005 ± 142 mm²), A-P distance (38 ± 4 vs. 32±2 mm), and AL-PM distance (47 ± 4 vs. 39±3 mm) (all p < 0.001). Substantial size changes were observed throughout the cardiac cycle, but with maximal and minimal sizes at different cardiac phases for the two groups. The interobserver agreement was excellent (ICC≥0.75) for annular circumference, PSA, A-P- and AL-PM distance.ConclusionA significant variation in the mitral annular measures between different cardiac phases and two groups was observed with excellent interobserver agreement.     

Impact of papillary and trabecular muscles on quantitative analyses of cardiac function in hypertrophic cardiomyopathy

Purpose:

To examine the impact of cardiovascular magnetic resonance (CMR) partitioning methods on volumetric analysis in hypertrophic cardiomyopathy (HCM) patients. The standard CMR method for partitioning ventricular myocardium from ventricular cavity includes the myocardial papillary and trabecular muscles in the cavity volume. This approach may misrepresent ventricular mass and volume in patients with HCM due to large papillary muscles and extensive trabeculations.

Materials and Methods:

Ventricular volume and mass analyses were performed in 30 patients with HCM using the standard method and a detailed method that excluded papillary and trabecular muscles from the left ventricular (LV) volume while including them in LV mass. We also analyzed the degree of mitral regurgitation and compared the results with Doppler echocardiography in a subgroup of 12 patients. Interobserver variability was assessed.

Results:

The detailed method yielded 17% higher indexed LV mass, 20% lower indexed LV diastolic volume, 13% higher LV ejection fraction (EF) (all P < 0.0001). The resultant mitral regurgitant volumes using the detailed method had less discrepancy with Doppler echocardiography results compared with the results from the standard methods. Interobserver variability was similar by both methods.

Conclusion:

For patients with HCM, a detailed analysis in which the ventricular papillary and trabecular muscles are excluded from LV volume is preferred. J. Magn. Reson. Imaging 2009;30:1197–1202. © 2009 Wiley‐Liss, Inc.     

Chronic mitral regurgitation detected on cardiac MDCT: differentiation between functional and valvular aetiologies

Objective

To determine whether cardiac computed tomography (MDCT) can differentiate between functional and valvular aetiologies of chronic mitral regurgitation (MR) compared with echocardiography (TTE).

Methods

Twenty-seven patients with functional or valvular MR diagnosed by TTE and 19 controls prospectively underwent cardiac MDCT. The morphological appearance of the mitral valve (MV) leaflets, MV geometry, MV leaflet angle, left ventricular (LV) sphericity and global/regional wall motion were analysed. The coronary arteries were evaluated for obstructive atherosclerosis.

Results

All control and MR cases were correctly identified by MDCT. Significant differences were detected between valvular and control groups for anterior leaflet length (30?±?7 mm vs. 22?±?4 mm, P?<?0.02) and thickness (3.0?±?1 mm vs. 2.2?±?1 mm, P?<?0.01). High-grade coronary stenosis was detected in all patients with functional MR compared with no controls (P?<?0.001). Significant differences in those with/without MV prolapse were detected in MV tent area (?1.0?±?0.6 mm vs. 1.3?±?0.9 mm, P?<?0.0001) and MV tent height (?0.7?±?0.3 mm vs. 0.8?±?0.8 mm, P?<?0.0001). Posterior leaflet angle was significantly greater for functional MR (37.9?±?19.1° vs. 22.9?±?14°, P?<?0.018) and less for valvular MR (0.6?±?35.5° vs. 22.9?±?14°, P?<?0.017). Sensitivity, specificity, and positive and negative predictive values of MDCT were 100%, 95%, 96% and 100%.

Conclusion

Cardiac MDCT allows the differentiation between functional and valvular causes of MR.     

Clinical impact of mitral calcium volume in patients undergoing transcatheter aortic valve implantation

BackgroundMitral annular calcification (MAC) has been associated with mitral valve (MV) disease and cardiovascular events in patients undergoing transcatheter aortic valve implantation (TAVI). We aimed to investigate the incidence and impact of mitral calcium volume (MCV) quantified by multidetector computed tomography (MDCT) on MV function and clinical outcomes after TAVI.MethodsConsecutive patients with exploitable echocardiography and MDCT performed during TAVI screening were enrolled in this retrospective analysis. Mitral calcium was assessed visually and measured using a semi-automatic tool developed for the aortic valve in an off-label fashion.ResultsMCV >0 mm³ was found in 65% of the 875 included patients. Patients with calcification were older (82 ± 6 versus 81 ± 7; P = 0.002) and had high prevalence of renal dysfunction (69% versus 61%; P = 0.017) and mitral stenosis (25% versus 4%, P < 0.001). MCV correlated well with visual MAC severity (r = 0.94; P < 0.001), but showed a greater predictive value for mitral stenosis (AUC = 0.804 vs. 0.780, P = 0.012) , while it was not a predictor of mitral regurgitation (AUC = 0.514). Correlations were found between MCV and echocardiographic parameters including MV area, mean transmitral gradient, and pressure half-time (P < 0.001 for all). MCV did not impact on cardiovascular mortality or new permanent pacemaker implantation after TAVI.ConclusionsCalcification of the mitral apparatus is common in TAVI candidates and results in mitral stenosis in 25% of the patients. Increasing MCV predicts mitral stenosis, but had no impact on clinical outcomes following TAVI.Clinical trial registrationNCT01368250.     

Late Gadolinium Enhancement of Left Ventricular Papillary Muscles in Patients with Mitral Regurgitation

ObjectiveArrhythmogenic mitral valve prolapse (MVP) is an important cause of sudden cardiac death characterized by fibrosis of the papillary muscles or left ventricle (LV) wall, and an association between late gadolinium enhancement (LGE) of the LV papillary muscles and ventricular arrhythmia in MVP has been reported. However, LGE of the papillary muscles may be observed in other causes of mitral regurgitation, and it is not limited to patients with MVP. This study was to evaluate the association of LGE of the LV papillary muscles or ventricular wall on cardiac magnetic resonance imaging (CMR) and ventricular arrhythmia in patients with mitral regurgitation.Materials and MethodsThis study included 88 patients (mean age ± standard deviation, 58.3 ± 12.0 years; male, 42%) with mitral regurgitation who underwent CMR. They were allocated to the MVP (n = 43) and non-MVP (n = 45) groups, and their LGE images on CMR, clinical characteristics, echocardiographic findings, and presence of arrhythmia were compared.ResultsLV myocardial wall enhancement was more frequent in the MVP group than in the non-MVP group (28% vs. 11%, p = 0.046). Papillary muscle enhancement was observed in 7 (7.9%) patients. Of the 43 patients with MVP, 15 (34.8%) showed LGE in the papillary muscles or LV myocardium, including 12 (27.9%) with LV myocardial wall enhancement and 4 (9.3%) with papillary muscle enhancement. One patient with bilateral diffuse papillary muscle enhancement experienced sudden cardiac arrest due to ventricular fibrillation. Univariable logistic regression analysis showed that high systolic blood pressure (BP; odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01–1.09; p = 0.027) and ventricular arrhythmia (OR, 6.84; 95% CI, 1.29–36.19; p = 0.024) were significantly associated with LGE of the papillary muscles.ConclusionLGE of the papillary muscles was present not only in patients with MVP, but also in patients with other etiologies of mitral regurgitation, and it was associated with high systolic BP and ventricular arrhythmia. Papillary muscle enhancement on CMR should not be overlooked.     

Automated quantification of mitral valve geometry on multi-slice computed tomography in patients with dilated cardiomyopathy – Implications for transcatheter mitral valve replacement

ObjectivesThe primary aim of this study was to quantify the dimensions and geometry of the mitral valve complex in patients with dilated cardiomyopathy and significant mitral regurgitation. The secondary aim was to evaluate the validity of an automated segmentation algorithm for assessment of the mitral valve compared to manual assessment on computed tomography.BackgroundTranscatheter mitral valve replacement (TMVR) is an evolving technique which relies heavily on the lengthy evaluation of cardiac computed tomography (CT) datasets. Limited data is available on the dimensions and geometry of the mitral valve in pathological states throughout the cardiac cycle, which may have implications for TMVR device design, screening of suitable candidates and annular sizing prior to TMVR.MethodsA retrospective study of 15 of patients with dilated cardiomyopathy who had undergone full multiphase ECG gated cardiac CT. A comprehensive evaluation of mitral valve geometry was performed at 10 phases of the cardiac cycle using the recommended D-shaped mitral valve annulus (MA) segmentation model using manual and automated CT interpretation platforms. Mitral annular dimensions and geometries were compared between manual and automated methods.ResultsMitral valve dimensions in patients with dilated cardiomyopathy were similar to previously reported values (MA_area Diastole: 12.22 ± 1.90 cm²), with dynamic changes in size and geometry between systole and diastole of up to 5%. The distance from the centre of the MA to the left ventricular apex demonstrated moderate agreement between automated and manual methods (ρ_c = 0.90) with other measurements demonstrating poor agreement between the two methods (ρ_c = 0.75–0.86).ConclusionsVariability of mitral valve annulus measurements are small during the cardiac cycle. Novel automated algorithms to determine cardiac cycle variations in mitral valve geometry may offer improved segmentation accuracy as well as improved CT interpretation times.     

心肌梗死伴二尖瓣返流影响因素的心脏MR研究

目的:采用心脏磁共振成像探究伴或不伴二尖瓣返流的心肌梗死患者的左心室结构和功能差异,并分析可能促使心肌梗死患者发生二尖瓣返流的影响因素.方法:回顾性分析心肌梗死患者131例,并将其分为不伴二尖瓣返流组(56例)以及伴二尖瓣返流组(75例),分析比较两组的一般临床资料、左心室结构功能数据及钆对比剂延迟强化数据.结果:与不...     

ECG-gated multi-detector row CT for assessment of mitral valve disease: initial experience

Our objective was to evaluate applicability and image quality of contrast-enhanced, retrospectively ECG-gated multi-detector row CT (MDCT) for visualization of anatomical details of the mitral valve and its apparatus, and to determine the value of MDCT for diagnosing abnormal findings of the mitral valve. Twenty consecutive patients with mitral valve disease underwent MDCT preoperatively. Two readers assessed visibility of the mitral valve annulus, mitral valve leaflets, tendinous cords, and papillary muscles by using a four-point Likert grading scale. Abnormal mitral valve findings [thickening of the mitral valve leaflets, presence of mitral annulus calcification (MAC), and calcification of the valvular leaflets] were compared with preoperative echocardiography and intraoperative findings. Visibility of the mitral valve annulus and mitral valve leaflets was good or excellent in 15 patients (75%) and in 19 patients (95%) for papillary muscles. The MDCT yielded a 95–100% agreement compared with echocardiography and surgery with regard to the assessment of mitral valve leaflet thickening and the presence of calcifications of the mitral valve annulus or mitral valve leaflets. Intermodality agreement between MDCT and echocardiography was excellent with regard to classification of mitral valve leaflet thickness (κ=1.00) and good regarding classification of MAC thickness (κ=0.73). Contrast-enhanced, retrospectively ECG-gated MDCT allows good to excellent visualization of anatomical details of the mitral valve and its apparatus, and demonstrates good agreement with echocardiography and surgery in diagnosing mitral valve abnormalities. Electronic Publication     

Clinical outcomes following transcatheter aortic valve implantation in patients with porcelain aorta

BackgroundCurrent guidelines favor transcatheter aortic valve implantation (TAVI) over surgical aortic valve replacement in patients with porcelain aorta (PAo). The clinical relevance of PAo in patients undergoing TAVI is however incompletely understood. The purpose of this study is to evaluate clinical outcome of patients with PAo undergoing TAVI.MethodsConsecutive patients undergoing TAVI were enrolled in a prospective single-center registry. Presence of PAo was evaluated by ECG-gated multi-slice computed tomography prior to the intervention. The primary endpoint was disabling stroke.ResultsAmong 2199 patients (mean age, 82.0 ?± ?6.3 years; 1135 females [51.6%]) undergoing TAVI between August 2007 and December 2019, 114 patients (5.2%) met VARC-2 criteria for PAo. Compared to individuals without PAo, patients with PAo were younger (79.4 ?± ?7.4 years vs. 82.1 ?± ?6.2 years; p ?< ?0.001), had a lower left ventricular ejection fraction (51.8 ?± ?14.9% vs. 55.3 ?± ?14.2%; p ?= ?0.009) and higher STS-PROM Scores (6.5 ?± ?4.3% vs. 4.9 ?± ?3.4%; p ?< ?0.001). At 1 year, disabling stroke occurred more often in patients with PAo (7.2%) than in those without (3.0%) (HR_adj, 2.49; 95% CI, 1.12–5.55). The risk difference emerged within 30 days after TAVI (HR_adj, 3.70; 95% CI, 1.52–9.03), and was driven by a high PAo-associated risk of disabling stroke in patients with alternative access (HR_adj, 5.79; 95% CI, 1.38–24.3), not in those with transfemoral (HR_adj, 1.47; 95% CI 0.45–4.85).ConclusionsTAVI patients with PAo had a more than three-fold increased risk of periprocedural disabling stroke compared to patients with no PAo. The difference was driven by a higher risk of stroke in patients treated by alternative access.     

Magnetic resonance evaluation of mitral stenosis

In order to study magnetic resonance (MR) abnormalities in mitral stenosis electrocardiogram (ECG)-gated MR imaging was performed with a 2.0 T MR system in 41 patients with mitral stenosis before catheterization. Mean transverse diameter of the left atrium was 8.9±1.4 cm and anteroposterior diameter was 5.1±1.0 cm, indicating significant enlargement. Homogeneous or inhomogeneous flow-related signals in ventricular diastole were detected in the left atrial cavity in 32 cases (78%), and in the atrial appendage in 35 cases (85%). In 21 patients having a mean wedge pulmonary arterial pressure higher than 20 mm Hg, 20 patients (95%) showed flow-related signals in ventricular diastole. Other MR findings were mitral valve doming in diastole, flow-related signal in the pulmonary artery during systole, and left atrial thrombi.     

Deep learning model to quantify left atrium volume on routine non-contrast chest CT and predict adverse outcomes

BackgroundLow-dose computed tomography (LDCT) are performed routinely for lung cancer screening. However, a large amount of nonpulmonary data from these scans remains unassessed. We aimed to validate a deep learning model to automatically segment and measure left atrial (LA) volumes from routine NCCT and evaluate prediction of cardiovascular outcomes.MethodsWe retrospectively evaluated 273 patients (median age 69 years, 55.5% male) who underwent LDCT for lung cancer screening. LA volumes were quantified by three expert cardiothoracic radiologists and a prototype AI algorithm. LA volumes were then indexed to the body surface area (BSA). Expert and AI LA volume index (LAVi) were compared and used to predict cardiovascular outcomes within five years. Logistic regression with appropriate univariate statistics were used for modelling outcomes.ResultsThere was excellent correlation between AI and expert results with an LAV intraclass correlation of 0.950 (0.936–0.960). Bland-Altman plot demonstrated the AI underestimated LAVi by a mean 5.86 ?mL/m². AI-LAVi was associated with new-onset atrial fibrillation (AUC 0.86; OR 1.12, 95% CI 1.08–1.18, p ?< ?0.001), HF hospitalization (AUC 0.90; OR 1.07, 95% CI 1.04–1.13, p ?< ?0.001), and MACCE (AUC 0.68; OR 1.04, 95% CI 1.01–1.07, p ?= ?0.01).ConclusionThis novel deep learning algorithm for automated measurement of LA volume on lung cancer screening scans had excellent agreement with manual quantification. AI-LAVi is significantly associated with increased risk of new-onset atrial fibrillation, HF hospitalization, and major adverse cardiac and cerebrovascular events within 5 years.     

Extent and severity of coronary artery disease by coronary CT angiography is associated with elevated left ventricular diastolic pressures and worsening diastolic function

BackgroundPatients with flow-limiting coronary stenoses exhibit elevated left ventricular end-diastolic pressure (LVEDP) and abnormal left ventricular (LV) relaxation.ObjectiveWe investigated the relationship of extent and severity of coronary artery disease (CAD) by coronary CT angiography (CTA) to LVEDP and measures of LV diastolic dysfunction.MethodsWe identified consecutive patients undergoing coronary CTA and transthoracic echocardiography who were assessed for diastolic function. CAD was evaluated on a per-patient, per-vessel, and per-segment basis for intraluminal diameter stenosis by using an 18-segment model (0 = none, 1 = 1%–49%, 2 = 50%–69%, and 3 = 70%–100%) and summed over segments to obtain overall coronary plaque burden (segment stenosis score [SSS]; maximum = 54). Transthoracic echocardiography evaluated mitral inflow E wave-to-A wave ratio, tissue Doppler early mitral annual tissue velocity axial excursion, stage of diastolic dysfunction, and LV dimensions and estimated LVEDP from the ratio of mitral inflow velocity to early mitral annular (medial) tissue velocity.ResultsFour hundred seventy-eight patients (57% women; mean age, 57.9 ± 14.6 years; 24.9% prior CAD) comprised the study population. Increasing per-patient maximal coronary stenosis, number of vessels with obstructive stenosis, and SSS were associated with increased LVEDP. The prevalence of advanced diastolic dysfunction increased with greater number of obstructive vessels. In multivariable analyses, SSS was associated with increased LVEDP (0.8 mm Hg per tertile increase in SSS, 0.5–1.1; P < .001); reduced E′ axial excursion (?0.3; 95% confidence interval [CI], ?0.5 to ?0.1; P = .001), increased LV mass index (1.6 g/m² per tertile increase in SSS; P = .04), and increased relative wall thickness (0.005; 95% CI, 0.004–0.009; P = .03), with consistent relationships persisting even among persons with per-patient maximal stenosis <50% and LV ejection fraction ≥55%.ConclusionsExtent and severity of obstructive as well as nonobstructive CAD by coronary CTA are associated with increased LVEDP and measures of diastolic dysfunction.     

Transcatheter mitral valve replacement in mitral annulus calcification – “The art of computer simulation”

There is considerable interest in transcatheter prosthetic valve treatment for mitral valve disease in high-risk individuals. Although the presence of mitral annular calcium (MAC) may provide an anchoring zone for such devices, results to date have been modest with reported technical failure rates approaching 30% in specialist centers. This in part relates to the risk of left ventricular outflow tract obstruction and device dislodgment but also to the lack of specific imaging guidelines to plan for such procedures. We present the use of finite element analysis and computer simulation based on cardiac CT in three patients with severe MAC in whom transcatheter devices were considered. In the first two cases, the computer simulations were performed after the clinical procedure and were concordant with the clinical outcome. For the third case, computer simulation was performed prior to the clinical procedure. This indicated unsuitability for transcatheter device deployment and a subsequent medical management was adopted. Overall, our initial results suggest that computer simulation may have the potential to improve patient selection for transcatheter mitral valve replacement in the presence of significant MAC.     

Sixty-four-slice multidetector computed tomography for preoperative evaluation of left ventricular function and mass in patients with mitral regurgitation: comparison with magnetic resonance imaging and echocardiography

Quantitative values of left ventricular (LV) function and muscle mass in patients with mitral regurgitation are independent predictors of cardiac morbidity and mortality. The aim of this study was to prospectively evaluate whether 64-MDCT can assess the LV function in patients with mitral regurgitation with high accuracy when compared with the MRI and echocardiography results. Fifty-one patients with mitral regurgitation underwent retrospectively ECG-gated 64-MDCT, echocardiography, and MRI for assessing the global ventricular function. End-diastolic and end-systolic volume, stroke volume, ejection fraction, and mass were measured on 64-MDCT and echocardiography, and compared with the results measured on MRI which served as the reference standard. Intertechnique agreement was tested by using Pearson’s correlation and Bland–Altman analyses. No significant differences were revealed in calculated LV function and mass between the 64-MDCT and MRI (paired t test, p = 0.07–0.53). Pearson’s correlation analysis showed the functional parameters and mass correlated closely between the 64-MDCT and MRI (r = 0.89–0.96, p < 0.001). When compared with MRI, echocardiography underestimated the volumetric parameters of LV (paired t test, p = 0.0003–0.004), but significantly overestimated the EF values (p = 0.003), and moderate correlations of functional parameters were obtained (r = 0.78, 0.60, 0.81, and 0.62, respectively). ECG-gated 64-MDCT allows for accurate and reliable assessment of LV function in patients with mitral regurgitation, whereas LV volumes measured by two-dimensional echocardiography were underestimated and the ejection fraction was overestimated when compared with those achieved by using MRI.