New echocardiographic screening tool for left ventricular tract obstruction risk assessment in TMVR.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) is an alternative to conventional surgery to treat severe mitral disease but its use is limited by the risk of left ventricular outflow tract obstruction (LVOTO). Screening depends on ECG-gated computed tomography (CT) that is not widely available and requires contrast. We developed and validated a transthoracic echocardiographic (TTE) method to assess the risk of LVOTO after TMVR with the Tendyne System. METHODS: We measured the LVOT longitudinal area on preoperative TTE dataset of patients screened for TMVR. The LVOT was measured as the box-area included by the aortic valve annulus, the anterior mitral leaflet (AML), the c-septum distance line, and the respective length of the AML on the interventricular septum. We analyzed the correlation between the TTE LVOT-box and the CT-measured neoLVOT area. Prediction performance for eligible patients was tested with ROC curves. RESULTS: Thirty-nine patients were screened, out of 14 patients (36%) not eligible for TMVR, 8 had risk of LVOTO. We found a linear correlation between the TTE LVOT-box and the CT-measured Neo-LVOT (r = 0.6, p = 0.002). ROC curve showed that the method is specific and sensitive and the cut-off value of the measure LVOT-box is 350 mm2. CONCLUSIONS: The proposed method is reliable to evaluate the risk of LVOTO after TMR with the Tendyne System. It is quick and easy and can be used as a first-line assessment in the outpatient clinic. Patients with LVOT-box <350 mm2 should not be further screened with ECG-gated cardiac CT.

Multiple ventricular septal defects associated to anomalous venous returns, mitral valve disease, myocardium hypertrophy, and right outflow obstruction: a multimodality imaging assessment.

We report a rare congenital heart disease characterized by multiple ventricular septal defects associated to anomalous systemic and pulmonary venous returns, marked apical myocardial hypertrophy of both ventricles and of right outflow, and hypoplastic mitral anulus. Multimodality imaging is mandatory to assess anatomical details.

Incidence and management of the left ventricular outflow obstruction in patients with atrioventricular septal defects.

OBJECTIVES: Left ventricular outflow tract obstruction (LVOTO) is a recognized complication after complete repair of atrioventricular septal defect (AVSD). This study reviewed the incidence and management of LVOTO following AVSD repair at a single institution. METHODS: From 1975 to 2019, 24 patients (3.3%, 24/730) underwent reoperation due to LVOTO following partial AVSD (pAVSD) and complete AVSD (cAVSD) repair. The data were retrospectively reviewed. RESULTS: The incidence of LVOTO following pAVSD and cAVSD repair was 4.4% (12/275) and 2.6% (12/455). Freedom from LVOTO reoperation following pAVSD and cAVSD repair at 25 years was 94.3% [95% confidence interval (CI); 89.7-96.7] and 95% (95% CI; 91.1-97.3). The median time from complete repair of pAVSD and cAVSD to LVOTO reoperation was 4.4 years [interquartile range (IQR): 3.4-6.7] and 2.6 years (IQR: 2.2-4.7). Freedom from second LVOTO reoperation at 5, 10 and 15 years was 83.7% (95% CI; 57.2-98.2), 59.2% (95% CI; 28.7, 80.3) and 39.5% (95% CI; 13.2-65.3). The median time between the first and the second LVOTO reoperation in the groups of pAVSD and cAVSD was 6.1 years (IQR: 3.4-8.9) and 8.6 years (IQR: 5.7-9.8). There was no significant difference regarding the first (P = 0.7406) and subsequent LVOTO (P = 0.7153) following complete repair of pAVSD and cAVSD. Combined access to the left ventricular outflow tract was not protective regarding LVOTO reoccurrence. Survival for both groups after LVOTO reoperation at 15 years was 95.6% (95% CI 99.4-72.9). CONCLUSIONS: Incidence of LVOTO after AVSD repair is low but the reoccurrence rate is high. Standard subaortic resection does not always provide definitive LVOTO relief. The survival after LVOTO reoperation is excellent.

Multiphase Assessment of Mitral Annular Dynamics in Consecutive Patients With Significant Mitral Valve Disease.

OBJECTIVES: The aim of this study was to clarify the dynamics of the mitral annulus throughout the cardiac cycle and its relevance to transcatheter mitral valve replacement (TMVR) sizing and case selection. BACKGROUND: Limited data are available regarding the relevance of mitral annular (MA) and neo-left ventricular outflow tract (LVOT) dynamics in the overall population presenting with significant mitral valve disease. METHODS: Patients attending a combined surgical-transcatheter heart valve clinic for severe symptomatic mitral valve disease were assessed using multiphase computed tomography. The relative influence of MA and neo-LVOT dynamics to TMVR case selection was studied. RESULTS: A total of 476 patients with significant mitral valve disease were evaluated. In 99 consecutive patients with severe mitral regurgitation, a 10-phase assessment showed that the mitral annulus was on average largest in late systole. On comparing maximal MA dimension with late systolic dimension, TMVR size assignment changed in 24.2% of patients. If the average MA perimeter was used to determine sizing, 48.5% were excluded because of MA dimension being too large; in a multiphase assessment of the neo-LVOT, an additional 16.2% were excluded on the basis of neo-LVOT dimension. In an expanded series of 312 consecutive patients, selection protocol influenced anatomical exclusion: a manufacturer-proposed early systolic approach excluded 69.2% of patients, whereas a late systolic approach excluded 82.7% of patients, the vast majority because of large mitral annuli. CONCLUSIONS: Contemporary TMVR can treat only a minority of patients with severe mitral regurgitation, principally because of limitations of large MA dimension.

Usefulness of Stress Echocardiography in Assessment of Dynamic Left Ventricular Obstructions: Case Series and Review of the Literature.

Dynamic left ventricular outflow tract obstruction (DLVOTO) or midcavity obstruction in patients with structurally normal hearts is not uncommon in routine clinical practice and can cause significant symptoms mimicking coronary artery disease or heart failure. Although exercise echocardiography is the gold standard for assessing DLVOTO, dobutamine stress echocardiography (DSE) may be valuable diagnostic modality in patients who are unable to exercise or have an uninterpretable 12-lead electrocardiogram. We provide an updated overview of the relevant literature regarding prevalence, pathophysiology, clinical significance, and prognostic impact of DLVOTO and midcavity obstruction in structurally normal hearts. We also present a clinical series of 4 cases of DLVOTO and midcavity obstruction documented by DSE and discuss the value of different kinds of modern stress imaging modalities involving: (1) contrast-enhanced DSE to assess myocardial perfusion and inducible ischemia; (2) adenosine stress echocardiography to assess coronary flow reserve/microvascular dysfunction; and (3) functional imaging with deformation echocardiography to assess subclinical myocardial dysfunction in patients with structurally normal heart and without significant coronary disease. Based upon our own experiences and a critical review of the current literature, we will then present a practical guidance for management of DLVOTO and midcavity obstruction.

In Vitro Assessment of Right Ventricular Outflow Tract Anatomy and Valve Orientation Effects on Bioprosthetic Pulmonary Valve Hemodynamics.

PURPOSE: The congenital heart defect Tetralogy of Fallot (ToF) affects 1 in 2500 newborns annually in the US and typically requires surgical repair of the right ventricular outflow tract (RVOT) early in life, with variations in surgical technique leading to large disparities in RVOT anatomy among patients. Subsequently, often in adolescence or early adulthood, patients usually require surgical placement of a xenograft or allograft pulmonary valve prosthesis. Valve longevity is highly variable for reasons that remain poorly understood. METHODS: This work aims to assess the performance of bioprosthetic pulmonary valves in vitro using two 3D printed geometries: an idealized case based on healthy subjects aged 11 to 13 years and a diseased case with a 150% dilation in vessel diameter downstream of the valve. Each geometry was studied with two valve orientations: one with a valve leaflet opening posterior, which is the native pulmonary valve position, and one with a valve leaflet opening anterior. RESULTS: Full three-dimensional, three-component, phase-averaged velocity fields were obtained in the physiological models using 4D flow MRI. Flow features, particularly vortex formation and reversed flow regions, differed significantly between the RVOT geometries and valve orientations. Pronounced asymmetry in streamwise velocity was present in all cases, while the diseased geometry produced additional asymmetry in radial flows. Quantitative integral metrics demonstrated increased secondary flow strength and recirculation in the rotated orientation for the diseased geometry. CONCLUSIONS: The compound effects of geometry and orientation on bioprosthetic valve hemodynamics illustrated in this study could have a crucial impact on long-term valve performance.

Concurring hypertrophic cardiomyopathy and takotsubo cardiomyopathy: Assessment and management.

The prevalence of takotsubo cardiomyopathy (TCM) has been on the rise, but co-occurrence with hypertrophic cardiomyopathy (HOCM) remains rare. Although presenting patient demographics were similar to those in TCM, the potential for hemodynamic compromise was significantly compounded by the presence of underlying HOCM. Management was similar to standalone TCM, although use of inotropic agents and mechanical support appears to be more prevalent. Despite the increased potential for complications and the paucity of data regarding management, outcomes appear to be mostly favorable in both the hospitalization period and at follow-up. Interestingly, despite a new diagnosis of HOCM in about half the cases described, which signifies no significant left ventricular outflow tract (LVOT) gradient prior to TCM, half of those patients had a persistently elevated LVOT gradient after resolution of TCM. This poses a question of whether or not TCM can predispose to LVOT obstruction in HOCM patients even after its resolution.

Right Ventricular Outflow Tract Reintervention in the Transcatheter Era: Outcomes and Cost Analysis.

Surgical pulmonary valve insertion (SPVI) for re-entry right ventricular outflow tract intervention (RVOTI) remains an established and reproducible approach. Fast-track in patients undergoing RVOTI of the comprehensive valve program targets early ICU and hospital discharge (Hd). Feasibility study for outcome and cost analysis was undertaken. Between January 2015 and December 2016, 34 patients underwent re-entry RVOTI. Seventeen had SPVI and 17 transcatheter PVI (TPVI). Surgical perioperative fast-track protocol was used. Echocardiographic evaluation preoperatively (TTE-1), after RVOTI (TTE-2), at hospital discharge (TTE-3), and follow-up (TTE-4) were obtained. Cost Analysis included procedural and hospital costs. Mean follow-up period was 11.3 ± 6.9 months. All patients were extubated prior to ICU arrival. Mean age was 8.5 ± 7.8 for SPVI [vs 28.5 ± 8.6 years for TPVI] (p < 0.05). There was no hospital mortality or 30-day readmission for SPVI (versus 1 for TPVI).Mean hospital length of stay (LOS) was 4.1 ± 1.1 days for SPVI [vs 1.1 ± 0.7 days for TPVI] (p < 0.05). Number of prior sternal re-entry had no influence on outcome. RV systolic pressure referenced to LVSP (rRVSP, %) and diastolic dimension (RVEDDi, z score) showed sustainable improvement (TTE-2, TTE-3, TTE-4) in both groups compared to TTE-1 (p < 0.05). Mean total hospital cost was $5475.86 ± 2503.91 lower after SPVI (p = 0.09), 21.7% procedural cost reduction. Patients undergoing RVOTI can be safely stratified, based on a customized concept, towards SPVI or TPVI. Standardized strategy can advocate a fast-track path. SPVI is associated with comparable mid-term outcomes to TPVI although SPVI is delivered in younger patients. Despite longer LOS SPVI is associated with reduced hospital cost. Multisite studies might help determine suitability for each strategy on cost containment/quality of life basis.

Novel Multiphase Assessment for Predicting Left Ventricular Outflow Tract Obstruction Before Transcatheter Mitral Valve Replacement.

OBJECTIVES: This study proposes a physiologic assessment of left ventricular outflow tract obstruction (LVOTO) that accommodates changes in systolic flow and accounts for the dynamic neo-left ventricular outflow tract (LVOT). BACKGROUND: Patients considered for transcatheter mitral valve replacement trials often screen-fail because of the perceived risk of LVOTO. In the Intrepid Global Pilot Study, assumed risk of LVOTO was based on computed tomography estimates of the neo-LVOT area computed at end-systole. However, this may overestimate actual risk. METHODS: Retrospective analyses were performed for screen-failed patients for potential LVOTO (n = 33) and treated patients (n = 29) with available dynamic computed tomography. A multiphase assessment of the neo-LVOT area was performed and represented as: 1) multiphase average; and 2) early systolic value. Prospective evaluation was performed in 9 patients approved for enrollment with multiphase and early systole methods that would have previously screen-failed with the end-systolic approach. RESULTS: Of 166 patients screened for possible inclusion; 32 were screen-failed for nonanatomical reasons. Screen failure for assumed LVOTO risk occurred in 37 of 134 (27.6%) patients. Retrospective analysis indicated a potential enrollment increase of 11 of 33 (33.3%) and 18 of 33 (54.5%) patients using multiphase and early systolic assessment methods. In the prospective cohort, there were no clinical observations of LVOTO 30 days post-procedure, despite assumed risk based on end-systolic estimates. CONCLUSIONS: Multiphase, and specifically early systolic, assessment of the neo-LVOT may better determine risk of LVOTO with transcatheter mitral valve replacement compared with end-systolic estimates. This novel approach has the potential to significantly increase patient eligibility, with over one-half of patients previously screen-failed now eligible for treatment.

Assessment of untreated fresh autologous pericardium as material for construction of heart valve: Result at 5 years.

Introduction: Tetralogy of Fallot requiring transannular repair of the right ventricular outflow tract (RVOT) are exposed to free pulmonary insufficiency and hence inevitable right ventricular dysfunction. This study analyzes the function and structure of untreated autologous pericardium monocusp used to create a competent pulmonary valve. Materials and Methods: This is a retrospective analysis of 52 cases operated between December 2006 and December 2012. Untreated autologous pericardium was used for creating a competent pulmonary valve following a transannular patch. They are followed for functional and structural assessment of the pulmonary valve by echocardiography. Positron emission tomography (PET) with 18 fluorodeoxyglucose was performed in two cases for profiling the pulmonary valve. Results: Median age was 10.5 years (1-38). The follow-up was complete for 42 (80.76%) patients for 3 years and 25 (48.07%) patients for 5 years. The RVOT gradient was 42 mmHg (16-96) in the year of surgery, which reduced to 26 mmHg (10-58) and pulmonary insufficiency that was present in 8.3% of patients in 1st year was witnessed in 22.7% in the 5th year of follow-up. The monocusp patch was successful in creating a competent valve while maintaining its structure at 3 years; however, it became distorted and retracted at 5 years of follow-up. There was no calcification in any of the patients. PET-computed tomography confirmed the uptake of glucose by monocusp at 1 year of follow-up. Conclusion: The untreated autologous pericardium functioned well when it was used to create a competent pulmonary valve at short term and midterm. Although it changed in its structure; there was no calcification at 5 years of follow-up.

Assessment of left ventricular outflow tract and aortic root: comparison of 2D and 3D transthoracic echocardiography with multidetector computed tomography.

AIMS: Accurate echocardiographic assessment of left ventricular outflow tract (LVOT) and the aortic root is necessary for risk stratification and choice of appropriate treatment in patients with pathologies of the aortic valve and aortic root. Conventional 2D transthoracic echocardiographic (TTE) assessment is based on the assumption of a circular shaped LVOT and aortic root, although previous studies have indicated a more ellipsoid shape. 3D TTE and multidetector computed tomography (MDCT) applies planimetry and are not dependent on geometrical assumptions. The aim was to test accuracy, feasibility, and reproducibility of 3D TTE compared to 2D TTE assessment of LVOT and aortic root areas, with MDCT as reference. METHODS AND RESULTS: We examined 51 patients with 2D/3D TTE and MDCT at the same day. All patients were re-examined with 2D/3D TTE on a different day to evaluate 2D and 3D re-test variability. Areas of LVOT, aortic annulus, and sinus were assessed using 2D, 3D TTE, and MDCT. Both 2D/3D TTE underestimated the areas compared to MDCT; however, 3D TTE areas were significantly closer to MDCT-areas. 2D vs. 3D mean MDCT-differences: LVOT 1.61 vs. 1.15 cm2, P = 0.019; aortic annulus 1.96 vs. 1.06 cm2, P < 0.001; aortic sinus 1.66 vs. 1.08 cm2, P = 0.015. Feasibility was 3D 76-79% and 2D 88-90%. LVOT and aortic annulus areas by 3D TTE had lowest variabilities; intraobserver coefficient of variation (CV) 9%, re-test variation CV 18-20%. CONCLUSION: Estimation of LVOT and aortic root areas using 3D TTE is feasible, more precise and more accurate than 2D TTE.

Percutaneous Versus Surgical Pulmonic Valve Implantation for Right Ventricular Outflow Tract Dysfunction.

BACKGROUND/PURPOSE: Percutaneous pulmonic valve implantation (PPVI) is an alternative treatment strategy to surgical pulmonic valve implantation (SPVI) for right ventricular outflow tract (RVOT) dysfunction. This study sought to compare outcomes of both treatment strategies. METHODS: The study population was extracted from the 2014 Nationwide Readmissions Database (NRD) using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for PPVI and SPVI. Study outcomes included all-cause in-hospital mortality, length of index hospital stay (LOS), post-procedural bleeding, mechanical complications of heart valve prosthesis, vascular complications (VC), infective endocarditis (IE), total hospitalization charges, and 30-day readmission rates. RESULTS: A total of 975 patient discharges (176 in PPVI and 799 in SPVI group) were identified (average age 25.7 years; 57.5% male). PPVI was associated with significantly shorter median LOS (1 versus 5 days, p < 0.01), lower risk of bleeding (4.6% versus 26.4%, p < 0.01), and lower total hospitalization charges ($169,551.7 versus $210,681.8, p = 0.02). There was no significant difference between both groups in terms of all-cause in-hospital mortality (0% versus 1.4%, p = 0.12), mechanical complications of heart valve prosthesis (1.7% versus 2.0%, p = 0.78), VC (2.3% versus 2.0%, p = 0.82), IE (1.7% versus 3.1%, p = 0.31), or 30-day readmission rates (4.4% versus 7.6%, p = 0.16). CONCLUSION: Compared with SPVI, PPVI was associated with shorter LOS, lower bleeding, and lower total charges. There was no significant difference between the two strategies in terms of all-cause in-hospital mortality, mechanical complications of heart valve prosthesis, VC, IE, or 30-day readmission rates.

Toward the integration of global longitudinal strain analysis in the assessment of neonatal aortic coarctation? A preliminary study.

BACKGROUND: Coarctation of the aorta (CoA) is still challenging to diagnose in neonates with patent ductus arteriosus (PDA). Speckle tracking echocardiography allows reliable analysis of myocardial deformation in newborns and seems to provide important insides into regional changes in patients with left ventricular (LV) outflow tract obstruction. AIMS: To assess the interest of LV global longitudinal strain (GLS) measurement for predicting CoA in neonates with PDA and prenatal suspicion. METHODS: Prospective single-center study. Twenty-two newborns with prenatal suspicion of CoA were included. All newborns were evaluated in the first 12 hours of life. To assess the feasibility and the reproducibility of GLS, 14 healthy full-term newborns with PDA (group 3) were screened. CoA was diagnosed when DA closed, according to usual echocardiographic criteria. RESULTS: Six neonates developed CoA after DA closure (group 1) whereas 16 did not (group 2). Mean gestational age and birth weight were not different between the groups. GLS measurements were possible in 100%. Intra- and inter-observer variability of strain measurements was acceptable. GLS values were significantly lower in neonates who developed CoA (P=0.015). To predict CoA, cut-off value of -17.42% gave the best compromise for sensitivity (83%) and specificity (72%). Aortic arch dimensions were modestly correlated with strain values. The presence of a bicuspid aortic valve was not associated with significant lower GLS values. CONCLUSION: LV GLS analysis is a feasible and reproducible echocardiographic technique in newborns with PDA. Newborns who will develop CoA seem to have lower values of GLS than healthy neonates. Further studies are needed to confirm these preliminary results.

Standardized Goal-Directed Valsalva Maneuver for Assessment of Inducible Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy.

BACKGROUND: The Valsalva maneuver is widely used to provoke left ventricular outflow tract obstruction in hypertrophic cardiomyopathy (HCM). Whereas early experiments used a standardized, goal-directed approach by maintaining an intraoral pressure >40 mm Hg for >10 sec, current practice depends on patients' understanding and effort. The aim of this study was to evaluate the clinical effectiveness of the goal-directed Valsalva maneuver (GDV) in HCM as a method to provoke left ventricular outflow tract obstruction. METHODS: In this prospective study, patients blew into a syringe barrel connected to a manometer with rubber tubing and maintained an intraoral pressure of >40 mm Hg for >10 sec (GDV). Using Doppler echocardiography, peak left ventricular outflow tract gradient (pLVOTG) was measured at rest and using the provocative maneuvers of the self-directed Valsalva maneuver (SDV), GDV, and exercise. RESULTS: A total of 52 patients were included. Mean pLVOTG with GDV was higher compared with SDV (48 vs 38 mm Hg, P = .001, n = 52) and was similar to exercise (GDV, 52 mm Hg; exercise, 58 mm Hg; P = .42; n = 43). Reclassification to obstructive HCM (pLVOTG ≥ 30 mm Hg) with GDV was significantly higher than with SDV (38% vs 16.6%, P = .016) and comparable with exercise (50%, P = .51). Reclassification to severe obstruction (pLVOTG ≥ 50 mm Hg) was higher with GDV compared with SDV (28.3% vs 13.5%, P = .045) and was similar to exercise (29.7%). Furthermore, GDV identified two patients with occult severe obstruction in isolation. CONCLUSIONS: GDV is an objective, practical, and effective physiologic method of provoking left ventricular outflow tract obstruction. It can significantly alter patient management by reclassifying disease severity and should be incorporated in the routine clinical evaluation of patients with HCM.

The advantages of live/real-time three-dimensional echocardiograhy in the assessment of left ventricular myxoma, which causes partial left ventricular outflow tract obstruction.

Myxomas are the most common cardiac primary tumors; however, left ventricular myxomas are extremely rare. We describe a young female patient with a giant left ventricular myxoma causing partial obstruction of the left ventricular outflow tract, who underwent successful surgical resection. Real-time three-dimensional echocardiography yielded incremental value to two-dimensional echocardiography by allowing better assess of the true size, extent, attachment, and morphology of the tumor. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46:273-277, 2018.

Reliability of Peak Exercise Stroke Volume Assessment by Impedance Cardiography in Patients with Residual Right Outflow Tract Lesions After Congenital Heart Disease Repair.

Global ventricular response to exercise may be useful in follow-up of patients with residual right outflow tract lesions after congenital heart disease repair. In this context, impedance cardiography is considered accurate for stroke volume (SV) measurement during exercise testing, however, to date, only partial assessment of its reliability has been reported. We retrospectively evaluated relative and absolute reliability of peak SV by impedance cardiography during exercise using intraclass correlation (ICC) and standard error of measurement (SEM) in this population. Peak SV was measured in 30 young patients (mean age 14.4 years ± 2.1) with right ventricular outflow tract reconstruction who underwent two cardiopulmonary exercise tests at a mean one-year interval. SV was measured using a signal morphology impedance cardiography analysis device (PhysioFlow®) and was indexed to body surface area. ICC of peak indexed SV measurement was 0.80 and SEM was 10.5%. High heterogeneity was seen when comparing patients according to peak indexed SV; in patients with peak SV < 50 ml/m2 (15 patients), ICC rose to 0.95 and SEM dropped to 2.7%, while in patients with a peak SV > 50 ml/m2 relative and absolute reliability decreased (ICC = 0.45, SEM = 12.2%). Peak exercise SV assessment by a PhysioFlow® device represents a highly reliable method in patients with residual right outflow tract lesions after congenital heart disease repair, especially in patients with peak SV < 50 ml/m2. In this latter group, a peak SV decrease > 7.3% (corresponding to the minimum "true" difference) should be considered a clinically-relevant decrease in global ventricular performance and taken into account when deciding whether to perform residual lesion removal.