Multimodal cardiovascular model for hemodynamic analysis: Simulation study on mitral valve disorders

Valvular heart diseases are a prevalent cause of cardiovascular morbidity and mortality worldwide, affecting a wide spectrum of the population. In-silico modeling of the cardiovascular system has recently gained recognition as a useful tool in cardiovascular research and clinical applications. Here, we present an in-silico cardiac computational model to analyze the effect and severity of valvular disease on general hemodynamic parameters. We propose a multimodal and multiscale cardiovascular model to simulate and understand the progression of valvular disease associated with the mitral valve. The developed model integrates cardiac electrophysiology with hemodynamic modeling, thus giving a broader and holistic understanding of the effect of disease progression on various parameters like ejection fraction, cardiac output, blood pressure, etc., to assess the severity of mitral valve disorders, naming Mitral Stenosis and Mitral Regurgitation. The model mimics an adult cardiovascular system, comprising a four-chambered heart with systemic, pulmonic circulation. The simulation of the model output comprises regulated pressure, volume, and flow for each heart chamber, valve dynamics, and Photoplethysmogram signal for normal physiological as well as pathological conditions due to mitral valve disorders. The generated physiological parameters are in agreement with published data. Additionally, we have related the simulated left atrium and ventricle dimensions, with the enlargement and hypertrophy in the cardiac chambers of patients with mitral valve disorders, using their Electrocardiogram available in Physionet PTBI dataset. The model also helps to create 'what if' scenarios and relevant analysis to study the effect in different hemodynamic parameters for stress or exercise like conditions.

Lessons from reoperations for mitral stenosis after mitral valve repair

BACKGROUND

The durability of mitral valve repair (MVr) is usually defined by the absence of recurrent significant mitral regurgitation. Postrepair mitral stenosis (MS) is a less frequent and less studied mode of failure of MVr. We analyzed our experience in patients who underwent reoperation for postrepair MS to characterize mechanisms resulting in MS and to summarize reoperative surgical strategies and mid-term outcomes.

METHODS

Using a prospective database, we retrospectively analyzed data on 35 consecutive patients who underwent reoperation for symptomatic moderate to severe MS between January 1, 2011, and February 1, 2020.

RESULTS

The mean patient age was 61.4 ± 11.4 years, and 69% were female. The median annuloplasty ring size used at the initial repair was 28 mm (interquartile range, 26-30 mm). Additional repair techniques at the initial operation included leaflet resection in 12 patients (34%) and commissuroplasty or edge-to-edge repair in 6 patients (18%). At reoperation, the most common mechanism of MS was pannus ingrowth in 20 patients (57%), leaflet calcification in 12 (34%), commissural fusion in 5 (14%), and tunnel effect (functional MS) in 3 (9%). Twenty-two patients (63%) underwent valve replacement, and 13 (37%) underwent valve re-repair. In patients who underwent re-repair, annuloplasty revision was performed in all patients, with 6 patients (46%) converted from complete ring to band, 4 (11%) converted from ring to pericardial annuloplasty, 2 (6%) converted to no annuloplasty, and 1 (8%) with annuloplasty ring upsizing. There were no in-hospital or 1-year mortalities. Survival at the 5-year follow-up was 93.9%.

CONCLUSIONS

MS causing late failure of MVr is frequently associated with smaller ring sizes and inflammatory or calcific changes in the valve. Highly selected patients may be good candidates for mitral valve re-repair.

Energy loss associated with in-vitro modeling of mitral annular calcification

Introduction

Study aims were to compare hemodynamics and viscous energy dissipation (VED) in 3D printed mitral valves–one replicating a normal valve and the other a valve with severe mitral annular calcification (MAC). Patients with severe MAC develop transmitral gradients, without the commissural fusion typifying rheumatic mitral stenosis (MS), and may have symptoms similar to classical MS. A proposed mechanism relates to VED due to disturbed blood flow through the diseased valve into the ventricle.

Methods

A silicone model of a normal mitral valve (MV) was created using a transesophageal echocardiography dataset. 3D printed calcium phantoms were incorporated into a second valve model to replicate severe MAC. The synthetic MVs were tested in a left heart duplicator under rest and exercise conditions. Fine particles were suspended in a water/glycerol blood analogue for particle image velocimetry calculation of VED.

Results

Catheter mean transmitral gradients were slightly higher in the MAC valve compared to the normal MV, both at rest (3.2 vs. 1.3 mm Hg) and with exercise (5.9 vs. 5.0 mm Hg); Doppler gradients were 2.7 vs. 2.1 mm Hg at rest and 9.9 vs 8.2 mm Hg with exercise. VED was similar between the two valves at rest. During exercise, VED increased to a greater extent for the MAC valve (240%) versus the normal valve (127%).

Conclusion

MAC MS is associated with slightly increased transmitral gradients but markedly increased VED during exercise. These energy losses may contribute to the exercise intolerance and exertional dyspnea present in MAC patients.

Functional assessment of bioprosthetic mitral valves by cardiovascular magnetic resonance: An in vitro validation and comparison to Doppler echocardiography

BACKGROUND

A comprehensive non-invasive evaluation of bioprosthetic mitral valve (BMV) function can be challenging. We describe a novel method to assess BMV effective orifice area (EOA) based on phase contrast (PC) cardiovascular magnetic resonance (CMR) data. We compare the performance of this new method to Doppler and in vitro reference standards.

METHODS

Four sizes of normal BMVs (27, 29, 31, 33 mm) and 4 stenotic BMVs (27 mm and 29 mm, with mild or severe leaflet obstruction) were evaluated using a CMR- compatible flow loop. BMVs were evaluated with PC-CMR and Doppler methods under flow conditions of; 70 mL, 90 mL and 110 mL/beat (n = 24). PC-EOA was calculated as PC-CMR flow volume divided by the PC- time velocity integral (TVI).

RESULTS

PC-CMR measurements of the diastolic peak velocity and TVI correlated strongly with Doppler values (r = 0.99, P < 0.001 and r = 0.99, P < 0.001, respectively). Across all conditions tested, the Doppler and PC-CMR measurement of EOA (1.4 ± 0.5 vs 1.5 ± 0.7 cm2, respectively) correlated highly (r = 0.99, P < 0.001), with a minimum bias of 0.13 cm2, and narrow limits of agreement (- 0.2 to 0.5 cm2).

CONCLUSION

We describe a novel method to assess BMV function based on PC measures of transvalvular flow volume and velocity integration. PC-CMR methods can be used to accurately measure EOA for both normal and stenotic BMV's and may provide an important new parameter of BMV function when Doppler methods are unobtainable or unreliable.

Degenerative Mitral Stenosis Versus Rheumatic Mitral Stenosis

Mitral stenosis is classically caused by rheumatic disease (RMS). However, degenerative mitral stenosis (DMS) is increasingly encountered, particularly in developed countries with aging populations. The aim of this study was to compare clinical and echocardiographic characteristics between the 2 entities. One hundred fifteen patients with DMS were identified from an echocardiographic database in the United States and compared with 510 patients with RMS from Seoul, Korea. All subjects had a mitral valve area (MVA) ≤2.5 cm² by continuity equation but were otherwise unselected. Patients with DMS were older and had more hypertension, diabetes, chronic kidney disease, and chronic obstructive pulmonary disease than those with RMS. Atrial fibrillation was more common in RMS patients. Mean mitral valve gradient was slightly lower in DMS versus RMS (7.63 ± 3.67 vs 8.50 ± 4.23 mm Hg, p = 0.04) but MVA was strikingly higher in the DMS group (1.35 ± 0.41 vs 0.95 ± 0.38 cm², p <0.0001). This appeared to be due to greater stroke volume in the DMS patients (70.4 ± 19.7 vs 55.7 ± 15.5 ml, p <0.0001). Indexed left atrial volume was greater in RMS (82.1 ± 40.3 vs 57.9 ± 21.4 ml, p <0.0001) while estimated pulmonary artery systolic pressure was greater in DMS (49.3 ± 16.5 vs 39.4 ± 13.6 mm Hg, p <0.0001). In conclusion, DMS patients are older and have more comorbidities than RMS patients. DMS presents with greater MVA relative to mean mitral valve gradient than RMS. This appears due to a higher stroke volume in DMS patients.

Impact of balloon mitral valvuloplasty on left ventricular rotational deformation: Magnetic Resonance Imaging follow up study

In patients with rheumatic mitral stenosis (MS), some previous studies have investigated the influence of balloon mitral valvuloplasty (BMV) on left ventricular (LV) systolic function. However, the impact of BMV on LV twisting motion in this clinical setting has not been studied before yet. To describe changes in LV torsion in patients with rheumatic MS following BMV. Thirty patients (median age 33 years, 22 women) with isolated severe MS were studied. CMR myocardial tissue tagging was used for assessment of LV rotational deformation. LV torsion was calculated as the twist value (the net difference between apical counterclockwise and basal clockwise rotation) normalized to the length of the ventricle and multiplied by the mean radius at the base and apex. All patients had CMR studies before, 6 months and 1 year after successful BMV. At baseline, patients had a mitral valve area of 0.9 (0.6-1.3) cm², mean pressure gradient of 12.5 (8-24) mmHg across the valve as measured by transthoracic echocardiography. Median LV ejection fraction (LVEF) estimated by CMR was 57 (range: 45-69) %. A significant improvement in LV base-apex torsion was shown at 6 months (3.3° vs. 2.5°, p < 0.001) with a further improvement at 1 year (4.1° vs. 3.3°, p = 0.05). Similar pattern of change was seen in LV base-mid torsion with a significant increase at 6 months (3.6° vs. 2.3°, p < 0.001) and a further increase at 1 year (4.7° vs. 3.6°, p = 0.007). These changes were associated with a significant increase in LVEF (62% vs. 57%, p < 0.001) at 1 year following BMV. Successful BMV is associated with a significant improvement in LV torsion that is accompanied by a significant improvement in LVEF.

Sequential Use of Alcohol Septal Ablation and Electrosurgical Leaflet Resection Prior to Transcatheter Mitral Valve Replacement

In patients with increased surgical risk and hemodynamically significant mitral disease, a transcatheter strategy for mitral valve replacement (TMVR) may be suitable; however, is also not without procedure risk. Obstruction of the left ventricular outflow tract (LVOT) is one of the most dreaded complications of TMVR, requiring careful consideration of potential candidates with preprocedural imaging and ex vivo valvular fit simulation as part of risk assessment for postprocedure obstruction. In patients at high risk of LVOT obstruction, early studies have shown that alcohol septal ablation or electrosurgical laceration of the anterior mitral leaflet (LAMPOON) procedure prior to TMVR may mitigate the risk of LVOT obstruction. We describe the recent successful management of a patient with severe mitral valve disease, mitral annular calcification (MAC), and high risk of post-TMVR LVOT obstruction, who underwent a sequential strategy of ASA followed by electrosurgical leaflet resection with the LAMPOON procedure prior to TMVR to successfully prevent LVOT obstruction. To our knowledge, this is the first time this dual strategy has been reported, and it may allow more patients with severe mitral valve disease to undergo TMVR in the future.

Left Atrial "Pinball" Thrombus Causing Recurrent Syncope

A 75-year-old female was admitted due to a syncopal episode. Transesophageal echocardiography demonstrated severe mitral stenosis with a 5 cm, free-floating, left atrial thrombus intermittently obstructing the mitral valve orifice; she underwent thrombus removal and mitral valve replacement.

Lumped-Parameter Circuit Platform for Simulating Typical Cases of Pulmonary Hypertensions from Point of Hemodynamics

Pulmonary hypertension (PH) presents unusual hemodynamic states characterized by abnormal high blood pressure in pulmonary artery. The objective of this study is to simulate how the hemodynamics develops in typical PH cases without treatment. A lumped-parameter circuit platform of human circulation system is set up to simulate hemodynamic abnormalities of PH in different etiologies and pathogenesis. Four typical cases are considered, which are distal pulmonary artery stenosis, left ventricular diastolic dysfunction, ventricular septal defect, and mitral stenosis. The authors propose regulation laws for chambers and vessels to adapt the abnormal hemodynamic conditions for each PH case. The occurrence and development of each PH case are simulated over time using the lumped-parameter circuit platform. The blood pressure, blood flow, pressure-volume relations for chambers and vessels are numerically calculated for each case of PH progression. The model results could be a quite helpful to understand the hemodynamic mechanism of typical PHs. Graphical Abstract.

Morphological and functional characteristics of mitral annular calcification and their relationship to stroke

BACKGROUND

Mitral annular calcification (MAC) is associated with risk of stroke. This study aimed to define the morphological and functional characteristics of MAC that are related to stroke.

METHODS

A total of 460 subjects with MAC from transthoracic echocardiography in a single center from 2012 to 2016 was retrospectively reviewed. Subjects were classified into two groups according to history of stroke [Group 1 (n = 366): without stroke; Group 2 (n = 94): with stroke]. Morphological and functional features of MAC on echocardiogram were scored from 0 to 3 according to MAC mobility, presence of echodense mass with central echolucencies in the periannular region suggesting caseous necrosis, and functional stenosis.

RESULTS

Significantly more patients in group 2 were men and had history of diabetes mellitus, dyslipidemia, atrial fibrillation, or infective endocarditis. Although MAC thickness and extent did not differ between the two groups, group 2 showed a considerably higher MAC score than group 1 (0.50 ± 0.77 vs. 0.23 ±0.52 p<0.001) as a result of the higher prevalence of each component in group 2 [mobility (22 vs. 11%, p = 0.003), echodense mass with central areas of echolucencies suggesting caseous necrosis (23 vs. 7%, p<0.001), and functional mitral stenosis (12 vs. 7%, p = 0.042)]. On logistic regression analysis, MAC score was independently associated with stroke and showed significant incremental value to demographic factors and comorbidities in association with stroke in a consecutive manner.

CONCLUSIONS

In conclusion, morphological and functional characteristics of MAC had incremental value in association with stroke over traditional risk factors. MAC score consisting of MAC mobility, typical echodense mass with central echolucencies suggesting caseous necrosis, and functional mitral stenosis was independently associated with stroke. MAC with high-risk features may act as a source of stroke or more potent composite surrogate markers for stroke-related risk factors.

Prolonged pulmonary pulse transit time is associated with symptoms in patients with significant mitral stenosis and sinus rhythm

INTRODUCTION

Pulmonary pulse transit time (pPTT) is a novel noninvasive echocardiographic measure to assess pulmonary arterial hemodynamics. It has been shown to be shorter in precapillary pulmonary hypertension (PHT). Mitral stenosis (MS) is one of the causes of postcapillary PHT. We aimed to investigate pPTT in patients with MS and its relationship with symptoms.

METHODS

We included 51 patients with MS (25 were asymptomatic, NYHA I, and 26 were symptomatic, NHYA II or III), and 50 controls, and evaluated their demographic characteristics and echocardiographic variables, including pPTT.

RESULTS

Baseline characteristics, including age, sex, body mass index, and cardiovascular risk factors, were similar between the MS and the control group. The pPTT was longer in the MS group than in the control group (0.21 ± 0.08 vs 0.15 ± 0.05, P < .001). Patients with symptomatic MS had longer pPTT than asymptomatic patients (P = .005). The pPTT was positively correlated with left atrial volume index and systolic pulmonary artery pressure, and negatively with tricuspid annular plane systolic excursion (r = .432; P < .001, r = .319; P = .001, r = -.293; and P = .003, respectively).

CONCLUSION

The measurement of pPTT appears clinically relevant in patients with PHT. Further studies evaluating whether it is useful in distinguishing precapillary from postcapillary PHT are required.

Vector Flow Imaging of the Ascending Aorta in Patients with Tricuspid and Bicuspid Aortic Valve Stenosis Treated with Biological and Mechanical Implants

Aortic valve stenosis (AS) is treated with biological prostheses (BPs) and mechanical prostheses (MPs). Vector flow imaging (VFI), an angle-independent ultrasound method, can quantify flow complexity (vector concentration (VC)) and secondary rotation (SR). Ten patients (mean age: 70.7 y) with tricuspid AS scheduled for BPs, 10 patients (mean age: 56.2 y) with bicuspid AS scheduled for MPs and 10 patients (mean age: 63.9 y) with normal aortic valves were scanned intra-operatively on the ascending aorta with VFI and conventional spectral Doppler. Bicuspid AS (peak systolic velocity (PSV): 380.9 cm/s, SR: 16.7 Hz, VC: 0.21) had more complex flow (p < 0.02) than tricuspid AS (PSV: 346.1 cm/s, SR: 17.1 Hz, VC: 0.33). Both groups had more complex and faster flow (p < 0.0001) than normal aortic valve patients (PSV: 124.0 cm/s, SR: 4.3 Hz, VC: 0.79). VC (r = 0.87) and SR (r = 0.89) correlated to PSV. After surgery, flow parameters changed (p < 0.0001) for patients with MPs (PSV: 250.4 cm/s, SR: 9.8 Hz, VC: 0.54) and BPs (PSV: 232.4 cm/s, SR: 12.5 Hz, VC: 0.61), with MPs having slower SR (p < 0.01). None of the implants had normal flow (p < 0.0001). In conclusion, VFI can provide new flow parameters for AS and implant assessment.

Subclinical Left Ventricular Dysfunction In Patients With Isolated Severe Rheumatic Mitral Stenosis Having Normal Left Ventricular Ejection Fraction

BACKGROUND

Mitral stenosis (MS) is a prevalent disease in the developing world. It is a preventable disease associated with considerably high morbidity and mortality rates. Myocarditis secondary to rheumatic MS can cause left ventricular (LV) dysfunction. In majority of the case this LV dysfunction is subclinical. Recent development in imaging techniques like tissue Doppler imaging (TDI) and strain imaging enabled us to detect subclinical LV dysfunction. One such example is Global Longitudinal Strain (GLS), which is a reliable mean of assessing LV dysfunction in patients diagnosed with mitral stenosis. This study is design to determine the frequency of subclinical LV dysfunction in patients presenting with severe MS of rheumatic etiology in our institute. Objective of the study was to determine frequency of subclinical LV dysfunction by mean GLS in patients with isolated severe Rheumatic MS having normal LV Ejection fraction measured by 2D/M-mode echocardiography. It was an observational crosssectional study, conducted at Department of Cardiology, Rawalpindi Institute of Cardiology, Rawalpindi, during the period of six months from 1st January to 30th June 2016.

METHODS

Fiftyfive patients with isolated severe mitral stenosis of underlying rheumatic aetiology with preserve LV function (EF>50%) were selected as per other inclusion and exclusion criteria. All patients were evaluated with detailed history, physical examination and echocardiographic examination. GLS was also noted and all other information was recorded on data collection form.

RESULTS

The average age and mean GLS was 48.20±11.62 years and -19.24±1.15% respectively. Left ventricular systolic impairment in patients under study using the Global Longitudinal Strain was seen in 16.36% (9/55) cases.

CONCLUSIONS

Our results suggest that GLS helps in detecting impairment of LV systolic function at an early stage in patients with mitral stenosis which helps in their risk stratification thus warranting their early management.

Minimally Invasive Hybrid Approach to High Risk Mitral Disease With Severe Mitral Annular Calcification

Severe circumferential mitral annular calcification (MAC) remains a significant challenge, complicating surgical treatment of mitral valve disease. Transcatheter treatment options are attractive; however, they remain fraught with risks of annular fixation, paravalvular leak, atrioventricular-groove disruption, and left-ventricular outflow tract obstruction. We describe a novel minimally invasive hybrid technique of transcatheter mitral valve replacement in a patient with severe circumferential MAC.

Left atrial mechanics in moderate mitral valve disease: earlier markers of damage

While the impairment of left atrial (LA) mechanics in mitral valve disease is well known, the exact onset of reservoir, conduit, and contractile dysfunction in mitral stenosis (MS) and mitral regurgitation (MR) remains unclear. We aimed to clarify the LA deformation mechanics in patients with moderate mitral valve disease. We conducted a prospective observational study of 80 patients with moderate isolated MR, 80 patients with moderate isolated MS, and 64 age-matched controls without mitral valve disease. Strain (ɛ) and strain rate (SR) on speckle tracking echocardiography were assessed as indicators of LA and right atrium (RA) reservoir (ɛsys, SRs), conduit (ɛe, SRe), and contractile (ɛa, SRa) functions. Conventional echocardiographic parameters of the left ventricle (LV) were also assessed. Comparisons were conducted according to mitral valve pathology (MR patients, MS patients, controls). The mean LV ejection fraction, end-diastolic diameter, and global longitudinal strain did not differ across the groups. The pulmonary artery systolic pressure, LA volume indexed to body surface area, and LA mechanics were significantly impaired in mitral valve disease (patients vs controls). While LA ɛ did not vary between MR and MS, MR patients had better LA SRs and SRe but worse SRa (p < 0.01). SRe > - 0.65% had higher specificity for MS, with an area under the curve of 0.85 (p < 0.01). RA mechanics were significantly impaired in mitral valve disease (patients vs controls) but did not vary significantly with disease pathology (MS vs MR). Patients with moderate mitral valve disease exhibit early and pathology-specific changes in the LA deformation mechanics, manifesting mainly as impaired contractile-phase SR in MR and impaired conduit-phase SR in MS. Our findings highlight SR as a potentially useful early marker of LA dysfunction in relation to mitral valve disease.

Multiscale simulation of the effects of atrioventricular block and valve diseases on heart performance

A new mathematical model of the cardiovascular system is proposed. The left ventricle is described by an axisymmetric multiscale model where myocardium is treated as an incompressible transversely isotropic medium with a realistic distribution of fibre orientation. Active tension and its regulation by Ca²⁺ ions are described by our recent kinetic model. A lumped parameter model is used for the simulation of blood circulation, in which the left and right atria and the right ventricle are described by a system of ordinary differential equations for active pressure-volume relationships. The stress and strain of the left ventricle myocardium were calculated by the finite element method implemented by the authors. The changes in the haemodynamics upon changes in preload of a healthy heart, upon physical exercise, and in case of atrioventricular block with different types of arrhythmias were simulated. To simulate the effect of stenosis or regurgitation of the aortic or mitral valves, the hydraulic and inertial flow resistances of the heart valves were set as functions of their orifice areas. The model reproduced a number of phenomena observed in clinical practice, including the classification of the severity of valve disease.

A Novel Multiparametric Score for the Detection and Grading of Prosthetic Mitral Valve Obstruction in Cases With Different Disc Motion Abnormalities

Prosthetic mechanical valves are the elective choice in mitral valve (MV) replacement, because of their reliability and easiness of implantation. However, these prostheses can suffer from complications, the major one being prosthetic mitral valve thrombosis (PMVT). In these cases, transthoracic doppler echocardiogram (TDE) is the standard diagnostic workup for diagnosis of valve malfunction. The American Society of Echocardiography (ASE) indicates the possible TDE-derived indexes, which can help in identifying insurgence of MV replacement complications. Unfortunately, in some cases, it is not possible to detect PMVT based on these criteria. In these cases, we speak of Doppler silent thrombosis and only more accurate and invasive analyses, such as fluoroscopy, allow for a correct diagnosis. In this work, computational fluid dynamic models were implemented to simulate valve fluid dynamics in different clinical scenarios in order to improve the reliability of PMVT diagnosis based on TDE. In detail, seven mechanical valve configurations, associated to different potential thrombotic conditions (symmetric and asymmetric stenosis), were designed and tested using five pathologic transmitral velocity profile, extracted from real TDE images; to obtain the flow rate profiles, each TDE velocity profile was scaled to yield a mean flow rate (MFR) of 4, 5 and 6 L/min, respectively. As a result, 105 (7 × 5 × 3) synthetic cases, accounting for different velocity profiles, MFRs and valve configurations, were simulated. TDE-derived indexes were calculated according to the ASE guidelines that were extracted. Advanced statistical methods were applied to propose a new diagnostic algorithm for detecting PMVT. Our results showed that there isn't any significant difference between symmetric and asymmetric stenosis, probe location and flow rate waveform and confirmed that the single modality diagnostic is not able to predict thrombosis in a relevant number of cases, referable to mild and mild-severe stenosis cases. To overcome the problem, a novel multi-parametric discrete score based on the designed diagnostic algorithm was attained and tested; the percentage of stenosis (POS) was predicted with an accuracy rate of 90.5%. Even more interestingly, the error rate of 9.5% is related to four false positive cases corresponding to mild stenosis (POS = 15%) which were erroneously classified as mild-severe stenosis. No false negatives were obtained. Our results suggest that a reliable estimation must take into account the mean flow rate as well as the transmitral velocity profile in order to provide a correct diagnosis.

Mitral Valve Stenosis after Transcatheter Aortic Valve Replacement: Case Report and Review of the Literature

Mitral stenosis is a rare and potentially severe complication of transcatheter aortic valve replacement (TAVR). Given the anatomic coupling and interdependence of the aortic and mitral valves, it comes by itself that procedures (either surgical or percutaneous) involving the aortic valve imply the risk of altering mitral valve function. Indeed, transcatheter aortic prostheses may impair adequate anterior mitral leaflet (AML) opening, especially when implanted in a "low" position, thus resulting in high transvalvular gradients. Hereby, we report the case of a 71-year-old male with symptomatic severe aortic stenosis and a history of previous surgical mitral valve repair who underwent TAVR with a self-expandable prosthesis. Notwithstanding an acceptable angiographic position, the prosthetic frame was shown to interfere with the AML, as evidenced by augmented transmitral gradients; nonetheless, pulmonary artery pressures remained unchanged, and the patient experienced symptomatic improvement. Therefore, a conservative approach was chosen and the patient was discharged home after medical therapy optimization. Moreover, we provide a review of the available literature regarding the incidence, predictors and possible management of this infrequent complication.

Association between late gadolinium enhancement and global longitudinal strain in patients with rheumatic mitral stenosis

The correlation between the extent of myocardial fibrosis and subclinical left ventricle (LV) systolic dysfunction in rheumatic mitral stenosis (MS) has not been widely studied. We sought to evaluate the correlation between the extent of LV myocardial fibrosis quantified by late gadolinium enhancement (LGE) using cardiac magnetic resonance (CMR) and global longitudinal strain (GLS) by speckle tracking echocardiography (STE) in patients with rheumatic MS. We prospectively evaluated 36 consecutive rheumatic MS patients who were planning to undergo mitral valve surgery. Then we evaluate the correlation between the extent of LV myocardial fibrosis quantified by LGE CMR and the systolic LV function by GLS using STE. Thirty-six patients with mean age of 45.7 ± 9.9 years old, showed mean LGE was 4.9 ± 2.7%. The mean LV ejection fraction (EF) measured by CMR was 50 ± 10.8%, and the mean LV GLS was 13.5 ± 3.9%. There was a moderate correlation between GLS and LGE (r - 0.432, p = 0.009). There were no correlations between GLS with mitral valve area (MVA) with r 0.149, p = 0.385, mean mitral valve gradient (MVG) with r -0.078, p = 0.653, and LVEF (r 0.299, p = 0.076). There was a moderate correlation between LGE and GLS in patients with rheumatic MS.

Lutembacher syndrome with mitral valve calcification in a 31-year old male

Lutembacher syndrome is characterized by a congenital ostium secundum atrial septal defect and an acquired mitral valve stenosis. We present a similar case in a 31-year old male who came in with orthopnoea, central cyanosis and pedal oedema. Examination revealed cardiac murmurs in tricuspid and apical regions. Chest x-ray showed signs of pulmonary congestion and ventricular enlargement. Electrocardiogaphy (ECG) revealed right axis deviation and right bundle branch block along with atrial fibrillation and Transthoracic Echocardiography (TTE) showed abnormal valves (mitral stenosis with calcification and tricuspid regurgitation) and dilated cardiac chambers. The patient was consequently treated with beta-blockers and diuretics and scheduled for valvular and septal repair via open heart surgery. The purpose of this case report is to assist cardiologists in diagnosing this syndrome accurately on the basis of symptoms and investigations.

Immediate impact of successful percutaneous balloon mitral valvuloplasty on right and left ventricular functions: An echocardiographic study using load independent tissue velocity imaging indices

Background

The impact of successful percutaneous balloon mitral valvuloplasty (PBMV) on left ventricular (LV) function has been a controversial subject. This study aimed to determine the immediate impact of PBMV on biventricular function using recent Tissue Velocity Imaging (TVI) derived load-independent indices.

Methods and results

A total of 30 patients with severe mitral stenosis (MS) who underwent PBMV at a tertiary center of India from August 2012 to December 2013 were included in the study. Thirty age-matched and gender-matched healthy controls were also enrolled.

Out of 30 patients, 27(90%) were female. Mean mitral valve area (MVA) of patients before and after PBMV was 0.78 and 1.82 cm² (p < 0.001), respectively. All TVI-derived LV and RV basal systolic (IVCV, Sm and the relatively load independent IVA) and diastolic velocities (Em, Em/Am) were significantly decreased in patients with MS compared to controls (p < 0.001 for all) which improved significantly after PBMV (6.4 ± 0.7 vs 11 ± 1.6; 5.8 ± 0.7 vs 9.9 ± 1.6; 1.5 ± 0.3 vs 4.2 ± 0.6; 6.4 ± 0.6 vs 13.1 ± 2.1; 0.7 ± 0.1 vs 1.7 ± 0.2 for mitral annulus respectively, p < 0.001 for all). Increment in MVA positively correlated with Tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular Sm and isovolumic contraction velocity (IVCV) and inversely with left atrium (LA) size and Pulmonary arterial systolic pressure (PASP) (p = 0.01 for LA size; p < 0.001 for others) while no such correlation was found with mitral annulus isovolumic acceleration (IVA) (r = −0.078; p = 0.679).

Conclusion

The improved right ventricular (RV) function appears to be predominantly due to afterload reduction, while that of LV appears to be more due to the acute relief of mechanical restraint.

Acute Severe Mitral Stenosis Immediately After Transcatheter Aortic Valve Implantation

An 86-year-old female patient was referred for treatment of symptomatic severe aortic stenosis. The heart team decided to perform transfemoral transcatheter aortic valve implantation. A 25 mm transcatheter aortic valve was implanted, but the valve migrated low into the left ventricular outflow tract. The subsequent removal and replacement procedures are described.

Transcatheter Mitral Valve Replacement with the Edwards Sapien 3 Valve

We describe the case of a 57-year-old man who had severe mitral valve stenosis and regurgitation without significant annular calcification. He was not a candidate for surgical valve replacement or repair because of his substantial comorbid conditions, overall frailty, and elevated surgical risk. He underwent successful transcatheter mitral valve replacement of his native mitral valve with compassionate, off-label use of an Edwards Sapien 3 valve. A search of the literature produced no other cases like ours, which represents a further evolution of the transcatheter valve implantation concept. Further studies are needed to help define accurate valve sizing, intraprocedural positioning, and long-term device stability, as well as to determine which patients might benefit from this commercially available valve. In the meantime, our findings could present a means of treating patients who have no other options.

Redo Scoring for Prediction of Success of Redo-Percutaneous Balloon Mitral Valvuloplasty in Patients with Mitral Restenosis

BACKGROUND

Echocardiographic predictors of redo-percutaneous balloon mitral valvuloplasty (redo-PBMV) have not been well studied, and indications are based mainly on Wilkins score. The study aim was to evaluate the immediate results of redo-PMBV and to introduce a simplified redo-score to predict the success of redo-PBMV.

METHODS

Two cohorts of symptomatic patients (derivation group, n = 218; validation group, n = 100) who had undergone redo-PBMV at a mean of 8.1 ± 2.9 years after a first successful PBMV were enrolled in the study. The mean Wilkins scores were 8.5 ± 1.7 in the derivation group and 8.4 ± 1.8 in the validation group. PBMV was performed using a multi-track technique. Independent echocardiographic predictors of outcome were assigned a points value: mitral valve area ≤1.0 cm2 (2 points), posterior mitral valve leaflet length (PMVL)/anterior mitral valve leaflet length (AMVL) ratio ≤1/2 (2 points), doming distance ≤12 mm (3 points), mitral annular calcification (mild = 1 point; moderate = 2 points; severe = 3 points), commissural status (no fusion = 0 points; uni-fusion = 2 points; bi-fusion = 3 points) and chordal length ≤10 mm (2 points).

RESULTS

The minimum score was 5 and the maximum was 13. A receiver operating curve analysis showed the redo score to be highly significant in predicting redo-PBMV immediate results. The cut-off value of redo score to predict a favorable outcome was ≤8, with a sensitivity of 96% and specificity of 85% in the derivation cohort, and a sensitivity of 95% and specificity of 83% in the validation cohort. A Wilkins score ≤8 had a sensitivity of 71% and a specificity of 59% in the derivation cohort, while sensitivity was 70% and specificity 62% in the validation cohort.

CONCLUSIONS

The described scoring system was significantly more predictive than the Wilkins score, and was particularly valuable in predicting outcome in patients with a prior PBMV. It may serve as a satisfactory scoring system for correctly selecting patients with mitral restenosis for PBMV.

Percutaneous Therapy of a Stenotic Parachute Mitral Valve Previously Treated by Surgery

Parachute mitral valve (PMV) is a congenital heart anomaly which consists of a unifocal attachment of the mitral valve chordae into a single or dominant papillary muscle. This morphological anomaly determines the impairment of mitral leaflet motion, resulting in different grades of mitral stenosis. Due to its frequent association with other congenital cardiac defects requiring surgical correction, the therapy of a relevant stenotic PMV is usually represented by surgical commissurotomy. Herein is reported the case of a PMV treated by surgery in infancy, which showed a severe restenosis after 34 years and was successfully treated by percutaneous valvuloplasty with the additional creation of a restrictive atrial communication.

Iatrogenic Lutembacher Syndrome after Percutaneous Mitral Commissurotomy

Atrial septal defects (ASDs) are common immediately after percutaneous mitral commissurotomy (PMC). They are usually small, hemodynamically insignificant, and tend to decrease or disappear within 6 to 12 months. Herein, a case is described of persistent ASD in a patient with mitral valve stenosis who had undergone successful PMC three years previously. The patient had signs and symptoms of right heart failure and severe tricuspid regurgitation (TR) with borderline right ventricular systolic function on echocardiography, in addition to the ASD. Cardiac magnetic resonance (CMR) imaging played a significant role in decision-making by clarifying the anatomy of the ASD and severity of the shunt, measuring right ventricular systolic function, and providing absolute quantification for TR. The right ventricular systolic function was normal on CMR, rendering the patient suitable for surgical treatment. Persistent iatrogenic ASDs have become an increasingly common finding after invasive procedures requiring trans-septal puncture and the manipulation of catheters. Multimodality imaging can provide significant aid in the management of patients with valvular heart disease complicated by iatrogenic shunts.

Percutaneous Mitral Balloon Valvuloplasty in a Pregnant Patient Under Guidance of Three-Dimensional Transesophageal Echocardiography and Right Atrial Mapping, without Using Fluoroscopy

Mitral stenosis is the most common valvular pathology complicating pregnancy. Herein are reported the details of a 26-week pregnant patient with severe mitral stenosis and NYHA class 3-4 symptoms. Percutaneous mitral balloon valvuloplasty was performed under guidance of three-dimensional transesophageal echocardiography and right atrial mapping, without using fluoroscopy. Video 1: Two-dimensional transesophageal echocardiography. The four-chamber view shows limited opening of the rheumatic mitral valve. Video 2: Two-dimensional transesophageal echocardiography while the balloon is inflated. Video 3: Live/real time three-dimensional transesophageal echocardiography showing the uninflated balloon passing through the mitral valve. Video 4: Live/real time three-dimensional transesophageal echocardiography showing the inflated balloon passing through the mitral valve.

Severe mitral stenosis in term pregnancy: management by simultaneous cesarean section and mitral valve replacement. Case report

A 38-year-old woman in the 37th week of pregnancy was admitted for acute presentation of severe cough and aggravated dyspnea. She was previously diagnosed with rheumatic heart disease (RHD) at the age of 31. During the present pregnancy, she reported at 37 weeks and had RHD, severe mitral stenosis, secondary pulmonary hypertension, and heart failure. As a consequence, the patient underwent an emergency cesarean section followed by reoperative mitral valve replacement, which was successfully under a cardiopulmonary bypass (CPB). In this report, the authors present the successful experience of management of severe mitral stenosis in pregnancy.

Pulmonary hypertension in rheumatic mitral stenosis revisited

BACKGROUND

In patients with mitral stenosis (MS), pulmonary hypertension (PH) is a significant contributor to the associated morbidity. We aimed to study factors associated with the presence of significant PH (sPH) and whether incorporating body surface area (BSA) in the mitral valve area (MVA) would improve the predictive value of the latter.

METHODS

The medical records of 558 patients with severe MS undergoing percutaneous balloon mitral commissurotomy were evaluated over a period of 8 years. Factors associated with the presence of significant PH (sPH) defined as mPAP ≥ 40 mm Hg were examined.

RESULTS

A total of 558 patients (423 women) were enrolled. Overall, 153 (27%) patients had sPH. Patients with sPH were similar to the rest of the subjects in terms of demographics, body habitus, blood group, and incidence of atrial fibrillation. Among echocardiographic findings, absolute MVA, indexed MVA, and mean transmitral valve gradient were associated with the presence of sPH. Transmitral valve gradient during right heart catheterization had the highest area under the curve for an association with sPH.

CONCLUSION

Age, gender, heart rhythm, and blood group were not associated with the presence of sPH in severe MS. The predictive value of the indexed MVA for the presence of sPH was not higher than that of absolute MVA.

Association of Transforming Growth Factor-β Superfamily Genes with Non-Regression of Pulmonary Artery Hypertension Following Balloon Mitral Valvotomy: A Pilot Study

BACKGROUND AND AIM OF THE STUDY

Pulmonary arterial hypertension (PAH) is a common accompaniment of rheumatic mitral stenosis (MS), with 70% of patients showing evidence of different grades of PAH. The latter condition is found to be a prognostic factor influencing disease outcome even after interventional or surgical therapy. The cause of the non-regression of PAH following successful balloon mitral valvotomy (BMV) is not clear. Hence, the study aim was to determine if there is an association of mutations in the genes of the TGF-β superfamily and non-regression of PAH in patients who undergo a successful BMV.

METHODS

Forty-six patients who underwent BMV and fulfilled the recruitment criteria were enrolled prospectively in this case-control study. Among the patients, 27 had non-regression of PAH while 19 had regression of PAH and served as controls. The mean age of the population was 32.63 ± 10.65 years.

RESULTS

No statistically significant differences were identified in any of the baseline parameters between the two groups. None of the samples had BMPR2 or ACVRL1 mutations. Ten of the patients and four of the controls were positive for Endoglin mutation, but the inter-group difference was not statistically significant (p = 0.25) CONCLUSIONS: The present study - the first of its kind - showed that deletion-duplication mutations in the BMPR2 or ACVRL1 genes may not be associated with non-regression of PAH, even after successful BMV, or in a wider sense serve as a contributor to PAH in rheumatic MS. The association of Endoglin mutation and non-regression of PAH warrants further investigation in a larger population.

Coagulation, Fibrinolytic System Activation and Endothelial Dysfunction in Patients With Mitral Stenosis and Sinus Rhythm

Anticoagulation treatment can prevent systemic embolism in patients with mitral stenosis (MS) and atrial fibrillation (AF), but this treatment is under debate if patients are in sinus rhythm. The authors aimed to determine the hemostatic changes in patients with MS and sinus rhythm. Forty-six patients (28 in sinus rhythm and 18 in AF) with mitral stenosis were enrolled in this study. They studied systemic venous fibrinogen, D-dimer, antithrombin-III, tissue plasminogen activator (tPA), plasminogen activator inhibitor-I (PAI-I), von Willebrand factor (vWF), and platelet factor 4 (PF 4) in these patients. The patients were first classified according to their rhythm as sinusal and AF, and then according to the presence of left atrial spontaneous echo contrast (LASEC). Fibrinogen, D-dimer, antithrombin-III, vWF, and PF 4 levels were significantly greater in patients with MS and sinus rhythm or atrial fibrillation compared to the control group (p<0.05). Whether the rhythm was sinus or AF, fibrinogen, D-dimer, antithrombin-III, vWF, and PF 4 levels were significantly higher in patients with LASEC than in the control group (p<0.05). Only PF 4 was higher in the AF group than in those with sinus rhythm (p<0.05). As to plasminogen activator and PAI-I levels, only tissue plasminogen activator levels were found to be higher in the AF group than in those with sinus rhythm and the control group (p<0.05). In patients with mitral stenosis and sinus rhythm, if LASEC is present, coagulation activation, platelet activation, and endothelial dysfunction are similar in patients with AF, and anticoagulation should be considered in these patients.

Outcome of Significant Functional Tricuspid Regurgitation Late After Mitral Valve Replacement for Predominant Rheumatic Mitral Stenosis

Significant tricuspid regurgitation (TR) can contribute to increased morbidity and mortality in patients undergoing mitral valve surgery for mitral stenosis. The aim of this study was to evaluate the association between the severity of preoperative functional TR and late adverse outcomes in patients undergoing mitral valve replacement (MVR). The study group comprised 68 patients (54 women, 14 men; mean age 45 ±10 years) with rheumatic mitral stenosis (MS) who had undergone MVR without tricuspid valve surgery between 4 and 13 years (mean 8.1 ±2.6 years) before their last clinical examination. All patients underwent a complete preoperative and late postoperative color-Doppler echocardiographic examination. The severity of TR was assessed echocardiographically by using color-Doppler flow images and flow direction in the inferior vena cava or hepatic veins. Patients were classified into 2 groups; 42 with mild (62%) and 26 with significant (38%) TR. Patients with significant TR showed longer preoperative symptomatic period and more atrial fibrillation than those with mild TR. All patients had medical treatment. Functional capacity and NYHA class of the patients in both groups improved significantly after MVR. Freedom from symptomatic heart failure (functional class III or IV) was higher (86% vs 54%) and the need for hospitalization was significantly lower for the mild TR group. Significant preoperative functional TR diagnosed by echocardiography was associated with an adverse outcome. Therefore, further studies are needed to evaluate the effect of concomitant tricuspid valve repair on the late outcome of patients undergoing mitral valve surgery in order to prevent significant late morbidity.

NT-ProBNP as a Potential Marker of Left Atrial Dysfunction in Rheumatic Mitral Stenosis: Correlation with Left Atrial Function after PBMV

BACKGROUND

Rheumatic heart disease is a common reason for cardiovascular morbidity and mortality. Plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) are known to rise in patients with MS, but the role of this compound as a non-invasive marker of left atrial (LA) dysfunction is yet to be established. The study aim was to correlate levels of NT-proBNP in patients with rheumatic mitral stenosis (MS), with echocardiographic parameters of LA function including tissue Doppler-derived strain/strain rate (S/Sr) indices, hemodynamic parameters of LA function, before and after percutaneous balloon mitral valvotomy (PBMV) for a follow up of one year.

METHODS

The study included 51 patients with severe MS and 10 age- and gender-matched controls. All patients and subjects underwent detailed clinical and echocardiographic evaluation (including LA S/Sr indices) prior to PBMV and at 12 h, one month and one year after PBMV. Venous blood samples were withdrawn to monitor NT-proBNP levels during the same period. LA functions were assessed echocardiographically, using conventional parameters, while S/Sr indices were calculated at mid-LA segments (septal, lateral, anterior and inferior) during ventricular systole, and at early and late diastole. The LA appendage contraction velocity was calculated using transesophageal echocardiography (TEE) and correlated with NT-proBNP levels. The cardiac output (CO) was calculated invasively. The pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure (PAP) and other parameters were correlated with NT-proBNP levels before and after PBMV.

RESULTS

The mean NT-proBNP level before PBMV was 761.76 ± 213.6 pg/ml, and was 425 pg/ml, 300 pg/ml and 50 pg/ml at one day, one month and one year, respectively (p <0.01). The S/Sr indices at each mid-LA segment (septal, lateral, anterior, and inferior) during ventricular systole (LAs), at early (LAe) and late diastole (LAa) were each significantly lower in patients than in controls (p <0.001). The S/Sr values were improved significantly (p <0.05) in most segments at one day and at one month after PBMV, but after one year the values were increased by >50%, in relation to the NT-proBNP level. There were significant falls in mean PAP and PCWP and a rise in CO, each of which correlated significantly with NTproBNP levels.

CONCLUSIONS

NT-proBNP levels correlated significantly with LA dysfunction, and can predict improvements in LA function following PBMV in rheumatic MS for up to one year. Tissue Doppler-derived S/Sr indices may be used to detect fine variations over and above conventional echocardiography, and this may be clinically valuable in the prognosis of MS patients.

Three-dimensional transesophageal echocardiography for determination of the mitral valve area after mitral valve repair surgery for mitral stenosis

BACKGROUND

Pressure half-time (PHT) method is usually unreliable for accurate determination of mitral valve area (MVA) immediately after surgical intervention of mitral stenosis (MS). The planimetry method using three-dimensional (3D) transesophageal echocardiography (3D-planimetery method) could enhance accurate determination of the intraoperative MVA. Authors investigated the efficacy of 3D-planimetry method in determining MVA immediately after mitral valve repair procedure (MVRep) for severe mitral stenosis (MS).

METHODS

In severe MS patients undergoing elective MVRep (N.=41), intraoperative MVAs were determined by using PHT-method and 3D-planimetry method before and immediately after cardiopulmonary bypass (pre- and post-MVAPHT, and -MVA3D-planimetry). MVAs were also determined by using multi-detector computed tomographic scan (MDCT) before MVRep and within 7 days after MVRep (pre- and post-MVACT). MVAs determined by using three different methods were analysed.

RESULTS

Mitral inflow pressure gradient (median [25th-75th percentile]) was significantly reduced after MVRep (3.0 [2.0-4.0] vs. 7.0 [6.0-9.0] mmHg; P<0.001). Pre-MVAPHT, pre-MVA3D-planimetry and preop-MVACT (mean [95% confidence interval]) did not differ significantly (1.08 [1.00-1.05], 1.08 [0.98-1.08], and 1.14 [1.07-1.22] cm2, respectively), but post-MVA3D-planimetry and post-MVACT (2.22 [2.07-2.36] and 2.31 [2.07-2.36] cm2, respectively) were significantly larger than post-MVAPHT (1.98 [1.83-2.13] cm2; P=0.007 and P<0.001, respectively). The correlation coefficient between post-MVA3D-planimetry and post-MVACT (0.59, P<0.01) was greater than that between post-MVAPHT and post-MVACT (0.39, P=0.01).

CONCLUSIONS

These results support the clinical efficacy of 3D-planimetry for accurate evaluation of the MVA immediately after MVRep for severe MS, as a valuable alternative to PHT-method which usually underestimates MVA during this period.

Assessment of the Melody valve in the mitral position in young children by echocardiography

OBJECTIVES

Mitral valve replacement (MVR) in young children is limited by the lack of small prostheses. Our institution began performing MVR with modified, surgically placed, stented jugular vein grafts (Melody valve) in 2010. We sought to describe key echocardiographic features for pre- and postoperative assessment of this novel form of MVR.

METHODS

The pre- and postoperative echocardiograms of 24 patients who underwent Melody MVR were reviewed. In addition to standard measurements, preoperative potential measurements of the mitral annulus were performed whereby dimensions were estimated for Melody sizing. A ratio of the narrowest subaortic region in systole to the actual mitral valve dimension (SubA:MV) was assessed for risk of postoperative left ventricular outflow tract obstruction (LVOTO).

RESULTS

Melody MVR was performed at a median of 8.5 months (5.6 kg) for stenosis (5), regurgitation (3), and mixed disease (16). Preoperatively, actual mitral z scores measured hypoplastic (median -3.1 for the lateral [lat] dimension; -2.1 for the anteroposterior [AP] dimension). The potential measurements often had normal z scores with fair correlation with intraoperative Melody dilation (ρ = 0.51 and 0.50 for lat and AP dimensions, respectively, both P = .01). A preoperative SubA:MV <0.5 was associated with postoperative LVOTO, which occurred in 4 patients. Postoperatively, mitral gradients substantially improved, with low values relative to the effective orifice area of the Melody valve. No patients had significant regurgitation or perivalvar leak.

CONCLUSIONS

Preoperative echocardiographic measurements may help guide intraoperative sizing for Melody MVR and identify patients at risk for postoperative LVOTO. Acute postoperative hemodynamic results were favorable; however, ongoing assessment is warranted.

Increased Systemic and Regional Coagulation Activity in Patients with Mitral Stenosis and Sinus Rhythm

A hypercoagulable state has been reported in patients with mitral stenosis (MS) and sinus rhythm (SR). However it has been suggested that the coagulation activity may be increased only within the left atrium in MS, with normal peripheral blood levels. The aim of the present study was to assess regional left atrial and systemic coagulation activities by measuring PF 1 +2 in patients with severe mitral stenosis and sinus rhythm, normal blood clotting times, and no left atrial thrombus. The study was conducted in 25 consecutive patients with moderate-to-severe MS and sinus rhythm who underwent percutaneous balloon mitral valvu loplasty. Transesophageal echocardiography was performed before the valvuloplasty procedure in all patients to exclude the presence of left atrial thrombus and left atrial spontaneous echo contrast (LASEC). There were no statistically significant differences between LASEC-positive and LASEC-negative patients with respect to age, gender, fibrinogen levels, prothrombin time, mitral valve area, mean mitral gradient, pulmonary artery pressure (in all p> 0.05). Regional (left atrial) PF1+2 levels of both LASEC-positive and LASEC-negative patients were significantly elevated when compared to control subjects (p<0.01). Statistically significant elevated systemic level of PF 1 +2 was observed only in LASEC-positive patients when compared to control subjects (p<0.01, p>0.05, respectively). In conclusion patients with severe mitral stenosis and SR have increased regional coagulation activity in both LASEC-negative and LASEC-positive groups. Although this increased regional coagulation activity has been reflected in peripheral blood of LASEC-positive patients, it has not been reflected in peripheral blood of LASEC-negative patients.

Interrupted commissural band annuloplasty prevents mitral stenosis

BACKGROUND

Mitral annuloplasty is an important component of the treatment of degenerative mitral valve disease. However, postoperative echocardiography reveals elevated mitral gradients in some patients. We developed a technique that we termed interrupted commissural band annuloplasty (iCBA), which does not shorten either the anterior or posterior annulus and is not associated with the development of a mitral gradient. We compared the echocardiographic characteristics of patients treated using this method versus Cosgrove ring (COS) placement, both at rest and during exercise.

METHODS

ICBA features placement of three sutures in the commissures using two bands and shortens the commissural annular length by 60 %. We used this method to treat 63 patients and placed Cosgrove bands in 58. Of all patients, 48 who underwent iCBA and 34 with COSs passed the exercise echocardiographic test.

RESULTS

The maximal transmitral pressures at rest in the iCBA and Cosgrove groups were 8.04 ± 0.74 and 11.30 ± 0.88 mmHg (P = 0.0029), respectively, and the mean transmitral pressures at rest were 2.46 ± 0.74 and 3.61 ± 0.32 mmHg (P = 0.0037), respectively. The maximal transmitral pressures during exercise were 11.79 ± 0.97 and 18.37 ± 1.16 mmHg (P < 0.0001), and the mean transmitral pressures during exercise were 4.95 ± 0.45 and 7.76 ± 0.53 mmHg (P < 0.0001).

CONCLUSIONS

ICBA prevents postoperative mitral stenosis both at rest and importantly during exercise.

Arterial-ventricular and interventricular interaction in isolated post-capillary and combined pulmonary hypertension in severe mitral stenosis

BACKGROUND

Isolated post-capillary pulmonary hypertension (Ipc-PH) is characterized by elevated left atrial pressures that are passively transmitted upstream, whereas combined pre- and post-capillary PH (Cpc-PH) demonstrates additional reactive changes in pulmonary vasculature. The increased load imposed on the right ventricle (RV) influences left ventricular (LV) mechanics by means of interventricular interaction. However, there is lack of evidence to substantiate the effect of possible additional alterations in the arterio-ventricular (AV) coupling and their effect on LV function. Considering the discrepant RV load in Cpc-PH and Ipc-PH, we sought to investigate whether these two conditions are also characterized by differential alterations in AV coupling.

METHODS AND RESULTS

Invasive hemodynamic and echocardiographic data of 120 patients with PH due to severe rheumatic mitral stenosis before and immediately after percutaneous valvulotomy, along with 40 age-matched healthy controls, were analyzed. Effective arterial (E a) and ventricular elastance (E es) were measured. PH patients demonstrated elevated LV afterload (E a) along with AV uncoupling, and these derangements were more evident in the Cpc-PH group [E a: 3.3 (2.3-5.4) vs 2.6 (2.1-3.5) mmHg/mL, E a/E es: 0.73 (0.6-0.9) vs 0.88 (0.7-1.2), p < 0.05]. In addition, PH was associated with reduced LV deformation, which was mainly determined by elevated E a, while the effect of interventricular interaction was limited to the septal wall.

CONCLUSIONS

Our results suggest that in addition to the interventricular interaction, an abnormal AV coupling contributes to the altered LV mechanics that has been associated with adverse prognosis in Cpc-PH.

Incidence and Predictors of Long-Term Adverse Outcomes in Patients with Rheumatic Mitral Stenosis in Sinus Rhythm

BACKGROUND

Rheumatic fever and rheumatic heart disease remain important health problems in developing countries. Mitral stenosis (MS) is the most common form of rheumatic heart disease. The aim of this study was to investigate incidence and echocardiographic predictors of long-term adverse outcomes in patients with rheumatic mitral stenosis in sinus rhythm.

MATERIAL AND METHOD

We retrospectively reviewed medical records of patients diagnosed with isolated rheumatic MS of any severity at Siriraj Hospital between 1996 and 2013. Demographic data, echocardiographic data, and long-term adverse outcomes were collected. Long-term adverse outcomes included all-cause mortality, hospitalization due to heart failure, new-onset atrial fibrillation, and/or embolic stroke during follow-up.

RESULTS

One hundred eighty five patients (aged 41.9 ± 13.2 years, 81.1% female) were included during the median follow-up period of 12.6 years (95% CI: 11.2-14.0). MS was classified as mild, moderate, and severe in 8.6%, 2 7.6%, and 63.8% of patients, respectively. Average mitral valve score was 8.25 ± 1.5. Most patients (61.6%) underwent percutaneous balloon mitral valvulotomy. Incidence of long-term adverse outcome was 43.2% (95% CI: 36.0-50.7%) and included mortality in two patients (1.1%, 95% CI: 0.13-3.9%), hospitalization due to heart failure in 20 patients (10.8%, 95% CI: 6.7-16.2%), new-onset atrial fibrillation in 71 patients (38.4%, 95% CI: 31.3-45.8%), and embolic stroke in 14 patients (7.6%, 95% CI: 4.2-12.4%). Echocardiographic parameters associated with long-term adverse outcomes were left atrial dimension greater than 50 mm (HR 2.61, 95% CI: 1.08-6.30; p = 0.03) and left ventricular end-systolic dimension less than 28 mm (HR 3.06, 95% CI: 1.25-7.49; p = 0.01).

CONCLUSION

Long-term adverse outcomes are common in patients with rheumatic MS in sinus rhythm. Long-term adverse outcomes were found to correlate with left atrial dimension and left ventricular end-systolic dimension.

An Unusual Case of Persistent Severe Pulmonary Artery Hypertension Following Balloon Mitral Valvuloplasty

Persistent pulmonary artery hypertension (PAH) after balloon mitral valvuloplasty (BMV) is not uncommon, and is generally associated with established pulmonary vascular disease, an inadequate result, or the development of mitral regurgitation. An unfavorable mitral valve morphology with a smaller post-procedural mitral valve area is among the most common causes of the condition. While routine cardiac catheterization is no longer recommended prior to intervention in valvular heart disease, patients with persistent PAH after BMV should undergo a thorough evaluation before they are considered for repeat BMV. Here, a rare case is reported of symptomatic persistent PAH in a patient referred for a third BMV, less than one year after the previous intervention, where a hypertensive patent ductus arteriosus was identified, the closure of which led to a regression of the PAH.

Transcatheter Mitral Valve-in-Ring for Progressive Mitral Stenosis after Prior Repair with Annuloplasty: A Novel Balloon Sizing Technique

An 83-year-old man with a previous mitral valve repair using a semi-rigid annuloplasty ring was found to have severe mitral stenosis. A transcatheter approach for mitral valve-in-ring replacement was selected due to the patient's high surgical risk. Pre-procedural computed tomography scans for transcatheter valve size selection were inconsistent with previously published recommendations. To determine the appropriate valve size, a 25 mm compliant balloon was inflated intraoperatively within the stenotic mitral ring, but yielded no resistance to movement and no 'waist'. Thus, a 29 mm balloon-expandable prosthetic valve was selected and deployed with no paravalvular leak. This novel balloon sizing technique helped lead to a successful outcome in this case. Video 1: Angiographic video displaying mitral valve-in-ring balloon sizing technique. The 25 mm compliant balloon was inflated within a stenotic mitral ring to determine which prosthetic transcatheter valve size was appropriate. As shown, this technique yielded no 'waist' and no resistance to movement, suggesting that a 29 mm valve was necessary.

Underlying Rheumatic Disease: An Important Determinant of Outcome in Tricuspid Valve Repair

BACKGROUND

Tricuspid regurgitation (TR) accompanying severe left-sided valve disease occurs on a functional basis, secondary to pulmonary hypertension and tricuspid annular dilatation. In the context of endemic left-sided rheumatic heart disease, non-recognition of organic disease of the tricuspid valve may adversely influence surgical decision-making, resulting in suboptimal outcomes.

METHODS

A retrospective analysis of the perioperative and follow up data of 30 patients who underwent tricuspid valve surgery with concomitant left-sided valve replacement was undertaken. Preoperative evaluation by two-dimensional transthoracic echocardiography was routinely employed. Outcomes were analyzed by evaluation of the perioperative and two-year follow up clinical and echocardiographic data.

RESULTS

All subjects had severe TR. Mixed tricuspid valve disease occurred in 11 subjects (36.7%). Tricuspid valve repair was performed in 28 patients. A significant improvement (p <0.05) in the following parameters occurred at six weeks postoperatively: NYHA functional class, tricuspid annular diameter, systolic pulmonary artery pressure, severity of TR and tricuspid transvalvular gradient. Severe residual postoperative TR occurred in 26.7% of patients, but there were no identifiable predictors for this phenomenon. Severe residual postoperative TR was not associated with major adverse cardiovascular events. Preoperative (p = 0.013) and postoperative (p<0.002) pulmonary hypertension were associated with the development of major adverse cardiovascular events. The technique of tricuspid valve repair was not associated with the occurrence of major adverse cardiovascular events, nor with the development of severe residual postoperative TR. A satisfactory outcome was observed in only 40% of the study population.

CONCLUSIONS

The coexistence of mixed tricuspid valve disease in rheumatic heart disease patients undergoing left-sided valve surgery is an important determinant of outcome in tricuspid valve repair. The persistence of severe TR contributes to poor long-term outcomes, and its incidence may be lowered by the adoption of appropriate perioperative imaging techniques to delineate valve morphology.

Mitral Stenosis Presenting as Asthma

Although wheezing is one of the most common symptoms and physical findings in asthma, other causes of wheezing should be kept in mind: vocal cord dysfunction, postnasal drip syndrome, chronic obstructive pulmonary disease, bronchiectasis, and non-pulmonary diseases, like heart failure and pulmonary edema. Here, we present a case of severe mitral stenosis with pulmonary edema treated for resistant asthma. If asthma is difficult to control, other etiologies of wheezing, including cardiac disease, should be taken into consideration during diagnosis.

A comparative study of ivabradine and atenolol in patients with moderate mitral stenosis in sinus rhythm

BACKGROUND

Beta-blockers are frequently used in patients with mitral stenosis to control the heart rate and alleviate exercise-related symptoms. The objective of our study was to examine whether ivabradine was superior to atenolol for achieving higher exercise capacity in patients with moderate mitral stenosis in sinus rhythm. We also evaluated their effects on left ventricular myocardial performance index (MPI).

METHODS AND RESULTS

Eighty-two patients with moderate mitral stenosis in sinus rhythm were randomized to receive ivabradine (n=42) 5mg twice daily or atenolol (n=40) 50mg daily for 6 weeks. Transthoracic echocardiography and treadmill test were performed at baseline and after completion of 6 weeks of treatment. Mean total exercise duration in seconds markedly improved in both study groups at 6 weeks (298.57±99.05s vs. 349.12±103.53s; p=0.0001 in ivabradine group, 290.90±92.42s vs. 339.90±99.84s; p=0.0001 in atenolol group). On head-to-head comparison, there was no significant change in improvement of exercise time between ivabradine and atenolol group (p=0.847). Left ventricular MPI did not show any significant change from baseline and at 6 weeks in both drug groups (49.8%±8% vs. 48.3%±7% in ivabradine group, 52.9%±10% vs. 50.9%±10% in atenolol groups; p=0.602).

CONCLUSION

Ivabradine or atenolol can be used for heart rate control in patients with moderate mitral stenosis in sinus rhythm. Ivabradine is not superior to atenolol for controlling heart rate or exercise capacity. Left ventricular MPI was unaffected by either of the drugs.

Left Atrial Reservoir Function in Symptomatic Versus Asymptomatic Patients with Moderate Mitral Stenosis

BACKGROUND AND AIM OF THE STUDY: Deformation of the left atrium during the reservoir phase may provide information regarding potential preclinical heart disease, but at present insufficient data are available concerning left atrial (LA) reservoir function in valvular heart disease. The study aim was to assess LA reservoir function in patients with moderate mitral stenosis (MS), and its relation to the patient’s clinical status. METHODS: A total of 40 patients (31 females, nine males; mean age 29.47 ± 19.1 years) with isolated moderate MS and in sinus rhythm were allocated to either symptomatic or asymptomatic groups (n = 20 in each group). All patients provided their complete medical history, were examined clinically and underwent transthoracic echocardiography to assess MS severity, systolic pulmonary artery pressure (SPAP), mean pulmonary artery pressure (MPAP), left atrial maximal volume (LAV(max)), left atrial minimal volume (LAV(min)), and indices of left atrial reservoir function, including total left atrial emptying volume Tot(empVol), indexed Tot(empVol), and total left atrial emptying fraction (LAEF). RESULTS: Symptomatic patients showed a significantly higher mean LAV(max) (79.25 ± 19.12 versus 70.65 ± 13.34 ml, p = 0.022), LAV(min) (54.63 ± 6.68 versus 47.1 ± 12.87 ml, p = 0.029), Tot(empVol) (23.83 ± 5.33 versus 18.4 ± 7.13 ml, p = 0.01), indexed Tot(empVol) (14.73 ± 2.49 versus 12.53 ± 3.18 ml/m2, p = 0.02), SPAP (44.35 ± 7.79 versus 32.65 ± 10.6 mmHg, p = 0.002), and MPAP (37.60 ± 10.78 versus 30.46 ± 7.55 mmHg, p = 0.02) and a significantly lower mean LAEF (30.40 ± 7.26 versus 36.13 ± 6.37%, p = 0.011). Significant negative correlations were noted between LAEF with SPAP, LAV(max) and LAV(min). Further significant associations were detected for the symptomatic group between LAEF (r = -0.43) and mitral valve area (r = -0.37). Similarly, multivariate linear regression analysis revealed a significant negative association between presence in the symptomatic group and LAEF (β = -4.78, SE = 2.22, p <0.05). Finally, Tot(empVol) was the strongest predictor of LAEF (β = 1.23). CONCLUSION: LA reservoir function is impaired in symptomatic patients with moderate MS.

Usefulness of the Macruz Index for Predicting Successful Percutaneous Mitral Balloon Valvuloplasty in Patients with Mitral Stenosis

OBJECTIVE

The aim of this study was to determine whether the Macruz index (P/P-R segment) could predict the severity of valvular involvement and the success of percutaneous mitral balloon valvuloplasty (PMBV) in patients with mitral stenosis (MS).

SUBJECTS AND METHODS

Sixty-one patients with MS eligible for PMBV and 72 healthy subjects (61 females and 11 males) with sinus rhythm were enrolled into this study. PMBV was performed in all patients using a percutaneous transseptal antegrade approach and a multitrack balloon technique. The P/P-R segment ratio and echocardiographic variables were measured before and 48-72 h after the procedure. The optimal cutoff point for differences in the Macruz index to determine clinical success was evaluated by receiver operating characteristic analysis by calculating the area under the curve as giving the maximum sum of sensitivity and specificity for the significant test.

RESULTS

In the patient group (mean age 42.9 ± 11.1 years), the preprocedural Macruz index was significantly higher than in the control group (2.79 ± 1.03 vs. 1.29 ± 0.11; p < 0.001). In the successful-procedure group (n = 53), the mean postindex value was significantly lower (2.12 ± 0.71 vs. 2.81 ± 1.0, p = 0.020), and the decrease in the Macruz index was significantly higher than in the unsuccessful-procedure group (p = 0.007). An index decrease of 0.105 was the best cutoff value to distinguish the successful-PMBV group from the unsuccessful- PMBV group (area under the curve = 0.888, 95% confidence interval 0.788-0.988, p < 0.001).

CONCLUSION

The Macruz index was significantly higher in patients with MS compared to healthy subjects. A greater decrease in the Macruz index was associated with a successful PMBV.

Mitral valve area during exercise after restrictive mitral valve annuloplasty: importance of diastolic anterior leaflet tethering

BACKGROUND

Restrictive mitral valve annuloplasty (RMA) for secondary mitral regurgitation might cause functional mitral stenosis, yet its clinical impact and underlying pathophysiological mechanisms remain debated.

OBJECTIVES

The purpose of our study was to assess the hemodynamic and clinical impact of effective orifice area (EOA) after RMA and its relationship with diastolic anterior leaflet (AL) tethering at rest and during exercise.

METHODS

Consecutive RMA patients (n = 39) underwent a symptom-limited supine bicycle exercise test with Doppler echocardiography and respiratory gas analysis. EOA, transmitral flow rate, mean transmitral gradient, and systolic pulmonary arterial pressure were assessed at different stages of exercise. AL opening angles were measured at rest and peak exercise. Mortality and heart failure readmission data were collected for at least 20 months after surgery.

RESULTS

EOA and AL opening angle were 1.5 ± 0.4 cm(2) and 68 ± 10°, respectively, at rest (r = 0.4; p = 0.014). EOA increased significantly to 2.0 ± 0.5 cm(2) at peak exercise (p < 0.001), showing an improved correlation with AL opening angle (r = 0.6; p < 0.001). Indexed EOA (EOAi) at peak exercise was an independent predictor of exercise capacity (maximal oxygen uptake, p = 0.004) and was independently associated with freedom from all-cause mortality or hospital admission for heart failure (p = 0.034). Patients with exercise EOAi <0.9 cm(2)/m(2) (n = 14) compared with ≥0.9 cm(2)/m(2) (n = 25) had a significantly worse outcome (p = 0.048). In multivariate analysis, AL opening angle at peak exercise (p = 0.037) was the strongest predictor of exercise EOAi.

CONCLUSIONS

In RMA patients, EOA increases during exercise despite fixed annular size. Diastolic AL tethering plays a key role in this dynamic process, with increasing AL opening during exercise being associated with higher exercise EOA. EOAi at peak exercise is a strong and independent predictor of exercise capacity and is associated with clinical outcome. Our findings stress the importance of maximizing AL opening by targeting the subvalvular apparatus in future repair algorithms for secondary mitral regurgitation.