Echocardiographic assessment of prosthetic heart valves

Renal function improvement correlates with 3D echocardiographic findings: Effect of surgical mitral valve repair

BACKGROUND

The association between surgical treatment of mitral regurgitation (MR) and renal function is not sufficiently well-known. We tried to evaluate renal function before and after the procedure of surgical mitral valve repair (SMVR) in degenerative severe MR.

METHODS

Patients with primary severe (4+) MR and normal left ventricular ejection fraction (LVEF) that underwent SMVR, examined by a cutting-edge 3-dimensional (3D) echocardiographic probe were enrolled in this study. We took three CKD-EPI equations to measure estimated glomerular filtration rate (eGFR) before SMVR and shortly before patients discharge. A total of 40 patients with baseline lower mean eGFR were evaluated.

RESULTS

Measurements substantiated statistically significant improvements in eGFR (p < 0.001), multivariable linear regression modeling indicating prominent associations between increase in eGFR and decrease of MR (p = 0.003), decline of pulmonary arterial systolic pressure (p = 0.018), as well as increment of forward stroke volume (p = 0.02), in spite of LVEF reduction, left ventricular global longitudinal strain worsening and left atrial ejection fraction impairment.

CONCLUSIONS

Renal function improves after SMVR in patients with degenerative significant MR and preserved LVEF, regardless of cardiac functional worsening.

Mitral regurgitation in the critically ill: the devil is in the detail

Mitral regurgitation (MR) is common in the critically unwell and encompasses a heterogenous group of conditions with diverging therapeutic strategies. MR may present acutely with haemodynamic instability or more insidiously with failure to wean from mechanical ventilation. Critical illness is associated with marked physiological stress and haemodynamic changes that dynamically influence the severity and implication of MR. The expanding role of critical care echocardiography uniquely positions the intensivist to apply advanced bedside valvular assessment to recognise haemodynanically significant MR, manipulate and optimise cardiopulmonary physiology and identify patients requiring urgent cardiology and surgical referral. This review will consider common clinical scenarios, therapeutic strategies and the pearls and pitfalls of echocardiographic assessment and quantification in the critically unwell.

Measuring HRQoL following heart valve surgery: the HeartQoL questionnaire is a valid and reliable core heart disease instrument

PURPOSE

Patient-reported health-related quality of life is a complementary healthcare outcome and important when assessing treatment efficacy. Using COSMIN methodological recommendations, this study evaluates the validity and reliability of a core heart disease-specific health-related quality of life questionnaire, the HeartQoL questionnaire (Danish version) in a sample of patients following heart valve surgery.

DESIGN

This project involved a cross-sectional validity study and a test-retest reliability study.

METHODS

Eligible patients completed the HeartQoL, the SF-36 health survey questionnaire, and the Hospital Anxiety and Depression Scale following heart valve surgery. Construct validity was tested using a priori hypotheses. Internal consistency reliability was assessed with Cronbach's alpha. An independent sample of patients participated in the test-retest study and reproducibility was determined with relative [intra-class correlation coefficient (ICC)] and absolute reliability [standard error of measurement (SEM) and smallest detectable change (SDC)].

RESULTS

Internal consistency was high with Cronbach's alpha ≥ 0.87. ICC was 0.86-0.92. SEM ranged from 0.17 to 0.26 points and SDC ranged from 0.5 to 0.7 points. Construct validity was confirmed with 87% of all a priori hypotheses for predicted variables.

CONCLUSIONS

The HeartQoL questionnaire demonstrates acceptable construct validity, internal consistency, and test-retest reproducibility in patients following heart valve surgery. Future studies should focus on assessing the responsiveness of the HeartQoL questionnaire over time and following heart valve surgery.

Ultrasound for In Vitro, Noninvasive Real-Time Monitoring and Evaluation of Tissue-Engineered Heart Valves

Tissue-engineered heart valves are developed in bioreactors where biochemical and mechanical stimuli are provided for extracellular matrix formation. During this phase, the monitoring possibilities are limited by the need to maintain the sterility and integrity of the valve. Therefore, noninvasive and nondestructive techniques are required. As such, optical imaging is commonly used to verify valve's functionality in vitro. It provides important information (i.e., leaflet symmetry, geometric orifice area, and closing and opening times), which is, however, usually limited to a singular view along the central axis from the outflow side. In this study, we propose ultrasound as a monitoring method that, in contrast to established optical imaging, can assess the valve from different planes, scanning the whole three-dimensional geometry. We show the potential benefits associated with the application of ultrasound to bioreactors, in advancing heart valve tissue engineering from design to fabrication and in vitro maturation. Specifically, we demonstrate that additional information, otherwise unavailable, can be gained to evaluate the valve's functionality (e.g., coaptation length, and effective cusp height and shape). Furthermore, we show that Doppler techniques provide qualitative visualization and quantitative evaluation of the flow through the valve, in real time and throughout the whole in vitro fabrication phase.

Prosthesis-patient mismatch - what cardiac anesthesiologists need to know?

Prosthesis-patient Mismatch (PPM) is not uncommon with an incidence reported up to 70% after aortic valve (AV) replacement. Severe forms of PPM are less common (up to 20%); PPM can lead to increased short- and long-term morbidity and mortality. It is important to discriminate PPM from other forms of prosthetic valve dysfunction. Sometimes, prosthetic valve degenerative disease may coexist with PPM. Echocardiography plays an important role in the prevention and diagnosis of PPM. Preemptive strategies to prevent PPM include insertion of newer generation prosthetic valves with better hemodynamic characteristics, stentless prosthesis, aortic root enlargement to insert a larger prosthesis, aortic homograft, and transcutaneous AV implantation. We present an illustrative case and review the literature on PPM pertinent to anesthesiologists.

Echocardiography in Pregnancy: Part 2

The prevalence of pregnant women with cardiovascular heart disease is increasing. Transthoracic echocardiography is safe during pregnancy, and it is an important diagnostic tool in pregnant women with established heart disease in order to monitor ventricular and valvular anatomy and function. In addition, it can be used to delineate cardiac anatomy in complex congenital heart disease and help stratify maternal risk during pregnancy. This review will focus on the use of echocardiography in the diagnosis and management of pregnant women with common congenital lesions and with prosthetic valves.

BioGlue-Associated Loss of Aortic Valve Leaflet Motility Sonographically Masked by Both Newly Replaced Mechanical Aortic and Mitral Valves

BioGlue is a surgical adhesive widely used to help reinforce complex cardiac and vascular repairs. Since its introduction, several case reports have emerged revealing complications that all providers should be mindful of whenever the product is used. This report considers a unique situation where BioGlue was used after double cardiac valve repair that resulted in adhesion of the new mechanical aortic valve leaflets and was difficult to visualize with transesophageal echocardiography.

Echocardiographic assessment of prosthetic mitral valves in children

AIMS

We studied how Doppler-derived hemodynamic parameters in children change as the relative prosthetic mitral valve (PMV) size decreases with somatic growth and evaluated the diagnostic utility of the parameters for detecting PMV obstruction in children.

METHODS AND RESULTS

We reviewed 26 echocardiographic examination results of 15 mechanical bileaflet PMVs in 12 children. The median age at echocardiographic examination was 6.6 (0.6-18.1) years. The PMV functioned normally in 24 examinations but was obstructed due to thrombosis in two cases. PMV sizes ranged between 16 and 25 mm, which were standardized to body surface area (BSA) at the examination with z-score calculations. We assessed the peak E velocity, mean pressure gradient (PG), and pressure half time (PHT) of the transprosthetic flow, the velocity-time integral (VTI) ratio of the PMV inflow to the left ventricular outflow, and the BSA-indexed effective orifice area (iEOA) of the PMV calculated with the continuity equation. Linear regression analysis revealed statistically significant correlations between all parameters of normally functioning PMVs and the PMV size z-scores (Pearson correlation coefficients: peak E velocity, -0.68; mean PG, -0.71; PHT, -0.82; VTI ratio, -0.76; iEOA, 0.79). Compared with the predictive values derived from the regression equations, the VTI ratio and iEOA exceeded ± 2 standard errors in both patients with obstructive PMVs.

CONCLUSION

To assess PMV function in children, Doppler-derived hemodynamic parameters should be compared with their predictive values based on relative PMV sizes. The deviation of the VTI ratio and iEOA from their predictive values may indicate prosthetic obstruction.

Echocardiographically derived effective valve opening area in mitral prostheses: a comparative analysis of various calculations using continuity equation and pressure half time method

Detection of dysfunctional mitral valve prostheses (MP) remains complex even though being optimized by considering echocardiographically derived prosthetic effective orifice area (VA). The purpose was to compare VA in MP, calculated by the continuity equation (CE) using peak velocities (CEVpeak), mean velocities (CEVmean), velocity-time integrals (CEVTI) and the pressure half time method using 220 ms as constant first (PHT220) as well as optimized constants. In 267 consecutive patients with normally functioning MP, we investigated VA within the first postoperative month. With increasing prosthetic sizes, mean VA values also increase in all calculations. The statistical curves demonstrate no significant difference in graphical steepness but show different levels. Comparison of mean VA showed the known systematic higher values of PHT220 and significantly decreased results when using CEVTI. This systematic difference between mean VA applying PHT220 versus CEVTI is approximately 1.0 cm(2) for all prosthetic sizes. Calculations via CEVpeak were close to the results of CEVTI. CEVmean produced values, which graphically correspond to the PHT220 curve. Only PHT220 detected the constructional equal prosthetic inner ring width between 29 and 31 mm. To compensate the systematic difference between CEVTI and PHT220, an optimized constant of 140 ms was calculated to be applied in PHT (PHT140). VA is a robust and, therefore, preferable parameter for investigating MP. If needed, both CE and PHT are applicable with a systematical difference between CEVTI and PHT220. An optimized constant of 140 ms (PHT140) should be applied when calculating VA of mitral valve prostheses via PHT.