Assessment of degradability and endothelialization of modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluders over time in vivo.

OBJECTIVE: To evaluate the fiber-degradation and endothelialization of a modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluder for a long time in vivo. METHODS: A total of 57 New Zealand rabbits were selected to establish the vasculature implantation model, which would be used to characterize the mechanical properties and pathological reaction of PLLA filaments (a raw polymer of ASD occluder). In total, 27 Experimental piglets were used to create the ASD model for the catheter implantation of PLLA ASD occluders. Then, X-ray imaging, transthoracic echocardiography, histopathology, and scanning electron microscope (SEM) were performed in the experimental animals at 3, 6, 12, and 24 months after implantation. RESULTS: In the rabbit models, the fibrocystic grade was 0 and the inflammatory response was grade 2 at 6 months after vasculature implantation of the PLLA filaments. The mass loss of PLLA filaments increased appreciably with the increasing duration of implantation, but their mechanical strength was decreased without broken. In the porcine models, the cardiac gross anatomy showed that all PLLA ASD occluders were stable in the interatrial septum without any vegetation or thrombus formation. At 24 months, the occluders had been embedded into endogenous host tissue nearly. Pathological observations suggested that the occluders degraded gradually without complications at different periods. SEM showed that the occluders were endothelialized completely and essentially became an integral part of the body over time. CONCLUSION: In the animal model, the modified PLLA ASD occluders exhibited good degradability and endothelialization in this long-term follow-up study.

A risk-based approach to cumulative effects assessment for large marine ecosystems to support transboundary marine spatial planning: A case study of the yellow sea.

Cumulative effects assessment (CEA) should be conducted at ecologically meaningful scales such as large marine ecosystems to halt further ocean degradation caused by anthropogenic pressures and facilitate ecosystem-based management such as transboundary marine spatial planning (MSP). However, few studies exist at large marine ecosystems scale, especially in the West Pacific seas, where countries have different MSP processes yet transboundary cooperation is paramount. Thus, a step-wise CEA would be informative to help bordering countries set a common goal. Building on the risk-based CEA framework, we decomposed CEA into risk identification and spatially-explicit risk analysis and applied it to the Yellow Sea Large Marine Ecosystem (YSLME), aiming to understand the most influential cause-effect pathways and risk distribution pattern. The results showed that (1) seven human activities including port, mariculture, fishing, industry and urban development, shipping, energy, and coastal defence, and three pressures including physical loss of seabed, input of hazardous substances, nitrogen, and phosphorus enrichment were the leading causes of environmental problems in the YSLME; (2) benthic organisms, fishes, algae, tidal flats, seabirds, and marine mammals were the most vulnerable ecosystem components on which cumulative effects acted; (3) areas with relatively high risk mainly concentrated on nearshore zones, especially Shandong, Liaoning, and northern Jiangsu, while coastal bays of South Korea also witnessed high risk; (4) certain risks could be observed in the transboundary area, of which the causes were the pervasive fishing, shipping, and sinking of pollutants in this area due to the cyclonic circulation and fine-grained sediments. In future transboundary cooperation on MSP, risk criteria and evaluation of existing management measures should be incorporated to determine whether the identified risk has exceeded the acceptable level and identify the next step of cooperation. Our study presents an example of CEA at large marine ecosystems scale and provides a reference to other large marine ecosystems in the West Pacific and elsewhere.

Green-Light Responsive Perylene Bisimides for Atom-Economic Thiol Generation and Click-Ligation.

Novel methylthiophene/benzo[b]thiophene perylene bisimide thiol-precursors that would generate thiols via a green-light-induced (λexc = 530 nm, φre = 0.33) photorearrangement are presented herein. The "no-wash", photoreleased thiols thus enabled a subsequent thiol-ene click ligation with electron-deficient substrates. Moreover, by virtue of the intrinsic fluorescence evolution from the rearrangement of perylene bisimide scaffolds, the whole process of thiol formation could be self-reported, further potentiating themselves with application versatilities.

SEIR model and simulation research on unsafe psychological state propagation of construction workers considering safety climate and intimate relationships.

The construction industry is a pillar industry of China and occupies an essential position in our economic development. However, in the fast-developing construction industry, the number of its safety accidents is also growing year by year. Safety accidents are often due to unsafe behaviors of construction workers, and unsafe precarious psychological states are important factors for unsafe behaviors. Therefore, this paper, based on a review of existing literature, uses the SEIR model and numerical simulation method to study the spread of unsafe psychological states among construction workers considering safety climate and intimate relationships. It puts forward corresponding countermeasures, which has great practical significance for reducing safety accidents in the construction industry. The results show that: (1) A good safety climate can help alleviate the spread of unsafe psychological states of construction workers. (2) The intimate relationship between construction workers will promote the association between communicable people and susceptible people, which will lead to the spread of an unsafe psychological state. (3) A larger network average degree will increase the spread speed and the density of communicable people, but will not increase the spread range.(4) Forgetting rate has a key role in the propagation of unsafe psychological states. Suggestions are made to hinder the propagation of these states, which will help to reduce the unsafe behavior of construction workers and the accident rate in the construction industry.

Remanufacturing an evaluation system for electrical control systems of drilling rig based on the improved FCE and ANN.

The decision process of different remanufacturing schemes in an electronic control system has great fuzziness and uncertainty. Therefore, it is essential to use an appropriate method to show the characteristics of different schemes and support the users' decision. Based on the concepts of the artificial neural network theory and the improved comprehensive evaluation method, the decision-making system of the electronic control remanufacturing scheme was constructed in the present study. In the first step, a classification method of parts is proposed from the perspective of manufacturing enterprises. Moreover, an artificial neural network model is used to determine parts of remanufacturing value. Then the pricing strategy is divided according to the users' needs, and then a decision model is constructed. The combined subjective and objective methods are used to solve the compound weight of different equipment, and a set of improved fuzzy comprehensive decision methods is formed. Then the proposed model was applied to an electronic control transformation project as an example to evaluate the performance of different schemes. The evaluation results were consistent with the results of a third-party organization. It was concluded that the proposed scheme can be used as the theoretical basis to choose the best remanufacturing scheme to ensure the efficient operation of each part in an ECS.

Group testing can improve the cost-efficiency of prospective-retrospective biomarker studies.

BACKGROUND: Cancer treatment is increasingly dependent on biomarkers for prognostication and treatment selection. Potential biomarkers are frequently evaluated in prospective-retrospective studies in which biomarkers are measured retrospectively on archived specimens after completion of prospective clinical trials. In light of the high costs of some assays, random sampling designs have been proposed that measure biomarkers for a random sub-sample of subjects selected on the basis of observed outcome and possibly other variables. Compared with a standard design that measures biomarkers on all subjects, a random sampling design can be cost-efficient in the sense of reducing the cost of the study substantially while achieving a reasonable level of precision. METHODS: For a biomarker that indicates the presence of some molecular alteration (e.g., mutation in a gene), we explore the use of a group testing strategy, which involves physically pooling specimens across subjects and assaying pooled samples for the presence of the molecular alteration of interest, for further improvement in cost-efficiency beyond random sampling. We propose simple and general approaches to estimating the prognostic and predictive values of biomarkers with group testing, and conduct simulation studies to validate the proposed estimation procedures and to assess the cost-efficiency of the group testing design in comparison to the standard and random sampling designs. RESULTS: Simulation results show that the proposed estimation procedures perform well in realistic settings and that a group testing design can have considerably higher cost-efficiency than a random sampling design. CONCLUSIONS: Group testing can be used to improve the cost-efficiency of biomarker studies.

Recent history of metal contamination in the Fangcheng Bay (Beibu Gulf, South China) utilizing spatially-distributed sediment cores: Responding to local urbanization and industrialization.

In this study, the recent history of heavy metal pollution in the Fangcheng Bay (South China) was reconstructed utilizing three 210Pb-dated sediment cores. The metal concentration profiles display three trends since the 1970s and clearly reflect local urbanization and industrialization. The metals in the Fangcheng Bay started to accumulate in the 1970s but remained relatively low until the 1990s which corresponds to the slow urbanization and industrialization. The metal accumulation in the eastern Fangcheng Bay peaked in the early 2000s following the steep increases in accordance with the rapid industrialization of the eastern Fangcheng Bay where the core HSL was collected. Conversely, the heavy metal profiles in the western Fangcheng Bay present slight step increases in the early 2000s followed by a dramatic metal enrichment in the late 2000s; the expansion of these two cores, which begins in the early 2000s, concurs well with the rapid local urbanization and industrialization.

Best (but oft-forgotten) practices: sample size and power calculation for a dietary intervention trial with episodically consumed foods.

Dietary interventions often target foods that are underconsumed relative to dietary guidelines, such as vegetables, fruits, and whole grains. Because these foods are only consumed episodically for some participants, data from such a study often contains a disproportionally large number of zeros due to study participants who do not consume any of the target foods on the days that dietary intake is assessed, thus generating semicontinuous data. These zeros need to be properly accounted for when calculating sample sizes to ensure that the study is adequately powered to detect a meaningful intervention effect size. Nonetheless, this issue has not been well addressed in the literature. Instead, methods that are common for continuous outcomes are typically used to compute the sample sizes, resulting in a substantially under- or overpowered study. We propose proper approaches to calculating the sample size needed for dietary intervention studies that target episodically consumed foods. Sample size formulae are derived for detecting the mean difference in the amount of intake of an episodically consumed food between an intervention and a control group. Numerical studies are conducted to investigate the accuracy of the sample size formulae as compared with the ad hoc methods. The simulation results show that the proposed formulae are appropriate for estimating the sample sizes needed to achieve the desired power for the study. The proposed method for sample size is recommended for designing dietary intervention studies targeting episodically consumed foods.

Inactivation of airborne bacteria using different UV sources: Performance modeling, energy utilization, and endotoxin degradation.

Airborne bacteria-containing bioaerosols have attracted increased research attention on account of their adverse effects on human health. Ultraviolet germicidal irradiation (UVGI) is an effective method to inactivate airborne microorganisms. The present study models and compares the inactivation performance of three UV sources in the UVGI for aerosolized Escherichia coli. Inactivation efficiency of 0.5, 2.2 and 3.1 logarithmic order was obtained at an exposure UV dose of 370 J/m3 under UVA (365 nm), UVC (254 nm) and UVD (185 nm) sources, respectively. A Beer-Lambert law-based model was developed and validated to compare the inactivation performances of the UV sources, and modeling enabled prediction of inactivation efficiency and analysis of the sensitivity of several parameters. Low influent E. coli concentrations and high UV doses resulted in high energy consumption (EC). The change in airborne endotoxin concentration during UV inactivation was analyzed, and UVC and UVA irradiation showed no marked effect on endotoxin degradation. By contrast, both free and bound endotoxins could be removed by UVD treatment, which is attributed to the ozone generated by the UVD source. The results of this study can provide a better understanding of the air disinfection and airborne endotoxin removal processes.

An Evaluation of the Implementation of Pharmacist-Prescribed Hormonal Contraceptives in California.

OBJECTIVE: To evaluate the implementation of pharmacist-prescribed hormonal contraceptives in California after a recent expansion of pharmacists' scope of practice. METHODS: A probability sample of 480 licensed California retail pharmacies (stratified by nonrural or rural location and independent or chain status) was included in a cross-sectional "secret shopper" telephone survey assessing the availability of pharmacist-prescribed hormonal contraceptives and service details. Survey data were analyzed using weighted descriptive statistics, CIs, and Wald tests. RESULTS: Findings included data from 457 pharmacies (response rate 95.2%). Only 5.1% of pharmacies reported providing pharmacist-prescribed hormonal contraceptives (95% CI 2.9-7.2%). This proportion did not differ significantly between rural and nonrural pharmacies (P=.83) nor between independent and chain pharmacies (P=.40). Five of the 22 pharmacies that were providing pharmacist-prescribed hormonal contraceptives informed secret shoppers that all allowed hormonal methods were available; most of these pharmacies (77.3%) did proactively describe that a health history was required before receiving medications. Only half of pharmacies providing pharmacist-prescribed hormonal contraceptives would do so for minors although this was allowed by law. CONCLUSION: In the first year after statewide protocol implementation, only a small proportion of retail pharmacies across California has begun offering hormonal contraception services. In the absence of additional supportive legislation regarding reimbursement for pharmacist services, increases in scope of practice regulations to build a larger network of contraceptive providers may not be effective in increasing access to birth control.

Mycoflora assessment, growth and toxigenic features of patulin-producers in kiwifruit in China.

BACKGROUND: Fungal development in agricultural products may cause mycotoxin contamination, which is a significant threat to food safety. Patulin (PAT) and PAT-producer contamination has been established as a worldwide problem. The present study aimed to investigate the mycoflora and PAT-producers present in kiwifruits and environmental samples collected from orchards and processing plants in Shaanxi Province, China. RESULTS: Variations in mycoflora were observed in different samples, with penicillia and aspergilli as the predominant genera. Approximately 42.86% of dropped fruits were contaminated with PAT-producers, which harbored the 6-methylsalicylic acid synthase and the isoepoxydon dehydrogenase genes that are involved in PAT biosynthesis. The growth of Penicillium expansum, Penicillium griseofulvum and Penicillium paneum in kiwi puree agar (KPA) medium and kiwi juice well fitted the modified Gompertz and Baranyi and Roberts models (R2 ≥ 0.95). A significant positive correlation between colony diameter and PAT content in KPA medium of P. expansum and P. griseofulvum was observed (P < 0.05). CONCLUSIONS: The present study analyzed the mycofloral composition and the potential risk for PAT and PAT-producer contamination in kiwifruit, which may be utilized in the establishment of proper management practices in the kiwifruit industry. © 2017 Society of Chemical Industry.

Identification, Synthesis, and Safety Assessment of Thidiazuron [1-Phenyl-3-(1,2,3-thidiazol-5-yl)urea] and Its Metabolites in Kiwifruits.

The quality of kiwifruit became worse as a result of the abuse of plant growth regulators (PGRs). The safety of the fruits treated with PGRs also worried consumers. Therefore, the present study analyzed the structure of thidiazuron [TDZ, (1-phenyl-3-(1,2,3-thidiazol-5-yl)-urea)] (1) and its metabolites of biotransformation in kiwifruits using liquid chromatography hybrid ion trap time-of-flight mass spectrometry (LC-IT-TOF-MS). Standard compounds were also synthesized and used for structural identification of those metabolites. In addition, cytotoxicity of TDZ and its metabolites was tested through sulforhodamine B assays against normal Chinese hamster ovary (CHO) cells. Four metabolites were identified. They were 4-hydroxy-thidiazuron (2), 3-hydroxy-thidiazuron (3), thidiazuron-4-O-ß-d-glucoside (4), and thidiazuron-3-O-ß-d-glucoside (5). Values of IC50 of compounds 1, 2, and 3 to CHO cells were 18.3 ± 1.8, 37.56 ± 1.5, and 23.36 ± 1.59 µM, respectively. Compounds 4 and 5 had no effect on CHO cells.

Generalized linear mixed models for multi-reader multi-case studies of diagnostic tests.

Diagnostic tests are often compared in multi-reader multi-case (MRMC) studies in which a number of cases (subjects with or without the disease in question) are examined by several readers using all tests to be compared. One of the commonly used methods for analyzing MRMC data is the Obuchowski-Rockette (OR) method, which assumes that the true area under the receiver operating characteristic curve (AUC) for each combination of reader and test follows a linear mixed model with fixed effects for test and random effects for reader and the reader-test interaction. This article proposes generalized linear mixed models which generalize the OR model by incorporating a range-appropriate link function that constrains the true AUCs to the unit interval. The proposed models can be estimated by maximizing a pseudo-likelihood based on the approximate normality of AUC estimates. A Monte Carlo expectation-maximization algorithm can be used to maximize the pseudo-likelihood, and a non-parametric bootstrap procedure can be used for inference. The proposed method is evaluated in a simulation study and applied to an MRMC study of breast cancer detection.

Association Between Changes in CMS Reimbursement Policy and Drug Labels for Erythrocyte-Stimulating Agents With Outcomes for Older Patients Undergoing Hemodialysis Covered by Fee-for-Service Medicare.

IMPORTANCE: In 2011, the US Centers for Medicare & Medicaid Services (CMS) changed its reimbursement policy for hemodialysis to a bundled comprehensive payment system that included the cost of erythrocyte-stimulating agents (ESAs). Also in 2011, the US Food and Drug Administration revised the drug label for ESAs, recommending more conservative dosing in patients with chronic kidney disease. In response to concerns that these measures could have adverse effects on patient care and outcomes, the CMS and the FDA initiated a collaboration to assess the effect. OBJECTIVE: To assess the effects of the changes in reimbursement policy and the ESA drug label on patients who underwent incident hemodialysis. DESIGN, SETTING, AND PARTICIPANTS: For this retrospective cohort study, patients 66 years or older who had undergone incident hemodialysis, and were enrolled in Medicare parts A, B, or D for at least 12 months prior to hemodialysis initiation between January 1, 2008, and December 31, 2013, were recruited from hemodialysis centers across the United States. Patients were divided into 2 cohorts based on their date of hemodialysis initiation and followed: January 1, 2008, to December 31, 2009, for the prepolicy cohort and July 1, 2011, to June 30, 2013, for the postpolicy cohort, with the exclusion of January 1, 2010, to June 30, 2011, as a transition period. INTERVENTIONS: Changes in CMS reimbursement policy for dialysis and the FDA label for ESAs. MAIN OUTCOMES AND MEASURES: Major adverse cardiovascular events (MACEs), including acute myocardial infarction (AMI), stroke, and all-cause mortality; hospitalized congestive heart failure (H-CHF); venous thromboembolism; and red blood cell transfusions. Secondary outcomes included evaluating effects on black and other patient subgroups. RESULTS: Baseline characteristics of the 69 718 incident hemodialysis patients were similar between cohorts. Compared with the prepolicy period, the risk of MACE, death, H-CHF, and venous thromboembolism were similar in the postpolicy period, and the risk of stroke decreased (hazard ratio [HR], 0.77; 95% CI, 0.64-0.93; P = .01); the use of ESAs also decreased, and the rate of blood transfusions increased (HR, 1.09; 95% CI, 1.07-1.12; P < .001). In the post-postpolicy period, black patients had a significant reduction in risk of MACE (HR, 0.82; 95% CI, 0.73-0.92; P < .001) and all-cause mortality (HR, 0.82; 95% CI, 0.73-0.93; P = .002). CONCLUSIONS AND RELEVANCE: After the bundling policy and ESA labeling changes in 2011, the risks of MACE and death for patients 66 years or older and covered by fee-for-service Medicare who had undergone incident hemodialysis did not change; the risk of stroke was reduced, and the rate of blood transfusions modestly increased. Black patients had substantial reductions in the risks of MACE and death.

Meta-analysis of CHADS2 Score in Predicting Atrial Fibrillation.

The CHADS2 score is a validated clinical tool used for the risk stratification of stroke in the presence of atrial fibrillation (AF). Recently, some studies have shown that CHADS2 score may predict the risk of AF, which yielded conflicting results. The purpose of this study is to perform a meta-analysis of observational studies to examine the association between the CHADS2 score and risk of AF. Using PubMed and EMBASE database, we searched published articles by November 2014 to identify studies that evaluated the association between CHADS2 score and the risk of AF. We used both fixed-effects and random-effects models to calculate the overall effect estimate. A sensitivity analysis and subgroup analysis were performed to find the origin of heterogeneity. Of the 1,806 studies identified initially, 19 studies were included into our analysis, with a total of 714,672 patients. The CHADS2 score was found to be an independent predictor of AF as both a continuous variable (odds ratio 1.43, 95% confidence interval 1.10 to 1.86, p = 0.007) and categorical variable (odds ratio 3.37, 95% confidence interval 2.65 to 4.28, p <0.00001). Subgroup analysis revealed that different patients' age in study population may be a possible reason for the significant heterogeneity in our meta-analysis. In conclusion, CHADS2 score predicts the risk of AF. Addressing risk factors and early recognition of AF are important and also awareness of CHADS2 score to reduce stroke risk with pharmacologic prophylaxis.

Identification, synthesis, and safety assessment of forchlorfenuron (1-(2-chloro-4-pyridyl)-3-phenylurea) and its metabolites in kiwifruits.

Identification and evaluation of safety of forchlorfenuron ((1-(2-chloro-4-pyridyl)-3-phenylurea)), 1, metabolites after biotransformation in kiwifruit is the objective of this study. To elucidate properties of these metabolites, liquid chromatography hybrid ion trap time-of-flight mass spectrometry (LC-IT-TOF-MS) was applied, with MetID Solution and Formula Predictor Software in positive mode. Cytotoxicity of forchlorfenuron and its metabolites were tested through sulforhodamine B assays against normal Chinese hamster ovary cells (CHO). As deduced from characteristic fragment ions of forchlorfenuron, then confirmed by comparison with synthetic standards, as well as characterized by NMR and mass spectrometry techniques, results indicate the presence of 4-hydroxyphenyl-forchlorfenuron, 2, 3-hydroxyphenyl-forchlorfenuron, 3, and forchlorfenuron-4-O-ß-D-glucoside, 5. Forchlorfenuron (IC50 = 12.12 ± 2.14 µM) and 4-hydroxyphenyl-forchlorfenuron (IC50 = 36.15 ± 1.59 µM), exhibits significant cytotoxicity against CHO, while 3-hydroxyphenyl-forchlorfenuron and forchlorfenuron-4-O-ß-D-glucoside show no cytotoxicity.

A TWO-STATE MIXED HIDDEN MARKOV MODEL FOR RISKY TEENAGE DRIVING BEHAVIOR.

This paper proposes a joint model for longitudinal binary and count outcomes. We apply the model to a unique longitudinal study of teen driving where risky driving behavior and the occurrence of crashes or near crashes are measured prospectively over the first 18 months of licensure. Of scientific interest is relating the two processes and predicting crash and near crash outcomes. We propose a two-state mixed hidden Markov model whereby the hidden state characterizes the mean for the joint longitudinal crash/near crash outcomes and elevated g-force events which are a proxy for risky driving. Heterogeneity is introduced in both the conditional model for the count outcomes and the hidden process using a shared random effect. An estimation procedure is presented using the forward-backward algorithm along with adaptive Gaussian quadrature to perform numerical integration. The estimation procedure readily yields hidden state probabilities as well as providing for a broad class of predictors.

Assessment of skewed exposure in case-control studies with pooling.

Pooling-based strategies that combine samples from multiple participants for laboratory assays have been proposed for epidemiologic investigations of biomarkers to address issues including cost, efficiency, detection, and when minimal sample volume is available. A modification of the standard logistic regression model has been previously described to allow use with pooled data; however, this model makes assumptions regarding exposure distribution and logit-linearity of risk (i.e., constant odds ratio) that can be violated in practice. We were motivated by a nested case-control study of miscarriage and inflammatory factors with highly skewed distributions to develop a more flexible model for analysis of pooled data. Using characteristics of the gamma distribution and the relation between models of binary outcome conditional on exposure and of exposure conditional on outcome, we use a modified logistic regression to accommodate nonlinearity because of unequal shape parameters in gamma distributed exposure for cases and controls. Using simulations, we compare our approach with existing methods for logistic regression for pooled data considering: (1) constant and dose-dependent effects; (2) gamma and log-normal distributed exposure; (3) effect size; and (4) the proportions of biospecimens pooled. We show that our approach allows estimation of odds ratios that vary with exposure level, yet has minimal loss of efficiency compared with existing approaches when exposure effects are dose-invariant. Our model performed similarly to a maximum likelihood estimation approach in terms of bias and efficiency, and provides an easily implemented approach for estimation with pooled biomarker data when effects may not be constant across exposure.

[Resources of survey in rare and endangered medicinal plant Sinopodophyllum emodi].

The resource of Sinopodophyllum emodi in Tibet, Qinghai, Gansu, Sichuan and Yunnan province were surveyed by the ways of documents, interview, quadrat and market investigation. The results indicated that S. emodi were mainly distributed in central part from Taibai Shan of Shanxi province along the middle and high mountain on either side of Hengduan mountain which from north to south and in Tibetan plateau of China, the suitable eco-environment of S. emodi was dominated by valleys, wet forests and low bush-woods vegetation which comparatively dry on plateau with the altitude focused on 1 5004 500 meters, and the distribution density of simple alpine meadow was relatively lower. Illumination, water, soil, temperature and altitude had significant influences on the growth, distribution and reserves of S. emodi from different angles. In recent years, there was sharp increase of market requirement in Xiaoyelian (fruit) which were used in Tibetan medicine and the underground part which was used for the extraction of podophyllotoxin, excess collection of the underground part was the primary cause of the rapid decreasing resource of S. emodi. It is suggested that the management of rational collection should be strengthen and the development of culturing and production should be meanwhile accelerated.

Preoperative assessment of mitral valve prolapse and chordae rupture using real time three-dimensional transesophageal echocardiography.

BACKGROUND: Mitral valve (MV) repair provides a better outcome in patients with significant mitral regurgitation than MV replacement. Valve repair requires a thorough understanding of MV morphology. Recently developed real time three-dimensional transesophageal echocardiography (RT3D TEE) can provide online acquisition and accurate information of cardiac structures. The study aim was to evaluate the feasibility and accuracy of using RT3D TEE to assess mitral valve prolapse (MVP) and chordae rupture for surgical planning purposes. METHODS: Fifty-six consecutive patients with moderate to severe mitral regurgitation due to MVP received two-dimensional (2D) TEE and RT3D TEE the day before operation. The accuracy of the assessment of MVP and chordae rupture by RT3D TEE was determined and compared with assessment by 2D TEE using surgical inspection as the gold standard. RESULTS: The overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 2D TEE in detection of MVP were 87%, 96%, 93%, 88%, and 95%, respectively, whereas those of RT3D TEE were 100%, 99%, 99%, 98%, and 100%, respectively (P<0.05 for all comparisons). The receiver operating characteristic (ROC) curve areas for assessment of anterior leaflet and posterior leaflet segment involvement using RT3D TEE (ROC areas 0.96 and 0.99) were higher than for those using 2D TEE (ROC areas 0.86 and 0.94). Interobserver agreement for RT3D TEE (κ=0.97, 95% confidence interval [CI] 0.92-1.00) was significantly greater than for 2D TEE (κ=0.89, 95% CI 0.81-0.93) (P<0.05). CONCLUSION: RT3D TEE is a feasible, accurate and reproducible method for evaluating MVP and chordae rupture in the clinical setting.