Background: Postoperative development of aortic insufficiency (AI) after implantation of left ventricular assist devices (LVADs) has recently been recognized, but the devices in the previous reports have been limited to the HeartMate I or II. The purposes of this study were to determine whether AI develops with other types of LVADs and to elucidate the factors associated with the development of AI. Methods and Results:Thirty-seven patients receiving LVADs without evident abnormalities in native aortic valves were enrolled (pulsatile flow LVAD [TOYOBO]: 76%, continuous flow LVAD [EVAHEART, DuraHeart, Jarvik2000, HeartMate II]: 24%). Frequency of aortic valve opening and grade of AI were evaluated by the most recent echocardiography during LVAD support. None of the patients had more than trace AI preoperatively. During LVAD support AI > -grade 2 developed in 9 patients (24%) across all 5 types of devices. More severe grade of AI correlated with higher plasma B-type natriuretic peptide concentration (r=0.53, P<0.01) and with less frequent of the aortic valve (r=−0.45, P<0.01). Multivariate analysis revealed that lower preoperative left ventricular ejection fraction and a continuous flow device type were independent risk factors for higher incidence of AI.Conclusions: AI, which is hemodynamically significant, develops after implantation of various types of LVADs. Physicians need to be more alert to the development of AI particularly with continuous flow devices. (Circ J 2011; 75: 1147 - 1155
Staphylocoagulase detection is the hallmark of a Staphylococcus aureus infection. Ten different serotypes of staphylocoagulases have been reported to date. We determined the nucleotide sequences of seven staphylocoagulase genes (coa) and their surrounding regions to compare structures of all 10 staphylocoagulase serotypes, and we inferred their derivations. We found that all staphylocoagulases are comprised of six regions: signal sequence, D1 region, D2 region, central region, repeat region, and C-terminal sequence. Amino acids at both ends, 33 amino acids in the N terminal (the signal sequences and the seven N-terminal amino acids in the D1 region) and 5 amino acids in the C terminal, were exactly identical among the 10 serotypes. The central regions were conserved with identities between 80.6 and 94.1% and similarities between 82.8 and 94.6%. Repeat regions comprising tandem repeats of 27 amino acids with a 92% identity on average were polymorphic in the number of repeats. On the other hand, D1 regions other than the seven N-terminal amino acids and D2 regions were less homologous, with diverged identities from 41.5 to 84.5% and 47.0 to 88.9%, respectively, and similarities from 53.5 to 88.7% and 56.8 to 91.9%, respectively, although the predicted prothrombin-binding sites were conserved among them. In contrast, flanking regions of coa were highly homologous, with nucleotide identities of more than 97.1%. Phylogenetic relations among coa did not correlate with those among the flanking regions or housekeeping genes used for multilocus sequence typing. These data indicate that coa could be transmitted to S. aureus, while the less homologous regions in coa presumed to be responsible for different antigenicities might have evolved independently.
To date, there have been few reports demonstrating preoperative predictors for left ventricular reverse remodeling (LVRR) after LV assist device (LVAD) implantation, especially among patients with dilated cardiomyopathy (DCM). We retrospectively analyzed 60 patients with stage D heart failure due to DCM who had received LVAD treatment [pulsatile flow (PF) type, 26; continuous flow type, 34]. Data were evaluated at 6 months or just before explantation of the LVAD. We defined "LV reverse remodeling" (LVRR) by the achievement of an LV ejection fraction (LVEF) of ≥ 35 % after 6 months of LVAD support or explantation of LVAD within 6 months. LVRR occurred in 16 of our patients (26.7 %). Uni/multivariate logistic regression analyses for LVRR demonstrated that of the preoperative variables evaluated, PF LVAD usage and insufficient preoperative β-blocker treatment were independent predictors for LVRR. Patients who accomplished LVRR had a better clinical course, including lower levels of aortic valve insufficiency and lower levels of plasma B-type natriuretic peptide. Of the six patients (10.0 %) in whom LVADs were eventually explanted, all had an LVEF of ≥ 35 % before explantation or at 6 months. Based on these results, we conclude that DCM patients with insufficient preoperative β-blocker treatment have a chance to achieve LVRR under LVAD support as a bridge to recovery.
We constructed a model using a support vector machine to determine whether an inpatient will suffer a fall on a given day, depending on patient status on the previous day. Using fall report data from our own facility and intensity-of-nursing-care-needs data accumulated through hospital information systems, a dataset comprising approximately 1.2 million patient-days was created. Approximately 50% of the dataset was used as training and testing data. A multistep grid search was conducted using the semicomprehensive combination of three parameters. A discriminant model for the testing data was created for each parameter to identify which parameter had the highest score by calculating the sensitivity and specificity. The score of the model with the highest score had a sensitivity of 64.9% and a specificity of 69.6%. By adopting a method that relies on daily data recorded in the electronic medical record system and accurately predicts unknown data, we were able to overcome issues described in previous studies while simultaneously constructing a discriminant model for patients' fall risk that does not burden nurses and patients with information gathering.
Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp utcomes after implantation of pulsatile left ventricular assist device (LVAD) appear to have been critically dependent on postoperative right ventricular (RV) function. 1-3 Recent innovations of LVAD pumps have dramatically decreased device-related complications and improved overall prognosis, 4-7 but postoperative RV failure is still a serious concern even in the era of continuous flow pumps. 7,8 Editorial p 2740Generally speaking, open heart surgery using cardiopulmonary bypass is often associated with postoperative RV dysfunction even if preoperative RV function is apparently normal. Postoperative RV failure usually manifests perioperatively or soon after surgery, but resolves within 1-2 weeks in most cases, but sometimes requires i.v. inotropes for >2 weeks and/or inhalation of nitric oxide for >48 h. In more severe cases of RV failure, mechanical support for RV with extracorporeal membrane oxygenation (ECMO) is necessary, albeit temporary. Furthermore, the implantation of RV assist device (RVAD) is an extreme and prolonged form of mechanical support of RV. The aforedescribed requirements of inotropes to RVAD are in fact the definition of postoperative RV failure, 1-3 which is thought to be a manifestation of pre-existing intrinsic RV impairment during the perioperative period.If patients with LVAD implantation have severe RV failure, biventricular assist device (BiVAD) is occasionally necessary, but those who require BiVAD have an extremely poor prognosis, 9 as we have also reported. 10 In this regard, proper and precise identification of patients at high risk for RV failure is indispensable. Thus far, many investigators have reported preoperative risk factors for RV failure. Combination Evaluation of Preoperative Risk Indices Predicts Requirement of Biventricular Assist Device
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.