大学对附属医院经营效果影响的研究

大学附属医院区别于普通公立医院的职能和体制会对其经营效果产生一些影响.文章以规模、实力和市场环境类似的大学附属医院和普通公立医院作为对比组,收集了它们相同年度的经营成果资料,采用定量对比分析方法研究大学是否对其附属医院经营效果产生影响.然后用德尔菲法定性研究出大学哪些行为及功能时其附属医院经营会产生影响.并把这些能产生影响的行为扣功能归纳为附属医院经营影响因子,形成大学对其附属医院经营效果影响三角模型和函数关系.     

Timing,Selection, Modulation,and Duration of P2Y12 Inhibitors for Patients With Acute Coronary Syndromes Undergoing PCI

Dual antiplatelet therapy with aspirin and the oral P2Y₁₂ inhibitor clopidogrel as the cornerstone of treatment for patients with an acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) was firstly established in 2001. Soon thereafter, the newer-generation P2Y₁₂ inhibitors prasugrel and ticagrelor became commercially available. The clinical management of ACS patients undergoing PCI has evolved significantly in the last 2 decades, with a shift toward more rapid invasive management, broader use of drug-eluting stents, and the increasing recognition that major bleeding due to antiplatelet therapy is detrimental. In this ever-changing scenario, numerous studies have addressed 4 main questions regarding P2Y₁₂ inhibition in ACS patients undergoing PCI: timing, selection, modulation, and duration. This paper reviews the latest evidence surrounding these topical questions, with a focus on efficacy and safety data, practice guidelines, and residual areas of uncertainty.     

No Antithrombotic Therapy After Transcatheter Aortic Valve Replacement: Insight From the OCEAN-TAVI Registry

BackgroundSeveral trials demonstrated that aspirin monotherapy compared with aspirin plus clopidogrel is associated with a lower incidence of bleeding without an increased risk of ischemic events in patients after transcatheter aortic valve replacement (TAVR); however, there remains a paucity of data to prove the necessity of even aspirin monotherapy.ObjectivesThis study aimed to compare clinical outcomes and valve performance of the 3 different antithrombotic strategies post-TAVR from the OCEAN-TAVI (Optimized transCathEter vAlvular iNtervention) registry.MethodsPatients who received anticoagulation or had procedural complications were excluded. The remaining patients were classified into 3 groups according to the antithrombotic regimen at discharge: 1) nonantithrombotic therapy (None); 2) single-antiplatelet therapy (SAPT); and 3) dual-antiplatelet therapy (DAPT). The primary outcome was the incidence of net adverse clinical events (NACEs) (ie, cardiovascular death, stroke, myocardial infarction, and life-threatening or major bleeding).ResultsOverall, 3,575 TAVR patients were included (None, 293; SAPT, 1,354; DAPT, 1,928). The median follow-up period was 841 days (IQR: 597-1,340 days). The incidence of NACEs did not differ between the groups (None vs SAPT: adjusted HR [aHR]: 1.18; P = 0.45; None vs DAPT: aHR: 1.09; P = 0.67). There was a lower incidence of all bleeding in patients with no antithrombotics (None vs SAPT: aHR: 0.63; P = 0.12; None vs DAPT: aHR: 0.51; P = 0.04). The valve performance was similar among the groups. Leaflet thrombosis was detected in 8.5% of the nonantithrombotic group.ConclusionsCompared with SAPT/DAPT, the nonantithrombotic strategy was not associated with an increased risk of NACEs and potentially reduced the risk of bleeding events. The nonantithrombotic strategy may be an acceptable alternative to SAPT/DAPT in selected patients with TAVR.     

KIR genotype and haplotype frequencies in the multi-ethnic population of Malaysia

Killer cell immunoglobulin-like receptors (KIR) genotype and haplotype frequencies have been reported to vary distinctly between populations, which in turn contributes to variation in the alloreactivity of natural killer (NK) cells. Utilizing the diverse KIR genes to identify suitable transplant donors would prove challenging in multi-ethnic countries, even more in resource-limited countries where KIR genotyping has not been established. In this study, we determined the KIR genotypes from 124 unrelated Malaysians consisting of the Malays, Chinese, Indians, and aboriginal people through polymerase chain reaction sequence-specific primer (PCR-SSP) genotyping and employing an expectation–maximization (EM) algorithm to assign haplotypes based on pre-established reference haplotypes. A total of 27 distinct KIR haplotypes were discerned with higher frequencies of haplotype A (55.2%) than haplotype B (44.8%). The most frequent haplotypes were cA01:tA01 (55.2%), cB01:tB01 (18.1%), and cB02:tA01 (13.3%), while the least frequent haplotypes were cB03:tB01 (1.2%), cB04:tB03 (0.4%), and cB03:tA01 (0.4%). Several haplotypes were identified to be unique to a specific ethnic group. The genotype with the highest frequency was genotype AB (71.8%), followed by AA (19.4%), and BB (8.9%). The Indians exhibited the lowest genotype AA but the highest genotype BB, whereas genotype BB was absent in the aboriginal people. Despite the limitations, the genotype and haplotypes in the Malaysian population were successfully highlighted. The identification of ethnic-specific KIR genotypes and haplotypes provides the first step to utilizing KIR in identifying suitable transplant donors to further improve the transplant outcome in the Malaysian population.     

Virtual high-resolution MR angiography from non-angiographic multi-contrast MRIs: synthetic vascular model populations for in-silico trials

Despite success on multi-contrast MR image synthesis, generating specific modalities remains challenging. Those include Magnetic Resonance Angiography (MRA) that highlights details of vascular anatomy using specialised imaging sequences for emphasising inflow effect. This work proposes an end-to-end generative adversarial network that can synthesise anatomically plausible, high-resolution 3D MRA images using commonly acquired multi-contrast MR images (e.g. T1/T2/PD-weighted MR images) for the same subject whilst preserving the continuity of vascular anatomy. A reliable technique for MRA synthesis would unleash the research potential of very few population databases with imaging modalities (such as MRA) that enable quantitative characterisation of whole-brain vasculature. Our work is motivated by the need to generate digital twins and virtual patients of cerebrovascular anatomy for in-silico studies and/or in-silico trials. We propose a dedicated generator and discriminator that leverage the shared and complementary features of multi-source images. We design a composite loss function for emphasising vascular properties by minimising the statistical difference between the feature representations of the target images and the synthesised outputs in both 3D volumetric and 2D projection domains. Experimental results show that the proposed method can synthesise high-quality MRA images and outperform the state-of-the-art generative models both qualitatively and quantitatively. The importance assessment reveals that T2 and PD-weighted images are better predictors of MRA images than T1; and PD-weighted images contribute to better visibility of small vessel branches towards the peripheral regions. In addition, the proposed approach can generalise to unseen data acquired at different imaging centres with different scanners, whilst synthesising MRAs and vascular geometries that maintain vessel continuity. The results show the potential for use of the proposed approach to generating digital twin cohorts of cerebrovascular anatomy at scale from structural MR images typically acquired in population imaging initiatives.     

Deep Learning of Coronary Calcium Scores From PET/CT Attenuation Maps Accurately Predicts Adverse Cardiovascular Events

BackgroundAssessment of coronary artery calcium (CAC) by computed tomographic (CT) imaging provides an accurate measure of atherosclerotic burden. CAC is also visible in computed tomographic attenuation correction (CTAC) scans, always acquired with cardiac positron emission tomographic (PET) imaging.ObjectivesThe aim of this study was to develop a deep-learning (DL) model capable of fully automated CAC definition from PET CTAC scans.MethodsThe novel DL model, originally developed for video applications, was adapted to rapidly quantify CAC. The model was trained using 9,543 expert-annotated CT scans and was tested in 4,331 patients from an external cohort undergoing PET/CT imaging with major adverse cardiac events (MACEs) (follow-up 4.3 years), including same-day paired electrocardiographically gated CAC scans available in 2,737 patients. MACE risk stratification in 4 CAC score categories (0, 1-100, 101-400, and >400) was analyzed and CAC scores derived from electrocardiographically gated CT scans (standard scores) by expert observers were compared with automatic DL scores from CTAC scans.ResultsAutomatic DL scoring required <6 seconds per scan. DL CTAC scores provided stepwise increase in the risk for MACE across the CAC score categories (HR up to 3.2; P < 0.001). Net reclassification improvement of standard CAC scores over DL CTAC scores was nonsignificant (−0.02; 95% CI: −0.11 to 0.07). The negative predictive values for MACE of zero CAC with standard (85%) and DL CTAC (83%) CAC scores were similar (P = 0.19).ConclusionsDL CTAC scores predict cardiovascular risk similarly to standard CAC scores quantified manually by experienced operators from dedicated electrocardiographically gated CAC scans and can be obtained almost instantly, with no changes to PET/CT scanning protocol.