Person: Ngo, Long
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Ngo, Long
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Publication The Short-Term and Long-Term Relationship Between Delirium and Cognitive Trajectory in Older Surgical Patients(Wiley, 2016-07) Inouye, Sharon; Marcantonio, Edward; Kosar, Cyrus M.; Tommet, Douglas; Schmitt, Eva M.; Travison, Thomas; Saczynski, Jane S.; Ngo, Long; Alsop, David; Jones, Richard N.INTRODUCTION Since the relationship between delirium and long-term cognitive decline has not been well-explored, we evaluated this association in a prospective study. METHODS SAGES is an on-going study involving 560 adults age 70+ without dementia scheduled for major surgery. Delirium was assessed daily in the postoperative period using the Confusion Assessment Method. General Cognitive Performance (GCP) and the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) were assessed preoperatively then repeatedly out to 36 months. RESULTS On average, patients with post-operative delirium had significantly lower preoperative cognitive performance, greater immediate (1 month) impairment, equivalent recovery at 2 months, and significantly greater long-term cognitive decline relative to the non-delirium group. Proxy reports corroborated the clinical significance of the long-term cognitive decline in delirious patients. DISCUSSION Cognitive decline following surgery is biphasic and accelerated among persons with delirium. The pace of long-term decline is similar to that seen with Mild Cognitive Impairment.Publication Left Atrial Epicardial Fat Volume Is Associated With Atrial Fibrillation: A Prospective Cardiovascular Magnetic Resonance 3D Dixon Study(John Wiley and Sons Inc., 2018) Nakamori, Shiro; Nezafat, Maryam; Ngo, Long; Manning, Warren; Nezafat, RezaBackground: Recent studies demonstrated a strong association between atrial fibrillation (AF) and epicardial fat around the left atrium (LA). We sought to assess whether epicardial fat volume around the LA is associated with AF, and to determine the additive value of LA‐epicardial fat measurements to LA structural remodeling for identifying patients with AF using 3‐dimensional multi‐echo Dixon fat–water separated cardiovascular magnetic resonance. Methods and Results: A total of 105 subjects were studied: 53 patients with a history of AF and 52 age‐matched patients with other cardiovascular diseases but no history of AF. The 3‐dimensional multi‐echo Dixon fat‐water separated sequence was performed for LA‐epicardial fat measurements. AF patients had significantly greater LA‐epicardial fat (28.9±12.3 and 14.2±7.3 mL for AF and non‐AF, respectively; P<0.001) and LA volume (110.8±38.2 and 89.7±30.3 mL for AF and non‐AF, respectively; P=0.002). LA‐epicardial fat adjusted for LA volume was still higher in patients with AF compared with those without AF (P<0.001). LA‐epicardial fat and hypertension were independently associated with the risk of AF (odds ratio, 1.17; 95% confidence interval, 1.10%–1.25%, P<0.001, and odds ratio, 3.29; 95% confidence interval, 1.17%–9.27%, P=0.03, respectively). In multivariable logistic regression analysis adjusted for body surface area, LA‐epicardial fat remained significant and an increase per mL was associated with a 42% increase in the odds of AF presence (odds ratio, 1.42; 95% confidence interval, 1.23%–1.62%, P<0.001). Combined assessment of LA‐epicardial fat and LA volume provided greater discriminatory performance for detecting AF than LA volume alone (c‐statistic=0.88 and 0.74, respectively, DeLong test; P<0.001). Conclusions: Cardiovascular magnetic resonance 3‐dimensional Dixon‐based LA‐epicardial fat volume is significantly increased in AF patients. LA‐epicardial fat measured by 3‐dimensional Dixon provides greater performance for detecting AF beyond LA structural remodeling.Publication Gray blood late gadolinium enhancement cardiovascular magnetic resonance for improved detection of myocardial scar(BioMed Central, 2018) Fahmy, Ahmed S.; Neisius, Ulf; Tsao, Connie; Berg, Sophie; Goddu, Elizabeth; Pierce, Patrick; Basha, Tamer A.; Ngo, Long; Manning, Warren; Nezafat, RezaBackground: Low scar-to-blood contrast in late gadolinium enhanced (LGE) MRI limits the visualization of scars adjacent to the blood pool. Nulling the blood signal improves scar detection but results in lack of contrast between myocardium and blood, which makes clinical evaluation of LGE images more difficult. Methods: GB-LGE contrast is achieved through partial suppression of the blood signal using T2 magnetization preparation between the inversion pulse and acquisition. The timing parameters of GB-LGE sequence are determined by optimizing a cost-function representing the desired tissue contrast. The proposed 3D GB-LGE sequence was evaluated using phantoms, human subjects (n = 45) and a swine model of myocardial infarction (n = 5). Two independent readers subjectively evaluated the image quality and ability to identify and localize scarring in GB-LGE compared to black-blood LGE (BB-LGE) (i.e., with complete blood nulling) and conventional (bright-blood) LGE. Results: GB-LGE contrast was successfully generated in phantoms and all in-vivo scans. The scar-to-blood contrast was improved in GB-LGE compared to conventional LGE in humans (1.1 ± 0.5 vs. 0.6 ± 0.4, P < 0.001) and in animals (1.5 ± 0.2 vs. -0.03 ± 0.2). In patients, GB-LGE detected more tissue scarring compared to BB-LGE and conventional LGE. The subjective scores of the GB-LGE ability for localizing LV scar and detecting papillary scar were improved as compared with both BB-LGE (P < 0.024) and conventional LGE (P < 0.001). In the swine infarction model, GB-LGE scores for the ability to localize LV scar scores were consistently higher than those of both BB-LGE and conventional-LGE. Conclusion: GB-LGE imaging improves the ability to identify and localize myocardial scarring compared to both BB-LGE and conventional LGE. Further studies are warranted to histologically validate GB-LGE. Electronic supplementary material The online version of this article (10.1186/s12968-018-0442-2) contains supplementary material, which is available to authorized users.Publication Kawasaki disease patients homozygous for the rs12252-C variant of interferon-induced transmembrane protein-3 are significantly more likely to develop coronary artery lesions(BlackWell Publishing Ltd, 2014) Bowles, Neil E; Arrington, Cammon B; Hirono, Keiichi; Nakamura, Tsuneyuki; Ngo, Long; Wee, Yin Shen; Ichida, Fukiko; Weis, John HPublication Response to hepatitis B vaccination among HIV-infected adults in Vietnam(Mediscript Ltd, 2016) Pollack, Todd; Trang, Le Thi Thu; Ngo, Long; Cuong, Do Duy; Thuy, Pham Thanh; Colby, Donn JAbstract Objectives: We sought to determine the rate of response to hepatitis B (HBV) vaccination among HIV-infected adults in Vietnam. Methods: We retrospectively abstracted data from a cohort of HIV-infected adults who had received HBV vaccine at an HIV clinic in Hanoi. We examined demographic, clinical and laboratory factors for associations with development of a protective antibody (Ab) response following vaccination (defined as ‘responders’ with anti-HBs >10 IU/L). Results: Out of 302 HIV-infected patients who completed the vaccine series and follow-up serology testing, 189 (62.6%) had a positive protective Ab response. Female patients had a higher response rate compared to male patients (71.4% vs 56.8%, P=0.01). Among responders, mean CD4 T cell count was 309 cells/μL as compared to 204 cells/μL in non-responders (P<0.0001). On multivariable analysis, CD4 T cell count prior to vaccination was the only factor independently associated with a positive Ab response. Compared to patients with a count less than 100 cells/μL, those with a CD4 T cell count between 100 and 200 cells/μL were 20% more likely to be responders (relative risk [RR] 1.20, 95% confidence interval [CI] 0.77–1.87), those with a CD4 T cell count between 200 and 300 cells/μL were 61% more likely to be responders (RR 1.61, 95% CI 1.05–2.45), and those with a CD4 T cell count greater than 300 cells/μL were 89% more likely to be responders (RR 1.89, 95% CI 1.26–2.83). Conclusions: We found that the CD4 T cell count at the time of vaccination to be the sole predictor of response to HBV vaccination among HIV-infected Vietnamese adults. Our findings highlight the importance of vaccinating HIV-infected adults prior to advanced immunosuppression.Publication Methodologic considerations in the design and analysis of nested case-control studies: association between cytokines and postoperative delirium(BioMed Central, 2017) Ngo, Long; Inouye, Sharon; Jones, Richard N.; Travison, Thomas; Libermann, Towia; Dillon, Simon; Kuchel, George A.; Vasunilashorn, Sarinnapha M.; Alsop, David; Marcantonio, EdwardBackground: The nested case-control study (NCC) design within a prospective cohort study is used when outcome data are available for all subjects, but the exposure of interest has not been collected, and is difficult or prohibitively expensive to obtain for all subjects. A NCC analysis with good matching procedures yields estimates that are as efficient and unbiased as estimates from the full cohort study. We present methodological considerations in a matched NCC design and analysis, which include the choice of match algorithms, analysis methods to evaluate the association of exposures of interest with outcomes, and consideration of overmatching. Methods: Matched, NCC design within a longitudinal observational prospective cohort study in the setting of two academic hospitals. Study participants are patients aged over 70 years who underwent scheduled major non-cardiac surgery. The primary outcome was postoperative delirium from in-hospital interviews and medical record review. The main exposure was IL-6 concentration (pg/ml) from blood sampled at three time points before delirium occurred. We used nonparametric signed ranked test to test for the median of the paired differences. We used conditional logistic regression to model the risk of IL-6 on delirium incidence. Simulation was used to generate a sample of cohort data on which unconditional multivariable logistic regression was used, and the results were compared to those of the conditional logistic regression. Partial R-square was used to assess the level of overmatching. Results: We found that the optimal match algorithm yielded more matched pairs than the greedy algorithm. The choice of analytic strategy—whether to consider measured cytokine levels as the predictor or outcome-- yielded inferences that have different clinical interpretations but similar levels of statistical significance. Estimation results from NCC design using conditional logistic regression, and from simulated cohort design using unconditional logistic regression, were similar. We found minimal evidence for overmatching. Conclusions: Using a matched NCC approach introduces methodological challenges into the study design and data analysis. Nonetheless, with careful selection of the match algorithm, match factors, and analysis methods, this design is cost effective and, for our study, yields estimates that are similar to those from a prospective cohort study design.Publication Diagnostic delay in progressive multifocal leukoencephalopathy(John Wiley and Sons Inc., 2016) Miskin, Dhanashri P.; Ngo, Long; Koralnik, Igor J.Abstract We investigated delay in diagnosing progressive multifocal leukoencephalopathy (PML). The median time from initial symptom to diagnosis was 74 days (range 1–1643) in 111 PML patients seen at our institution from 1993 to 2015. Another diagnosis was considered before PML in nearly two–thirds, and more than three–quarters of patients suffered from diagnostic delay greater than 1 month, irrespective of their underlying immunosuppressive condition. Extended diagnostic delay occurred more frequently in patients with possible PML, and among HIV + patients with higher CD4+ T‐cell counts at symptom onset. Prompt diagnosis may improve survival of PML in so far as immune reconstitution can be effected, and prevent unnecessary interventions.Publication Blood T1 measurements using slice-interleaved T1 mapping (STONE) sequence(BioMed Central, 2016) Bellm, Steven; Ngo, Long; Jang, Jihye; Berg, Sophie; Kissinger, Kraig V; Goddu, Beth; Manning, Warren; Nezafat, RezaPublication Reproducibility of slice-interleaved myocardial T2 mapping sequences(BioMed Central, 2016) Bellm, Steven; Basha, Tamer A; Ngo, Long; Berg, Sophie; Kissinger, Kraig V; Goddu, Beth; Manning, Warren; Nezafat, RezaPublication Reproducibility of slice-interleaved T1 (STONE) mapping sequence(BioMed Central, 2016) Bellm, Steven; Basha, Tamer A; Ngo, Long; Berg, Sophie; Kissinger, Kraig V; Goddu, Beth; Manning, Warren; Nezafat, Reza