Research Spotlight

Xenogiannis, I., Choi, J.W., Alaswad, K., Khatri, J.J., Doing, A.H., Dattilo, P., Jaffer, F.A., Uretsky, B., Krestyaninov, O., Khelimskii, D., Patel, M., Mahmud, E., Potluri, S., Koutouzis, M., Tsiafoutis, I., Jaber, W., Samady, H., Jefferson, B.K., Patel, T., Megaly, M.S., Hall, A.B., Vemmou, E., Nikolakopoulos, I., Rangan, B.V., Abdullah, S., Garcia, S., Banerjee, S., Burke, M.N. and Brilakis, E.S. (2020). “Outcomes of subintimal plaque modification in chronic total occlusion percutaneous coronary intervention.” Catheter Cardiovasc Interv 96(5): 1029-1035.

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BACKGROUND: When crossing into the distal true lumen fails during chronic total occlusion (CTO) percutaneous coronary intervention (PCI), subintimal plaque modification (SPM) is often performed to restore antegrade flow and facilitate subsequent lesion recanalization. METHODS: Between January 2012 and May 4, 2019, 4,659 CTO PCIs were included in the PROGRESS-CTO registry, of which 935 (20%) had a prior unsuccessful attempt. Of those 935 patients, 119 (13%) had prior SPM. We analyzed the outcomes of the 58 SPM procedures for which data were available, as well as the outcomes of the 60 subsequent CTO PCI attempts. RESULTS: Mean patient age was 67 ± 9 years and 86% were men. Patients had high prevalence of cardiovascular risk factors such as dyslipidemia (91%), hypertension (93%) diabetes (48%), prior PCI (61%), and prior coronary artery bypass graft surgery (47%). The target CTO lesions often had proximal cap ambiguity (54%), moderate/severe calcification (73%), moderate/severe tortuosity (63%), and high J-CTO score (mean 3.2 ± 1.1). The technical and procedural success of subsequent CTO PCI were high (83% for both) with an acceptable rate of in-hospital major adverse cardiovascular events (3.3%). Technical and procedural success were higher for repeat attempts that were performed ≥60 days after the index CTO PCI (94% vs. 69%, p = .015). Median (interquartile range) subsequent procedure time was 147 (100, 215) min, contrast volume was 185 (150, 260) ml, and air kerma radiation dose was 2.5 (1.4, 4.2) Gray. CONCLUSION: Repeat CTO PCI attempts after SPM are associated with high likelihood for successful revascularization with acceptable risks.

Chiruvolu, A., Mallett, L.H., Govande, V.P., Raju, V.N., Hammonds, K. and Katheria, A.C. (2020). “Variations in umbilical cord clamping practices in the United States: a national survey of neonatologists.” J Matern Fetal Neonatal Med Oct 20;1-7. [Epub ahead of print].

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OBJECTIVE: Since the first publication of the American College of Obstetricians and Gynecologists committee opinion in 2012, and following the update in 2017, multiple institutions in the United States (US) adopted the practice of delayed cord clamping (DCC) and/or umbilical cord milking (UCM) in preterm and term infants. However, there have been variations reported in practices with regard to method of placental transfusion, timing of cord clamping and gestational age thresholds. Furthermore, the optimal cord clamping practice in situations of depressed infants needing resuscitation or in higher-risk delivery situations, such as placental abruption, intrauterine growth restriction, multiple gestation, chorioamnionitis, maternal human immunodeficiency virus syndrome/hepatitis or maternal general anesthesia is often debated. An evaluation of these variations and exploration of associated factors was needed to optimally target opportunities for improvement and streamline research activities. The objective of this survey, specifically aimed at neonatologists working in the US was to identify and describe current cord clamping practices and evaluate factors associated with variations. STUDY DESIGN: The survey was distributed electronically to the US neonatologists in August 2019 with a reminder email sent in October 2019. Clinicians were primarily identified from Perinatal Section of AAP, with reminders also sent through various organizations including California Association of Neonatologists, Pediatrix and Envision national groups. Descriptive variables of interest included years of experience practicing neonatology, affiliation with a teaching institution, level of the neonatal intensive care unit (NICU) and practicing region of the US. Questions on variations in cord management practices included information about center specific guideline/protocol, cord clamping practices, gestational age threshold of placental transfusion, performance of UCM and practice in higher-risk delivery situations. RESULTS: The response rate was 14.8%. Among 517 neonatologists whom responded, majority (85.5%) of the practices had a guideline and performed (81.7%) DCC in all gestational ages. The cord clamping practice was predominantly DCC and it was categorized as reporting clamping times <60 s in 46.6% and ≥60 s in 48.7% of responses. A significant association was detected between time of delay in cord clamping and region of practice. The Northeast region was more likely to clamp the cord in <60 s than other regions in the US. More than half of the providers responded not performing any UCM (57.3%) in their practice. Significant associations were detected between performance of UCM and all queried demographic variables independently. Clinicians with >20 years of experience were more likely from institutions performing UCM compared to the providers with fewer years of experience. However, teaching hospitals were less likely to perform UCM compared to non-teaching hospitals. Similarly, practices with level IV NICUs were less likely to perform UCM compared to practices with level III units. Hospitals in the Midwest region of US were less likely to perform UCM compared to hospitals in the Western region. Significant variations were also noticed for not providing placental transfusion in higher-risk deliveries. Demographic and professional factors were noted to be associated with these differences. CONCLUSION: Although the majority of practices have a guideline/protocol and are performing DCC in all gestational ages, there are variations noted with regard to timing, method, and performance in higher-risk deliveries. Demographic and professional factors play an important role in these variations. Future research needs to focus on the modifiable factors to optimize the procedure and impact of DCC.

Black, S.R., Meyers, K.N., Nguyen, J.T., Green, D.W., Brady, J.M., Maher, S.A. and Shubin Stein, B.E. (2020). “Comparison of Ligament Isometry and Patellofemoral Contact Pressures for Medial Patellofemoral Ligament Reconstruction Techniques in Skeletally Immature Patients.” Am J Sports Med Nov 2;363546520966609. [Epub ahead of print].

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BACKGROUND: Adult medial patellofemoral ligament (MPFL) reconstruction techniques are not appropriate for the skeletally immature patient given the proximity of the distal femoral physis. Biomechanical consequences of reconstructions aimed at avoiding the physis have not been adequately studied. PURPOSE: To quantify the biomechanical effects of MPFL reconstruction techniques intended for skeletally immature patients. STUDY DESIGN: Controlled laboratory study. METHODS: Four MPFL reconstruction techniques were evaluated using a computationally augmented cadaveric model: (1) Schoettle point: adult-type reconstruction; (2) epiphyseal: socket distal to the femoral physis; (3) adductor sling: graft wrapped around the adductor tendon; (4) adductor transfer: adductor tendon transferred to patella. A custom testing frame was used to cycle 8 knees for each technique from 10° to 110° of flexion. Patellofemoral kinematics were recorded using a motion camera system, contact stresses were recorded using Tekscan pressure sensors, and MPFL length was computed using an inverse kinematics computational model. Change in MPFL length, patellar facet forces, and patellar kinematics were compared using generalized estimating equation modeling. RESULTS: Schoettle point reconstruction was the most isometric, demonstrating isometry from 10° to 100°. The epiphyseal technique was isometric until 60°, after which the graft loosened with increasing flexion. The adductor sling and adductor transfer techniques were significantly more anisometric from 40° to 110°. Both grafts tightened with knee flexion and resulted in significantly more lateral patellar tilt versus the intact state in early flexion and significantly higher contact forces on the medial facet versus the epiphyseal technique in late flexion. CONCLUSION: In this cadaveric simulation, the epiphyseal technique allowed for a more isometric ligament until midflexion, when the patella engaged within the trochlear groove. The adductor sling and adductor transfer grafts became tighter in flexion, resulting in potential loss of motion, pain, graft stretching, and failure. Marginal between-condition differences in patellofemoral contact mechanics and patellar kinematics were observed in late flexion. CLINICAL RELEVANCE: In the skeletally immature patient, using an epiphyseal type MPFL reconstruction with the femoral attachment site distal to the physis results in a more isometric graft compared with techniques with attachment sites proximal to the physis.

Benge, J.F., Artz, J.D. and Kiselica, A.M. (2020). “The ecological validity of the Uniform Data Set 3.0 neuropsychological battery in individuals with mild cognitive impairment and dementia.” Clin Neuropsychol Oct 26;1-18. [Epub ahead of print].

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Ecological validity refers to the ability of neuropsychological measures to predict real world performance. Questions remain as to the ecological validity of commonly used measures, particularly regarding their relationships to global versus specific activities of daily living among those with neurodegenerative disease. We explored these issues through the lens of the Uniform Data Set 3.0 Neuropsychological battery (UDS3NB) in individuals with mild cognitive impairment and dementia. Method: UDS3NB and informant rated Functional Activities Questionnaire scales were evaluated from 2,253 individuals with mild cognitive impairment and dementia. Ordinal regression equations were used to explore the relationships of demographic and cognitive variables with overall and specific instrumental activities of daily living. Results: Delayed recall for visual and verbal material, and performance on trail making tests were consistent predictors of global and specific functions. Specific skills (i.e. naming or figure copy) showed differential relationships with specific activities, while phonemic fluency was not related to any particular activity. Conclusions: Measures in the UDS3NB predicted activities of daily living in individuals with MCI and dementia, providing initial support for the ecological validity of these tests. Specifically, measures that tap core deficits of Alzheimer’s disease, such as delayed recall and sequencing/shifting, are consistent predictors of performance in daily tasks.

Sarmast, N., Ogola, G.O., Kouznetsova, M., Leise, M.D., Bahirwani, R., Maiwall, R., Tapper, E., Trotter, J., Bajaj, J.S., Thacker, L.R., Tandon, P., Wong, F., Reddy, K.R., O’Leary, J.G., Masica, A., Modrykamien, A.M., Kamath, P.S. and Asrani, S.K. (2020). “Model for End-Stage Liver Disease-Lactate and Prediction of Inpatient Mortality in Patients With Chronic Liver Disease.” Hepatology 72(5): 1747-1757.

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BACKGROUND AND AIMS: Compared to other chronic diseases, patients with chronic liver disease (CLD) have significantly higher inpatient mortality; accurate models to predict inpatient mortality are lacking. Serum lactate (LA) may be elevated in patients with CLD due to both tissue hypoperfusion as well as decreased LA clearance. We hypothesized that a parsimonious model consisting of Model for End-Stage Liver Disease (MELD) and LA at admission may predict inpatient mortality in patients with CLD. APPROACH AND RESULTS: We examined all patients with CLD in two large and diverse health care systems in Texas (North Texas [NTX] and Central Texas [CTX]) between 2010 and 2015. We developed (n = 3,588) and validated (n = 1,804) a model containing MELD and LA measured at the time of hospitalization. We further validated the model in a second cohort of 14 tertiary care hepatology centers that prospectively enrolled nonelective hospitalized patients with cirrhosis (n = 726). MELD-LA was an excellent predictor of inpatient mortality in development (concordance statistic [C-statistic] = 0.81, 95% confidence interval [CI] 0.79-0.82) and both validation cohorts (CTX cohort, C-statistic = 0.85, 95% CI 0.78-0.87; multicenter cohort C-statistic = 0.82, 95% CI 0.74-0.88). MELD-LA performed especially well in patients with specific cirrhosis diagnoses (C-statistic = 0.84, 95% CI 0.81-0.86) or sepsis (C-statistic = 0.80, 95% CI 0.78-0.82). For MELD score 25, inpatient mortality rates were 11.2% (LA = 1 mmol/L), 19.4% (LA = 3 mmol/L), 34.3% (LA = 5 mmol/L), and >50% (LA > 8 mmol/L). A linear increase (P < 0.01) was seen in MELD-LA and increasing number of organ failures. Overall, use of MELD-LA improved the risk prediction in 23.5% of patients compared to MELD alone. CONCLUSIONS: MELD-LA (bswh.md/meldla) is an early and objective predictor of inpatient mortality and may serve as a model for risk assessment and guide therapeutic options.