Nationwide Incidence and Trends in Central Retinal Arterial Occlusion Management: A 5000-Patient Analysis.

Central retinal artery occlusion (CRAO) is a rare and visually debilitating vascular condition characterized by sudden and severe vision loss. CRAO is a compelling target for intravenous alteplase (tPA) and endovascular mechanical thrombectomy (MT) due to pathophysiological similarities with acute ischemic stroke; however, the utility of these interventions in CRAO remains dubious due to limited sample sizes and potential risks. To assess usage and outcomes of tPA and MT in CRAO, we queried the National Inpatient Sample database using International Classification of Disease, Ninth and Tenth edition for patients with CRAO and acute ischemic stroke between 2010 and 2019. Our cohort of 5009 CRAO patients were younger with higher rates of obesity, hypertension, long-term anticoagulant use, and tobacco use compared to acute ischemic stroke patients. CRAO patients had lower rates of tPA administration (3.41% vs 6.21%) and endovascular MT (0.38% vs 1.31%) but fewer complications, including deep vein thrombosis, pneumonia, urinary tract infection, acute kidney injury, and acute myocardial infarction (all P < 0.01). CRAO patients had lower rates of poor functional outcome (31.74% vs 58.1%) and in-hospital mortality (1.2% vs 5.64%), but higher rates of profound blindness (9.24% vs 0.58%). A multivariate regression showed no relationship between tPA and MT and profound blindness, although the limited sample size of patients receiving interventions may have contributed to this apparent insignificance. Further investigation of larger patient cohorts and alternative treatment modalities could provide valuable insights for revascularization therapies in CRAO to optimize visual restoration and clinical outcomes.

Ultra-Early Hemostatic Therapy for Acute Intracerebral Hemorrhage: An Updated Review.

Intracerebral hemorrhage (ICH) is the second most common type of stroke, accounting for approximately 10-20% of all strokes, and is linked to severe neurological disability and death. Since the most accurate predictor of outcome in patients with ICH is hematoma volume, there is a great need for pharmacologic therapy that can reduce hematoma expansion and resultant mass effect and edema. This is especially critical within the ultra-early window of 3-4 hours after the presentation. Hemostatic therapies are exceptionally important for those patients taking antiplatelet or anticoagulant medications to reverse the effects of these medications and therefore prevent hematoma expansion. Furthermore, the recent publication of the 2023 Guideline for the Management of Patients with Aneurysmal Subarachnoid Hemorrhage by the American Heart Association/American Stroke Association, the first update to the guidelines since 2012, underscores the importance of optimizing anticoagulation reversal for this population. The purpose of this selective, nonsystematic review is to examine current literature regarding the use of hemostatic therapies in ICH, with particular attention paid to antiplatelet, anticoagulation, and antifibrinolytic therapies.

A double-hit: End-stage renal disease patients suffer worse outcomes in intracerebral hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) carries significant morbidity and mortality. Previous single-center retrospective analysis suggests that end-stage renal disease (ESRD) is a risk factor for severe ICH and worse outcomes. This investigation aims to examine the impact of ESRD on ICH severity, complications, and outcomes using a multicenter national database. METHODS: The International Classification of Disease, Ninth and Tenth Revision Clinical Modification codes were used to query the National Inpatient Sample for patients with ICH and ESRD between 2010 and 2019. Primary endpoints were the functional outcome, length of stay (LOS), and in-hospital mortality. Multivariate variable regression models and a propensity-score matched analysis were established to analyze patient outcomes associated with baseline patient characteristics. RESULTS: We identified 211,266 patients with ICH, and among them, 7,864 (3.77%) patients had a concurrent diagnosis of ESRD. Patients with ESRD were younger (60.85 vs. 67.64, P < 0.01) and demonstrated increased ICH severity (0.78 vs. 0.77, P < 0.01). ESRD patients experienced higher rates of sepsis (15.9% vs. 6.15%, P < 0.01), acute myocardial infarction (8.05% vs. 3.65%, P < 0.01), and cardiac arrest (5.94% vs. 2.4%, P < 0.01). In addition, ESRD predicted poor discharge disposition (odds ratio [OR]: 2.385, 95% confidence interval [CI]: 2.227-2.555, P < 0.01), longer hospital LOS (OR: 1.629, 95% CI: 1.553-1.709, P < 0.01), and in-hospital mortality (OR: 2.786, 95% CI: 2.647-2.932, P < 0.01). CONCLUSIONS: This study utilizes a multicenter database to analyze the effect of ESRD on ICH outcomes. ESRD is a significant predictor of poor functional outcomes, in-hospital mortality, and prolonged stay in the ICH population.

Effect of chronic antiplatelet therapy on clinical outcomes of endovascular thrombectomy for treatment of acute ischemic stroke.

OBJECTIVE: The objective of this study was to investigate the prognostic significance of chronic antiplatelet therapy (APT) usage in acute ischemic stroke (AIS) treated with endovascular thrombectomy (EVT). Long-term APT may enhance recanalization but may also predispose patients to an increased risk of hemorrhagic transformation. METHODS: Weighted hospitalizations for anterior-circulation AIS treated with EVT were identified in a large United States claims-based registry. Baseline clinical characteristics and outcomes were compared between patients with and without chronic APT usage prior to admission. Multivariable logistic regression analysis was performed to assess adjusted associations between APT and study endpoints. RESULTS: This analysis identified 36,560 patients, of whom 8170 (22.3%) were on a chronic APT regimen prior to admission. These patients were older and demonstrated a higher burden of comorbid disease, but had similar stroke severity on presentation in comparison with those not on APT. On unadjusted analysis, patients with prior APT demonstrated higher rates of favorable outcomes (24.3% vs 21.5%, p < 0.001), lower rates of mortality (7.0% vs 10.1%, p < 0.001), and lower rates of any intracranial hemorrhage (ICH; 20.3% vs 24.2%, p < 0.001), but no difference in rates of symptomatic ICH (sICH). Following multivariable adjustment for baseline clinical characteristics including age, acute stroke severity, and comorbidity burden, prior APT was associated with favorable outcome (adjusted odds ratio [aOR] 1.21, 95% CI 1.17-1.24, p < 0.001) and a lower likelihood of mortality (aOR 0.73, 95% CI 0.70-0.77, p < 0.001), without an increased likelihood of ICH (any ICH aOR 0.84, 95% CI 0.81-0.87, p < 0.001; sICH aOR 0.92, 95% CI 0.82-1.03, p = 0.131). CONCLUSIONS: Retrospective evaluation of patients with AIS treated with EVT using registry-based data demonstrated an association of prior APT usage with favorable outcomes, without an increased risk of hemorrhagic transformation.

Neuroendovascular Surgery Applications in Craniocervical Trauma.

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.

Significant increase in mortality and risk of acute ischemic stroke in infective endocarditis patients with subarachnoid hemorrhage secondary to mycotic aneurysms.

Infective Endocarditis (IE) patients are known to have a variety of complications with one of the rarest, but serious being cerebral mycotic aneurysm, which can result in subarachnoid hemorrhage (SAH). Using the National In-Patient Sample database, we sought to determine the rate of acute ischemic stroke (AIS) and outcomes in IE- patients with and without SAH. In total, we identified 82,844 IE-patients from 2010 to 2016, of which 641 had a concurrent diagnosis of SAH. IE patients with SAH had a more complicated course, higher mortality rate (OR 4.65 CI 95% 3.9-5.5, P < 0.001), and worse outcomes. This patient population also had a significantly higher rate of AIS (OR 6.3 CI 95% 5.4-7.4, P < 0.001). Overall, 41.5% of IE-patients with SAH had AIS during their hospitalization as compared to 10.1% of IE only patients. IE-patients with SAH were more likely to undergo endovascular treatment (3.6%) with 0.8% of the IE patients with AIS undergoing mechanical thrombectomy. While IE-patients are at risk for various complications, our study suggests a significant increase in the mortality and risk of AIS in those with SAH.

Incidence, Characteristics, and Outcomes of Stroke in Pediatric Patients with Celiac Disease.

(1) Background: Celiac disease (CD) can cause long-term inflammation and endothelial dysfunction and has been cited as a risk factor for acute ischemic stroke (AIS) in pediatric patients. However, the rate and outcomes of AIS in pediatric patients with CD has not been explored in a large population. Our objective is to explore the rate, severity, and outcomes of CD amongst pediatric AIS patients on a nationwide level. (2) Methods: The National Inpatient Sample (NIS) database was queried from 2016 to 2020 for pediatric patients with a principal diagnosis of AIS. Patients with a concurrent diagnosis of CD (AIS-CD) were compared to those without (AIS). Baseline demographics and comorbidities, clinical variables of severity, hospital complications, and the rates of tissue plasminogen activator (tPA) and mechanical thrombectomy were compared between the two groups. The main outcomes studied were mortality, discharge disposition, length of stay (LOS), and total hospital charges. (3) Results: Of 12,755 pediatric patients with a principal diagnosis of AIS, 75 (0.6%) had concurrent CD. There were no differences in the severity, discharge disposition, or mortality between the AIS-CD and AIS patients. Patients with AIS-CD were more likely to receive tPA at an outside hospital within 24 h of admission (p < 0.01) and more likely to undergo mechanical thrombectomy (p < 0.01) compared to the AIS patients. (4) Conclusions: CD patients made up only 0.6% of all pediatric AIS patients. No differences in the severity, mortality, or discharge disposition suggests a minimal to absent role of CD in the etiology of stroke. The CD-AIS patients were more likely to receive a tPA or undergo a mechanical thrombectomy; studies are needed to confirm the safety and efficacy of these interventions in pediatric patients.

Podcasting as an Innovative Tool for National Physical Therapy Examination Preparation.

The National Physical Therapy Examination (NPTE) is the gold standard for aspiring physical therapists. The NPTE Studycast is an innovative way for physical therapy students to prepare for the NPTE. The NPTE Studycast combines recorded information and content questions in a quiz format. To date, the podcast is widely downloaded.

Aneurysmal Subarachnoid Hemorrhage and Cardiac Related Fatality: Who Dies and Why?

Medical complications are a notable source of in-hospital death following aneurysmal subarachnoid hemorrhage (aSAH). However, there is a paucity of literature examining medical complications on a national scale. This study uses a national dataset to analyze the incidence rates, case fatality rates, and risk factors for in-hospital complications and mortality following aSAH. We found that the most common complications in aSAH patients (N = 170, 869) were hydrocephalus (29.3%) and hyponatremia (17.3%). Cardiac arrest was the most common cardiac complication (3.2%) and was associated with the highest case fatality rate overall (82%). Patients with cardiac arrest also had the highest odds of in-hospital mortality [odds ratio (OR), 22.92; 95% confidence interval (CI), 19.24-27.30; P < 0.0001], followed by patients with cardiogenic shock (OR, 2.96; 95% CI, 2.146-4.07; P < 0.0001). Advanced age and National Inpatient Sample-SAH Severity Score were found to be associated with an increased risk of in-hospital mortality (OR, 1.03; 95% CI, 1.03-1.03; P < 0.0001 and OR, 1.70; 95% CI, 1.65-1.75; P < 0.0001, respectively). Renal and cardiac complications are significant factors to consider in aSAH management, with cardiac arrest being the strongest indicator of case fatality and in-hospital mortality. Further research is needed to characterize factors that have contributed to the decreasing trend in case fatality rates identified for certain complications.

Early tracheostomy in patients undergoing mechanical thrombectomy for acute ischemic stroke.

PURPOSE: Respiratory failure following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is a known complication, and requirement of tracheostomy is associated with worse outcomes. Our objective is to evaluate characteristics associated with tracheostomy timing in AIS patients treated with MT. METHODS: The National Inpatient Sample was queried for adult patients treated with MT for AIS from 2016 to 2019. Baseline demographic characteristics, comorbidities, and inpatient outcomes were analyzed for associations in patients who received tracheostomy. Timing of early tracheostomy (ETR) was defined as placement before day 8 of hospital stay. RESULTS: Of 3505 AIS-MT patients who received tracheostomy, 915 (26.1%) underwent ETR. Patients who underwent ETR had shorter length of stay (LOS) (25.39 days vs 32.43 days, p < 0.001) and lower total hospital charges ($483,472.07 vs $612,362.86, p < 0.001). ETR did not confer a mortality benefit but was associated with less acute kidney injury (OR, 0.697; p = 0.013), pneumonia (OR, 0.449; p < 0.001), and sepsis (OR, 0.536; p = 0.002). CONCLUSION: An expected increase in complications and healthcare resource utilization is seen in AIS-MT patients receiving tracheostomy, likely reflecting the severity of patients' post-stroke neurologic injury. Among these high-risk patients, ETR was predictive of shorter LOS and fewer complications.

The gut-brain connection: Inflammatory bowel disease increases risk of acute ischemic stroke.

OBJECTIVES: Chronic inflammation of the gastrointestinal tract is a hallmark of inflammatory bowel disease (IBD). This increased inflammation is thought to induce a hypercoagulable state that increases the risk for stroke. However, few studies have examined the association between IBD and acute ischemic stroke (AIS). Thus, this study aims to investigate the incidence, treatments, complications, and outcomes of AIS in patients with IBD. MATERIALS & METHODS: ICD-9-CM and ICD-10-CM codes were used to query the National Inpatient Sample for AIS and IBD diagnosis. Baseline demographics, clinical characteristics, complications, treatments, and outcomes were assessed through descriptive statistics, multivariate regression, and propensity score matching (PSM) analysis. Acute stroke severity was assessed using the National Institute of Heath's Stroke Severity Score (SSS) as a template. RESULTS: 1,609,817 patients were diagnosed with AIS between 2010 through 2019. 7468 (0.46%) had concomitant diagnoses of IBD. AIS patients with IBS were younger, more likely to be white and female, but less likely to be obese. Although IBD patients had comparable stroke severities (p = 0.64) to their non-IBS counterparts, they received stroke intervention at statistically different rates than their non-IBD counterparts. Additionally, IBD patients had higher rates of in-hospital complications (p < 0.01) and longer lengths of stay (LOS) (p < 0.01). CONCLUSIONS: IBD patients develop AIS at a younger age with similar rates of stroke severity to their non-IBD counterparts, but receive higher rates of tissue plasminogen activator administration and decreased rates of mechanical thrombectomy. Our research shows that patients with IBD are at risk for AIS at an earlier age and are more likely to have complications. This underlies a connection between IBD and a hypercoagulable state that could predispose patients to AIS.

Ruptured arteriovenous malformation mortality: Incidence, risk factors, and inpatient outcome score.

BACKGROUND: Limited literature exists on the morbidity and mortality of AVM associated intracerebral hemorrhage (ICH) compared with non-AVM ICH. OBJECTIVE: We examine morbidity and mortality in cAVM in a large nationwide inpatient sample to create a prognostic inpatient ruptured AVM mortality score. METHODS: This retrospective cohort study from 2008 to 2014 compares outcomes in cAVM related hemorrhages and ICH utilizing the National Inpatient Sample database. Diagnostic codes for ICH and AVM underlying ICH were identified. We compared case fatality according to medical complications. Multivariate analysis was used to derive hazard ratios and 95% confidence intervals to assess odds of mortality. RESULTS: We identified 6496 patients with ruptured AVMs comparing them to 627,185 admitted with ICH. Mortality was lower for ruptured AVMs (11%) compared to ICH (22%) [p < 0.01]. Mortality associated factors were liver disease (OR 2.64, CI 1.81-3.85, p < .001), diabetes mellitus (OR 2.42, CI 1.38-4.22, p = 0.002), alcohol abuse (OR 1.81, CI 1.31-2.49, p = 0.001), hydrocephalus (OR 3.35 CI 2.81-4.00, p < 0.001), cerebral edema (OR 1.5, 1.25-1.85, p < 0.001), cardiac arrest (OR 15, CI 7.9-30, p < 0.001), and pneumonia (OR 1.93, CI 1.51-2.47, p < 0.001). A 0-5 ruptured AVM mortality score was developed: Cardiac arrest (=3), age >60 (=1), Black race (=1), chronic liver failure (=1) diabetes mellitus (=1), pneumonia (=1), alcohol abuse (=1) and cerebral edema (=1). Mortality increased with score. No patient with 5 or more points survived. CONCLUSION: The Ruptured AVM Mortality Score allows for risk stratification on patients with ICH due to ruptured AVM. This scale could prove useful in prognostication and patient education.

Complication Rates Following Cerebral and Coronary Angiography: Nationwide Analysis 2008-2014.

Catheter-based angiography is an essential procedure for the diagnosis and treatment of vascular complications in patients. Since cerebral and coronary angiography are similar techniques that utilize the same access sites and general principles, the associated risks overlap and should be identified to help direct patient care. The purpose of this study was to determine complication rates in a combined cohort of cerebral and coronary angiography patients, as well as conduct a comparative analysis of coronary and cerebral angiography complications. The National Inpatient Sample was queried from 2008 to 2014 to identify patients who underwent coronary or cerebral angiography. After assessment of baseline characteristics, complication rates, and disposition in the combined cohort, propensity matching was utilized to create sub-cohorts of coronary and cerebral angiography patients based on demographics and comorbidities. Comparative analysis of procedural complications and disposition was then performed. A total of 3,763,651 hospitalizations were included in our study cohort (3,505,715 coronary angiographies and 257,936 cerebral angiographies). The median age was 62.9 years, with females being 46.42%. The most prevalent comorbidities in the overall cohort were hypertension (69.92%), coronary artery disease (69.48%), smoking (35.64%), and diabetes mellitus (35.13%). Propensity matching demonstrated that the cerebral angiography cohort had lower rates of acute and unspecified renal failure (5.4% vs 9.2%, OR 0.57, 95% CI, 0.53-0.61, P < 0.001), hemorrhage/hematoma formation (0.8% vs 1.3%, OR 0.63, 95% CI, 0.54-0.73, P < 0.001), and equivalent rates of retroperitoneum hematoma formation (0.03% vs 0.04%, OR 1.49, 95% CI, 0.76-2.90, P = 0.247) and arterial embolism/ thrombus formation (0.3% vs 0.3%, OR 1.01, 95% CI, 0.81-1.27, P = 0.900). Our study showed both cerebral and coronary angiography have generally low rates of procedural complications. Matched cohort analysis demonstrated that cerebral angiography patients are at no greater risk for complications than coronary angiography patients.

The glitz and glamour randomized trial: the effect of fingernail polish on post-caesarean surgical site infection.

Current surgical scrub guidelines suggest that fingernail polish should not be worn by healthcare providers despite collective evidence not demonstrating a relationship between fingernail polish and surgical-site infection (SSI). The purpose of this study was to determine the effect of surgical staff wearing nail polish on the incidence of SSI after caesarean delivery. In this calendar block-randomised clinical trial, surgical staff were assigned to wear nail polish or to have unpainted nails for alternating two-week periods. The primary outcome was surgical site infection within 6 weeks of caesarean delivery. There were 372 patients in the nail polish arm and 465 in the polish-free arm. The rate of SSIs was not significantly different between the nail polish arm and the polish-free arm (1.3% vs 2.8% p = .155). We found the rate of SSI following caesarean delivery is not significantly affected by surgical staff wearing fingernail polish.Impact StatementWhat is already known on this subject? Current surgical scrub guidelines state that fingernail polish should not be worn by healthcare providers even though the collective evidence has not been able to show the relationship between fingernail polish and surgical site infection. Previous studies have only used bacterial colony count after handwashing as a primary endpoint. The evidence they provide for developing scrub guidelines have been contradictory and inconclusive.What do the results of this study add? To better inform surgical scrub guidelines, evidence is needed that evaluates the effect of fingernail polish on clinically significant endpoints. Our study, Glitz & Glamour, examined 885 non-emergent Caesarian sections using a calendar-block schedule to determine if wearing nail polish had an impact on rates of surgical site infection.What are the implications of these findings for clinical practice and/or further research? Results suggested that fingernail polish had no difference on frequency of surgical site infections, and neither condition of the polish (chipped vs. freshly applied) nor the type of polish (gel vs. regular) had any impact either.

Mechanistic Coupling of a Novel in silico Cotyledon Perfusion Model and a Physiologically Based Pharmacokinetic Model to Predict Fetal Acetaminophen Pharmacokinetics at Delivery.

Little is known about placental drug transfer and fetal pharmacokinetics despite increasing drug use in pregnant women. While physiologically based pharmacokinetic (PBPK) models can help in some cases to shed light on this knowledge gap, adequate parameterization of placental drug transfer remains challenging. A novel in silico model with seven compartments representing the ex vivo cotyledon perfusion assay was developed and used to describe placental transfer and fetal pharmacokinetics of acetaminophen. Unknown parameters were optimized using observed data. Thereafter, values of relevant model parameters were copied to a maternal-fetal PBPK model and acetaminophen pharmacokinetics were predicted at delivery after oral administration of 1,000 mg. Predictions in the umbilical vein were evaluated with data from two clinical studies. Simulations from the in silico cotyledon perfusion model indicated that acetaminophen accumulates in the trophoblasts; simulated steady state concentrations in the trophoblasts were 4.31-fold higher than those in the perfusate. The whole-body PBPK model predicted umbilical vein concentrations with a mean prediction error of 24.7%. Of the 62 concentration values reported in the clinical studies, 50 values (81%) were predicted within a 2-fold error range. In conclusion, this study presents a novel in silico cotyledon perfusion model that is structurally congruent with the placenta implemented in our maternal-fetal PBPK model. This allows transferring parameters from the former model into our PBPK model for mechanistically exploring whole-body pharmacokinetics and concentration-effect relationships in the placental tissue. Further studies should investigate acetaminophen accumulation and metabolism in the placenta as the former might potentially affect placental prostaglandin synthesis and subsequent fetal exposure.

Cross-Network Directory Service: Infrastructure to enable collaborations across distributed research networks.

INTRODUCTION: Existing large-scale distributed health data networks are disconnected even as they address related questions of healthcare research and public policy. This paper describes the design and implementation of a fully functional prototype open-source tool, the Cross-Network Directory Service (CNDS), which addresses much of what keeps distributed networks disconnected from each other. METHODS: The set of services needed to implement a Cross-Directory Service was identified through engagement with stakeholders and workgroup members. CNDS was implemented using PCORnet and Sentinel network instances and tested by participating data partners. RESULTS: Web services that enable the four major functional features of the service (registration, discovery, communication, and governance) were developed and placed into an open-source repository. The services include a robust metadata model that is extensible to accommodate a virtually unlimited inventory of metadata fields, without requiring any further software development. The user interfaces are programmatically generated based on the contents of the metadata model. CONCLUSION: The CNDS pilot project gathered functional requirements from stakeholders and collaborating partners to build a software application to enable cross-network data and resource sharing. The two partners-one from Sentinel and one from PCORnet-tested the software. They successfully entered metadata about their organizations and data sources and then used the Discovery and Communication functionality to find data sources of interest and send a cross-network query. The CNDS software can help integrate disparate health data networks by providing a mechanism for data partners to participate in multiple networks, share resources, and seamlessly send queries across those networks.

Influential Mutations in the SMAD4 Trimer Complex Can Be Detected from Disruptions of Electrostatic Complementarity.

This article examines three techniques for rapidly assessing the electrostatic contribution of individual amino acids to the stability of protein-protein complexes. Whereas the energetic minimization of modeled oligomers may yield more accurate complexes, we examined the possibility that simple modeling may be sufficient to identify amino acids that add to or detract from electrostatic complementarity. The three methods evaluated were (a) the elimination of entire side chains (e.g., glycine scanning), (b) the elimination of the electrostatic contribution from the atoms of a side chain, called nullification, and (c) side chain structure prediction using SCWRL4. These techniques generate models in seconds, enabling large-scale mutational scanning. We evaluated these techniques on the SMAD2/SMAD4 heterotrimer, whose formation plays a crucial role in antitumor pathways. Many studies have documented the clinical and structural effect of specific mutations on trimer formation. Our results describe how glycine scanning yields more specific predictions, although nullification may be more sensitive, and how side chain structure prediction enables the identification of uncharged-to-charge mutations.