About

Professor Nicholas Cheng is associated with the Bronfenbrenner Center for Translational Research at Cornell University. The center assists faculty in developing translational research projects by providing support such as proposal preparation assistance, training, technical support, and facilitating collaborative relationships with other investigators. The center offers various workshops, an intensive summer institute, and talks on current research to support researchers in their endeavors. The BCTR also helps with gaining access to diverse research participants and unique data sets for secondary analysis, aiming to enhance the likelihood of funding and successful dissemination of research results.

Research topics

• Internal medicine
• Cardiology
• Medicine
• Pathology
• Radiology

Selected publications

• Population-Level Digital Stroke Surveillance: Building a Fair and Accurate ICD-10 Detection Model

  Cerebrovascular Diseases · 2026-03-20

  articleOpen access

  INTRODUCTION: The International Classification of Diseases, 10th Revision (ICD-10), is widely used for clinical care, quality assurance, and stroke research. Its ubiquity across healthcare systems makes it an attractive foundation for digital health tools that can support stroke surveillance and population health monitoring. However, a major limitation is that stroke detection algorithms derived from ICD codes have been developed primarily in socially homogenous populations, raising concerns about generalizability and fairness across racially diverse populations. METHODS: We developed and validated an acute ischemic stroke (AIS) detection algorithm using Classification and Regression Tree (CART) supervised machine learning, using a diverse derivation cohort. Input variables consisted of diagnostic and procedural ICD-10 codes, stratified by position and presence on admission. The model was trained on 75% and tested on 25% of the derivation cohort and externally validated in a second tertiary institution serving patients living in predominantly underrepresented and socially vulnerable communities. Performance of the algorithm was measured by sensitivity, specificity, positive predictive value (PPV), and Cohen's κ. Subgroup analyses were conducted by sex and race/ethnicity. RESULTS: In the derivation cohort, the CART model achieved sensitivity of 96%, specificity of 90%, PPV of 99%, and κ = 0.78. Applied to the independent validation cohort, the algorithm identified 1,050 AIS cases and 1,664 non-AIS cases, with sensitivity 89%, specificity 95%, PPV of 92%, and κ = 0.84. Performance was comparable between women and men (κ = 0.80 for both), and strong across Black (κ = 0.81), Hispanic (κ = 0.76), and White (κ = 0.80) subgroups. Lower accuracy was observed in the Asian subgroup (κ = 0.73, PPV = 62%). CONCLUSION: Our findings demonstrate that CART-based algorithms can provide accurate and interpretable AIS detection using ICD-10 data while explicitly addressing social fairness. The algorithm's reproducibility across independent and diverse populations highlights its potential as a low-friction, scalable, and cost-efficient tool for clinical care, surveillance, and quality improvement. Importantly, subgroup analyses underscore the necessity of ongoing fairness evaluation as performance varied by race/ethnicity, particularly in the Asian subgroup. Limitations include potential missed cases in the gold standard, lack of confidence intervals due to retrospective data, and dependence on local coding practices. This study shows that ICD-10-based machine learning algorithms, specifically CART, can serve as a model for developing an accurate and equitable digital health platform for AIS surveillance.

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• Aspirin-ticagrelor use after mild acute ischemic stroke: Findings from the get with the guidelines-stroke registry

  Journal of Stroke and Cerebrovascular Diseases · 2026-01-19

  articleOpen access

  BACKGROUND: Recent guidelines suggest that aspirin-ticagrelor may be considered for stroke prevention after mild acute ischemic stroke. However, it is unclear how commonly this dual antiplatelet therapy (DAPT) regimen is used in practice. METHODS: We performed a cross-sectional analysis of the Get With The Guidelines-Stroke registry 2017-2023. Patients with a non-cardioembolic mild ischemic stroke (defined as NIHSS <6) who presented within 24 hours of last known well without a contraindication to DAPT were included. The primary study outcome was the proportion of patients prescribed aspirin-ticagrelor at hospital discharge; temporal patterns of prescribing aspirin-ticagrelor and aspirin-clopidogrel over time are also described. In addition to standard tests of comparison, we used multiple logistic regression to evaluate associations between patient and facility factors and aspirin-ticagrelor use reported as odds ratios (OR) with 95% confidence intervals (CI). RESULTS: Among 1,018,736 patients meeting study criteria, 478,049 (46.9%) were female and median age was 68 (IQR: 59, 78) years. A total of 12,845 (1.3%) patients were discharged on aspirin-ticagrelor whereas 448,348 (44.0%) were discharged on aspirin-clopidogrel. Prescriptions for aspirin-ticagrelor and for aspirin-clopidogrel significantly increased over the study time-period. In regression analysis, coronary artery disease/prior myocardial infarction (OR: 2.6 [95% CI: 2.5-2.7]), Asian race (OR: 2.1 [95% CI: 1.9-2.2]), aspirin-clopidogrel prescription upon admission (OR: 2.0 [95% CI:1.9-2.1]), and history of stroke/TIA (OR: 1.98 [95% CI: (1.9-2.1)]), were substantially associated with aspirin-ticagrelor use whereas lacking insurance/self-pay (OR: 0.7 [95% CI: 0.6-0.8]), rural setting (OR: 0.8 [95% 0.7-0.9]), and primary stroke centers (OR: 0.3 [95% CI: 0.3-0.4]) were inversely associated with aspirin-ticagrelor. In the subgroup of 176,897 (17.4%) patients with NIHSS 4-5, 74,912 (50.8%) were discharged on aspirin-clopidogrel and 2,394 (1.4%) on aspirin-ticagrelor. CONCLUSION: Unlike aspirin-clopidogrel, aspirin-ticagrelor is infrequently administered after mild acute ischemic stroke (NIHSS <6) despite current guidelines, though the use of both DAPT regimens increased over time.

  PublisherDOI

• Abstract WP114: Elevated Troponin Is Associated With Mortality In Patients With Acute Cardioembolic Stroke And Atrial Fibrillation

  Stroke · 2022-02-01

  article

  Introduction: Stroke is the fifth leading cause of death in the US and a major cause of disability. Atrial fibrillation (AF) increases the risk of ischemic stroke fivefold. Cardioembolic stroke in patients with AF is associated with high mortality. The association of elevated cardiac troponin with mortality in patients with acute ischemic stroke has been studied previously; however, there is limited data in subgroups of ischemic stroke etiology. We sought to determine the association of troponin elevation at presentation with 90-day all-cause mortality in patients with acute ischemic stroke and AF. Methods: The I nitiation of A nticoagulation after C ardioembolic Stroke (IAC) study is a multicenter cohort drawn from eight US Stroke Centers. We included consecutive patients hospitalized with acute ischemic stroke and AF between 2015-2018, who had an initial baseline cardiac troponin I (bcTnI) obtained at presentation. The primary outcome was all-cause mortality at 90 days from stroke onset. We undertook multivariable logistic regression to determine the association between elevated bcTnl (≥0.1 ng/mL) and 90-day mortality. Results: Of the 2084 patients enrolled in IAC, 1889 patients had 90-day follow-up of which 1461 patients had bcTnI available. 239 of the included patients (16.4%) had an elevated bcTnl, and death within 90-days occurred in 323 patients (22.1%). Elevated bcTnI was associated with 90-day mortality in univariable analysis (49.4% vs 24.9%; OR 1.71, 95% CI 1.17-2.50, p&lt;0.001). This association persisted after adjusting for potential confounders: age, NIHSS, coronary artery disease, congestive heart failure and initial systolic blood pressure (OR 1.71, 95% CI 1.17-2.50, p=0.006); and in sensitivity analysis adding CrCl to the adjusted model above (OR 1.57, 95% CI 1.03-2.39, p=0.037). Conclusion: In acute ischemic stroke patients with AF, elevated bcTnI was independently associated with 90-day all-cause mortality.

  PublisherDOI

• Factors Associated with Anticoagulation Initiation for New Atrial Fibrillation in an Urban Emergency Department

  Ethnicity & Disease · 2022-10-20 · 1 citations

  articleOpen access

  Objective: To explore factors associated with anticoagulation (AC) initiation after atrial fibrillation (AF) diagnosis.Design: Retrospective cohort study.Setting: Urban medical center.Patients: Adults with emergency depart­ment (ED) diagnosis of new onset AF from 1/1/2017-1/1/2020 discharged home.Methods: We compared patients initiated on AC, our primary outcome, to those not initiated on AC. Stroke, major bleeding, and AC initiation within 1 year of visit were secondary outcomes. We hypothesized that minority race and non-English language preference are associated with failure to initiate AC.Results: Of 111 patients with AF, 88 met inclusion criteria. Mean age was 65 (SD 15); 47 (53%) were women. 49 (56%) patients were initiated on AC. Age (61 vs 68 years; P=.02), non-English language (28% vs 10%; P=.03), leaving ED against medical advice (AMA) (36% vs 14%; P=.04), and CHA2DS2- VASc score of 1 (41% vs 6%; P&lt;=.001) were associated with no AC initiation. There were no associations between patient-reported race/ethnicity and AC. Cardiology consultation (83.67% vs 30.78%; P&lt;.0001) and higher median CHA2DS2-VASc score (3[2-4]) vs. 2[1-4]; P=.047) were associated with AC. Of 73 patients with follow-up data at 1 year, 2 (8%) not initiated on AC had strokes, 2 (4%) initiated on AC had major bleeds, and 15 (62.5%) not initiated on AC in the ED subsequently were initiated on AC.Conclusion: More than half of ED patients with new AF eligible for AC were initi­ated on it. Work to improve AC utilization among patients with new AF who left AMA from ED and those who prefer to commu­nicate in a non-English language may be warranted. Ethn Dis. 2022;32(4):325-332; doi:10.18865/ed.32.4.325

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• Abstract P10: Posterior Circulation Strokes Are Less Likely to Receive Alteplase or Mechanical Thrombectomy: Analysis From the IAC Study

  Stroke · 2021-03-01 · 1 citations

  article

  Background: Emergent treatment with intravenous thrombolysis and mechanical thrombectomy improved outcomes in patients with acute ischemic stroke. We aim to identify differences in acute stroke treatment trends between strokes occurring in the anterior versus posterior circulation. Methods: The IAC (Initiation of Anticoagulation after Cardioembolic stroke) study represents pooled data registry of 8 comprehensive stroke centers across the United States and included patients with cardioembolic stroke in the setting of AFib. In a post hoc analysis, we identified and separated patients into posterior circulation stroke (PCS) and anterior circulation stroke (ACS) groups based on imaging. Patients without infarct locations or those with multi-circulation infarcts were excluded. We compared baseline characteristics, stroke severity and the treatment trends with alteplase (tPA) and mechanical thrombectomy (MT) in PCS vs ACS using Fisher exact test, t-test and non-parametric tests. We then performed multivariable logistic regression adjusted for baseline differences to determine the associations between PCS and tPA or MT. Results: Of the 2084 patients in IAC cohort, 1589 met inclusion criteria for this study, in which 294 (22.7%) had PCS. Mean age was 76.8 years, 29.3% received tPA and 26.9% had MT. When compared to ACS, patients with PCS were more likely to be men (55.4% vs 45.6%, p=0.003), have diabetes (42.8% vs 29.8, p&lt; 0.001) and lower median NIHSS score on admission (4 vs 8, p&lt;0.001). Patients with PCS were less likely to receive tPA (16.3% vs 32.3%, p&lt;0.001) or MT (10.9% vs 30.6%, p&lt;0.001). Other variables were not significantly different. When adjusted for baseline differences, patients with PCS remained less likely to be treated with tPA (adjusted OR 0.49, 95%CI 0.35-0.70, p&lt;0.001) or MT (adjusted OR 0.38, 95%CI 0.25-0.58, p&lt;0.001). Conclusion: Posterior circulation strokes are half as likely to receive thrombolytic therapy and almost a third as likely to have thrombectomy, even after adjusting for baseline stroke severity scores. This is possibly due to difficulty in timely identification and diagnostic delays. There is need for better tools incorporating posterior circulation stroke signs and symptoms to allow for early detection and treatment.

  PublisherDOI

• Abstract P12: Alteplase Reduces Mortality in Patients With Ischemic Stroke and Atrial Fibrillation: Analysis of the IAC Study

  Stroke · 2021-03-01

  article

  Background and Purpose: Multiple studies have established that intravenous thrombolysis with alteplase improves outcome after acute ischemic stroke. However, assessment of thrombolysis’ efficacy in stroke patients with atrial fibrillation (AF) has yielded mixed results. We sought to determine the association of alteplase with mortality, hemorrhagic transformation (HT), infarct volume, and mortality in patients with AF and acute ischemic stroke. Methods: We retrospectively analyzed consecutive acute ischemic stroke patients with AF included in the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study, which pooled data from 8 comprehensive stroke centers in the United States. 1889 (90.6%) had available 90-day follow up data and were included. For our primary analysis we used a cohort of 1367/1889 (72.4%) patients who did not undergo mechanical thrombectomy (MT). Secondary analyses were repeated in the patients that underwent MT (n=522). Binary logistic regression was used to determine whether alteplase use was independently associated with risk of HT, final infarct volume, and 90-day mortality, respectively, adjusting for potential confounders. Results: In our primary analyses we found that alteplase use was independently associated with an increased risk for HT (adjusted OR 2.14, 95% CI 1.49 - 3.07, p &lt;0.001) but overall reduced risk of 90-day mortality (adjusted OR 0.58, 95% CI 0.39 - 0.87, p = 0.009). Among patients undergoing MT, alteplase use was associated with a trend towards a reduction in 90-day mortality (adjusted OR 0.68 95% CI 0.45 - 1.04, p = 0.077). In the subgroup of patients prescribed DOAC treatment (n = 327; 24 received alteplase), alteplase treatment was associated with a trend towards smaller infarct size (&lt; 10 mL), (adjusted OR 0.40, 95% CI 0.15 - 1.12, p = 0.082) without a significant difference in the odds of 90-day mortality (adjusted OR 0.51, 95% CI 0.12 - 2.13, p = 0.357) or hemorrhagic transformation (adjusted OR 0.27, 95% CI 0.03 - 2.07, p = 0.206). Conclusion: Thrombolysis with intravenous alteplase was associated with reduced 90-day mortality in AF patients with acute ischemic stroke not undergoing MT. Further study is required to assess the safety and efficacy of alteplase in AF patients undergoing MT and those on DOACs.

  PublisherDOI

• Ischaemic stroke on anticoagulation therapy and early recurrence in acute cardioembolic stroke: the IAC study

  Journal of Neurology Neurosurgery & Psychiatry · 2021 · 66 citations

  • Medicine
  • Internal medicine
  • Cardiology

  BACKGROUND AND PURPOSE: A subset of ischaemic stroke patients with atrial fibrillation (AF) have ischaemic stroke despite anticoagulation. We sought to determine the association between prestroke anticoagulant therapy and recurrent ischaemic events and symptomatic intracranial haemorrhage (sICH). METHODS: We included consecutive patients with acute ischaemic stroke and AF from the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study from eight comprehensive stroke centres in the USA. We compared recurrent ischaemic events and delayed sICH risk using adjusted Cox regression analyses between patients who were prescribed anticoagulation (ACp) versus patients who were naïve to anticoagulation therapy prior to the ischaemic stroke (anticoagulation naïve). RESULTS: Among 2084 patients in IAC, 1518 had prior anticoagulation status recorded and were followed for 90 days. In adjusted Cox hazard models, ACp was associated with some evidence of a higher risk higher risk of 90-day recurrent ischaemic events only in the fully adjusted model (adjusted HR 1.50, 95% CI 0.99 to 2.28, p=0.058) but not increased risk of 90-day sICH (adjusted HR 1.08, 95% CI 0.46 to 2.51, p=0.862). In addition, switching anticoagulation class was not associated with reduced risk of recurrent ischaemic events (adjusted HR 0.41, 95% CI 0.12 to 1.33, p=0.136) nor sICH (adjusted HR 1.47, 95% CI 0.29 to 7.50, p=0.641). CONCLUSION: AF patients with ischaemic stroke despite anticoagulation may have higher recurrent ischaemic event risk compared with anticoagulation-naïve patients. This suggests differing underlying pathomechanisms requiring different stroke prevention measures and identifying these mechanisms may improve secondary prevention strategies.

  PublisherOA PDFDOI

• Emergency medicine physicians’ perspectives on diagnostic accuracy in neurology: a qualitative study

  Diagnosis · 2021-12-02 · 4 citations

  article

  OBJECTIVES: We sought to understand the knowledge, attitudes, and beliefs of emergency medicine (EM) physicians towards non-specific neurological conditions and the use of clinical decision support (CDS) to improve diagnostic accuracy. METHODS: We conducted semi-structured interviews of EM physicians at four emergency departments (EDs) affiliated with a single US healthcare system. Interviews were conducted until thematic saturation was achieved. Conventional content analysis was used to identify themes related to EM physicians' perspectives on acute diagnostic neurology; directed content analysis was used to explore views regarding CDS. Each interview transcript was independently coded by two researchers using an iteratively refined codebook with consensus-based resolution of coding differences. RESULTS: We identified two domains regarding diagnostic safety: (1) challenges unique to neurological complaints and (2) challenges in EM more broadly. Themes relevant to neurology included: (1) knowledge gaps and uncertainty, (2) skepticism about neurology, (3) comfort with basic as opposed to detailed neurological examination, and (4) comfort with non-neurological diseases. Themes relevant to diagnostic decision making in the ED included: (1) cognitive biases, (2) ED system/environmental issues, (3) patient barriers, (4) comfort with diagnostic uncertainty, and (5) concerns regarding diagnostic error identification and measurement. Most participating EM physicians were enthusiastic about the potential for well-designed CDS to improve diagnostic accuracy for non-specific neurological complaints. CONCLUSIONS: Physicians identified diagnostic challenges unique to neurological diseases as well as issues related more generally to diagnostic accuracy in EM. These physician-reported issues should be accounted for when designing interventions to improve ED diagnostic accuracy.

  PublisherDOI

• Biomarkers of Coagulation and Inflammation in COVID-19–Associated Ischemic Stroke

  Stroke · 2021 · 32 citations

  • Medicine
  • Cardiology
  • Internal medicine

  [Figure: see text].

  PublisherOA PDFDOI

• Abstract P389: External Validation of the 2CAN Score for Inpatient Stroke Detection

  Stroke · 2021-03-01

  article

  Introduction: Up to 15% of all strokes occur in patients who are already hospitalized for other conditions. A validated clinical tool to help rapidly discriminate between mimics and stroke among inpatients could greatly improve acute stroke care. Recently, the 2CAN score was developed and validated at a single Midwest academic medical center to identify inpatient strokes; a score of ≥2 was highly sensitive and specific for stroke. We sought to externally validate the 2CAN score at our institution. Methods: We conducted a retrospective cohort study of consecutive inpatient stroke codes at a single Northeast academic medical center from 7/1/2018 to 11/1/2019. Pre-specified variables, including patient demographics, vascular risk factors, and clinical features (neurological examination, vital signs, laboratory values, and final diagnoses), were abstracted from the electronic medical record. We determined the sensitivity, specificity, positive and negative predictive value of a 2CAN score ≥2 for stroke (ischemic stroke, hemorrhagic stroke, or TIA) in our cohort. The 2CAN score consists of clinical deficit score (0-3 points), recent cardiac procedure (1 point), atrial fibrillation (1 point), and code called within 24 hours of admission (1 point). We used multivariate logistic regression to identify additional determinants of stroke. Results: We identified 111 inpatient stroke codes on 110 patients, mean age 67 ± 1 year, 46.8% women, and 73.8% Black or Hispanic. Final diagnosis was stroke for 54 codes (48.6%) and mimic for 57 codes (51.3%), most commonly toxic-metabolic encephalopathy. 2CAN score ≥2 had 96.3% sensitivity, 45.6% specificity, 62.7% positive predictive value, and 92.3% negative predictive value for stroke. In a multivariable logistic regression model, only recent cardiac procedure (OR: 5.5; 95% CI: 1.1-27.5) and high clinical deficit score (OR: 3.9; 95% CI: 1.9-6.1) predicted stroke. Conclusion: The 2CAN score is externally valid and helps distinguish stroke from mimic in inpatients; having a score of &lt;2 makes stroke very unlikely.

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Frequent coauthors

• Alexander E. Merkler

  Cornell University

  79 shared

• Hooman Kamel

  Cornell University

  71 shared

• Jacqueline Stone

  70 shared

• Babak B. Navi

  Memorial Sloan Kettering Cancer Center

  69 shared

• Ava L. Liberman

  Weill Cornell Medicine

  53 shared

• Charles Esenwa

  Albert Einstein College of Medicine

  52 shared

• Samuel Singer

  50 shared

• Lisa M. DeAngelis

  Memorial Sloan Kettering Cancer Center

  47 shared

Education

• B.S., Food Science and Technology

  University of California, Davis