Endoscopic and histologic utility of transnasal endoscopy in pediatric eosinophilic esophagitis.

Unsedated transnasal endoscopy (TNE) is an alternative method of examining the esophageal mucosa in pediatric patients with eosinophilic esophagitis (EoE), reducing cost, time, and risk associated with frequent surveillance esophagogastroduodenoscopies (EGD). Adequacy of transnasal esophageal biopsies for the evaluation of eosinophilic esophagitis histologic scoring system (EoEHSS) has not yet been evaluated. We compared procedure times, endoscopic findings, and EoEHSS scoring for EoE patients undergoing TNE versus standard EGD. Sixty-six TNE patients and 132 EGD controls matched for age (mean age 14.0 years) and disease status (29.3% active) were included. Compared to patients undergoing standard EGD, patients undergoing TNE spent 1.94 h less in the GI suite (p < 0.0001), with comparable occurrence rates of all visual endoscopic findings and most EoEHSS components. TNE serves as a useful tool for long-term disease surveillance, and consideration should be given to its use in clinical trials for EoE.

PHQ-9 and GAD-7 Score Response After Parathyroidectomy for Primary Hyperparathyroidism: a Systematic Review and Meta-analysis.

OBJECTIVE: Currently, the relationship between parathyroidectomy and objective neuropsychiatric outcomes are not clearly defined. The purpose of this study is to perform the first ever Meta-analysis of preoperative and postoperative PHQ-9 and GAD-7 scores in patients with primary hyperparathyroidism undergoing parathyroidectomy with the goal of identifying a specific psychometric score that could be used as an indication for surgical intervention. DATA SOURCES: A comprehensive search of the literature was performed using PubMed, Embase, PsycINFO, Web of Science, and Ovid All EBM Reviews. REVIEW METHODS: Studies met inclusion criteria if they evaluated preoperative and postoperative PHQ-9 and/or GAD-7 scores in patients with primary hyperparathyroidism undergoing parathyroidectomy. Random effects Meta-analyses were used to analyze the compiled data. RESULTS: The literature search returned 1433 articles for initial review of which 6 (1105 participants) met criteria for inclusion and Meta-analysis. Meta-analysis revealed that primary hyperparathyroidism patients had significantly higher presurgical PHQ-9 scores when compared to control groups. Additionally, patients experienced a statistically significant and sustained decrease in PHQ-9 scores following parathyroidectomy. Notably, there was a dramatic decrease in the percentage of patients with PHQ-9 scores ≥10 (considered clinically significant for depression) following parathyroidectomy. CONCLUSION: Patients with primary hyperparathyroidism experience a statistically significant and sustained improvement in PHQ-9 scores following parathyroidectomy. Additionally, symptoms of anxiety and suicidal ideation appear to decrease after parathyroidectomy. We propose that a PHQ-9 score ≥10 could potentially be used as an indication for parathyroidectomy in patients with asymptomatic primary hyperparathyroidism.

What Is Sinus Surgery?

This Patient Page describes the risks and benefits of sinus surgery for acute or chronic sinusitis.

The molecular and clinical role of Tensin 1/2/3 in cancer.

Tensin 1 was originally described as a focal adhesion adaptor protein, playing a role in extracellular matrix and cytoskeletal interactions. Three other Tensin proteins were subsequently discovered, and the family was grouped as Tensin. It is now recognized that these proteins interact with multiple cell signalling cascades that are implicated in tumorigenesis. To understand the role of Tensin 1-3 in neoplasia, current molecular evidence is categorized by the hallmarks of cancer model. Additionally, clinical data involving Tensin 1-3 are reviewed to investigate the correlation between cellular effects and clinical phenotype. Tensin proteins commonly interact with the tumour suppressor, DLC1. The ability of Tensin to promote tumour progression is directly correlated with DLC1 expression. Members of the Tensin family appear to have tumour subtype-dependent effects on oncogenesis; despite numerous data evidencing a tumour suppressor role for Tensin 2, association of Tensins 1-3 with an oncogenic role notably in colorectal carcinoma and pancreatic ductal adenocarcinoma is of potential clinical relevance. The complex interplay between these focal adhesion adaptor proteins and signalling pathways are discussed to provide an up to date review of their role in cancer biology.

Barriers to completion of cascade genetic testing: how can we improve the uptake of testing for hereditary breast and ovarian cancer syndrome?

Cascade testing for familial cancer syndromes has historically been difficult to execute. As part of a facilitated cascade testing pathway, we evaluated barriers to completion of cascade testing. Our previously published study evaluated a facilitated cascade testing pathway whereby a genetics team facilitated at-risk relative (ARR) cascade testing through telephone genetic counseling and mailed saliva kit testing. This follow-up study evaluated barriers to completion of cascade genetic testing through six-month follow-up telephone interviews. Probands identified 114 ARRs, of whom 97 were successfully contacted by telephone. Among those contacted, 83 (86%) reported interest in genetic testing and 14 (14%) declined. Among those reporting interest in testing, 71% (69/83) completed testing. Follow-up telephone interviews revealed that 14 ARRs did not complete testing despite reporting interest for the following reasons: concern about genetic discrimination, fear of a positive result and belief that the pathogenic variant was not relevant to his/her health. Five ARRs reported that they remained interested in testing and the telephone call prompted completion of testing. Even when facilitated by a medical team with prioritization of relative convenience, significant barriers to cascade testing ARRs for hereditary breast and ovarian cancer syndrome persist due to concern about genetic discrimination, cost, and fear of positive test results.

Cannabidiol Treatment for Neurological, Cognitive, and Psychiatric Symptoms in Sturge-Weber Syndrome.

BACKGROUND: A prior drug trial of cannabidiol for treatment-resistant epilepsy in patients with Sturge-Weber syndrome (SWS), a rare neurovascular condition, implicated improvements in neurological, quality of life (QOL), neuropsychologic, psychiatric, and motor outcomes. METHODS: Ten subjects with SWS brain involvement, controlled seizures, and cognitive impairments received study drug in this Johns Hopkins institutional review board-approved, open-label, prospective drug trial. Oral cannabidiol was taken for six months (dose ranged from 5 to 20 mg/kg/day). SWS neuroscore, port-wine birthmark score, QOL, and adverse events were recorded every four to 12 weeks. Neuropsychologic, psychiatric, and motor assessments were administered at baseline and six months' follow-up. Most evaluations were conducted virtually due to the coronavirus disease 2019 pandemic. RESULTS: Cannabidiol was generally well tolerated. Six subjects reported mild to moderate side effects related to study drug and continued on drug; one subject withdrew early due to moderate side effects. No seizures were reported. Significant improvements in SWS neuroscore, patient-reported QOL, anxiety and emotional regulation, and report of bimanual ability use were noted. Migraine QOL scores were high at baseline in these subjects, and remained high. Neuropsychologic and other QOL and motor outcomes remained stable, with some within-subject improvements noted. CONCLUSIONS: Further studies are needed to determine whether Epidiolex can improve quality of life and be beneficial for neurological, anxiety, and motor impairments in SWS independent of seizure control. Large multicentered studies are needed to extend these preliminary findings.

Coronary Wave Intensity Analysis as an Invasive and Vessel-Specific Index of Myocardial Viability.

BACKGROUND: Coronary angiography and viability testing are the cornerstones of diagnosing and managing ischemic cardiomyopathy. At present, no single test serves both needs. Coronary wave intensity analysis interrogates both contractility and microvascular physiology of the subtended myocardium and therefore has the potential to fulfil the goal of completely assessing coronary physiology and myocardial viability in a single procedure. We hypothesized that coronary wave intensity analysis measured during coronary angiography would predict viability with a similar accuracy to late-gadolinium-enhanced cardiac magnetic resonance imaging. METHODS: Patients with a left ventricular ejection fraction ≤40% and extensive coronary disease were enrolled. Coronary wave intensity analysis was assessed during cardiac catheterization at rest, during adenosine-induced hyperemia, and during low-dose dobutamine stress using a dual pressure-Doppler sensing coronary guidewire. Scar burden was assessed with cardiac magnetic resonance imaging. Regional left ventricular function was assessed at baseline and 6-month follow-up after optimization of medical-therapy±revascularization, using transthoracic echocardiography. The primary outcome was myocardial viability, determined by the retrospective observation of functional recovery. RESULTS: Forty participants underwent baseline physiology, cardiac magnetic resonance imaging, and echocardiography, and 30 had echocardiography at 6 months; 21/42 territories were viable on follow-up echocardiography. Resting backward compression wave energy was significantly greater in viable than in nonviable territories (-5240±3772 versus -1873±1605 W m-2 s-1, P<0.001), and had comparable accuracy to cardiac magnetic resonance imaging for predicting viability (area under the curve 0.812 versus 0.757, P=0.649); a threshold of -2500 W m-2 s-1 had 86% sensitivity and 76% specificity. CONCLUSIONS: Backward compression wave energy has accuracy similar to that of late-gadolinium-enhanced cardiac magnetic resonance imaging in the prediction of viability. Coronary wave intensity analysis has the potential to streamline the management of ischemic cardiomyopathy, in a manner analogous to the effect of fractional flow reserve on the management of stable angina.

Epstein-Barr Virus-Positive Plasma Cell Neoplasm of Nasal Cavity in an Immunocompetent Adult.

This case report describes patient in their 40s with a medical history of sleep apnea and diabetes and no history of immunosuppression who presented with left-sided nasal obstruction for 1 year and was found to have an Epstein-Barr virus­positive plasmacytoma.

Hemadsorption for removal of ticagrelor and direct oral anticoagulants in cardiac surgery.

INTRODUCTION: Cardiac patients on antiplatelets or oral anticoagulation undergoing emergent cardiac surgery without appropriate washout periods are at increased risk for developing perioperative bleeding. CytoSorb is a commercially available hemadsorption adsorber that can simultaneously remove a wide range of substances including ticagrelor, and direct oral anticoagulants (DOACs). AREAS COVERED: Although CytoSorb has been used to remove various protein-bound substances, this review will specifically evaluate and review current evidence for applying CytoSorb in removing ticagrelor and DOACs using four in vitro studies, three case reports, one retrospective study and two cost analysis studies. Based on limited evidence, CytoSorb may be effective in reducing perioperative bleeding by reducing chest tube output, blood product transfusions, and re-thoracotomy rates. CytoSorb can also reduce length of intensive care unit (ICU) and hospital stay. Although, CytoSorb has an initial upfront cost, it was proven to be cost-effective due to potential health resource savings on both short- and long-term projections. EXPERT COMMENTARY: CytoSorb provides a novel strategy to remove ticagrelor and DOACs in patients requiring emergency cardiac surgery. Although promising results, more solid evidence is required to establish its clinical effectiveness in reducing perioperative bleeding, bleeding-related complications, mortality, and finally, its overall safety.

Myocardial viability testing: all STICHed up, or about to be REVIVED?

Patients with ischaemic left ventricular dysfunction frequently undergo myocardial viability testing. The historical model presumes that those who have extensive areas of dysfunctional-yet-viable myocardium derive particular benefit from revascularization, whilst those without extensive viability do not. These suppositions rely on the theory of hibernation and are based on data of low quality: taking a dogmatic approach may therefore lead to patients being refused appropriate, prognostically important treatment. Recent data from a sub-study of the randomized STICH trial challenges these historical concepts, as the volume of viable myocardium failed to predict the effectiveness of coronary artery bypass grafting. Should the Heart Team now abandon viability testing, or are new paradigms needed in the way we interpret viability? This state-of-the-art review critically examines the evidence base for viability testing, focusing in particular on the presumed interactions between viability, functional recovery, revascularization and prognosis which underly the traditional model. We consider whether viability should relate solely to dysfunctional myocardium or be considered more broadly and explore wider uses of viability testingoutside of revascularization decision-making. Finally, we look forward to ongoing and future randomized trials, which will shape evidence-based clinical practice in the future.

Gender differences in female and male Australian Football injuries - A prospective observational study of emergency department presentations.

OBJECTIVES: To compare injury-profiles of females and males presenting to Emergency Departments (EDs) with an Australian Football injury. DESIGN: Prospective observational study. METHODS: All patients presenting to one of 10 EDs in Victoria, Australia, with an Australian Football injury were included in the study. Data were prospectively collected over a 10 month period, coinciding with a complete Australian Football season, including pre-season training and practice matches. Relevant information was extracted from patient medical records regarding injury-type, body part injured, investigations and treatments required. Female and male data were compared with chi-squared and Fisher's exact tests. RESULTS: 1635 patients were included, of whom 242 (14.8%) were female. Females had a higher proportion of hand/finger injuries (34.3% v 23.4%), neck injuries (6.6% v 2.5%) and patella dislocations (2.9% v 0.6%). Males had a higher proportion of shoulder injuries (11.5% v 5.8%), skin lacerations (8.0% v 1.7%), and thorax/abdominal/pelvic injuries (5.7% v 2.1%). Concussion rates were similar between the genders, occurring in 14.1% of all patients. Anterior cruciate ligament injuries were infrequent (1.0%) and not significantly different between genders. Females received more imaging investigations (83.1% v 74.7%) and analgesia (62.4% v 48.5%). A higher proportion of males required admission to hospital (5.0% v 2.1%), usually for surgery. CONCLUSION: Australian Football injury profiles differed between females and males. Gender-specific injury prevention and management programs would be indicated based on the study findings.

Coronary revascularisation in patients with ischaemic cardiomyopathy.

Heart failure resulting from ischaemic heart disease is associated with a poor prognosis despite optimal medical treatment. Despite this, patients with ischaemic cardiomyopathy have been largely excluded from randomised trials of revascularisation in stable coronary artery disease. Revascularisation has multiple potential mechanisms of benefit, including the reversal of myocardial hibernation, suppression of ventricular arrhythmias and prevention of spontaneous myocardial infarction. Coronary artery bypass grafting is considered the first-line mode of revascularisation in these patients; however, evidence from the Surgical Treatment of Ischaemic Heart Failure (STICH) trial showed a reduction in mortality, though this only became apparent with extended follow-up due to an excess of early adverse events in the surgical arm. There is currently no randomised controlled trial evidence for percutaneous coronary intervention in patients with ischaemic cardiomyopathy; however, the REVIVED-BCIS2 trial has recently completed recruitment and will address this gap in the evidence. Future directions include (1) clinical trials of revascularisation in patients hospitalised with heart failure, (2) defining the role of viability and ischaemia testing in heart failure, (3) studies to enhance the understanding of the mechanistic effects of revascularisation and (4) generating models to refine pre- and post-revascularisation risk prediction.

Sirolimus Treatment in Sturge-Weber Syndrome.

BACKGROUND: Sturge-Weber syndrome is a rare neurovascular disorder associated with capillary malformation, seizures, cognitive impairments, and stroke-like episodes (SLEs), arising from a somatic activating mutation in GNAQ. Studies suggest this mutation may cause hyperactivation of the mammalian target of rapamycin pathway. Sirolimus is an mammalian target of rapamycin inhibitor studied in other vascular anomalies and a potentially promising therapy in Sturge-Weber syndrome. METHODS: Ten patients with Sturge-Weber syndrome brain involvement and cognitive impairments were enrolled. Oral sirolimus was taken for six months (maximum dose: 2 mg/day, target trough level: 4-6 ng/mL). Neuropsychological testing, electroencephalography, and port-wine score were performed at baseline and after six months on sirolimus. Neuroquality of life, adverse events, and Sturge-Weber Syndrome Neurological Score (neuroscore) were recorded at each visit. RESULTS: Sirolimus was generally well tolerated; one subject withdrew early. Adverse events considered related to sirolimus were mostly (15/16) grade 1. A significant increase in processing speed was seen in the overall group (P = 0.031); five of nine patients with available data demonstrated statistically rare improvement in processing speed. Improvements were seen in the neuroquality of life subscales measuring anger (P = 0.011), cognitive function (P = 0.015), and depression (P = 0.046). Three subjects experiencing SLEs before and during the study reported shortened recovery times while on sirolimus. CONCLUSIONS: Sirolimus was well tolerated in individuals with Sturge-Weber syndrome and may be beneficial for cognitive impairments, especially in patients with impaired processing speed or a history of SLE. A future, randomized, placebo-controlled trial of sirolimus in patients with Sturge-Weber syndrome is needed to further understand these potentially beneficial effects.

Impact of Pre-operative Multidisciplinary Evaluation on Laryngotracheal Reconstruction Outcomes.

OBJECTIVE/HYPOTHESIS: Determine if diagnostic findings from pre-operative multidisciplinary evaluations are associated with single surgery or overall success rates in pediatric laryngotracheal reconstruction (LTR). STUDY DESIGN: Retrospective cohort. METHODS: Retrospective cohort study of patients undergoing LTR at a tertiary care children's hospital between January 01, 2008 and December 31, 2017. Success is defined as decannulation rate if tracheostomy present, and resolution of symptoms if tracheostomy not present. Cohorts compared were those who did and did not receive pulmonary and gastrointestinal preoperative testing. Multivariate, logistic regression, and Kaplan Meier analyses performed. RESULTS: About 165 children were included in the study. Median age was 3 years at the time of surgery; 73% of LTRs were double-stage procedures. Single surgery and overall success rates were 75% and 87%, respectively. After adjusting for severity of stenosis and surgical approach, performing esophagogastroduodenoscopy (EGD) and normal gross appearance on EGD were associated with increased single surgery (P = .01, .005) and overall success (P = .005, .0003). Performing pH probe and normal EGD biopsy results was associated with increased overall success (P = .03, .007). Asthma and musculoskeletal comorbidities, postoperative complications, and need for postoperative balloon dilation were associated with decreased success. No other comorbidities evaluated impacted success. CONCLUSIONS: Aerodigestive comorbidities are common in children undergoing LTR, and preoperative multidisciplinary workup often results in changes in management. After adjusting for grade and level of stenosis and staged approach, performing EGD and pH/impedance probe as well as normal gross and microscopic EGD findings was independently associated with increased LTR surgical success. LEVEL OF EVIDENCE: 4 (retrospective cohort study) Laryngoscope, 131:E2356-E2362, 2021.

Targeted Molecular Therapies in Allergy and Rhinology.

Biologic agents, monoclonal antibodies that target highly-specific molecular pathways of inflammation, are becoming integrated into care pathways for multiple disorders that are relevant in otolaryngology and allergy. These conditions share common inflammatory mechanisms of so-called Type 2 inflammation with dysregulation of immunoglobulin E production and eosinophil and mast cell degranulation leading to tissue damage. Biologic agents are now available for the treatment of chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, eosinophilic granulomatosis with polyangiitis (EGPA), atopic dermatitis (AD), and chronic spontaneous urticaria (CSU). This paper summarizes the diagnosis and management of these conditions and critically reviews the clinical trial data that has led to regulatory approval of biologic agents for these conditions.

Metastatic epithelial ovarian cancer to Meckel's cave with leptomeningeal spread at time of diagnosis.

BACKGROUND: Brain metastasis occurs in 1-2.5% of epithelial ovarian cancer (EOC) cases and carries a poor prognosis. Typically, brain metastases arise 2-3 years following the primary diagnosis of EOC. Malignant spread to the brain discovered at the time of initial ovarian cancer presentation is exceedingly rare with minimal reported cases in literature. CASE: This is a rare case of highly aggressive EOC in a previously healthy 32-year-old woman with evidence of brain, bone, and vertebral metastasis at the time of initial diagnosis. This is the first reported case of EOC with spread to Meckel's cave with symptoms consistent with trigeminal nerve disruption. The disease rapidly progressed through radiation and front-line chemotherapy. CONCLUSION: This report highlights the first reported case of EOC with invasion of Meckel's cave-present at time of diagnosis. Consistent with most cases in the literature of brain metastasis in the setting of EOC, our patient had a highly aggressive tumor associated with a poor prognosis. With better primary management of EOC, along with increased overall survival in EOC patients following spread to the brain secondary to multimodal therapies, we can continue to expect increasing numbers of brain metastasis with uncommon sites of recurrence.

Optimal Use of Vasodilators for Diagnosis of Microvascular Angina in the Cardiac Catheterization Laboratory.

BACKGROUND: Among patients with angina and nonobstructive coronary artery disease, those with coronary microvascular dysfunction have a poor outcome. Coronary microvascular dysfunction is usually diagnosed by assessing flow reserve with an endothelium-independent vasodilator like adenosine, but the optimal diagnostic threshold is unclear. Furthermore, the incremental value of testing endothelial function has never been assessed before. We sought to determine what pharmacological thresholds correspond to exercise pathophysiology and myocardial ischemia in patients with coronary microvascular dysfunction. METHODS: Patients with angina and nonobstructive coronary artery disease underwent simultaneous acquisition of coronary pressure and flow during rest, supine bicycle exercise, and pharmacological vasodilatation with adenosine and acetylcholine. Adenosine and acetylcholine coronary flow reserve were calculated as vasodilator/resting coronary blood flow (CFR and AchFR, respectively). Coronary wave intensity analysis was used to quantify the proportion of accelerating wave energy; a normal exercise response was defined as an increase in accelerating wave energy from rest to peak exercise. Ischemia was assessed by quantitative 3-Tesla stress perfusion cardiac magnetic resonance imaging and dichotomously defined by a hyperemic endo-epicardial gradient <1.0. RESULTS: Ninety patients were enrolled (58±10 years, 77% female). Area under the curve using receiver-operating characteristic analysis demonstrated optimal CFR and AchFR thresholds for identifying exercise pathophysiology and ischemia as 2.6 and 1.5, with positive and negative predictive values of 91% and 86%, respectively. Fifty-eight percent had an abnormal CFR (of which 96% also had an abnormal AchFR). Of those with a normal CFR, 53% had an abnormal AchFR, and 47% had a normal AchFR; ischemia rates were 83%, 63%, and 14%, respectively. CONCLUSIONS: The optimal CFR and AchFR diagnostic thresholds are 2.6 and 1.5, with high-positive and negative predictive values, respectively. A normal CFR value should prompt the measurement of AchFR. A stepwise algorithm incorporating both vasodilators can accurately identify an ischemic cause in patients with nonobstructive coronary artery disease.

Intravenous vs oral acetaminophen in sinus surgery: A randomized clinical trial.

BACKGROUND: Multimodal perioperative analgesia including acetaminophen is recommended by current guidelines. The comparative efficacy of intravenous vs oral acetaminophen in sinus surgery is unknown. We aimed to determine whether intravenous or oral acetaminophen results in superior postoperative analgesia following sinus surgery. METHODS: This was a prospective randomized trial with blinded endpoint assessments conducted at a single large academic medical center. Subjects undergoing functional endoscopic sinus surgery were randomized to intravenous vs oral acetaminophen in addition to standard anesthetic and surgical care. The primary outcome was visual analogue scale pain score at 1 hour postoperatively. RESULTS: One hundred and ten adult patients were randomized; 9 were excluded from the data analysis. Fifty patients were assigned to intravenous acetaminophen and 51 to oral acetaminophen. Postoperative pain scores at 1 hour (primary endpoint) were not significantly different between the intravenous and oral acetaminophen groups. Similarly, there was no significant difference in pain scores at 24 hours postoperatively. Finally, there was no significant difference in postoperative opioid usage in the postanesthesia care unit or over the first 24 hours postoperatively. CONCLUSIONS: This is the first comparative efficacy trial of oral vs intravenous acetaminophen in sinus surgery. There was no significant difference in pain scores at 1 or 24 hours postoperatively, and no difference in postoperative opioid use. Intravenous acetaminophen offers no apparent advantage over oral acetaminophen in patients undergoing sinus surgery. LEVEL OF EVIDENCE: 1b.

Physiological Stratification of Patients With Angina Due to Coronary Microvascular Dysfunction.

BACKGROUND: Coronary microvascular dysfunction (CMD) is defined by diminished flow reserve. Functional and structural CMD endotypes have recently been described, with normal and elevated minimal microvascular resistance, respectively. OBJECTIVES: This study determined the mechanism of altered resting and maximal flow in CMD endotypes. METHODS: A total of 86 patients with angina but no obstructive coronary disease underwent coronary pressure and flow measurement during rest, exercise, and adenosine-mediated hyperemia and were classified as the reference group or as patients with CMD by a coronary flow reserve threshold of 2.5; functional or structural endotypes were distinguished by a hyperemic microvascular resistance threshold of 2.5 mm Hg/cm/s. Endothelial function was assessed by forearm blood flow (FBF) response to acetylcholine, and nitric oxide synthase (NOS) activity was defined as the inverse of FBF reserve to NG-monomethyl-L-arginine. RESULTS: Of the 86 patients, 46 had CMD (28 functional, 18 structural), and 40 patients formed the reference group. Resting coronary blood flow (CBF) (24.6 ± 2.0 cm/s vs. 16.6 ± 3.9 cm/s vs. 15.1 ± 4.7 cm/s; p < 0.001) and NOS activity (2.27 ± 0.96 vs. 1.77 ± 0.59 vs. 1.30 ± 0.16; p < 0.001) were higher in the functional group compared with the structural CMD and reference groups, respectively. The structural group had lower acetylcholine FBF augmentation than the functional or reference group (2.1 ± 1.8 vs. 4.1 ± 1.7 vs. 4.5 ± 2.0; p < 0.001). On exercise, oxygen demand was highest (rate-pressure product: 22,157 ± 5,497 beats/min/mm Hg vs. 19,519 ± 4,653 beats/min/mm Hg vs. 17,530 ± 4,678 beats/min/mm Hg; p = 0.004), but peak CBF was lowest in patients with structural CMD compared with the functional and reference groups. CONCLUSIONS: Functional CMD is characterized by elevated resting flow that is linked to enhanced NOS activity. Patients with structural CMD have endothelial dysfunction, which leads to diminished peak CBF augmentation and increased demand during exercise. The value of pathophysiologically stratified therapy warrants investigation.