Neonatal Male Circumcision: Clearly Beneficial for Public Health or an Ethical Dilemma? A Systematic Review.

Contrasting ethical and legal arguments have been made concerning neonatal male circumcision (NMC) that merit the first systematic review on this topic. We performed PRISMA-compliant keyword searches of PubMed, EMBASE, SCOPUS, LexisNexis, and other databases and identified 61 articles that met the inclusion criteria. In the bibliographies of these articles, we identified 58 more relevant articles and 28 internet items. We found high-quality evidence that NMC is a low-risk procedure that provides immediate and lifetime medical and health benefits and only rarely leads to later adverse effects on sexual function or pleasure. Given this evidence, we conclude that discouraging or denying NMC is unethical from the perspective of the United Nations Convention on the Rights of the Child, which emphasizes the right to health. Further, case law supports the legality of NMC. We found, conversely, that the ethical arguments against NMC rely on distortions of the medical evidence. Thus, NMC, by experienced operators using available safety precautions, appears to be both legal and ethical. Consistent with this conclusion, all of the evidence-based pediatric policies that we reviewed describe NMC as low-risk and beneficial to public health. We calculated that a reduction in NMC in the United States from 80% to 10% would substantially increase the cases of adverse medical conditions. The present findings thus support the evidence-based NMC policy statements and are inconsistent with the non-evidence-based policies that discourage NMC. On balance, the arguments and evidence reviewed here indicate that NMC is a medically beneficial and ethical public health intervention early in life because it reduces suffering, deaths, cases, and costs of treating adverse medical conditions throughout the lifetimes of circumcised individuals.

Aspiration thrombectomy: safe removal of thrombi too big to aspirate.

Aspiration thrombectomy has been associated with an increased risk of stroke, and its routine use is not recommended. Ill-defined procedural techniques for aspiration thrombectomy may provide an explanation for inconsistent outcomes and adverse event rates in trials. Large thrombi can plug the aspiration port of the aspiration catheter and then be dislodged into the central circulation when they are retracted into the guide catheter, or when the aspiration catheter is removed from the Tuohy connector. We report a case of thrombus aspiration where a large distal thrombus was aspirated into the mouth of the aspiration catheter, held there with suction as it was removed and delivered outside the body without being dislodged. We offer several tips for safe removal of coronary thrombi too big to aspirate.

Comments by opponents on the British Medical Association's guidance on non-therapeutic male circumcision of children seem one-sided and may undermine public health.

The British Medical Association (BMA) guidance on non-therapeutic circumcision (NTMC) of male children is limited to ethical, legal and religious issues. Here we evaluate criticisms of the BMA's guidance by Lempert et al. While their arguments promoting autonomy and consent might be superficially appealing, their claim of high procedural risks and negligible benefits seem one-sided and contrast with high quality evidence of low risk and lifelong benefits. Extensive literature reviews by the American Academy of Pediatrics and the United States Centers for Disease Control and Prevention in developing evidence-based policies, as well as risk-benefit analyses, have found that the medical benefits of infant NTMC greatly exceed the risks, and there is no reduction in sexual function and pleasure. The BMA's failure to consider the medical benefits of early childhood NTMC may partly explain why this prophylactic intervention is discouraged in the United Kingdom. The consequence is higher prevalence of preventable infections, adverse medical conditions, suffering and net costs to the UK's National Health Service for treatment of these. Many of the issues and contradictions in the BMA guidance identified by Lempert et al stem from the BMA's guidance not being sufficiently evidence-based. Indeed, that document called for a review by others of the medical issues surrounding NTMC. While societal factors apply, ultimately, NTMC can only be justified rationally on scientific, evidence-based grounds. Parents are entitled to an accurate presentation of the medical evidence so that they can make an informed decision. Their decision either for or against NTMC should then be respected.

Ethics of Transitioning from Curative Care to Palliative Care: Potential Conflicts of Interest Using the Example of Neurosurgery.

BACKGROUND: Neurosurgical conditions are often incurable and lead to disability, severe physical symptoms, and distress for patients and families. Neurosurgeons may be responsible for transitioning management from curative to palliative. We sought to analyze the ethics of transitioning care from curative to palliative in patients in one's own specialty. METHODS: This was a case-based narrative review. PubMed and Google Scholar were searched with no restrictions on date. Studies relevant to the topic were included. RESULTS: After providing an introductory case, we defined the curative and palliative neurosurgical treatment paradigms, clarified the concept of transition of care from curative to palliative, and contrasted generalist and specialist palliative care. Next, we provided an overview of core ethical principles. We then described key considerations involved in transitioning patients from curative to palliative care in one's own specialty, namely, knowledge, communication, uncertainty, and futility. Finally, we provided an analysis of the introductory case, highlighting the conflict of interest inherent in the transition. CONCLUSIONS: It is acceptable for neurosurgeons and other specialists with adequate palliative care training to manage the transition to palliative care in most cases, preferably as part of multidisciplinary care teams. While we discuss the example of neurosurgery, this analysis applies to other specialties where care transitions from curative to palliative intent occur. Across specialties, patient preferences and values are foundational in the timing and specifics of this transition.

Ethical Principles in Personal Protective Equipment Inventory Management Decisions and Partnerships Across State Lines During the COVID-19 Pandemic.

The COVID-19 pandemic created unprecedented strain on the personal protective equipment (PPE) supply chain. Given the dearth of PPE and consequences for transmission, GetMePPE Chicago (GMPC) developed a PPE allocation framework and system, distributing 886 900 units to 274 institutions from March 2020 to July 2021 to address PPE needs. As the pandemic evolved, GMPC made difficult decisions about (1) building reserve inventory (to balance present and future, potentially higher clinical acuity, needs), (2) donating to other states/out-of-state organizations, and (3) receiving donations from other states. In this case study, we detail both GMPC's experience in making these decisions and the ethical frameworks that guided these decisions. We also reflect on lessons learned and suggest which values may have been in conflict (eg, maximizing benefits vs duty to mission, defined in the context of PPE allocation) in each circumstance, which values were prioritized, and when that prioritization would change. Such guidance can promote a values-based approach to key issues concerning distribution of PPE and other scarce medical resources in response to the COVID-19 pandemic and related future pandemics.

Family Meetings in the Intensive Care Unit During the Coronavirus Disease 2019 Pandemic.

PURPOSE: Visitor restrictions during the COVID-19 pandemic limit in-person family meetings for hospitalized patients. We aimed to evaluate the quantity of family meetings by telephone, video and in-person during the COVID-19 pandemic by manual chart review. Secondary outcomes included rate of change in patient goals of care between video and in-person meetings, the timing of family meetings, and variability in meetings by race and ethnicity. METHODS: A retrospective cohort study evaluated patients admitted to the intensive care unit at an urban academic hospital between March and June 2020. Patients lacking decision-making capacity and receiving a referral for a video meeting were included in this study. RESULTS: Most patients meeting inclusion criteria (N = 61/481, 13%) had COVID-19 pneumonia (n = 57/61, 93%). A total of 650 documented family meetings occurred. Few occurred in-person (n = 70/650, 11%) or discussed goals of care (n = 233/650, 36%). For meetings discussing goals of care, changes in patient goals of care occurred more often for in-person meetings rather than by video (36% vs. 11%, p = 0.0006). The average time to the first goals of care family meeting was 11.4 days from admission. More documented telephone meetings per admission were observed for White (10.5, SD 9.5) and Black/African-American (7.1, SD 6.6) patients compared to Hispanic or Latino patients (4.9, SD 4.9) (p = 0.02). CONCLUSIONS: During this period of strict visitor restrictions, few family meetings occurred in-person. Statistically significant fewer changes in patient goals of care occurred following video meetings compared to in-person meetings, providing support limiting in-person meetings may affect patient care.

Informed consent in neurosurgery: a systematic review.

OBJECTIVE: Informed consent has served as a main principle of medical ethics and laws in the United States. The 1986 American Association of Neurological Surgeons Code of Ethics implied medicolegal liability for the failure to obtain informed consent without providing practical guidance regarding the application of informed consent to individual patient encounters in a medicolegal environment. Here, the authors aimed to identify baseline patient recall after discussions with neurosurgeons and their capacity to provide informed consent, describe the effects of interventions to improve patient comprehension, and elucidate the role of informed consent in malpractice litigation in neurosurgery. Their findings may guide neurosurgeons in discussions to properly inform patients and reduce the risk of litigation. METHODS: A systematic review was conducted to explore informed consent within neurosurgery and its application to medicolegal liability using the PubMed, Embase, and Scopus databases. Titles and abstracts from articles identified in the search were read and selected for full-text review. Studies meeting prespecified inclusion criteria were reviewed in full and analyzed for study design, aim, population, interventions, and outcomes. RESULTS: Of 1428 resultant articles, 21 were included in the review. Baseline patient recall was low, particularly for risks and alternatives of treatments, and even decreased over time. Cognitive impairment was noted as a factor limiting the ability to provide informed consent. Interventions incorporating a combination of modalities in informed consent discussions, a specialized consent form with points for neurosurgeons to check off upon discussion, interactive websites, question prompt lists, and illustrations were found to be effective in improving patient knowledge. Lack of informed consent was a common factor for malpractice litigation. Spine surgery was particularly prone to costly lawsuits. Payments were generally greater for plaintiff verdicts than for settlements. CONCLUSIONS: The application of informed consent to patient encounters is an important facet of clinical practice. Neurosurgeons have a duty to provide patients with all pertinent information to allow them to make decisions about their care. The authors examined baseline patient comprehension and capacity, interventions to improve informed consent, and malpractice litigation; it appears that determining the proper capacity to provide informed consent and considering informed consent as a process that depends on the setting are important. There is room to improve the informed consent process centered on baseline patient health literacy and understanding as well as clear communication using multiple modalities.

Walkability and its association with walking/cycling and body mass index among adults in different regions of Germany: a cross-sectional analysis of pooled data from five German cohorts.

OBJECTIVES: To examine three walkability measures (points of interest (POI), transit stations and impedance (restrictions to walking) within 640 m of participant's addresses) in different regions in Germany and assess the relationships between walkability, walking/cycling and body mass index (BMI) using generalised additive models. SETTING: Five different regions and cities of Germany using data from five cohort studies. PARTICIPANTS: For analysing walking/cycling behaviour, there were 6269 participants of a pooled sample from three cohorts with a mean age of 59.2 years (SD: 14.3) and of them 48.9% were male. For analysing BMI, there were 9441 participants of a pooled sample of five cohorts with a mean age of 62.3 years (SD: 12.8) and of them 48.5% were male. OUTCOMES: (1) Self-reported walking/cycling (dichotomised into more than 30 min and 30 min and less per day; (2) BMI calculated with anthropological measures from weight and height. RESULTS: Higher impedance was associated with lower prevalence of walking/cycling more than 30 min/day (prevalence ratio (PR): 0.95; 95% CI 0.93 to 0.97), while higher number of POI and transit stations were associated with higher prevalence (PR 1.03; 95% CI 1.02 to 1.05 for both measures). Higher impedance was associated with higher BMI (ß: 0.15; 95% CI 0.04 to 0.25) and a higher number of POI with lower BMI (ß: -0.14; 95% CI -0.24 to 0.04). No association was found between transit stations and BMI (ß: 0.005, 95% CI -0.11 to 0.12). Stratified by cohort we observed heterogeneous associations between BMI and transit stations and impedance. CONCLUSION: We found evidence for associations of walking/cycling with walkability measures. Associations for BMI differed across cohorts.

Comorbidity phenotypes and risk of mortality in patients with ischaemic heart disease in the UK.

OBJECTIVES: The objective of this study is to use latent class analysis of up to 20 comorbidities in patients with a diagnosis of ischaemic heart disease (IHD) to identify clusters of comorbidities and to examine the associations between these clusters and mortality. METHODS: Longitudinal analysis of electronic health records in the health improvement network (THIN), a UK primary care database including 92 186 men and women aged ≥18 years with IHD and a median of 2 (IQR 1-3) comorbidities. RESULTS: Latent class analysis revealed five clusters with half categorised as a low-burden comorbidity group. After a median follow-up of 3.2 (IQR 1.4-5.8) years, 17 645 patients died. Compared with the low-burden comorbidity group, two groups of patients with a high-burden of comorbidities had the highest adjusted HR for mortality: those with vascular and musculoskeletal conditions, HR 2.38 (95% CI 2.28 to 2.49) and those with respiratory and musculoskeletal conditions, HR 2.62 (95% CI 2.45 to 2.79). Hazards of mortality in two other groups of patients characterised by cardiometabolic and mental health comorbidities were also higher than the low-burden comorbidity group; HR 1.46 (95% CI 1.39 to 1.52) and 1.55 (95% CI 1.46 to 1.64), respectively. CONCLUSIONS: This analysis has identified five distinct comorbidity clusters in patients with IHD that were differentially associated with risk of mortality. These analyses should be replicated in other large datasets, and this may help shape the development of future interventions or health services that take into account the impact of these comorbidity clusters.

Walkability and its association with prevalent and incident diabetes among adults in different regions of Germany: results of pooled data from five German cohorts.

BACKGROUND: Highly walkable neighbourhoods may increase transport-related and leisure-time physical activity and thus decrease the risk for obesity and obesity-related diseases, such as type 2 diabetes (T2D). METHODS: We investigated the association between walkability and prevalent/incident T2D in a pooled sample from five German cohorts. Three walkability measures were assigned to participant's addresses: number of transit stations, points of interest, and impedance (restrictions to walking due to absence of intersections and physical barriers) within 640 m. We estimated associations between walkability and prevalent/incident T2D with modified Poisson regressions and adjusted for education, sex, age at baseline, and cohort. RESULTS: Of the baseline 16,008 participants, 1256 participants had prevalent T2D. Participants free from T2D at baseline were followed over a mean of 9.2 years (SD: 3.5, minimum: 1.6, maximum: 14.8 years). Of these, 1032 participants developed T2D. The three walkability measures were not associated with T2D. The estimates pointed toward a zero effect or were within 7% relative risk increase per 1 standard deviation with 95% confidence intervals including 1. CONCLUSION: In the studied German settings, walkability differences might not explain differences in T2D.

Heart disease in Friedreich's ataxia.

Friedreich's ataxia (FRDA), which occurs in 1/50000 live births, is the most prevalent inherited neuromuscular disorder. Nearly all FRDA patients develop cardiomyopathy at some point in their lives. The clinical manifestations of FRDA include ataxia of the limbs and trunk, dysarthria, diabetes mellitus, and cardiac diseases. However, the broad clinical spectrum makes FRDA difficult to identify. The diagnosis of FRDA is based on the presence of suspicious clinical factors, the use of the Harding criteria and, more recently, the use of genetic testing for identifying the expansion of a triplet nucleotide sequence. FRDA is linked to a defect in the mitochondrial protein frataxin; an epigenetic alteration interferes with the folding of this protein, causing a relative deficiency of frataxin in affected patients. Frataxins are small essential proteins whose deficiency causes a range of metabolic disturbances, including oxidative stress, iron-sulfur cluster deficits, and defects in heme synthesis, sulfur amino acid metabolism, energy metabolism, stress responses, and mitochondrial function. The cardiac involvement seen in FRDA is a consequence of mitochondrial proliferation as well as the loss of contractile proteins and the subsequent development of myocardial fibrosis. The walls of the left ventricle become thickened, and different phenotypic manifestations are seen, including concentric or asymmetric hypertrophy and (less commonly) dilated cardiomyopathy. Dilated cardiomyopathy and arrhythmia are associated with mortality in patients with FRDA, whereas hypertrophic cardiomyopathy is not. Systolic function tends to be low-normal in FRDA patients, with an acute decline at the end of life. However, the literature includes only a few long-term prospective studies of cardiac progression in FRDA, and the cause of death is often attributed to heart failure and arrhythmia postmortem. Cardiomyopathy tends to be correlated with the clinical neurologic age of onset and the nucleotide triplet repeat length (i.e., markers of phenotypic disease severity) rather than the duration of disease or the severity of neurologic symptoms. As most patients are wheelchair-bound within 15 years of diagnosis, the clinical determination of cardiac involvement is often complicated by comorbidities. Researchers are currently testing targeted therapies for FRDA, and a centralized database, patient registry, and natural history study have been launched to support these clinical trials. The present review discusses the pathogenesis, clinical manifestations, and spectrum of cardiac disease in FRDA patients and then introduces gene-targeted and pathology-specific therapies as well as screening guidelines that should be used to monitor cardiac disease in this mitochondrial disorder.

Pharmacological cognitive enhancement in pediatrics.

PURPOSE OF REVIEW: Given the pervasiveness of psychotropic medication in the youth population and an increasingly competitive culture regarding educational performance, children, teenagers, and/or their parents may increasingly seek psychotropic substances in an effort to enhance a student's cognitive abilities and/or academic performance. Physicians must become aware of this very important and clinically relevant issue and work to ensure that medications remain in the hands of patients seeking wellness and not enhancement. RECENT FINDINGS: The current article highlights findings on the pervasiveness of stimulant misuse and diversion in youth, the motivations and effects of stimulant use, health and legal consequences associated with use, and physician perceptions and preventive practices. Ethical concerns regarding pharmacological cognitive enhancement in pediatrics are also outlined - including coercion for nonusers, inequities in access, and threats to an individual's sense of self with regard to authenticity and autonomy. SUMMARY: Pharmacological cognitive enhancement in pediatrics will become a larger, clinically relevant issue in the coming years. Physicians who care for children and adolescents must become more aware of this issue. Given the myriad health, legal, and ethical concerns, clinicians should discourage use of pharmaceuticals for enhancement purposes in the pediatric population.

Three-vessel coronary artery aneurysmal disease complicated by multivessel thrombosis and cardiogenic shock: the saving role of intracoronary thrombolysis.

The benefit of intracoronary thrombolytics in ST-elevation myocardial infarction (STEMI) is not well established. Mainstays of STEMI management include intravenous thrombolytics, percutaneous coronary interventions and surgical revascularisation. However, in cases of STEMI secondary to coronary artery aneurysmal disease (CAAD), standard treatment options may not be suitable due to high thrombus burden, perioperative risk and factors unique to each patient. Thus, STEMI management in CAAD can represent a therapeutically challenging clinical scenario. Here, we describe a patient with severe three-vessel CAAD complicated by multivessel thrombosis and cardiogenic shock for whom traditional management options including placement of haemodynamic support devices were not feasible. As an alternative measure, the patient was treated with intracoronary thrombolysis with remarkable clinical stabilisation and angiographic resolution of thrombosis. He remains clinically stable several years later without recurrent events. This case serves to demonstrate the potential lifesaving benefit of intracoronary thrombolysis in complicated multivessel CAAD.

Impact of ranolazine on coronary microvascular dysfunction (MICRO) study.

BACKGROUND: Patients with angina and coronary microvascular dysfunction, without evidence of structural or epicardial coronary disease (Type I CMVD) remain without evidence based treatment options. Previous work has demonstrated that ranolazine can improve angina frequency and stability among patients with Type 1 CMVD; however, the mechanism remains unclear. Therefore, the objective of this pilot project was to assess the impact of ranolazine on Type I CMVD as measured using an invasive tool to measure global resistance (index of microcirculatory resistance (IMR)). METHODS: Patients with Type 1 CMVD diagnosed using IMR were enrolled and treated with ranolazine 1000mg BID. Coronary angiography and IMR were performed at baseline and on treatment after four weeks. The primary outcome measure was change in IMR pre- and post-treatment. Secondary outcome measures, improvement in angina and activity level, were assessed using the Seattle Angina Questionnaire (SAQ), Duke Activity Status Index (DASI) and Metabolic equivalent for Task (MET) scores. RESULTS: A total of 7 patient were enrolled and completed the study. Mean age was 57.6±7.5, 43% were female and 43% were Hispanic. Mean baseline IMR was 37.25±16.27 which decreased to 19.48±5.69 (p=0.02; (-48% Δ) after treatment with ranolazine. Four of the five SAQ domains improved on treatment with significant improvement in physical limitation (p=0.001), angina frequency (p=0.04), angina stability (p=0.05) and disease perception (p=0.001). Non-significant improvements in activity were also seen in both the DASI and MET scores. CONCLUSION: Among patients with Type 1 CMVD, our pilot data suggest favorable changes in IMR, anginal symptoms and activity status with ranolazine treatment. These findings support further evaluation of the effects of ranolazine on microcirculatory function and angina symptoms in a larger cohort of patients with Type 1 CMVD.

Association of radial versus femoral access with contrast-induced acute kidney injury in patients undergoing primary percutaneous coronary intervention for ST-elevation myocardial infarction.

BACKGROUND: Patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) are at an increased risk of developing contrast-induced acute kidney injury (CI-AKI). Data on the association between transradial (TRA) vs. transfemoral (TFA) access and the risk of CI-AKI in this setting are limited. METHODS: We analyzed data on 1162 patients undergoing primary PCI for STEMI at two tertiary care centers between 2010 and 2014. Primary outcome was CI-AKI, defined as a relative rise in serum creatinine of ≥25%, or an absolute increase of ≥0.5mg/dL, within 48h of primary PCI. We used multivariable logistic regression and propensity analysis to determine the association between vascular access site and CI-AKI. RESULTS: Of 1162 patients who underwent primary PCI for STEMI, TFA was used in 857 (73.8%), and TRA in 305 (26.2%) patients. In the unmatched cohort, TRA was associated with numerically lower rates of CI-AKI as compared with TFA; however, this difference did not reach statistical significance (5.9% vs. 7.0%; unadjusted OR 0.83, 95%CI 0.48-1.44, p=0.510; adjusted OR 0.84, 95%CI 0.44-1.62, p=0.610). Similar results were seen in a propensity matched cohort of 508 patients (254 TRA and 254 TFA; CI-AKI 5.5% vs. 8.3%, OR 0.65, 95% CI 0.32-1.30, p=0.220). CONCLUSIONS: In patients with STEMI undergoing primary PCI, TRA was not associated with a lower risk of CI-AKI, as compared with TFA. Randomized controlled trials are needed to definitely assess the role of vascular access site in reducing the risk of CI-AKI in patients undergoing primary PCI for STEMI. SUMMARY: In patients with STEMI undergoing primary PCI, the overall incidence of contrast-induced acute kidney injury (CI-AKI) was low (6.7%). Transradial access was not associated with a lower risk of CI-AKI as compared with transfemoral access.

Dementia Care Management in an Underserved Community: The Comparative Effectiveness of Two Different Approaches.

OBJECTIVES: To compare the effectiveness and costs of telephone-only approach to in-person plus telephone for delivering an evidence-based, coordinated care management program for dementia. METHODS: We randomized 151 patient-caregiver dyads from an underserved predominantly Latino community to two arms that shared a care management protocol but implemented in different formats: in-person visits at home and/or in the community plus telephone and mail, versus telephone and mail only. We compared between-arm caregiver burden and care-recipient problem behaviors (primary outcomes) and patient-caregiver dyad retention, care quality, health care utilization, and costs (secondary outcomes) at 6- and 12-months follow-up. RESULTS: Care quality improved substantially over time in both arms. Caregiver burden, care-recipient problem behaviors, retention, and health care utilization did not differ across arms but the in-person program cost more to deliver. DISCUSSION: Dementia care quality improved regardless of how care management was delivered; large differences in effectiveness or cost offsets were not detected.

Coronary artery aneurysms in acute coronary syndrome: case series, review, and proposed management strategy.

Coronary artery aneurysm (CAA) is an uncommon clinical finding, with an incidence varying from 1.5%-4.9% in adults, and is usually considered a variant of coronary artery disease (CAD). CAA identified in the context of acute coronary syndrome (ACS) represents a unique management challenge, particularly if the morphology of the CAA is suspected to have provoked the acute clinical syndrome. CAA is associated with thrombus formation due to abnormal laminar flow, as well as abnormal platelet and endothelial-derived pathophysiologic factors within the CAA. Once formed, mural thrombus may potentiate the deposition of additional thrombus within aneurysmal segments. Percutaneous revascularization of CAA has been associated with complications including distal embolization of thrombus, no-reflow phenomenon, stent malapposition, dissection, and rupture. Presently, there are no formal guidelines to direct the management of CAA in patients presenting with ACS; controversies exist whether conservative, surgical, or catheter-based management should be pursued. In this manuscript, we present an extensive review of the existing literature and associated clinical guidelines, and propose a management algorithm for patients with this complex clinical scenario. Armed with this perspective, therapeutic decisions may be tailored to synthesize patient factors and preferences, individualized clinical assessment, and existing American Heart Association/American College of Cardiology guidelines for management of ACS.

Appropriate timing of nitroglycerin prior to intravascular ultrasound.

OBJECTIVES: To determine the time to maximal coronary dilation following intracoronary (IC) nitroglycerin (NTG) and whether the decrease in aortic pressure (AoP) is a surrogate marker for coronary vasodilatation. BACKGROUND: Intravascular ultrasound (IVUS) facilitates assessment of coronary plaque severity and morphology and aids in stent sizing. NTG is often administered prior to IVUS to prevent catheter-induced spasm and to facilitate standardized and accurate vessel size measurements. The impact of dose, timing, and route of delivering NTG on vessel size remains undefined. METHODS: Twelve patients undergoing IVUS-guided stent placement were studied. An IVUS catheter was positioned proximal to the target lesion and the following measurements made at baseline and 30 second (sec) intervals for 180 sec following 200 mcg IC NTG: AoP, IVUS-derived lumen diameter (Ld), lumen cross-sectional area (La), external elastic membrane diameter (EEMd) and EEM area (EEMa). Lumen and EEM measurements were compared at different time intervals and the relationship between time to max Ld and nadir AoP was analyzed. RESULTS: All patients had a vasodilatory response to IC NTG. Increase from baseline to max Ld following IC NTG was statistically significant (mean change 0.31 ± 0.18 mm, P=.0001). Mean time to max Ld following IC NTG was 117 sec (range, 60-180 sec). No correlation between time to max Ld and AoP nadir was observed (r = 0.19). CONCLUSIONS: Our study suggests that administration of 200 mcg IC NTG results in a significant change in lumen diameter and area with maximal vasodilation occurring on average approximately 2 minutes following IC NTG administration. There was no significant correlation between AoP change and maximal NTG-induced coronary vasodilation.