Hypoparathyroidism update

PURPOSE OF REVIEW

Since the release of the 2022 Second International Workshop Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines, updates and advances are now available in the cause, complications, and treatment of adult chronic hypoparathyroidism (hypoPTH). This review aims to highlight these new findings and implications to patient care.

RECENT FINDINGS

Postsurgical hypoparathyroidism remains the most common cause, immune-related hypoparathyroidism from checkpoint inhibitors is an emerging autoimmune cause. In a large retrospective cohort study of thyroidectomies, incident fracture was lower, particularly in the vertebra, in the hypoPTH cohort, compared with postthyroidectomy control group. Hypercalciuria increases risk for renal calculi in hypoPTH independent of disease duration and treatment dose. Quality of life is impaired in hypoPTH patients on conventional therapy, improvement was noted post-PTH replacement. TranCon PTH phase 3 RCT reported eucalcemia with reduced renal calcium excretion, normalization of bone turn-over markers, stable BMD and improved quality of life.

SUMMARY

HypoPTH is a chronic disease associated with significant morbidity and poor Quality of Life. Awareness of treatment targets and follow-up investigations can alleviate patient anxiety regarding over-treatment and under-treatment. Progress in long-acting PTH replacement strategies might provide accessible, feasible alternatives to conventional therapy in brittle hypoPTH patients.

Opportunistic screening for osteoporosis using routine clinical care computed tomography brain studies

OBJECTIVE

Osteoporosis and falls are both prevalent in the elderly, and CT brain (CTB) is frequently performed post head-strike. We aim to validate the relationship between frontal bone density (Hounsfield unit) from routine CTB and bone mineral density from dual-energy X-ray absorptiometry (DEXA) scan for opportunistic osteoporosis screening.

MATERIALS AND METHODS

Patients who had a non-contrast CTB followed by a DEXA scan in the subsequent year were included in this multi-center retrospective study. The relationship between frontal bone density on CT and femoral neck T-score on DEXA was examined using ANOVA, Pearson's correlation, and receiver operating curve (ROC) analysis. Sensitivity, specificity, negative and positive predictive values, and area under the curve (AUC) were calculated.

RESULTS

Three hundred twenty-six patients (205 females and 121 males) were analyzed. ANOVA analysis showed that frontal bone density was lower in patients with DEXA-defined osteoporosis (p < 0.001), while Pearson's correlation analysis demonstrated a fair correlation with femoral neck T-score (r = 0.3, p < 0.001). On subgroup analysis, these were true in females but not in males. On ROC analysis, frontal bone density weakly predicted osteoporosis (AUC 0.6, 95% CI 0.5-0.7) with no optimal threshold identified. HU < 610 was highly specific (87.5%) but poorly sensitive (18.9%). HU > 1200 in females had a strong negative predictive value for osteoporosis (92.6%, 95% CI 87.1-98.1%).

CONCLUSION

Frontal bone density from routine CTB is significantly different between females with and without osteoporosis, but not between males. However, frontal bone density was a weak predictor for DEXA-defined osteoporosis. Further research is required to determine the role of CTB in opportunistic osteoporosis screening.

Biological Variation Estimates for Plasma Copeptin and Clinical Implications

BACKGROUND

Plasma copeptin measurement is useful for the differential diagnoses of polyuria-polydipsia syndrome. It has also been proposed as a prognostic marker for cardiovascular diseases. However, limited information is available about the within- (CVI) and between-subject (CVG) biological variation (BV). This study presents BV estimates for copeptin in healthy individuals.

METHODS

Samples were collected weekly from 41 healthy subjects over 5 weeks and analyzed using the BRAHMS Copeptin proAVP KRYPTOR assay after at least 8 h of food and fluid abstinence. Outlier detection, variance homogeneity, and trend analysis were performed followed by CV-ANOVA for BV and analytical variation (CVA) estimation with 95% confidence intervals. Reference change values (RCVs), index of individuality (II), and analytical performance specification (APS) were also calculated.

RESULTS

The analysis included 178 results from 20 males and 202 values from 21 females. Copeptin concentrations were significantly higher in males than in females (mean 8.5 vs 5.2 pmol/L, P < 0.0001). CVI estimates were 18.0% (95% CI, 15.4%-21.6%) and 19.0% (95% CI, 16.4%-22.6%), for males and females, respectively; RCVs were -35% (decreasing value) and 54% (increasing value). There was marked individuality for copeptin. No result exceeded the diagnostic threshold (>21.4 pmol/L) for arginine vasopressin resistance.

CONCLUSIONS

The availability of BV data allows for refined APS and associated II, and RCVs applicable as aids in the serial monitoring of patients with specific diseases such as heart failure. The BV estimates are only applicable in subjects who abstained from oral intake due to the rapid and marked effects of fluids on copeptin physiology.

Bone Density and Trabecular Bone Score Decline Rapidly in the First Year After Bone Marrow Transplantation with a Marked Increase in 10-Year Fracture Risk

As outcomes from allogeneic bone marrow transplantation (BMT) have improved, prevention of long-term complications, such as fragility fractures, has gained importance. We aimed to assess areal bone mineral density (aBMD) and trabecular bone score (TBS) changes post BMT, and determine their relationship with fracture prevalence. Patients who attended the Royal Melbourne Hospital (RMH) BMT clinic between 2005-2021 were included. Patient characteristics and dual-energy X-ray absorptiometry (DXA) values were collected from the electronic medical record and a survey. TBS iNsight™ was used to calculate TBS for DXA scans performed from 2019 onwards. 337 patients with sequential DXAs were eligible for inclusion. Patients were primarily male (60%) and mean age ± SD was 45.7 ± 13.4 years. The annualised decline in aBMD was greater at the femoral neck (0.066g/cm2 (0.0038-0.17)) and total hip (0.094g/cm2 (0.013-0.19)), compared to the lumbar spine (0.049g/cm2 (- 0.0032-0.16)), p < 0.0001. TBS declined independently of aBMD T-scores at all sites. Eighteen patients (5.3%) sustained 19 fractures over 3884 person-years of follow-up post-transplant (median follow-up 11 years (8.2-15)). This 5.3% fracture prevalence over the median 11-year follow-up period is higher than what would be predicted with FRAX® estimates. Twenty-two patients (6.5%) received antiresorptive therapy, and 9 of 18 (50%) who fractured received or were on antiresorptive therapy. In BMT patients, aBMD and TBS decline rapidly and independently in the first year post BMT. However, FRAX® fracture probability estimates incorporating these values significantly underestimate fracture rates, and antiresorptive treatment rates remain relatively low.

Increased Thyroidal Activity on Routine FDG-PET/CT after Combination Immune Checkpoint Inhibition: Temporal Associations with Clinical and Biochemical Thyroiditis

BACKGROUND

FDG-PET/CT used for immune checkpoint inhibitor (ICI) response assessment can incidentally identify immune-related adverse events (irAEs), including thyroiditis. This study aimed to correlate the time course of FDG-PET/CT evidence of thyroiditis with clinical and biochemical evolution of thyroid dysfunction.

METHODS

A retrospective review was performed by two independent blinded nuclear medicine physicians (NMPs) of thyroidal FDG uptake in 127 patients who underwent PET/CT between January 2016 and January 2019 at baseline and during treatment monitoring of combination ICI therapy for advanced melanoma. Interobserver agreement was assessed and FDG-PET/CT performance defined by a receiver-operating characteristic (ROC) curve using thyroid function tests (TFTs) as the standard of truth. Thyroid maximum standardized uptake value (SUVmax) and its temporal changes with respect to the longitudinal biochemistry were serially recorded.

RESULTS

At a median of 3 weeks after commencing ICI, 43/127 (34%) had a diagnosis of thyroiditis established by abnormal TFTs. FDG-PET/CT was performed at baseline and at a median of 11 weeks (range 3-32) following the start of therapy. ROC analysis showed an area under the curve of 0.87 (95% CI 0.80, 0.94) for FDG-PET/CT for detection of thyroiditis with a positive predictive value of 93%. Among patients with biochemical evidence of thyroiditis, those with a positive FDG-PET/CT were more likely to develop overt hypothyroidism (77% versus 35%, p < 0.01). In the evaluation of the index test, there was an almost perfect interobserver agreement between NMPs of 93.7% (95% CI 89.4-98.0), kappa 0.83.

CONCLUSION

Increased metabolic activity of the thyroid on routine FDG-PET/CT performed for tumoral response of patients undergoing ICI therapy is generally detected well after routine biochemical diagnosis. Elevation of FDG uptake in the thyroid is predictive of overt clinical hypothyroidism and suggests that an ongoing robust inflammatory response beyond the initial thyrotoxic phase may be indicative of thyroid destruction.

Imaging for assessment of cancer treatment response to immune checkpoint inhibitors can be complementary in identifying hypophysitis

Introduction

Hypophysitis is reported in 8.5%-14% of patients receiving combination immune checkpoint inhibition (cICI) but can be a diagnostic challenge. This study aimed to assess the role of routine diagnostic imaging performed during therapeutic monitoring of combination anti-CTLA-4/anti-PD-1 treatment in the identification of hypophysitis and the relationship of imaging findings to clinical diagnostic criteria.

Methods

This retrospective cohort study identified patients treated with cICI between January 2016 and January 2019 at a quaternary melanoma service. Medical records were reviewed to identify patients with a documented diagnosis of hypophysitis based on clinical criteria. Available structural brain imaging with magnetic resonance imaging (MRI) or computed tomography (CT) of the brain and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography with computed tomography (FDG-PET/CT) were assessed retrospectively. The main radiological outcome measures were a relative change in pituitary size or FDG uptake temporally attributed to cICI.

Results

There were 162 patients (median age 60 years, 30% female) included. A total of 100 and 134 had serial CT/MRI of the brain and FDG-PET/CT, respectively. There were 31 patients who had a documented diagnosis of hypophysitis and an additional 20 who had isolated pituitary imaging findings. The pituitary gland enlargement was mild, and the largest absolute gland size was 13 mm, with a relative increase of 7 mm from baseline. There were no cases of optic chiasm compression. Pituitary enlargement and increased FDG uptake were universally transient. High-dose glucocorticoid treatment for concurrent irAEs prevented assessment of the pituitary-adrenal axis in 90% of patients with isolated imaging findings.

Conclusion

Careful review of changes in pituitary characteristics on imaging performed for assessment of therapeutic response to iICI may lead to increased identification and more prompt management of cICI-induced hypophysitis.

A Quantification Method for Disorganized Bone Components: Application to the Femoral Shaft

Based on the current paradigm, a healthy bone is one with adequate mass without microarchitectural decay. However, these two features may not be sufficient to ensure that a bone is healthy. In addition, components must be correctly assembled and aligned. This ensures "the right amount of bone, at the right place" and thus, an optimal cohesion or interplay between constituents. Disorganization may be an independent contributor to bone abnormalities including fragility fractures. Indeed, many bone diseases may be characterized by the presence of disorganized bone, including osteogenesis imperfecta, hypophosphatasia, and atypical femur fractures (AFFs). Despite its likely importance, currently, there are no tools to quantify disorganization in vivo. We address this unmet need by describing a novel method for quantifying bone disorganization from X-ray images. Disorganization is quantified as variations in the orientation of bone components in relation to a target reference point. True disorganization created by disarranging (misplacing) pixels within the bone served as "gold standard." To further validate the method in clinical settings, we compared disorganization in three groups of femurs: (i) femurs of women with AFFs (n = 9); (ii) fracture-free femurs contralateral to AFFs (n = 9); and (iii) fracture-free femurs from controls (n = 25). There was excellent agreement between measured disorganization and "gold standard," with R ² values ranging from 0.84 to 0.99. Precision error ranged from 1.72% to 4.69%. Disorganization produced by abnormalities associated with AFFs was accurately captured. Disorganization level was lowest in fracture-free control femurs, higher in fracture-free contralateral femurs to AFFs, and highest in femurs with AFFs (all p < 0.0001). Quantification of disorganization, a novel biomarker, may provide novel insights into the pathogenesis of metabolic bone diseases beyond that provided by bone mineral density (BMD) or microarchitecture. We provide evidence that measurement of disorganization is likely to help identify patients at risk for fractures, especially in those poorly explained by BMD or microarchitecture such as AFFs. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Acanthosis nigricans in a patient with metastatic insulinoma post peptide receptor radionuclide therapy

Summary

Acanthosis nigricans (AN) is a common dermatosis associated with hyperinsulinemia and insulin resistance. However, AN has been rarely reported in patients with insulinoma, a state of persistent hyperinsulinemia. We present a case of metastatic insulinoma, in whom AN manifested after the first cycle of peptide receptor radionuclide therapy (PRRT). A 40-year-old man was diagnosed with metastatic insulinoma after 5 months of symptomatic hypoglycemia. Within 1 month post PRRT, the patient became euglycemic but developed a pigmented, pruritic rash which was confirmed on biopsy as AN. We discuss the rare manifestation of AN in subjects with insulinoma, the role of insulin in the pathogenesis of AN, malignant AN in non-insulin-secreting malignancies and association with other insulin-resistant endocrinopathies such as acromegaly.

Learning points

Acanthosis nigricans (AN) is a common dermatosis which is typically asymptomatic and associated with the hyperinsulinemic state. Malignant AN can rapidly spread, cause pruritus and affect mucosa and the oral cavity. AN is extremely rare in patients with insulinoma despite marked hyperinsulinemia. Peptide receptor radionuclide therapy might have triggered TGF-α secretion in this subject which led to malignant AN. Rapid spread or unusual distribution of pruritic AN warrants further investigation to exclude underlying malignancy.

Adjudicating Mild Cognitive Impairment Due to Alzheimer's Disease as a Novel Endpoint Event in the TOMMORROW Prevention Clinical Trial

BACKGROUND

The onset of mild cognitive impairment (MCI) is an essential outcome in Alzheimer's disease (AD) prevention trials and a compelling milestone for clinically meaningful change. Determining MCI, however, may be variable and subject to disagreement. Adjudication procedures may improve the reliability of these determinations. We report the performance of an adjudication committee for an AD prevention trial.

METHODS

The TOMMORROW prevention trial selected cognitively normal participants at increased genetic risk for AD and randomized them to low-dose pioglitazone or placebo treatment. When adjudication criteria were triggered, a participant's clinical information was randomly assigned to a three-member panel of a six-member independent adjudication committee. Determination of whether or not a participant reached MCI due to AD or AD dementia proceeded through up to three review stages - independent review, collaborative review, and full committee review - requiring a unanimous decision and ratification by the chair.

RESULTS

Of 3494 participants randomized, the committee adjudicated on 648 cases from 386 participants, resulting in 96 primary endpoint events. Most participants had cases that were adjudicated once (n = 235, 60.9%); the rest had cases that were adjudicated multiple times. Cases were evenly distributed among the eight possible three-member panels. Most adjudicated cases (485/648, 74.8%) were decided within the independent review (stage 1); 14.0% required broader collaborative review (stage 2), and 11.1% needed full committee discussion (stage 3). The primary endpoint event decision rate was 39/485 (8.0%) for stage 1, 29/91 (31.9%) for stage 2, and 28/72 (38.9%) for stage 3. Agreement between the primary event outcomes supported by investigators' clinical diagnoses and the decisions of the adjudication committee increased from 50% to approximately 93% (after around 100 cases) before settling at 80-90% for the remainder of the study.

CONCLUSIONS

The adjudication process was designed to provide independent, consistent determinations of the trial endpoints. These outcomes demonstrated the extent of uncertainty among trial investigators and agreement between adjudicators when the transition to MCI due to AD was prospectively assessed. These methods may inform clinical endpoint determination in future AD secondary prevention studies. Reliable, accurate assessment of clinical events is critical for prevention trials and may mean the difference between success and failure.

Bone microarchitecture and estimated failure load are deteriorated whether patients with chronic kidney disease have normal bone mineral density, osteopenia or osteoporosis

INTRODUCTION

Measurement of bone mineral density (BMD) is recommended in patients with chronic kidney disease (CKD). However, most persons in the community and most patients with CKD have osteopenia, suggesting fracture risk is low. Bone loss compromises bone microarchitecture which increases fragility disproportionate to modest deficits in BMD. We therefore hypothesized that patients with CKD have reduced estimated failure load due to deterioration in microarchitecture irrespective of whether they have normal femoral neck (FN) BMD, osteopenia or osteoporosis.

METHODS

We measured distal tibial and distal radial microarchitecture in 128 patients with CKD and 275 age- and sex-matched controls using high resolution peripheral quantitative computed tomography, FN-BMD using bone densitometry and estimated failure load at the distal appendicular sites using finite element analysis.

RESULTS

Patients versus controls respectively had: lower tibial cortical area 219 (40.7) vs. 237 (35.3) mm², p = 0.002, lower cortical volumetric BMD 543 (80.7) vs. 642 (81.7) mgHA/cm³ due to higher porosity 69.6 (6.19) vs. 61.9 (6.48)% and lower matrix mineral density 64.2 (0.62) vs. 65.1 (1.28)%, lower trabecular vBMD 92.2 (41.1) vs. 149 (43.0) mgHA/cm³ due to fewer and spatially disrupted trabeculae, lower FN-BMD 0.78 (0.12) vs. 0.94 (0.14) g/cm² and reduced estimated failure load 3825 (1152) vs. 5778 (1467) N, all p < 0.001. Deterioration in microarchitecture and estimated failure load was most severe in patients and controls with osteoporosis. Patients with CKD with osteopenia and normal FN-BMD had more deteriorated tibial microarchitecture and estimated failure load than controls with BMD in the same category. In univariate analyses, microarchitecture and FN-BMD were both associated with estimated failure load. In multivariable analyses, only microarchitecture was independently associated with estimated failure load and accounted for 87% of the variance.

CONCLUSIONS

Bone fragility is likely to be present in patients with CKD despite them having osteopenia or normal BMD. Measuring microarchitecture may assist in targeting therapy to those at risk of fracture.

Approach to Interpreting Common Laboratory Pathology Tests in Transgender Individuals

CONTEXT

As the number of transgender (trans) people (including those who are binary and/or nonbinary identified) seeking gender-affirming hormone therapy rises, endocrinologists are increasingly asked to assist with interpretation of laboratory tests. Many common laboratory tests such as hemoglobin, iron studies, cardiac troponin, and creatinine are affected by sex steroids or body size. We seek to provide a summary of the impact of feminizing and masculinizing hormone therapy on common laboratory tests and an approach to interpretation.

CASES

Case scenarios discussed include 1) hemoglobin and hematocrit in a nonbinary person undergoing masculinizing hormone therapy; 2) estimation of glomerular filtration rate in a trans woman at risk of contrast-induced nephropathy; 3) prostate-specific antigen (PSA) in a trans woman; and 4) chest pain in a trans man with a cardiac troponin concentration between the reported male and female reference ranges.

CONCLUSIONS

The influence of exogenous gender-affirming hormone therapy on fat and muscle distribution and other physiological changes determines interpretation of laboratory tests that have sex-specific differences. In addition to affirmative practice to ensure a patient's name, gender, and pronoun are used appropriately, we propose that once individuals have commenced gender-affirming hormone therapy, the reference range of the affirmed gender be reported (and specified by treating clinicians) except for PSA or cardiac troponin, which are dependent on organ size. While suggestions may be challenging to implement, they also represent an opportunity to lead best practice to improve the quality of care and experiences of healthcare for all trans people.

Approach to Interpreting Common Laboratory Pathology Tests in Transgender Individuals

CONTEXT

As the number of transgender (trans) people (including those who are binary and/or nonbinary identified) seeking gender-affirming hormone therapy rises, endocrinologists are increasingly asked to assist with interpretation of laboratory tests. Many common laboratory tests such as hemoglobin, iron studies, cardiac troponin, and creatinine are affected by sex steroids or body size. We seek to provide a summary of the impact of feminizing and masculinizing hormone therapy on common laboratory tests and an approach to interpretation.

CASES

Case scenarios discussed include 1) hemoglobin and hematocrit in a nonbinary person undergoing masculinizing hormone therapy; 2) estimation of glomerular filtration rate in a trans woman at risk of contrast-induced nephropathy; 3) prostate-specific antigen (PSA) in a trans woman; and 4) chest pain in a trans man with a cardiac troponin concentration between the reported male and female reference ranges.

CONCLUSIONS

The influence of exogenous gender-affirming hormone therapy on fat and muscle distribution and other physiological changes determines interpretation of laboratory tests that have sex-specific differences. In addition to affirmative practice to ensure a patient's name, gender, and pronoun are used appropriately, we propose that once individuals have commenced gender-affirming hormone therapy, the reference range of the affirmed gender be reported (and specified by treating clinicians) except for PSA or cardiac troponin, which are dependent on organ size. While suggestions may be challenging to implement, they also represent an opportunity to lead best practice to improve the quality of care and experiences of healthcare for all trans people.

Troponin least significant change (z-score) is associated with poor clinical outcomes in patients presenting to the emergency department

BACKGROUND

A rise and/or fall in high sensitivity cardiac troponin (hs-Tn) is critical in defining acute myocardial injury and therefore the diagnosis of acute myocardial infarction. A significant rise in hs-Tn is not well defined in current guidelines. Calculation of a z-score for two consecutive hs-Tn measurements is a method-independent measure of dynamic troponin elevation. However, the association of hs-Tn z-score with outcomes for unselected emergency department admissions is unknown. Moreover, the association of non-dynamic troponin elevations, as defined by a normal z-score, with clinical outcomes remains to be assessed.

METHODS

We retrospectively calculated z-scores for patients presenting to emergency department over 18 months who had serial troponin measurements with at least one result >99th percentile using the Abbott hs-TnI assay. We assessed the association of z-score with discharge diagnosis, cardiac interventions, inpatient mortality, length of stay and readmission rates.

RESULTS

There were 2062 presentations for 1830 patients where a z-score was calculated. Z-score was elevated in 1080 presentations. Dynamic troponin elevation (z-score ≥ 2) was associated with acute myocardial infarction (OR = 9.1, P < 0.01), admission to an inpatient unit (95 vs. 88%, P < 0.01), increased inpatient length of stay (97 vs. 65 days, P < 0.01), inpatient coronary intervention (21 vs. 6%, P < 0.01) and mortality (4.4 vs. 2.4%, P < 0.05) compared with myocardial injury with a static troponin elevation.

CONCLUSIONS

Z-score is an assay-independent tool to alert clinicians of significant, dynamic troponin elevation and acute myocardial injury. It is associated with poorer clinical outcomes.

Performance of the ESC 0/1-hour algorithm for diagnosis of myocardial infarction: systematic review and meta-analysis

Background

The European Society of Cardiology (ESC) 0/1-hour algorithm has been recommended for early rule-out and rule-in of non ST-segment elevation acute coronary syndromes. This algorithm has primarily been validated in Europe, America, and Australasia, with less knowledge of its performance outside of these settings.

Purpose

We aim to conduct a systematic review and meta-analysis to evaluate the performance of the ESC 0/1-hour algorithm across different contexts.

Methods

We searched PubMed, Embase, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials for relevant studies published between 1 January 2008 and 31 May 2019. The primary outcome was index myocardial infarction and the secondary outcome was major adverse cardiac event or mortality. A bivariate random-effects meta-analysis was used to derive the pooled estimate of each outcome.

Results

A total of 11,014 patients from 10 cohorts were included in this meta-analysis. The algorithm based on hs-cTnT (Roche), hs-cTnI (Abbott), and hs-cTnI (Siemens) had pooled sensitivity of 98.4% [95% CI=95.1%-99.5%], 98.1% [95% CI=94.6%-99.3%], and 98.7% [95% CI=97.3%-99.3%], respectively. The algorithm based on hs-cTnT (Roche) and hs-cTnI (Siemens) had pooled specificity of 91.2% [95% CI=86.0%-94.6%] and 95.9% [95% CI=94.1%-97.2%], respectively. Among patients in the rule-out category, the pooled mortality rate at 30 days and at 1 year was 0.1% [95% CI=0.0%-0.4%] and 0.8% [95% CI=0.5%-1.2%], respectively. Among patients in the observation zone, the pooled mortality rate was 0.7% [95% CI=0.3%-1.2%] at 30-days but increased to 8.1% [95% CI=6.1%-10.4%] at 1-year, comparable to the mortality rate in the rule-in group.

Conclusion

Our results support the use of the 0/1-hour algorithm to triage patients with suspected non-ST segment elevation acute coronary syndromes. However, the algorithm may not be sufficiently safe if the 1% miss-rate for myocardial infarction is desired. Patients in the observation zone have a poor prognosis and management strategies for these patients are urgently needed.

Performance of the 0/1-hour algorithm

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Ministry of Science and Technology, R.O.C

Performance of the ESC 0/3-hour algorithm for rapid triage of myocardial infarction: systematic review and meta-analysis

Objective

The European Society of Cardiology (ESC) 0/3-hour algorithm is one of the most widely strategies used for rule-out or rule-in of acute myocardial infarction (AMI). However, a systematic evaluation of its performance has not been conducted. Furthermore, recent studies showed that the 0/3-hour algorithm is non-superior to the 0/1-hour algorithm.

Purpose

This study aims to summarize the safety and efficacy of the 0/3-hour algorithm and its comparative performance with the 0/1-hour algorithm.

Methods

We conducted literature search on PubMed, Embase, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials for studies published between 1 January 2008 and 31 May 2019. A bivariate random-effects meta-analysis was used to estimate the primary and secondary outcomes, defined as index myocardial infarction and triage efficacy, major adverse cardiac event (MACE) or mortality at 30 days, respectively.

Results

A total of 10,832 patients from 9 studies with a pooled AMI prevalence of 16% were analyzed. The 0/3-hour algorithm ruled out 69% of the patients with a pooled sensitivity of 94.2% [95% CI: 87.6%–97.4%] and negative predictive value of 98.6% [95% CI: 97.0%–99.4%]; 17% of the patients were ruled in with a pooled specificity of 94.9% [95% CI: 88.6%–97.8%] and positive predictive value of 72.9% [95% CI: 54.6%–85.7%]. The 30-day mortality and 30-day MACE for patients that were ruled out were 0.0% [95% CI: 0.0%–0.0%] and 1.4% [95% CI: 0.9%–2.0%], respectively. In a pooled analysis of 3 cohorts, the 0/3-hour algorithm had a non-superior sensitivity compared with the 0/1-hour algorithm (94.4% [95% CI: 87.0%–97.7%] vs. 98.4% [95% CI: 95.4%–99.7%]). The 0/3-hour algorithm also had a similar rule-out efficacy compared with the 0/1-hour algorithm (52% [95% CI: 39%–65%] vs. 53% [95% CI: 42%–64%]).

Conclusion

The widely used 0/3-hour algorithm has sensitivity substantially below the consensus goal of 99% and may not be sufficiently safe for triage of myocardial infarction. Furthermore, the 0/3-hour algorithm is not superior to the 0/1-hour algorithm despite the additional triage time.

Performance of ESC 0/3-hour algorithm

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Taiwan National Ministry of Science and Technology Grants

Utility of adrenocorticotropic hormone in adrenal vein sampling despite the occurrence of discordant lateralization

BACKGROUND

Adrenal vein sampling (AVS) is crucial for accurate lateralization of aldosterone excess but it is technically challenging due to the difficulty of adrenal vein cannulation. The use of adrenocorticotropic hormone (ACTH) to improve cannulation success is controversial and can lead to discordant lateralization outcomes.

OBJECTIVE

To evaluate the utility of ACTH in two centres with different levels of AVS expertise and formulate a strategy for interpreting discordant results.

DESIGN

A retrospective cross-sectional analysis of AVS results and postoperative patient outcomes.

SETTING

Two large tertiary hospitals with harmonized AVS protocols where adrenal venous samples are collected both before and after ACTH stimulation.

MEASUREMENTS

Cannulation success (measured by selectivity index, SI), lateralization (measured by lateralization index, LI) and postoperative biochemical cure.

RESULTS

Number of AVS procedures judged to have successful bilateral adrenal vein cannulation increased from 53% pre- to 73% post-ACTH. The increase in cannulation success was significantly higher in centre where AVS was performed by multiple radiologists with a lower basal success rate. In both centres, the proportion of cases deemed to display lateralization significantly decreased with the use of ACTH (70% pre- to 52% post-ACTH). Based on postoperative outcomes of patients with discordant results who underwent unilateral adrenalectomy, the combination of LI >3 pre-ACTH and LI >2 post-ACTH was predictive of a biochemical cure.

CONCLUSION

Adrenocorticotropic hormone can increase the rate of cannulation success during AVS at the expense of reduced lateralization. The criteria for lateralization should be carefully determined based on local data when ACTH is used.

MON-270 Diagnostic Value of Copeptin in Central Diabetes Insipidus

Background: The diagnosis of diabetes insipidus (DI) relies on indirect measurement of serum and urine sodium and osmolality. Since the diagnosis can only be made when an inappropriately dilute urine is paired with a significantly concentrated serum, the process is tedious for the clinician and uncomfortable for the patient. Copeptin is the C-terminal portion of the anti-diuretic hormone (ADH) prohormone which correlates with the less stable ADH, therefore providing a direct measurement of posterior pituitary response to hyperosmolar stress. (1,2)

Aim: This study aims to assess the diagnostic accuracy of copeptin in patients with central DI compared with subjects who underwent pituitary surgery without developing DI.

Methods: Serum samples from subjects with central DI, control subjects post pituitary surgery with no DI (NDI) and control subjects with SIADH were collected and analysed on the BRAHMS KRYPTOR copeptin assay. Groups were compared using unpaired T-test and Levene’s test for equal variance.

Results: 56 samples from 22 subjects (13 females, 9 males, mean age 53.9 ± 15.5 y.o.) were analysed. Two subjects had resolved DI (RDI) after copeptin analysis and were successfully weaned off DDAVP and reclassified as NDI. Of the DI subjects, 1 had acute and 5 had chronic DI. Copeptin was lower in DI compared to NDI group (p = 0.013), while serum sodium, osmolality, urine osmolality were similar. Copeptin did not differentiate between the SIADH and NDI groups. After exclusion of NDI samples with serum sodium ≤ 140 mmol/L, the area under the curve was 0.97 (95% CI 0.9 to 1.0), a copeptin cut-off of 2.9 pmol/L predicts DI with a sensitivity of 92% and a specificity of 90%.

Conclusion: Copeptin concentration of &lt; 3.0 pmol/L concurrently with serum sodium concentration of &gt; 140mmol/L predicted central DI when using post pituitary surgery subjects without DI as controls.

1. Winzeler, B., Zweifel, C., Nigro, N., Arici, B., Bally, M., Schuetz, P., Blum, C., Kelly, C., Berkmann, S., Huber, A., Gentili, F., Zadeh, G., Landolt, H., Mariani, L., Müller, B. and Christ-Crain, M. (2015). Postoperative Copeptin Concentration Predicts Diabetes Insipidus After Pituitary Surgery. The Journal of Clinical Endocrinology & Metabolism, 100(6), pp.2275-2282.

2. Fenske, J., Refardt, I., SchnyderI., Winzeler, B., Drummond J., Ribeiro-Oliveira, Jr. A., Drescher, T., Bilz S., Vogt, D.R., Malzahn, U., Kroiss, M., Christ, E., Henzen, C., Fischli S., Tönjes, A., Mueller, B., Schopohl, J., Flitsch, J., Brabant, G., Fassnacht M., Christ-Crain, M. (2018). Copeptin in the Diagnosis of Diabetes Insipidus. New England Journal of Medicine, 379(18), pp.1784-1786.

Quantifying Use of a Health Virtual Community of Practice for General Practitioners' Continuing Professional Development: A Novel Methodology and Pilot Evaluation

Background

Health care practitioners (HPs), in particular general practitioners (GPs), are increasingly adopting Web-based social media platforms for continuing professional development (CPD). As GPs are restricted by time, distance, and demanding workloads, a health virtual community of practice (HVCoP) is an ideal solution to replace face-to-face CPD with Web-based CPD. However, barriers such as time and work schedules may limit participation in an HVCoP. Furthermore, it is difficult to gauge whether GPs engage actively or passively in HVCoP knowledge-acquisition for Web-based CPD, as GPs’ competencies are usually measured with pre- and posttests.

Objective

This study investigated a method for measuring the engagement features needed for an HVCoP (the Community Fracture Capture [CFC] Learning Hub) for learning and knowledge sharing among GPs for their CPD activity.

Methods

A prototype CFC Learning Hub was developed using an Igloo Web-based social media software platform and involved a convenience sample of GPs interested in bone health topics. This Hub, a secure Web-based community site, included 2 key components: an online discussion forum and a knowledge repository (the Knowledge Hub). The discussion forum contained anonymized case studies (contributed by GP participants) and topical discussions (topics that were not case studies). Using 2 complementary tools (Google Analytics and Igloo Statistical Tool), we characterized individual participating GPs’ engagement with the Hub. We measured the GP participants’ behavior by quantifying the number of online sessions of the participants, activities undertaken within these online sessions, written posts made per learning topic, and their time spent per topic. We calculated time spent in both active and passive engagement for each topic.

Results

Seven GPs participated in the CFC Learning Hub HVCoP from September to November 2017. The complementary tools successfully captured the GP participants’ engagement in the Hub. GPs were more active in topics in the discussion forum that had direct clinical application as opposed to didactic, evidence-based discussion topics (ie, topical discussions). From our knowledge hub, About Osteoporosis and Prevention were the most engaging topics, whereas shared decision making was the least active topic.

Conclusions

We showcased a novel complementary analysis method that allowed us to quantify the CFC Learning Hub’s usage data into (1) sessions, (2) activities, (3) active or passive time spent, and (4) posts made to evaluate the potential engagement features needed for an HVCoP focused on GP participants’ CPD process. Our design and evaluation methods for ongoing use and engagement in this Hub may be useful to evaluate future learning and knowledge-sharing projects for GPs and may allow for extension to other HPs’ environments. However, owing to the limited number of GP participants in this study, we suggest that further research with a larger cohort should be performed to validate and extend these findings.

Polyuria-polydipsia syndrome: a diagnostic challenge

The main determinants for the maintenance of water homeostasis are the hormone arginine vasopressin (AVP) and thirst. Disturbances in these regulatory mechanisms can lead to polyuria-polydipsia syndrome, which comprises of three different conditions: central diabetes insipidus (DI) due to insufficient secretion of AVP, nephrogenic DI caused by renal insensitivity to AVP action and primary polydipsia due to excessive fluid intake and consequent physiological suppression of AVP. It is crucial to determine the exact diagnosis because treatment strategies vary substantially. To differentiate between the causes of the polyuria-polydipsia syndrome, a water deprivation test combined with desmopressin administration is the diagnostic 'gold standard'. Thereby, AVP activity is indirectly evaluated through the measurement of urine osmolality after prolonged dehydration. However, this test has several limitations and may fail to distinguish precisely between patients with primary polydipsia and mild forms of central and nephrogenic DI. The direct measurement of AVP during the water deprivation test, which was reported in the 1980s, has not been widely adopted due to availability, assay issues and diagnostic performance. Recently, copeptin, the c-terminal portion of the larger precursor peptide of AVP, has been evaluated in the setting of polyuria-polydipsia syndrome and appears to be a useful candidate biomarker for the differential diagnosis. A standardised method for the water deprivation test is presented as part of a joint initiative of the Endocrine Society of Australia, the Australasian Association of Clinical Biochemists and the Royal College of Pathologists of Australasia to harmonise dynamic endocrine tests across Australia.

Diabetes associated with immune checkpoint inhibition: presentation and management challenges

BACKGROUND

In recent years, immune checkpoint blockade has become a standard therapy for a wide range of cancers. Adverse events including endocrinopathies result from the induction of autoimmunity.

CASE REPORT

We report a case series of nine individuals who presented with immunotherapy-induced type 1 diabetes between 2015-2017.

DISCUSSION

Onset of diabetes occurred within 12 weeks of commencing therapy. Anti- GAD antibodies were present in six people. Retrospective testing of islet antibodies in pre-treatment samples was possible in two people and this revealed anti-GAD seroconversion in the first and high anti-GAD titres pre and post-treatment in the second person. Six people had high risk HLA haplotypes. Clinical and genetic factors are described and compared with previously published cases. This article is protected by copyright. All rights reserved.

The use of bone turnover markers in chronic kidney disease-mineral and bone disorders

Bone turnover markers assist in fracture risk prediction, management and monitoring of osteoporosis in patients without chronic kidney disease (CKD). The use in CKD-mineral bone disorder (MBD) has been limited as many of these markers and breakdown products are renally excreted, including the most commonly used and well standardized procollagen type I N propeptide and C-terminal cross-linking telopeptide of type I collagen. Of the markers unaffected by renal function, bone specific alkaline phosphatase is associated with mortality and fracture rate in CKD subjects and is now available on several automated analysers. When used in combination with PTH, bone specific alkaline phosphatase as a bone formation marker correlated well with bone biopsy histomorphometry in predicting adynamic bone disease. Tartrate-resistant acid phosphatase 5b is a resorption marker that is under development for automation. Both high and low bone turnover in CKD-MBD patients are associated with increased fracture and mortality risk. Bone biopsy as the gold standard to differentiate between adynamic bone disease and osteitis fibrosa is limited by availability and cost. Appropriate use of bone turnover markers is vital in the decision to commence anti-resorptive agents, and to monitor efficacy in order to avoid over suppression of bone turnover, which may lead to stress fractures. Further efforts are required to develop markers unaffected by renal function with standardized cut-off values and fracture as well as vascular calcification end-points.

Serum 25-Hydroxyvitamin D Insufficiency in Search of a Bone Disease

CONTEXT

Vitamin D "insufficiency" and "deficiency" are defined as serum 25-hydroxyvitamin D [25(OH)D] levels <75 and <30 nmol/L, respectively. We aimed to determine whether these values signal hypocalcemia and hypophosphatemia, secondary hyperparathyroidism, high bone remodeling, low areal bone mineral density (aBMD), microstructural deterioration, or reduced matrix mineralization density (MMD) and so suggest whether bone fragility is present.

METHODS

Concentrations of 25(OH)D, calcium, phosphate, creatinine, and parathyroid hormone (PTH) were measured in 11,855 participants. Serum C-terminal telopeptide of type 1 collagen, procollagen type 1 N-terminal propeptide (P1NP), aBMD, and distal radius microstructure and MMD were measured in a second subset of 150 participants.

RESULTS

A breakpoint for calcium, PTH, and alkaline phosphatase was identified at a threshold 25(OH)D level <30 nmol/L. There was no plateau beyond 75 nmol/L. In the subgroup with measurements of bone morphology, no associations were detectable between serum 25(OH)D concentration, aBMD, trabecular density, cortical porosity, or MMD. Among 1439 participants with serum 25(OH)D <30 nmol/L, 6.1% had low serum calcium, 3.4% had low serum phosphate, 6.1% had high alkaline phosphatase, and 34.2% had elevated PTH. Most participants did not have any abnormalities.

CONCLUSION

At a 25(OH)D threshold of ≤30 nmol/L, abnormalities in biochemical features support the notion of a "deficiency" state predisposing to bone disease. However, no deleterious effects were found in participants within an insufficiency threshold of a 25(OH)D level of 30 to 75 nmol/L, which challenges the rationale justifying vitamin D supplementation in these individuals.

Long-term weight-change slope, weight fluctuation and risk of type 2 diabetes mellitus in middle-aged Japanese men and women: findings of Aichi Workers' Cohort Study

OBJECTIVE

This study aims to investigate the association of long-term weight-change slopes, weight fluctuation and the risk of type 2 diabetes mellitus (T2DM) in middle-aged Japanese men and women.

METHODS

A total of 4234 participants of Aichi Workers' Cohort Study who were aged 35-66 years and free of diabetes in 2002 were followed through 2014. Past body weights at the ages of 20, 25, 30, 40 years, and 5 years before baseline as well as measured body weight at baseline were regressed on the ages. Slope and root-mean-square-error of the regression line were obtained and used to represent the weight changes and the weight fluctuation, respectively. The associations of the weight-change slopes and the weight fluctuation with incident T2DM were estimated by Cox proportional hazards models.

RESULTS

During the median follow-up of 12.2 years, 400 incident cases of T2DM were documented. After adjustment for baseline overweight and other lifestyle covariates, the weight-change slopes were significantly associated with higher incidence of T2DM (hazard ratio (HR): 1.80, 95% confident interval (CI): 1.17-2.77 for men; and HR: 2.78, 95% CI: 1.07-7.23 for women), while the weight fluctuation was not (HR: 1.08, 95% CI: 1.00-1.18 for men and HR: 1.02, 95% CI: 0.84-1.25 for women).

CONCLUSIONS

Regardless of the presence of overweight, the long-term weight-change slopes were significantly associated with the increased risk of T2DM; however, the weight fluctuation was not associated with the risk of T2DM in middle-aged Japanese men and women.