Ten-year territory-wide trends in the utilisation and clinical outcomes of extracorporeal membrane oxygenation in Hong Kong

INTRODUCTION

The utilisation of extracorporeal membrane oxygenation (ECMO) has been rapidly increasing in Hong Kong. This study examined 10-year trends in the utilisation and clinical outcomes of ECMO in Hong Kong.

METHODS

We retrospectively reviewed the records of all adult patients receiving ECMO who were admitted to the intensive care units (ICUs) of public hospitals in Hong Kong between 2010 and 2019. Temporal trends across years were assessed using the Mann-Kendall test. Observed hospital mortality was compared with the Acute Physiology and Chronic Health Evaluation (APACHE) IV-predicted mortality.

RESULTS

The annual number of patients receiving ECMO increased from 18 to 171 over 10 years. In total, 911 patients received ECMO during the study period: 297 (32.6%) received veno-arterial ECMO, 450 (49.4%) received veno-venous ECMO, and 164 (18.0%) received extracorporeal cardiopulmonary resuscitation. The annual number of patients aged ≥65 years increased from 0 to 47 (27.5%) [P for trend=0.001]. The median (interquartile range) Charlson Comorbidity Index increased from 1 (0-1) to 2 (1-3) [P for trend<0.001] while the median (interquartile range) APACHE IV score increased from 90 (57-112) to 105 (77-137) [P for trend=0.003]. The overall standardised mortality ratio comparing hospital mortality with APACHE IV-predicted mortality was 1.11 (95% confidence interval=1.01-1.22). Hospital and ICU length of stay both significantly decreased (P for trend=0.011 and <0.001, respectively).

CONCLUSION

As ECMO utilisation increased in Hong Kong, patients put on ECMO were older, more critically ill, and had more co-morbidities. It is important to combine service expansion with adequate resource allocation and training to maintain quality of care.

Outcomes of patients with high bleeding risks characteristics presenting with acute coronary syndrome undergoing percutaneous coronary intervention

Background

Patients with high bleeding risk characteristics (HBR) presenting with acute coronary syndrome (ACS) pose a clinical challenge to balance risk for recurrent ischemic events versus incurring bleeding with dual antiplatelet therapy.

Purpose

We seek to determine the incidence and predictors of short and long term ischemic and bleeding outcomes in patients with HBR factors presenting with ACS after percutaneous coronary intervention (PCI).

Method

Consecutive patients over a 1-year period, who underwent PCI for ACS were categorized as having HBR based on: age ≥75, anemia (hemoglobin&lt;110g/L), thrombocytopenia (platelet&lt;100x109/L), renal failure (eGFR&lt;30umol/L) or concurrent use of oral anticoagulation. Primary outcome was major adverse cardiovascular event (MACE) defined as composite of cardiovascular death, myocardial infarction, and stroke at 1 year. Key secondary outcomes include significant bleeding defined as Bleeding Academic Research Consortium (BARC) type 3 or 5, and net adverse cardiovascular event (NACE), as a composite of MACE and significant bleeding.

Results

Of 1351 patients presented with ACS, 389 (28.8%) had at least one HBR criteria. At 1 year, patients with HBR, compared to those without, had increased MACE (11.1% vs 4.2%, p&lt;0.001) and cardiovascular death (5.7% vs 1.7%, p&lt;0.001). Patients with HBR had increased significant bleeding (3.6% vs 2.3%, p=0.011) and NACE (14.4% vs 5.4%, p&lt;0.001). Multivariate analysis showed the presence of HBR and prior history of myocardial infarction were predictors for 1-year MACE (OR 2.67, CI [1.62–4.42], p&lt;0.001 and OR 2.18, CI [1.29–3.70], p=0.004, respectively), whereas the use of second-generation antiplatelet agent was not. Increased MACE and NACE were observed in HBR patients beyond 1 month of DAPT.

Conclusion

Among patients with ACS undergoing PCI, those with HBR had higher risk for both ischemic and bleeding complications. Novel strategies need to be considered for this high-risk group. Current guidelines, recommending 1 year of DAPT for patients with ACS, should be re-evaluated among patients with HBR.

Funding Acknowledgement

Type of funding sources: None. Kaplan-Meier curve for 1 year MACEKaplan-Meier curve for 1 year death

Admission triage tool for adult intensive care unit admission in Hong Kong during the COVID-19 outbreak

Intensive care is expensive, and the numbers of intensive care unit (ICU) beds and trained specialist medical staff able to provide services in Hong Kong are limited. The most recent increase in coronavirus disease 2019 (COVID-19) infections over July to August 2020 resulted in more than 100 new cases per day for a prolonged period. The increased numbers of critically ill patients requiring ICU admission posed a capacity challenge to ICUs across the territory, and it may be reasonably anticipated that should a substantially larger outbreak occur, ICU services will be overwhelmed. Therefore, a transparent and fair prioritisation process for decisions regarding patient ICU admission is urgently required. This triage tool is built on the foundation of the existing guidelines and framework for admission, discharge, and triage that inform routine clinical practice in Hospital Authority ICUs, with the aim of achieving the greatest benefit for the greatest number of patients from the available ICU resources. This COVID-19 Crisis Triage Tool is expected to provide structured guidance to frontline doctors on how to make triage decisions should ICU resources become overwhelmed by patients requiring ICU care, particularly during the current COVID-19 pandemic. The triage tool takes the form of a detailed decision aid algorithm based on a combination of established prognostic scores, and it should increase objectivity and transparency in triage decision making and enhance decision-making consistency between doctors within and across ICUs in Hong Kong. However, it remains an aid rather than a complete substitute for the carefully considered judgement of an experienced intensive care clinician.

Transitioning a randomized controlled trial to a digital registry – experience from the TAILOR-PCI digital follow-up study on onboarding, engagement and geofencing consent rate

Background/Introduction

TAILOR-PCI is the largest cardiovascular genotype-based randomized trial (NCT#01742117) investigating whether genotype-guided selection of oral P2Y12 inhibitor therapy improves ischemic outcomes after percutaneous coronary intervention (PCI). The TAILOR-PCI Digital Sub-Study tests the feasibility of extending original follow-up of 1 year to 2 years using state-of-the-art digital solutions. Deep phenotyping acquired during a clinical trial can be leveraged by extending follow-up in an efficient and cost-effective manner using digital technology.

Purpose

Our objective is to describe onboarding and engagement of participants initially recruited in a large, pragmatic, international, multi-center clinical trial to a digital registry.

Methods

TAILOR-PCI participants, within 23 months of their index PCI, were invited by letters containing a URL to the Digital Sub-Study website (http://tailorpci.eurekaplatform.org). These invitations were followed by phone calls, if no response to the letter, to determine reason for non-participation. A NIH-funded direct-to-participant digital research platform (the Eureka Research Platform) was used to onboard, consent and enroll participants for the digital follow-up. Participants were asked to answer health-related surveys at fixed intervals using the Eureka mobile app and desktop platform. To capture hospitalizations, participants could enable geofencing to allow background location tracking, which triggered surveys if a hospitalization was detected.

Result(s)

Letters were mailed to 893 of 929 eligible participants across 22 sites in the United States and Canada leading to 226 homepage visits and 118 registrations. There were 107 consents (12.0% of invited; mean age: 66.4±9.0; 19 females [18%]): 47 (44%) participants consented after the letter, 36 (34%) consented after the 1st call and 24 (22%) consented after a 2nd call. Among those who consented, 100 were eligible (7 did not have a smartphone) 81 downloaded the study mobile app and 73 agreed for geofencing (Figure 1). Among the 722 invited participants who were surveyed, 354 declined participation: due to lack of time (146; 20.2%), lack of smartphone (125; 17.3%), difficulty understanding (41; 5.7%), concern about using smartphone (34; 4.7%), concern of data privacy (14; 1.9%), concerns of location tracking (6; 0.8%) and other reasons (57; 7.9%).

Conclusion

Extended follow-up of a clinical trial using a digital platform is feasible but uptake in this study population was limited largely due to lack of time or a smartphone among participants. Based on data from other digital studies, uptake may also have been limited since digital follow-up consent was not incorporated at the time of consent for the main trial.

Figure 1. Onboarding of the digital substudy

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institute of Health (NIH), National Heart, Lung, and Blood Institute (NHLBI)

Comparing clinical outcomes following 1 year of dual antiplatelet therapy in patients risk stratified by the PRECISE-DAPT and DAPT scores

Background

Dual antiplatelet therapy (DAPT) is the standard of care following PCI. DAPT reduces ischemic events but increases bleeding risk. Duration of DAPT following PCI remains controversial. Current guidelines recommend duration be individualized based on risk of ischemia and bleeding. Although multiple strategies exist to risk stratify patients, including application of the PRECISE-DAPT and DAPT scores, there is currently no standardized risk assessment protocol.

Purpose

To determine if the PRECISE-DAPT and DAPT scores can identify patients at increased risk of ischemia or bleeding in a cohort prescribed 12 months of DAPT following PCI.

Methods

We calculated the PRECISE-DAPT and DAPT scores for 469 consecutive patients at baseline after PCI. Patients were grouped based on score treatment recommendation; PRECISE-DAPT prolonged or shortened (PRECISE DAPT &lt;25 vs. ≥25) and DAPT prolonged or shortened (DAPT ≥2 vs &lt;2). End points included 1-year rates of major adverse cardiovascular events (MACE) and TIMI major or minor bleeding.

Results

Among 469 patients, mean age was 64.4 (SD 12.2); 102 (21.7%) were women. Index presentation consisted of a STEMI in 207 (44.1%), NSTEMI in 99 (21.1%), and UA in 60 (12.8%). At presentation, 174 (37.1%) were current smokers, 115 (24.5%) had a prior MI, 118 (25.2%) had diabetes, 249 (53.1%) had dyslipidemia and 281 (60.0%) were previously diagnosed as hypertensive. Overall, there was an increase in bleeding and no difference in MACE for patients with a PRECISE-DAPT score ≥25 (13.3% vs. 4.1% P&lt;0.001). No difference in bleeding or MACE was present in patients stratified by the DAPT score.

Conclusion

A PRECISE-DAPT score ≥25 was associated with an increased rate of bleeding and no difference in MACE in patients prescribed 12 months of DAPT. This supports the use of the PRECISE-DAPT as a prospective tool in clinical practice.

Funding Acknowledgement

Type of funding source: None

P1933Comparing treatment recommendations for the DAPT and PRECISE-DAPT scores after percutaneous coronary intervention

Background

Dual antiplatelet therapy (DAPT), with aspirin and a P2Y12 inhibitor, is the standard therapy for patients following PCI. Duration of treatment with DAPT has been controversial despite large studies. Current guidelines recommend treatment duration be individualized based on risk of ischemia and bleeding. To facilitate treatment decisions, risk assessment tools, including the DAPT and PRECISE-DAPT scores, have been developed.

Purpose

As components of these scores differ, the variability of recommendation remains unknown. We set to evaluate inter-tool concordance in treatment recommendation in a cohort of patients after PCI.

Methods

Using data from our local PCI registry, we calculated the PRECISE-DAPT at baseline following PCI and the DAPT after 1 year of treatment for 311 consecutive patients with complete data for both scores to be calculated. Based on their DAPT and PRECISE-DAPT scores, patients were grouped into concordant for long-term treatment (DAPT ≥2 and PRECISE-DAPT <25) or concordant for shortened treatment (DAPT <2 and PRECISE- DAPT ≥25). All other patients were considered discordant. We then performed a concordance analysis using Cohen's kappa to measure degree of agreement.

Results

Among the 311 patients, mean age was 63.4 (SD 11.6); 245 (79%) were men, 93 (29.9%) had history of a prior MI, 130 (41.8%) were current smokers, 32 (10.3%) had a history of CHF or LVEF <30%, 82 (26.3%) had diabetes and 196 (63.0%) were previously diagnosed with hypertension. Index event consisted of a STEMI in 101 (32.4%), NSTEMI in 93 (29.9%), unstable angina in 27 (8.7%), stable angina in 67 (21.5%) and the remaining 23 (7.4%) had other indications for PCI. Mean DAPT score was 1.52 (SD 1.37). Mean PRECISE-DAPT was 17.65 (SD 12.73). The DAPT recommended long-term treatment for 162 (52.1%) and shortened treatment for 149 (47.9%). The PRECISE-DAPT recommended long-term treatment for 245 (78.9%) and shortened treatment for 66 (21.2%). The overall proportion of agreement between the two risk scores was 56.6% with a Cohen's kappa index of 0.110 (95% CI, 0.017 to 0.204). See Table.

Concordance Analysis PRECISE-DAPT Score Recommendation Long Term (N=245) Shortened (N=66) DAPT Score Recommendation Long Term (N=162) 136 (43.7%) 26 (8.4%) Concordant for Long Term Treatment Shortened (N=149) 109 (35%) 40 (12.8%) Concordant for Shortened Treatment

Conclusion

Comparison of the DAPT score and the PRECISE-DAPT score showed concordance in treatment recommendation in only 56.6% of patients. Given the poor agreement between these tools, prospective concurrent evaluations and correlation to outcomes will be required in future studies.

Abstract 478: Small Molecule ICG-001, Sodium Butyrate, and Retinoic Acid Enhanced Direct Cardiac Reprogramming of Induced Cardiomyocytes (iCMs)

Background: Reprogramming of cardiac fibroblasts into induced cardiomyocyte-like cells (iCMs) in situ represents a promising strategy for cardiac regeneration. A combination of three cardiac transcription factors Gata4, Mef2c and Tbx5 (GMT), and microRNAs can convert fibroblasts into iCMs, albeit with low efficiency in vitro . We aimed to increase the efficiency, maturation and speed of direct reprogramming using a unique combination of small molecules, in combination with previously identified reprogramming transcription factors, that we selected and combined in a cocktail specifically formulated to effect optimal impact on the aspects of reprogramming pathways thought to represent “roadblocks” or points of opportunity in these pathways.

Methods: We screened a variety of such candidate compounds in primary rat/human cardiac fibroblast. Cardiac reprogramming was induced by lentivirus encoding Gata4, Mef2c and Tbx5 plus small molecules, and the presence of iCM was confirmed 10 days later by QRT-PCR, IFs and FACS analysis for the activation of endogenous cardiac troponin T (cTnT).

Results: After validating and optimizing the dose and conditions for adding small molecules to the reprogramming cocktail, we treated GMT-overexpressing fibroblast with a combination of sodium butyrate (SB, 1mM; HDAC inhibitor), ICG-001(1μM; WNT inhibitor), and retinoic acid (RA, 1μM). We found that that a combination of SB, ICG-001, and RA significantly increased GMT-induced reprogramming efficiency to 22 % cTnT + iCMs from primary rat cardiac fibroblasts compared to 8% in the presence of single compounds and 3.5% without any added small molecule compound alone. QRT-PCR and IFs, analysis shows that a combination of the SB, ICG-001, and RA increased cTnT gene expression 4-6 fold when added to GMT-overexpressing rat cardiac fibroblasts. We also demonstrated that combined addition of SB, ICG-001, and RA increased cardiac fibroblast reprogramming efficiency 4 fold when added to GMTHM plus miR-590-overexpressing human cardiac fibroblasts.

Conclusions: Thus, HDAC and WNT inhibitors along with RA, jointly accelerate GMT-induced cardiac reprogramming from rat/human cardiac fibroblasts and pave the way for new translational approaches for cardiac regeneration.

Abstract 470: Gata4, Mef2c and Tbx5 More Efficiently Transdifferentiate Endothelial Cells into Cardiomyocyte-like Cells Through Endothelial-Mesenchymal Transition Process

Background: The cardiac transcription factors Gata4, Mef2c, and Tbx5 (GMT) have been used to successfully reprogram cardiac fibroblasts into induced cardiomyocyte-like cells (iCMs). However their effects on other cell types remain largely unknown. Endothelial cells are an important population of the heart by Pinto et al. (2016). Given the more profound iCM induction effects observed in vivo, we have speculated that reprogramming of endogenous endothelial cells may also play an important role.

Purpose: To investigate the cellular reprograming effects and mechanisms of GMT factors on cardiac endothelial cells and compare the outcomes with that from cardiac fibroblasts.

Methods: Adult rat cardiac endothelial cells (REC) and cardiac fibroblasts (RCF) were purchased commercially. The cells were cultured in appropriate media and infected with GMT-expressing lentivirus and maintained with iCM media. Fourteen days later Immunofluorescence staining, FACS, and qRT-PCR were performed.

Results: Both GMT treated RCFs and RECs showed positive staining of cardiac marker cTnT and αActinin-positive cells via immunofluorescence staining. FACS analysis showed GMT treated RECs had 16.7% of cTnT positive cells versus 3.3% in GMT treated RCF’s. qRT-PCR results demonstrated significant up-regulation of cTnT in GMT infected RECs (74.4±23.3 times, p<0.05) as compared to the control group. Similar upregulation of cTnT was observed in RCFs but to a lesser degree (16.1±7.2 times, p=NS). Moreover, RECs presented a significant change in cell morphology from rounded cells in a cobblestone arrangement to elongated spindle-shaped cells during 14 days culture. In addition, qRT-PCR analysis demonstrated that endothelial-mesenchymal transition (EndoMT) markers such as Slug, Snail, Oct4, and αSMA were upregulated in the cells with GFP encoded virus infection and those markers were downregulated in the GMT-treated RECs (p<0.01 for Snail, p<0.05 for Slug, and αSMA).

Conclusion: This report suggests that RECs are susceptive to GMT induced cardiac reprogramming than in RCFs. Our study also indicate that EMT and MET sequential process are involved in the reprogramming of RECs toward iCM cells. RECs could be targeted towards iCM generation for a higher reprogramming rate.

192 Craniotomy for Acute Subdural Hematoma-Outcomes in Patients Over 70 years

INTRODUCTION

The mortality rate for elderly patients with surgery for acute subdural hematoma (aSDH) has been reported to be as high as 90%, but with the possibility of functional survivors, surgery is still frequently performed. Therefore, we examined our outcomes for patients 70 years and older who underwent craniotomy for aSDH.

METHODS

We retrospectively reviewed patients 70 years and older who had an open surgical intervention for aSDH between 2006 and 2016 at Memorial Hermann Hospital in Houston, Texas. A multivariable analysis of the clinical data and outcomes was then performed.

RESULTS

>Of the 112 patients reviewed, 95% sustained their injuries after a fall from standing. The mortality rate was 42%, but 24% of patients were discharged to home or to a rehabilitation facility. Multivariable analysis demonstrated that age, preexisting dementia, and surgery type had significant impact on outcome. Specifically, patient who were older than 80 years of age, had dementia or Parkinson's disease, or who required decompressive craniectomy (as opposed to craniotomy) had a worse outcome.

CONCLUSION

Elderly patients with aSDH requiring surgery have a high likelihood of death or significant disability. It is important to note that the mortality rate for large aSDHs is higher given that some patients with this disease were not deemed to be surgical candidates and therefore were not included in this study. However, up to one quarter of surgical patients will be functional enough to go home or to a rehabilitation facility from the hospital. The data suggest that age over 80 years old, dementia, or cerebral edema significant enough to warrant decompressive craniectomy are associated with an increased risk of death.

Abstract WMP106: Soluble CD163 as a Prognostic Marker for Perihematomal Edema Formation and Functional Outcomes in Intracerebral Hemorrhage

Introduction: Macrophages are the predominant cell capable of removing toxic hemoglobin at sites of tissue injury, and CD163 has been recognized as the hemoglobin scavenger receptor present on the macrophage cell surface. In this study, we explored the levels of soluble CD163 (sCD163) in patients with intracerebral hemorrhage (ICH) to ascertain whether sCD163 was associated with clinicoradiologic features and long-term functional outcomes.

Methods: Our ICH cohort was comprised of 50 patients with moderate-sized basal ganglia hematomas. We collected serial serum and cerebrospinal fluid (CSF) at pre-specified timepoints (24 hours, 48 hours, 3-5 days, 6-8 days, and greater than 10 days post-ictus). We also obtained samples from 10 healthy controls. Levels of sCD163 were measured by enzyme-linked immunosorbent assay. A linear mixed model was used to compare sCD163 values among various groups, using a Bonferroni correction for multiple test adjustment. The method of generalized estimating equations was used to determine associations with dichotomized outcomes (modified Rankin Scale score 0-3 versus 4-6).

Results: Compared to healthy controls, serum sCD163 was higher in the ICH patients (40.6 versus 128.4 ng/mL). Within the ICH cohort, early values (24 hours to 5 days post-ictus) of serum sCD163 were significantly higher in patients who elaborated minimal perihematomal edema (PHE) (200.3 in patients with less than 10 mL PHE versus 71.8; p = 0.046). 6 to greater than 10 days post-ictus, sCD163 levels tailed off for patients with less PHE whereas levels rose in patients with greater PHE. Continued subacute elevation of sCD163, particularly in the CSF, was highly associated with poorer outcomes, both at discharge and at 90 days (p < 0.001). These associations were independent of age, gender, peak hematoma volume, and ICH score; there was a statistically significant association of CSF sCD163 values with degree of intraventricular hemorrhage (p = 0.04).

Conclusions: sCD163 may be a dynamic marker in ICH, with acute levels distinguishing edema patterns and subacute levels predicting functional outcome. Further studies are needed to confirm these findings and explore the pathophysiology behind these observations.

Solid-state colloidal CuInS2 quantum dot solar cells enabled by bulk heterojunctions

Colloidal copper indium sulfide (CIS) nanocrystals (NCs) are Pb- and Cd-free alternatives for use as absorbers in quantum dot solar cells. In a heterojunction with TiO₂, non-annealed ligand-exchanged CIS NCs form solar cells yielding a meager power conversion efficiency (PCE) of 0.15%, with photocurrents plummeting far below predicted values from absorption. Decreasing the amount of zinc during post-treatment leads to improved mobility but marginal improvement in device performance (PCE = 0.30%). By incorporating CIS into a porous TiO₂ network, we saw an overall drastic improvement in device performance, reaching a PCE of 1.16%, mainly from an increase in short circuit current density (J_sc) and fill factor (FF) and a 10-fold increase in internal quantum efficiency (IQE). We have determined that by moving from a bilayer to a bulk heterojunction architecture, we have reduced the trap-assisted recombination as seen in changes in the ideality factor, the intensity dependence of the photocurrent and transient photocurrent (TPC) and photovoltage (TPV) characteristics.

The PR status of the originating cell of ER/PR-negative mouse mammary tumors

Progesterone receptor (PR) is usually co-localized with estrogen receptor (ER) in normal mammary cells. It is not known whether ER/PR-negative human breast cancer arises from an ER/PR-negative cell or from an ER/PR-positive cell that later lost ER/PR. Using intraductal injection of a lentivirus to deliver both an oncogene (ErbB2) and a floxed green fluorescent protein (GFP) in PR(Cre/+)mice, whose Cre gene is under the control of the PR promoter, we were able to trace the PR status of the infected cells as they progressed to cancer. We found that the resulting early lesions stained negative for PR in most of the cells and usually retained GFP. The resulting tumors lacked ER and PR, and 75% (15/20) of them retained the GFP signal in all tumor cells, suggesting PR was never expressed throughout the evolution of a majority of these tumors. In conclusion, our data demonstrate that ErbB2-initiated ER/PR-negative mammary tumors primarily originate from the subset of the mammary epithelium that is negative for PR and probably ER as well. These findings also provide an explanation for why antihormonal therapy fails to prevent ER-negative breast cancers.

Comparison of seven serum thyroglobulin assays in the follow-up of papillary and follicular thyroid cancer patients

BACKGROUND

Serum thyroglobulin (Tg) is the marker of differentiated thyroid cancer after initial treatment and TSH stimulation increases its sensitivity for the diagnosis of recurrent disease.

AIM

The goal of the study is to compare the diagnostic values of seven methods for serum Tg measurement for detecting recurrent disease both during L-T4 treatment and after TSH stimulation.

METHODS

Thyroid cancer patients who had no evidence of persistent disease after initial treatment (total thyroidectomy and radioiodine ablation) were studied at 3 months on L-T4 treatment (Tg1) and then at 9-12 months after withdrawal or recombinant human TSH stimulation (Tg2). Sera with anti-Tg antibodies or with an abnormal recovery test result were excluded from Tg analysis with the corresponding assay. The results of serum Tg determination were compared to the clinical status of the patient at the end of follow-up.

RESULTS

Thirty recurrences were detected among 944 patients. A control 131I total body scan had a low sensitivity, a low specificity, and a low clinical impact. Assuming a common cutoff for all Tg assays at 0.9 ng/ml, sensitivity ranged from 19-40% and 68-76% and specificity ranged from 92-97% and 81-91% for Tg 1 and Tg2, respectively. Using assays with a functional sensitivity at 0.2-0.3 ng/ml, sensitivity was 54-63% and specificity was 89% for Tg1. Using the two methods with a lowest functional sensitivity at 0.02 and 0.11 ng/ml resulted in a higher sensitivity for Tg1 (81% and 78%), but at the expense of a loss of specificity (42% and 63%); finally, for these two methods, using an optimized functional sensitivity according to receiver operating characteristic curves at 0.22 and 0.27 ng/ml resulted in a sensitivity at 65% and specificity at 85-87% for Tg1.

CONCLUSION

Using an assay with a lower functional sensitivity may give an earlier indication of the presence of Tg in the serum on L-T4 treatment and may be used to study the trend in serum Tg without performing any TSH stimulation. Serum Tg determination obtained after TSH stimulation still permits a more reliable assessment of cure and patient's reassurance.