Prediction of Early Recurrence Following CRS/HIPEC in Patients With Disseminated Appendiceal Cancer

INTRODUCTION

In patients with disseminated appendiceal cancer (dAC) who underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), characterizing and predicting those who will develop early recurrence could provide a framework for personalizing follow-up. This study aims to: (1) characterize patients with dAC that are at risk for recurrence within 2 y following of CRS ± HIPEC (early recurrence; ER), (2) utilize automated machine learning (AutoML) to predict at-risk patients, and (3) identifying factors that are influential for prediction.

METHODS

A 12-institution cohort of patients with dAC treated with CRS ± HIPEC between 2000 and 2017 was used to train predictive models using H2O.ai's AutoML. Patients with early recurrence (ER) were compared to those who did not have recurrence or presented with recurrence after 2 y (control; C). However, 75% of the data was used for training and 25% for validation, and models were 5-fold cross-validated.

RESULTS

A total of 949 patients were included, with 337 ER patients (35.5%). Patients with ER had higher markers of inflammation, worse disease burden with poor response, and received greater intraoperative fluids/blood products. The highest performing AutoML model was a Stacked Ensemble (area under the curve = 0.78, area under the curve precision recall = 0.66, positive predictive value = 85%, and negative predictive value = 63%). Prediction was influenced by blood markers, operative course, and factors associated with worse disease burden.

CONCLUSIONS

In this multi-institutional cohort of dAC patients that underwent CRS ± HIPEC, AutoML performed well in predicting patients with ER. Variables suggestive of poor tumor biology were the most influential for prediction. Our work provides a framework for identifying patients with ER that might benefit from shorter interval surveillance early after surgery.

Automated machine learning (AutoML) can predict 90-day mortality after gastrectomy for cancer

Early postoperative mortality risk prediction is crucial for clinical management of gastric cancer. This study aims to predict 90-day mortality in gastric cancer patients undergoing gastrectomy using automated machine learning (AutoML), optimize models for preoperative prediction, and identify factors influential in prediction. National Cancer Database was used to identify stage I-III gastric cancer patients undergoing gastrectomy between 2004 and 2016. 26 features were used to train predictive models using H2O.ai AutoML. Performance on validation cohort was measured. In 39,108 patients, 90-day mortality rate was 8.8%. The highest performing model was an ensemble (AUC = 0.77); older age, nodal ratio, and length of inpatient stay (LOS) following surgery were most influential for prediction. Removing the latter two parameters decreased model performance (AUC 0.71). For optimizing models for preoperative use, models were developed to first predict node ratio or LOS, and these predicted values were inputted for 90-day mortality prediction (AUC of 0.73-0.74). AutoML performed well in predicting 90-day mortality in a larger cohort of gastric cancer patients that underwent gastrectomy. These models can be implemented preoperatively to inform prognostication and patient selection for surgery. Our study supports broader evaluation and application of AutoML to guide surgical oncologic care.

ODP215 Insulinoma Evaluation Before and After Development of End Stage Renal Failure: A Case Report

Introduction

Fasting hypoglycemia in chronically ill patients with kidney disease is frequently multifactorial. Patients with chronic kidney disease are prone to hypoglycemia due to decreased renal clearance of insulin, impaired renal gluconeogenesis and increased prevalence of other medical problems and medications. However, ruling out the presence of an insulinoma can be difficult in this patient population due to the impact of kidney disease on laboratory evaluation of hypoglycemia.

Case

A 43-year-old male with history of paraplegia from gunshot wound, neurogenic bladder, colostomy, chronic osteomyelitis, frequent polymicrobial bacteremia was noted to have persistent, asymptomatic hypoglycemia during multiple inpatient hospitalizations dating back to 2007. He was taking no medications associated with hypoglycemia. Following normal ACTH stimulation and thyroid testing, he underwent a 72-hour fast in 2017 when his creatinine was 1.32 mg/dL and GFR was >60; BMI was 22.32 kg/m 2 with prealbumin of 15 mg/dL. The fast was concluded after 23.5 hours with serum glucose of 46 mg/dL, insulin level of 3.1 uIU/mL, c-peptide of 2.4 ng/mL, undetectable proinsulin, and beta-hydroxybutyrate of 0.62mmol/L and a negative sulfonylurea screen. Administration of glucagon at time of fast completion improved glucose to 65 mg/dL. He was started on diazoxide 85mg every 8 hours during that hospitalization, which he discontinued without medical recommendation in 2018. He developed end stage renal disease requiring hemodialysis in 2019. During an admission in 2020, serum fasting glucose as low as 30mg/dL. Further laboratory evaluation at that time revealed glucose of 47 mg/dL, with insulin level 39.1 uIU/mL, c-peptide 18.2 ng/mL, and proinsulin of 20.1 pmol/L. Multiple CT abdomen imaging studies confirmed normal pancreas. Diazoxide 110mg every 8 hours was resumed and patient had decreased frequency of hypoglycemia episodes. Diazoxide has since the tapered to 80mg twice daily without increase in hypoglycemia frequency, with goal to taper further in the future.

Conclusion

Here we present the case of an individual patient who underwent laboratory evaluation of hypoglycemia before and after development of end stage renal disease with profound differences in lab results despite similar degree of hypoglycemia. It has been demonstrated previously that c-peptide and insulin levels are elevated in patients with end stage renal disease and that these labs decrease with hemodialysis while remaining above normal range. The elevation of c-peptide in this population is thought to be due to the kidney being the main site of beta-cell polypeptide degradation. Additionally, this case suggests successful use of diazoxide therapy in patients without classic endogenous hyperinsulinism.

Presentation: No date and time listed

OP0132 EFFECT OF IBERDOMIDE ON CUTANEOUS MANIFESTATIONS IN SYSTEMIC LUPUS ERYTHEMATOSUS: RESULTS OF A 24-WEEK, PLACEBO-CONTROLLED, PHASE 2 STUDY

Background:

Iberdomide is a high-affinity cereblon ligand that promotes proteasomal degradation of Ikaros (IKZF1) and Aiolos (IKZF3), transcription factors involved in innate and adaptive immune cell development and homeostasis, and linked to the genetic risk for systemic lupus erythematosus (SLE). A phase 2, placebo-controlled study evaluated the efficacy and safety of iberdomide in patients (pts) with moderate to severe SLE.

Objectives:

To examine the effect of iberdomide on cutaneous manifestations in SLE pts.

Methods:

Adult autoantibody-positive SLE pts with a SLE Disease Activity Index 2000 (SLEDAI 2K) score ≥6 were randomized (2:2:1:2) to oral iberdomide (0.45, 0.3, 0.15 mg) or placebo once daily (QD) for 24 weeks while continuing standard background lupus medications. The Cutaneous Lupus Area and Severity Index Activity score (CLASI-A) was assessed every 4 weeks through week 24. As prespecified, exploratory analyses, change from baseline and the proportion of pts who achieved ≥50% reduction from baseline (CLASI-50) were evaluated for all pts, pts with baseline CLASI-A ≥8, and by cutaneous lupus subtypes (acute [ACLE], subacute [SCLE], chronic [CCLE]). CLASI-A outcomes were also evaluated post hoc for subgroups with high baseline expression of IKZF3 or the type 1 interferon (IFN) gene signatures in the blood.

Results:

Of 288 randomized pts, the mean and median (range) baseline CLASI-A scores were 6.9 and 5.0 (0-49), with 28% of pts having a score ≥8. 56% of pts had ACLE, 29% CCLE, and 16% SCLE. CLASI-50 responses were not significantly different comparing iberdomide to placebo in all pts and pts with baseline CLASI-A ≥8 at week 24, where high placebo response rates were observed (Table). Numerically greater mean improvement from baseline in CLASI-A scores in pts with baseline CLASI-A ≥8 was observed for iberdomide 0.45 mg vs placebo beginning at week 4, with continuous improvement through week 24. For pts with SCLE or CCLE, CLASI-50 response rates were significantly higher with iberdomide 0.45 mg vs placebo (P<0.04; Table). SCLE pts had significantly greater mean change and median percent improvement in CLASI-A from baseline with iberdomide 0.45 mg vs placebo at week 24 (P<0.03). Treatment differences in CLASI-A between iberdomide 0.45 mg and placebo were larger for SCLE and CCLE subgroups with high baseline IKZF3 or type 1 IFN gene signatures, with statistical significance achieved for SCLE pts but not CCLE pts (Figure).

Table 1.

CLASI-50 Response Rates by Subgroups at Week 24

0.15 mg QD0.3 mg QD0.45 mg QD(n=42)(n=82)(n=81)PlaceboSubgroup(n=83)0.15 mg QD vs Placebo0.3 mg QD vs Placebo0.45 mg QD vs Placebon/m (%)n/m (%)Str Diff in % (95% CI)P valuen/m (%)Str Diff in % (95% CI)P valuen/m (%)Str Diff in % (95% CI)P valueAll pts37/83 (44.6)19/42 (45.2)0.4 (-17.33, 18.55) P=0.96141/82 (50.0)5.3 (-9.93, 20.11) P=0.49945/81 (55.6)10.9 (-4.30, 25.51) P=0.163CLASI-A ≥810/20 (50.0)8/13 (61.5)15.9 (-17.42, 45.45) P=0.39913/24 (54.2)12.1 (-17.57, 39.97) P=0.45816/24 (66.7)15.1 (-15.51, 42.49) P=0.368ACLE23/50 (46.0)15/30 (50.0)4.8 (-17.22, 26.31) P=0.66220/43 (46.5)-3.3 (-22.95, 16.67) P=0.73817/38 (44.7)-3.0 (-23.20, 17.65) P=0.782SCLE9/17 (52.9)5/9 (55.6)2.6a (-33.04, 36.33) P=0.9663/9 (33.3)-6.6 (-38.98, 31.86) P>0.99911/12 (91.7)38.7a(4.54, 61.75) P=0.035CCLE5/18 (27.8)7/14 (50.0)22.2a (-10.51, 50.00) P=0.19810/23 (43.5)23.8 (-6.89, 48.88) P=0.12918/29 (62.1)34.1 (4.43, 56.16) P=0.029

CI, confidence interval; Str Diff, stratified difference.

aUnstratified difference.

Conclusion:

Iberdomide showed beneficial effects on skin manifestations in pts with SLE. Efficacy appears to be more pronounced in pts with SCLE and CCLE skin subtypes, and in pts with high IKZF3 or IFN gene expression signatures.

Δ, treatment difference of adjusted means; CCLE, chronic cutaneous lupus erythematosus; CLASI-A, Cutaneous Lupus Erythematosus Disease Area and Severity Index-activity score; IFN, interferon; SCLE, subacute cutaneous lupus erythematosus.

Acknowledgements:

This study was sponsored by Bristol Myers Squibb. Professional medical writing assistance was provided by Peloton Advantage, LLC, an OPEN Health company, and funded by Bristol Myers Squibb.

Disclosure of Interests:

Victoria Werth Consultant of: Bristol Myers Squibb, Grant/research support from: Bristol Myers Squibb, Joan Merrill Consultant of: UCB, GlaxoSmithKline, AbbVie, EMD Serono, Remegen, Celgene/Bristol Myers Squibb, AstraZeneca, Lilly, Immupharma, Amgen, Janssen, Resolve, Alpine, Aurinia, Astellas, Alexion, and Provention, Grant/research support from: GlaxoSmithKline and AstraZeneca, Richard Furie Consultant of: Bristol Myers Squibb, Grant/research support from: Bristol Myers Squibb, Thomas Dörner Consultant of: support for clinical studies and honoraria for scientific advice: AbbVie, Bristol Myers Squibb Company, Celgene, Eli Lilly, Janssen, Novartis, Roche, Employee of: Charite Universitätsmedizin, Berlin and DRFZ Berlin, Germany, Ronald van Vollenhoven Speakers bureau: UCB, AbbVie, Galapagos, Janssen, Pfizer, Paid instructor for: support for educational programs: Pfizer, Roche, Consultant of: AstraZeneca, Biogen, Biotest, Celgene, Gilead, Servier, UCB, AbbVie, Galapagos, Janssen, Pfizer, Grant/research support from: Bristol Myers Squibb, GlaxoSmithKline, Eli Lilly, UCB, Peter Lipsky Employee of: RILITE Foundation, Michael Weiswasser Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Shimon Korish Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Peter Schafer Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Mark Stern Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Zhaohui Liu Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Shaojun Tang Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Nikolay Delev Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb

MON-440 Unusual Case of Metastatic Struma Ovarii Diagnosed at the Time of Hysterectomy

Introduction: Struma ovarii is rare ovarian teratoma composed of more than 50% mature thyroid tissue, which can rarely transform to malignancy. There are fewer than 200 cases reported and no established treatment approach. We present a case of metastatic malignant struma ovarii. Case Presentation: A 41 year old female was diagnosed with metastatic papillary thyroid carcinoma (PTC) after it was found on uterine histopathology. History was notable for remote left ovarian cystectomy of a mature teratoma with prominent thyroid component. She had no personal or family history of craniocervical radiation or thyroid cancer. Eight years later, she had a total hysterectomy for menorrhagia. Pathology showed subcentimeter serosal deposits of follicular variant PTC, staining positive for thyroglobulin, CK19, and HBME1. Endometrial and cervical pathology were normal; the myometrium had many leiomyomata. Post-hysterectomy TSH was 2.3 (0.34 - 5.66 µIU/mL), and thyroglobulin 44.3 (&lt;=33.0 ng/mL). Thyroid ultrasound showed a 7 mm isoechoic nodule without lymphadenopathy. Whole body PET/CT showed multiple hypermetabolic masses in the pelvic peritoneum and liver. The right ovary had many cystic lesions and was enlarged to 5.3 x 4.5 cm. She underwent partial hepatectomy, oophorectomy, salpingectomy, and omental resection with no residual disease. Pathology showed follicular variant PTC in both ovaries, peritoneum, colonic mesentery, and omentum. Thyroglobulin fell to 6.9 ng/mL 3 weeks later. A 0.2 cm focus of follicular variant PTC with capsular invasion was found on pathology after total thyroidectomy. She underwent radioiodine ablation with 150 mCi. Postablative scan showed residual activity in the thyroid bed and right hemipelvis, but no new foci of activity. CT abdomen showed resolution of perihepatic lesions and thyroglobulin declined further to 0.5 ng/mL. Discussion: A low risk of recurrence (7.5%) has been reported in patients with malignant struma ovarii, with survival rates of 96.7% at 5 years and 84.9% at 20 years, despite a variety of surgical and adjuvant management strategies. Unilateral cystectomy, unilateral salpingo-oophorectomy, or total abdominal hysterectomy and bilateral salpingo-oophorectomy may be sufficient for patients with well differentiated thyroid cancer arising in struma ovarii without metastases. Thyroid ultrasound should be performed to exclude primary thyroid malignancy. Patients with distant metastases may benefit from aggressive treatment including resection of gross abdominal and pelvic disease and total thyroidectomy to facilitate radioactive iodine ablation and surveillance for recurrence. Conclusion: Due to its rarity, there is no consensus on optimal treatment of malignant struma ovarii. More research in this field is warranted.

Effect of beta blocker use and type on hypoglycemia risk among hospitalized insulin requiring patients

Background

Although beta blockers could increase the risk of hypoglycemia, the difference between subtypes on hypoglycemia and mortality have not been studied. This study sought to determine the relationship between type of beta blocker and incidence of hypoglycemia and mortality in hospitalized patients.

Methods

We retrospectively identified non-critically ill hospitalized insulin requiring patients who were undergoing bedside glucose monitoring and received either carvedilol or a selective beta blocker (metoprolol or atenolol). Patients receiving other beta blockers were excluded. Hypoglycemia was defined as any glucose < 3.9 mmol/L within 24 h of admission (Hypo_1day) or throughout hospitalization (Hypo_T) and any glucose < 2.2 mmol/L throughout hospitalization (Hypo_severe).

Results

There were 1020 patients on carvedilol, 886 on selective beta blockers, and 10,216 on no beta blocker at admission. After controlling for other variables, the odds of Hypo_1day, Hypo_T and Hypo_severe were higher for carvedilol and selective beta blocker recipients than non-recipients, but only in basal insulin nonusers. The odds of Hypo_1day (odds ratio [OR] 1.99, 95% confidence interval [CI] 1.28, 3.09, p = 0.0002) and Hypo_T (OR 1.38, 95% CI 1.02, 1.86, p = 0.03) but not Hypo_severe (OR 1.90, 95% CI 0.90, 4.02, p = 0.09) were greater for selective beta blocker vs. carvedilol recipients in basal insulin nonusers. Hypo_1day, Hypo_T, and Hypo_severe were all associated with increased mortality in adjusted models among non-beta blocker and selective beta blocker recipients, but not among carvedilol recipients.

Conclusions

Beta blocker use is associated with increased odds of hypoglycemia among hospitalized patients not requiring basal insulin, and odds are greater for selective beta blockers than for carvedilol. The odds of hypoglycemia-associated mortality are increased with selective beta blocker use or nonusers but not in carvedilol users, warranting further study.

Relationship of coronary calcium and myocardial perfusion in individuals with chest pain

Aim: The integrated value of coronary calcium scoring added to myocardial perfusion assessment in hybrid PETCT imaging remains poorly defined. In the present study, we sought to determine the relationship between calcium burden, other risk factors, and tissue perfusion in a group of patients with chest pain and predominantly intermediate likelihood for coronary artery disease. Patients, methods: In 70 patients, coronary calcium scores (CCS) were obtained in addition to rest/dipyridamole stress 82Rb perfusion images using a GE Discovery Rx hybrid PET-CT system. From static perfusion images, summed rest, stress and difference scores (SRS, SSS, SDS) were calculated using a 20-segment model. Absolute CCS was determined according to Agatston and age-, gender-, and ethnicity-matched CCS percentiles were calculated using the MESA database. Results: SSS, SRS and SDS were abnormal (.4) in 25 (36%), 17 (24%), and 12 (17%) patients. Mean CCS according to Agatston was 180 ± 446(range 0.2122), and CCS percentile was 42 ± 43(range 0.99). Absolute CCS correlated mildly but significantly with SSS (r = 0.31, p = 0.01), while CCS percentile did not (r = 0.11, p = 0.36). Of 49 patients with normal perfusion, 25 (57%) had CCS = 0, and 8 (18%) had a CCS percentile .75th. Of 35 patients with a CCS = 0, 26 (74%) had normal perfusion. Individuals in whom review of patient records revealed events during follow-up (n = 10) had significantly higher SSS than those where no events were recorded (6.0 ± 7.2 versus 2.9 ± 3.1, p = 0.03), and there was a trend towards higher CCS percentiles (62 ± 36 versus 35 ± 43, p = 0.06). Conclusion: Coronary calcifications and myocardial tissue perfusion, as interrogated in a single PET-CT imaging session, show only partial agreement in patients with chest pain. Both tests seem to reflect different pathophysiologic components, and may be complementary for definition of individual disease patterns.

Study of Flare Assessment in Systemic Lupus Erythematosus Based on Paper Patients

Objective

To determine the level of agreement of disease flare severity (distinguishing severe, moderate, and mild flare and persistent disease activity) in a large paper‐patient exercise involving 988 individual cases of systemic lupus erythematosus.

Methods

A total of 988 individual lupus case histories were assessed by 3 individual physicians. Complete agreement about the degree of flare (or persistent disease activity) was obtained in 451 cases (46%), and these provided the reference standard for the second part of the study. This component used 3 flare activity instruments (the British Isles Lupus Assessment Group [BILAG] 2004, Safety of Estrogens in Lupus Erythematosus National Assessment [SELENA] flare index [SFI] and the revised SELENA flare index [rSFI]). The 451 patient case histories were distributed to 18 pairs of physicians, carefully randomized in a manner designed to ensure a fair case mix and equal distribution of flare according to severity.

Results

The 3‐physician assessment of flare matched the level of flare using the 3 indices, with 67% for BILAG 2004, 72% for SFI, and 70% for rSFI. The corresponding weighted kappa coefficients for each instrument were 0.82, 0.59, and 0.74, respectively. We undertook a detailed analysis of the discrepant cases and several factors emerged, including a tendency to score moderate flares as severe and persistent activity as flare, especially when the SFI and rSFI instruments were used. Overscoring was also driven by scoring treatment change as flare, even if there were no new or worsening clinical features.

Conclusion

Given the complexity of assessing lupus flare, we were encouraged by the overall results reported. However, the problem of capturing lupus flare accurately is not completely solved.

Clinical manifestations and coronary artery disease risk factors at diagnosis of systemic lupus erythematosus: data from an international inception cohort

Systemic Lupus International Collaborating Clinics (SLICC) comprises 27 centres from 11 countries. An inception cohort of 918 SLE patients has been assembled according to a standardized protocol between 2000 and 2006. Clinical features, classic coronary artery disease (CAD) risk factors, as well as other potential risk factors were collected. Of the 918 patients 89% were females, and of multi racial origin. Less than half the patients were living in a permanent relationship, 58% had post secondary education and 51% were employed. Eight percent had family history of SLE. At enrolment, with at mean age of diagnosis of 34.5 years, a significant number of patients already had CAD risk factors, such as hypertension (33%) and hypercholesterolemia (36%). Only 15% of the patients were postmenopausal, 16% were current smokers and 3.6% had diabetes at entry to the SLICC-RAS (Registry for Atherosclerosis). A number of patients in this multi-racial, multi-ethnic inception cohort of lupus patients have classic CAD risk factors within a mean of 5.4 months from diagnosis. This cohort will be increased to 1500 patients to be followed yearly for 10 years. This will provide a unique opportunity to evaluate risk factors for accelerated atherosclerosis in SLE. Lupus (2007) 16, 731—735.

Cardiovascular events prior to or early after diagnosis of systemic lupus erythematosus in the systemic lupus international collaborating clinics cohort

Objective

To describe the frequency of myocardial infarction (MI) prior to the diagnosis of systemic lupus erythematosus (SLE) and within the first 2 years of follow-up.

Methods

The systemic lupus international collaborating clinics (SLICC) atherosclerosis inception cohort enters patients within 15 months of SLE diagnosis. MIs were reported and attributed on a specialised vascular event form. MIs were confirmed by one or more of the following: abnormal ECG, typical or atypical symptoms with ECG abnormalities and elevated enzymes (≥2 times upper limit of normal), or abnormal stress test, echocardiogram, nuclear scan or angiogram. Descriptive statistics were used.

Results

31 of 1848 patients who entered the cohort had an MI. Of those, 23 patients had an MI prior to SLE diagnosis or within the first 2 years of disease. Of the 23 patients studied, 60.9% were female, 78.3% were Caucasian, 8.7% black, 8.7% Hispanic and 4.3% other. The mean age at SLE diagnosis was 52.5±15.0 years. Of the 23 MIs that occurred, 16 MIs occurred at a mean of 6.1±7.0 years prior to diagnosis and 7 occurred within the first 2 years of follow-up. Risk factors associated with early MI in univariate analysis are male sex, Caucasian, older age at diagnosis, hypertension, hypercholesterolaemia, family history of MI and smoking. In multivariate analysis only age (OR=1.06 95% CI 1.03 to 1.09), hypertension (OR=5.01, 95% CI 1.38 to 18.23), hypercholesterolaemia (OR=4.43, 95% CI 1.51 to 12.99) and smoking (OR=7.50, 95% CI 2.38 to 23.57) remained significant risk factors.

Conclusions

In some patients with lupus, MI may develop even before the diagnosis of SLE or shortly thereafter, suggesting that there may be a link between autoimmune inflammation and atherosclerosis.

Effects of automated immunization registry reporting via an electronic health record deployed in community practice settings

BACKGROUND

Among the expected benefits of electronic health records (EHRs) is increased reporting of public health information, such as immunization status. State and local immunization registries aid control of vaccine-preventable diseases and help offset fragmentation in healthcare, but reporting is often slow and incomplete. The Primary Care Information Project (PCIP), an initiative of the NYC Department of Health and Mental Hygiene, has implemented EHRs with immunization reporting capability in community settings.

OBJECTIVE AND METHODS

To evaluate the effect of automated reporting via an EHR on use and efficiency of reporting to the NY Citywide Immunization Registry, we conducted a secondary analysis of 1.7 million de-identified records submitted between January 2007 and June 2011 by 217 primary care practices enrolled in PCIP, pre and post launch of automated reporting via an EHR. We examined differences in records submitted per day, lag time, and documentation of eligibility for subsidized vaccines.

RESULTS

Mean submissions per day did not change. Automated submissions of new and historical records increased by 18% and 98% respectively. Submissions within 14 days increased from 84% to 87%, and within 2 days increased from 60% to 77%. Median lag time decreased from 13 to 10 days. Documentation of eligibility decreased. Results are significant at p<0.001.

CONCLUSIONS

Significant improvements in registry use and efficiency of reporting were found after launch of automated reporting via an EHR. A decrease in eligibility documentation was attributed to EHR workflow. The limitations to comprehensive evaluation found in these data, which were extracted from a registry initiated prior to widespread EHR implementation suggests that reliable evaluation of immunization reporting via the EHR may require modifications to legacy registry databases.

An information systems model of the determinants of electronic health record use

OBJECTIVES

The prominence given to universal implementation of electronic health record (EHR) systems in U.S. health care reform, underscores the importance of devising reliable measures of factors that predict medical care providers' use of EHRs. This paper presents an easily administered provider survey instrument that includes measures corresponding to core dimensions of DeLone and McClean's (D & M) model of information system success.

METHODS

Study data came from self-administered surveys completed by 460 primary care providers, who had recently begun using an EHR.

RESULTS

Based upon assessment of psychometric properties of survey items, a revised D&M causal model was formulated that included four measures of the determinants of EHR use (system quality, IT support, ease of use, user satisfaction) and five indicators of provider beliefs about the impact on an individual's clinical practice. A structural equation model was estimated that demonstrated a high level of inter-correlation between the four scales measuring determinants of EHR use. All four variables had positive association with each of the five individual impact measures. Consistent with our revised D&M model, the association of system quality and IT support with the individual impact measures was entirely mediated by ease of use and user satisfaction.

CONCLUSIONS

Survey research provides important insights into provider experiences with EHR. Additional studies are in progress to investigate how the variables constructed for this study are related to direct measures of EHR use.

⁸²Rb PET myocardial perfusion imaging is superior to ⁹⁹mTc-labelled agent SPECT in patients with known or suspected coronary artery disease

PURPOSE

We compared the quality, interpretive confidence and interreader agreement between SPECT and PET myocardial perfusion imaging (MPI) in the same group of patients.

METHODS

The study group comprised 27 patients (age 55 ± 8.5 years, 12 men) with known or suspected coronary artery disease (CAD) who had undergone gated rest/stress MPI with (99m)Tc-labelled agent SPECT (with and without attenuation correction, AC), and subsequent clinical confirmation with (82)Rb PET. Three experienced readers blinded to the clinical information interpreted all MPI studies.

RESULTS

Interreader agreement was significantly superior for PET studies than for SPECT studies. Following consensus interpretation, the quality of 22 % of the non-AC SPECT studies, 33 % of the AC SPECT studies and 63 % of the PET studies was assessed as excellent or good (p = 0.016). Interpretations were definitely normal or abnormal in 7 % of non-AC SPECT studies, 30 % of AC SPECT studies and 85 % of PET studies (p = 0.046). In 13 patients who had received either invasive coronary angiography or CT angiography with no significant CAD, the true-positive rate for significant CAD was higher for PET, and the true-negative rate was equal for PET and AC SPECT, and lower for non-AC SPECT.

CONCLUSION

(82)Rb PET MPI, used as a confirmatory test after SPECT, offers improved image quality, interpretive confidence and interreader agreement.

Impaired global myocardial flow dynamics despite normal left ventricular function and regional perfusion in chronic kidney disease: a quantitative analysis of clinical 82Rb PET/CT studies

Impaired global myocardial flow reserve (MFR) may be associated with increased risk for cardiac events and coronary artery disease progression. Chronic kidney disease (CKD) is also considered a risk factor for cardiovascular disease. We sought to investigate the effect of CKD on the myocardial microcirculation in patients referred for clinical (82)Rb PET/CT, who had normal left ventricular (LV) function and no flow-limiting coronary artery disease.

METHODS

Estimated glomerular filtration rate (eGFR) was available for 230 patients who had undergone rest and pharmacologic stress (82)Rb PET/CT for suspected coronary artery disease. CKD was defined as an eGFR less than 60 mL/min/1.73 m(2). After patients with hemodialysis, a renal transplant, abnormal regional perfusion (summed stress score > 4), or reduced LV function (LV ejection fraction < 45%) were excluded, 40 CKD patients remained. Those were compared with a control group without CKD, which was matched for age, sex, coronary risk factors, and systemic hemodynamics (n = 42). List-mode acquisition of PET enabled quantification of myocardial blood flow (MBF) and MFR using a previously validated retention model with correction for (82)Rb extraction. Rest MBF was normalized to rate-pressure product.

RESULTS

Mean eGFR in the CKD group was reduced (44 ± 14 vs. 99 ± 28 mL/min/1.73 m(2); P < 0.0001), and creatinine was significantly elevated, compared with controls (1.9 ± 1.1 vs. 0.8 ± 0.2 mg/dL; P < 0.0001). MFR was significantly reduced in CKD (2.2 ± 1.0 vs. 3.0 ± 1.2 for controls; P = 0.027). This reduction was mainly due to increased rest MBF (1.1 ± 0.4 in CKD vs. 0.8 ± 0.2 mL/min/g in controls; P = 0.007). Stress myocardial flow was comparable between both groups (2.3 ± 0.9 vs. 2.3 ± 0.8 mL/min/g; P = 0.08). Overall, MFR was significantly correlated with eGFR (r = 0.41; P = 0.0005). Stress MBF did not correlate with eGFR (r = 0.002; P = 0.45), but rest MBF showed an inverse correlation (r = -0.49; P < 0.0001). Rest MBF was also inversely correlated with hemoglobin (r = -0.28; P = 0.014), but only eGFR was an independent correlate at multivariate analysis.

CONCLUSION

MFR is impaired in patients with renal insufficiency with normal regional perfusion and LV function, mostly because of elevated rest flow. Absolute quantification of flow may be useful to identify microvascular dysfunction as a precursor of clinically overt coronary disease in this specific risk group.

Transient ischemic dilation ratio in 82Rb PET myocardial perfusion imaging: normal values and significance as a diagnostic and prognostic marker

In myocardial perfusion SPECT, transient ischemic dilation ratio (TID) is a well-established marker of severe ischemia and adverse outcome. However, its role in the setting of (82)Rb PET is less well defined.

METHODS

We analyzed 265 subjects who underwent clinical rest-dipyridamole (82)Rb PET/CT. Sixty-two subjects without a prior history of cardiac disease and with a normal myocardial perfusion study had either a low or a very low pretest likelihood of coronary artery disease or negative CT angiography. These subjects were used to establish a reference range of TID. In the remaining 203 patients with an intermediate or high pretest likelihood, subgroups with normal and abnormal TID were established and compared with respect to clinical variables, perfusion defect scores, left ventricular function, and absolute myocardial flow reserve. Follow-up was obtained for 969 ± 328 d to determine mortality by review of the social security death index.

RESULTS

In the reference group, TID ratio was 0.98 ± 0.06. Accordingly, a threshold for abnormal TID was set at greater than 1.13 (0.98 + 2.5 SDs). In the study group, 19 of 203 patients (9%) had an elevated TID ratio. Significant differences between subgroups with normal and abnormal TID ratio were observed for ejection fraction reserve (5.0 ± 6.4 vs. 1.8 ± 7.9; P < 0.05), difference between end-systolic volume (ESV) at rest and stress (ΔESV[stress-rest]; 1.8 ± 7.4 vs. 12.3 ± 13.0 mL; P < 0.0001), difference between end-diastolic volume (EDV) at rest and stress (ΔEDV[stress-rest]; 10.8 ± 11.5 vs. 23.8 ± 14.6 mL; P < 0.0001), summed rest score (1.8 ± 3.8 vs. 3.8 ± 7.6; P < 0.05), summed stress score (3.0 ± 5.4 vs. 7.5 ± 9.8; P < 0.002), summed difference score (1.3 ± 2.6 vs. 3.7 ± 5.3; P < 0.02), and global myocardial flow reserve (2.1 ± 0.8 vs. 1.7 ± 0.6; P < 0.02). Additionally, TID-positive patients had a significantly lower overall survival probability (P < 0.05). In a subgroup analysis of patients without regional perfusion abnormalities, TID-positive patients' overall survival probability was significantly smaller (P < 0.03), and TID was an independent predictor (exponentiation of the B coefficients [Exp(b)] = 6.22; P < 0.009) together with an ejection fraction below 45% (Exp[b] = 6.16; P < 0.002).

CONCLUSION

The present study suggests a reference range of TID for (82)Rb PET myocardial perfusion imaging that is in the range of previously established values for SPECT. Abnormal TID in (82)Rb PET is associated with more extensive left ventricular dysfunction, ischemic compromise, and reduced global flow reserve. Preliminary outcome analysis suggests that TID-positive subjects have a lower overall survival probability.

Can lifestyle interventions do more than reduce diabetes risk? Treating depression in adults with type 2 diabetes with exercise and cognitive behavioral therapy

The epidemic of metabolic syndrome, prediabetes, and type 2 diabetes is global in scope and comprehensive in its impact on individuals, health care systems, and societies. One in four patients with diabetes will experience depression in their lifetime. Comorbid depression is associated with poorer outcomes, greater functional disability, and early mortality. Prior studies have demonstrated beneficial effects of exercise as an efficacious form of treatment for depression in the general population. Few studies have evaluated this strategy in patients with prediabetes or type 2 diabetes. Program ACTIVE (Appalachians Coming Together to Increase Vital Exercise) was designed to treat depression among adults with type 2 diabetes by pairing aerobic activity with individual cognitive behavioral therapy. This combination treatment approach has been shown to be feasible to implement in a rural environment and promising in terms of depression, diabetes, and cardiovascular outcomes. Data from this study suggest that exercise can be used to achieve multiple benefits for adults with type 2 diabetes. Future work to compare this approach to singular treatment strategies for adults at risk for type 2 diabetes is needed.

PET/CT assessment of symptomatic individuals with obstructive and nonobstructive hypertrophic cardiomyopathy

Patients with obstructive hypertrophic cardiomyopathy (HCM) exhibit elevated left ventricular outflow tract gradients (LVOTGs) and appear to have a worse prognosis than those with nonobstructive HCM. The aim of this study was to evaluate whether patients with obstruction, compared with nonobstructive HCM, demonstrate significant differences in PET parameters of microvascular function.

METHODS

PET was performed in 33 symptomatic HCM patients at rest and during dipyridamole stress (peak) for the assessment of regional myocardial perfusion (rMP), left ventricular ejection fraction (LVEF), myocardial blood flow (MBF), and myocardial flow reserve (MFR). Myocardial wall thickness and LVOTG were measured with an echocardiogram. Patients were divided into the following 3 groups: nonobstructive (LVOTG < 30 mm Hg at rest and after provocation test with amyl nitrite), obstructive (LVOTG ≥ 30 mm Hg at rest and with provocation), and latent HCM (LVOTG < 30 at rest but ≥ 30 mm Hg with provocation).

RESULTS

Eleven patients were classified as nonobstructive (group 1), 12 as obstructive (group 2), and 10 as latent HCM (group 3). Except for age (42 ± 18 y for group 1, 58 ± 7 y for group 2, and 58 ± 12 y for group 3; P = 0.01), all 3 groups had similar baseline characteristics, including maximal wall thickness (2.3 ± 0.5 cm for group 1, 2.2 ± 0.4 cm for group 2, and 2.1 ± 0.7 cm for group 3; P = 0.7). During peak flow, most patients in groups 1 and 2, but fewer in group 3, exhibited rMP defects (73% for group 1, 100% for group 2, and 40% for group 3; P = 0.007) and a drop in LVEF (73% for group 1, 92% for group 2, and 50% for group 3; P = 0.09). Peak MBF (1.58 ± 0.49 mL/min/g for group 1, 1.72 ± 0.46 mL/min/g for group 2, and 1.97 ± 0.32 mL/min/g for group 3; P = 0.14) and MFR (1.62 ± 0.57 for group 1, 1.90 ± 0.31 for group 2, and 2.27 ± 0.51 for group 3; P = 0.01) were lower in the nonobstructive and higher in the latent HCM group. LVOTGs demonstrated no significant correlation with any flow dynamics. In a multivariate regression analysis, maximal wall thickness was the only significant predictor for reduced peak MBF (β = -0.45, P = 0.003) and MFR (β = -0.63, P = 0.0001).

CONCLUSION

Maximal wall thickness was identified as the strongest predictor of impaired dipyridamole-induced hyperemia and flow reserve in our study, whereas outflow tract obstruction was not an independent determinant.

Comparison of the myocardial blood flow response to regadenoson and dipyridamole: a quantitative analysis in patients referred for clinical 82Rb myocardial perfusion PET

BACKGROUND

Regadenoson is a novel selective A2A adenosine receptor agonist, which is administered as an intravenous bolus at a fixed dose. It is currently not clear if the absolute flow increase in response to this fixed dose is a function of distribution volume in individual patients or if it is generally comparable to the previous standard agents dipyridamole or adenosine, which are dosed based on weight. We used quantitative analysis of clinical 82Rb PET/CT studies to obtain further insights.

METHODS

A total of 104 subjects with normal clinical rest/stress 82Rb perfusion PET/CT were included in a retrospective analysis. To rule out confounding factors, none had evidence of prior cardiac disease, ischaemia or infarction, cardiomyopathy, diabetes with insulin use, calcium score>400, renal disease or other significant systemic disease. A group of 52 patients stressed with regadenoson were compared with a group of 52 patients stressed with dipyridamole before regadenoson became available. The groups were matched for clinical characteristics, risk factors and baseline haemodynamics. Myocardial blood flow (MBF) and myocardial flow reserve (MFR) were quantified using a previously validated retention model, after resampling of dynamic studies from list-mode 82Rb datasets.

RESULTS

At rest, heart rate, blood pressure and MBF were comparable between the groups. Regadenoson resulted in a significantly higher heart rate (34±14 vs. 23±10 beats per minute increase from baseline; p<0.01) and rate-pressure product. Patients in the regadenoson group reported less severe symptoms and required less aminophylline. Stress MBF and MFR were not different between the groups (2.2±0.6 vs. 2.1±0.6 ml/min/g, p=0.39, and 2.9±0.8 vs. 2.8±0.7, p=0.31, respectively). In the regadenoson group, there was no correlation between stress flow or MFR and body weight or BMI.

CONCLUSION

Despite its administration at a fixed dose, regadenoson results in an absolute increase in MBF which is comparable to that following dipyridamole administration and is independent of patient distribution volume. This further supports its usefulness as a clinical stress agent.

Radiation dosimetry of 82Rb in humans under pharmacologic stress

(82)Rb is used with PET for cardiac perfusion studies. Using human biokinetic measurements, in vivo, we recently reported on the resting-state dosimetry of this agent. The objective of this study was to obtain (82)Rb dose estimates under stress.

METHODS

(82)Rb biokinetics were obtained in 10 healthy volunteers (5 male, 5 female; mean age ± SD, 33 ± 10 y; age range, 18-50 y) using whole-body PET/CT. The 76-s half-life of (82)Rb and the corresponding need for pharmacologic vasodilation require that all imaging be completed within 10 min. To accommodate these constraints, while acquiring the data needed for dosimetry we used the following protocol. First, a whole-body attenuation correction CT scan was obtained. Then, a series of 3 whole-body PET scans was acquired after a single infusion of 1.53 ± 0.12 GBq of (82)Rb at rest. Four minutes after the infusion of a 0.56 mg/kg dose of the vasodilator, dipyridamole, 3 serial whole-body PET scans were acquired after a single infusion of 1.50 ± 0.16 GBq of (82)Rb under stress. The time-integrated activity coefficient (TIAC) for stress was obtained by scaling the mean rest TIAC obtained from our previous rest study by the stress-to-rest TIAC ratio obtained from the rest-stress measurements described in this report.

RESULTS

The highest mean organ-absorbed doses under stress were as follows: heart wall, 5.1, kidneys, 5.0, lungs, 2.8, and pancreas, 2.4 μGy/MBq (19, 19, 10.4, and 8.9 mrad/mCi, respectively). The mean effective doses under stress were 1.14 ± 0.10 and 1.28 ± 0.10 μSv/MBq using the tissue-weighting factors of the International Commission on Radiological Protection, publications 60 and 103, respectively.

CONCLUSION

Appreciable differences in source-organ biokinetics were observed for heart wall and kidneys during stress when compared with the previously reported rest study. The organ receiving the highest dose during stress was the heart wall. The mean effective dose calculated during stress was not significantly different from that obtained at rest.

Human biodistribution and radiation dosimetry of 82Rb

Prior estimates of radiation-absorbed doses from (82)Rb, a frequently used PET perfusion tracer, yielded discrepant results. We reevaluated (82)Rb dosimetry using human in vivo biokinetic measurements.

METHODS

Ten healthy volunteers underwent dynamic PET/CT (6 contiguous table positions, each with separate (82)Rb infusion). Source organ volumes of interest were delineated on the CT images and transferred to the PET images to obtain time-integrated activity coefficients. Radiation doses were estimated using OLINDA/EXM 1.0.

RESULTS

The highest mean absorbed organ doses (μGy/MBq) were observed for the kidneys (5.81), heart wall (3.86), and lungs (2.96). Mean effective doses were 1.11 ± 0.22 and 1.26 ± 0.20 μSv/MBq using the tissue-weighting factors of the International Commission on Radiological Protection (ICRP), publications 60 and 103, respectively.

CONCLUSION

Our current (82)Rb dosimetry suggests reasonably low radiation exposure. On the basis of this study, a clinical (82)Rb injection of 2 × 1,480 MBq (80 mCi) would result in a mean effective dose of 3.7 mSv using the weighting factors of the ICRP 103-only slightly above the average annual natural background exposure in the United States (3.1 mSv).

Reference ranges for LVEF and LV volumes from electrocardiographically gated 82Rb cardiac PET/CT using commercially available software

Electrocardiographic gating is increasingly used for (82)Rb cardiac PET/CT, but reference ranges for global functional parameters are not well defined. We sought to establish reference values for left ventricular ejection fraction (LVEF), end systolic volume (ESV), and end diastolic volume (EDV) using 4 different commercial software packages. Additionally, we compared 2 different approaches for the definition of a healthy individual.

METHODS

Sixty-two subjects (mean age +/- SD, 49 +/- 9 y; 85% women; mean body mass index +/- SD, 34 +/- 10 kg/m(2)) who underwent (82)Rb-gated myocardial perfusion PET/CT were evaluated. All subjects had normal myocardial perfusion and no history of coronary artery disease (CAD) or cardiomyopathy. Subgroup 1 consisted of 34 individuals with low pretest probability of CAD (<10%), and subgroup 2 comprised 28 subjects who had no atherosclerosis on a coronary CT angiogram obtained concurrently during the PET/CT session. LVEF, ESV, and EDV were calculated at rest and during dipyridamole-induced stress, using CardIQ Physio (a dedicated PET software) and the 3 major SPECT software packages (Emory Cardiac Toolbox, Quantitative Gated SPECT, and 4DM-SPECT).

RESULTS

Mean LVEF was significantly different among all 4 software packages. LVEF was most comparable between CardIQ Physio (62% +/- 6% and 54% +/- 7% at stress and rest, respectively) and 4DM-SPECT (64% +/- 7% and 56% +/- 8%, respectively), whereas Emory Cardiac Toolbox yielded higher values (71% +/- 6% and 65% +/- 6%, respectively, P < 0.001) and Quantitated Gated SPECT lower values (56% +/- 8% and 50% +/- 8%, respectively, P < 0.001). Subgroup 1 (low likelihood) demonstrated higher LVEF values than did subgroup 2 (normal CT angiography findings), using all software packages (P < 0.05). However, mean ESV and EDV at stress and rest were comparable between both subgroups (p = NS). Intra- and interobserver agreement were excellent for all methods.

CONCLUSION

The reference range of LVEF and LV volumes from gated (82)Rb PET/CT varies significantly among available software programs and therefore cannot be used interchangeably. LVEF results were higher when healthy subjects were defined by a low pretest probability of CAD than by normal CT angiography results.

Depression Among Adults With Diabetes: Prevalence, Impact, and Treatment Options

In Brief

Patients with type 1 or type 2 diabetes are two times more likely to experience depression than their peers without diabetes. Comorbid depression results in deleterious effects on glycemic control, worsened diabetes complications, functional disability, and premature mortality. Once identified, depression can be effectively treated with antidepressant medications, psychotherapy, or a combination of both. Patients and providers should monitor depressive symptoms to identify their recurrence and work collaboratively to address barriers to care that exist in both urban and rural areas.

A Model of Community-Based Behavioral Intervention for Depression in Diabetes: Program ACTIVE

Depression affects one in four people with diabetes and significantly affects diabetes health. Earlier studies of the treatment of depression have documented that cognitive behavioral therapy (CBT) and exercise have each been found to be effective in treating depression in people with and without diabetes in the context of medical settings. Individuals in rural areas lack regular access to medical centers and require treatment options that may be adapted for local communities. To date, no studies have combined CBT and exercise for people with diabetes. This article presents a translational behavioral depression intervention study designed for individuals with type 2 diabetes in a rural Appalachian region as a model of an interdisciplinary approach to the treatment of depression in diabetes.

Integration of Infarct Size, Tissue Perfusion, and Metabolism by Hybrid Cardiac Positron Emission Tomography/Computed Tomography

Background— Hybrid positron emission tomography/computed tomography (PET-CT) allows for combination of PET perfusion/metabolism imaging with infarct detection by CT delayed contrast enhancement. We used this technique to obtain biomorphological insights into the interrelation between tissue damage, inflammation, and microvascular obstruction early after myocardial infarction.

Methods and Results— A porcine model of left anterior descending coronary artery occlusion/reperfusion was studied. Seven animals underwent PET-CT within 3 days of infarction, and a control group of 3 animals was scanned at >4 weeks. Perfusion and glucose uptake were assessed by [ 13 N]-ammonia/[ 18 F]-deoxyglucose (FDG), and 64-slice CT delayed contrast enhancement was measured. In the acute infarct model, CT revealed a no-reflow phenomenon suggesting microvascular obstruction in 80% of all infarct segments. PET showed increased FDG uptake in 68% of the CT-defined infarct segments. Ex vivo staining and histology showed active inflammation in the acute infarct area as an explanation for increased glucose uptake. In chronic infarction, CT showed no microvascular obstruction and agreed well with matched perfusion/metabolism defects on PET.

Conclusions— Perfusion/metabolism PET and delayed enhancement CT can be combined within a single hybrid PET-CT session. Increased regional FDG uptake in the acute infarct area is frequently observed. In contrast to the chronic infarct setting, this indicates tissue inflammation that is commonly associated with microvascular obstruction as identified by no reflow on CT. The consequences of these pathophysiological findings for subsequent ventricular remodeling should be explored in further studies.

Opioid detoxification using naloxone

A method of brief inpatient opioid detoxification using naloxone is described. Daily injections of naloxone were administered to 20 patients who were dependent on opioids until no physical withdrawal reaction occurred. A reducing regime of clonidine and diazepam was used to treat withdrawal symptoms. Seventy-five percent of patients successfully completed detoxification within 6 days. Withdrawal symptoms were minimal and rapidly declined during treatment. Unlike other techniques using opioid antagonists detoxification with daily naloxone injections requires minimal medical supervision, enables full participation in a daily relapse prevention programme and results in discharge from hospital without medication for symptomatic relief.

Complement receptor 2 polymorphisms associated with systemic lupus erythematosus modulate alternative splicing

Genetic factors influence susceptibility to systemic lupus erythematosus (SLE). A recent family-based analysis in Caucasian and Chinese populations provided evidence for association of single-nucleotide polymorphisms (SNPs) in the complement receptor 2 (CR2/CD21) gene with SLE. Here we confirmed this result in a case-control analysis of an independent European-derived population including 2084 patients with SLE and 2853 healthy controls. A haplotype formed by the minor alleles of three CR2 SNPs (rs1048971, rs17615, rs4308977) showed significant association with decreased risk of SLE (30.4% in cases vs 32.6% in controls, P=0.016, OR=0.90 (0.82-0.98)). Two of these SNPs are in exon 10, directly 5' of an alternatively spliced exon preferentially expressed in follicular dendritic cells (FDC), and the third is in the alternatively spliced exon. Effects of these SNPs and a fourth SNP in exon 11 (rs17616) on alternative splicing were evaluated. We found that the minor alleles of these SNPs decreased splicing efficiency of exon 11 both in vitro and ex vivo. These findings further implicate CR2 in the pathogenesis of SLE and suggest that CR2 variants alter the maintenance of tolerance and autoantibody production in the secondary lymphoid tissues where B cells and FDCs interact.

A polymorphism within interleukin-21 receptor (IL21R) confers risk for systemic lupus erythematosus and is associated with malar rash in lupus patients (49.17)

Interleukin (IL) 21 is a member of the type I cytokine superfamily that exerts a variety of effects on the immune system including B cell activation, plasma cell differentiation, and immunoglobulin production. The IL21 receptor (IL21R) is expressed on B cells, T cells, NK cells, and monocyte-derived dendritic cells. The expression of IL21R is reduced in B cells from lupus patients, while IL21 serum levels are increased in both lupus patients and some lupus-murine models. We recently reported that polymorphisms within the IL21 gene are associated with increased susceptibility to lupus. Herein, we genotyped SNPs in the IL21R gene located on chromosome 16p11. We identify and confirm the association between rs3093301 and lupus in two independent European-derived and Hispanic cohorts (p=7.2X10-5). In addition, the presence of the homozygous risk genotype in rs3093301 (A/A) was associated with the development of malar rash in the European-derived female lupus patients (OR=2.83, 95% CI=1.56-5.13, p=0.00045).

C8orf13/BLK association with systemic lupus erythematosus across different ethnicities (136.28)

SLE is a complex autoimmune disease with immunological abnormalities that targets B cell functions and development. Previous genome-wide association studies identified C8orf13/BLK as a novel SLE risk factor. BLK (B lymphoid tyrosine kinase) has been shown to have potential effects on B cell develoment. The main objectives of this study are to: 1.) assess this association in independent populations and 2.) determine if BLK risk alleles correlate with alteration in peripheral blood B cell development and protein expression. We genotyped 52 SNPs within the C8orf13/BLK region in European-derived, Asian and African American populations. rs13277113 is associated with SLE in all three populations. A few novel upstream SNPs within the intergenic region demonstrate a stronger association in Asians. Flow cytometry data suggests there is a significant difference in BLK expression and T2 cells B cell numbers between high-risk and non-risk individuals based on the risk haplotype. Our results suggest that the BLK genetic polymorphisms alter immune system development and function to increase the risk for SLE development. Supported by NIH RR020143, RR015577, NIAID-DAIT-BAA-05-11, AI031584, AR053483, AR48940, AI063274, AR052125, AR043247 and OCAST # HR08-037.

The effect of ractopamine supplementation at 5 ppm of swine finishing diets on growth performance, carcass composition and ultimate pork quality

Five hundred thirty-six finishing pigs were placed on experiment for an average of 26 d prior to slaughter, to determine the effects of 5 mg ractopamine hydrochloride (RAC) per kg of diet on growth performance, carcass composition and the eating quality of pork. Treatments included a control diet similar to a western Canadian commercial finishing diet and a treatment diet containing 5 mg RAC kg-1 with elevated amino acids, vitamins and minerals. The experiment started when average animal weight was 86 kg; pigs were marketed at an average liveweight of 118 kg. Two pigs were selected from each of 32 pens in week 4 of the experiment, for detailed carcass and meat quality evaluation, providing 16 pigs per gender per treatment. RAC-fed pigs reached market weight 4 d sooner (P < 0.05), grew 13 % faster (P < 0.05) and had 13% better feed efficiency (P < 0.05) than the controls. RAC-fed pigs also had 1 mm less backfat and 2.5 mm thicker loins (P < 0.05). Ultimate pH, purge loss and visual colour scores were unaffected by treatment but RAC-fed pigs had lower CIE a* and b* measurements (P < 0.05). RAC had no effect on juiciness, flavour, saltiness or overall acceptability (P > 0.10), but increased Warner-Bratzler shear force and reduced taste panel tenderness slightly (P < 0.05). The inclusion of 5 mg RAC kg-1 in a commercial finishing diet will increase the rate and efficiency of gain and improve carcass composition. Minimal impact on pork quality can also be expected with the use of RAC fed at this level. Key words: Ractopamine, swine, carcass composition, pork quality, beta-adrenergic agonist

Relationship of coronary calcium and myocardial perfusion in individuals with chest pain. Assessed by integrated rubidium-82 PET-CT

AIM

The integrated value of coronary calcium scoring added to myocardial perfusion assessment in hybrid PET-CT imaging remains poorly defined. In the present study, we sought to determine the relationship between calcium burden, other risk factors, and tissue perfusion in a group of patients with chest pain and predominantly intermediate likelihood for coronary artery disease.

PATIENTS, METHODS

In 70 patients, coronary calcium scores (CCS) were obtained in addition to rest/dipyridamole stress 82Rb perfusion images using a GE Discovery Rx hybrid PET-CT system. From static perfusion images, summed rest, stress and difference scores (SRS, SSS, SDS) were calculated using a 20-segment model. Absolute CCS was determined according to Agatston and age-, gender-, and ethnicity-matched CCS percentiles were calculated using the MESA database.

RESULTS

SSS, SRS and SDS were abnormal (>or=4) in 25 (36%), 17 (24%), and 12 (17%) patients. Mean CCS according to Agatston was 180+/-446(range 0-2122), and CCS percentile was 42+/-43(range 0-99). Absolute CCS correlated mildly but significantly with SSS (r=0.31, p=0.01), while CCS percentile did not (r=0.11, p=0.36). Of 49 patients with normal perfusion, 25 (57%) had CCS=0, and 8 (18%) had a CCS percentile>or=75th. Of 35 patients with a CCS=0, 26 (74%) had normal perfusion. Individuals in whom review of patient records revealed events during follow-up (n=10) had significantly higher SSS than those where no events were recorded (6.0+/-7.2 versus 2.9+/-3.1, p=0.03), and there was a trend towards higher CCS percentiles (62+/-36 versus 35+/-43, p=0.06).

CONCLUSION

Coronary calcifications and myocardial tissue perfusion, as interrogated in a single PET-CT imaging session, show only partial agreement in patients with chest pain. Both tests seem to reflect different pathophysiologic components, and may be complementary for definition of individual disease patterns.

Determinants of the response of left ventricular ejection fraction to vasodilator stress in electrocardiographically gated 82rubidium myocardial perfusion PET

PURPOSE

Myocardial perfusion imaging with (82)Rb PET allows for ECG-gated studies to be obtained early after radiotracer injection, capturing ventricular function close to peak pharmacologic action of dipyridamole. This is different from gated SPECT and may potentially provide additional diagnostic information. We sought to identify potential correlates of the PET-derived ejection fraction response to vasodilator stress.

METHODS

One hundred ten consecutive patients undergoing (82)Rb PET myocardial perfusion imaging during evaluation for coronary artery disease were included. Using a GE Discovery STRx PET-CT scanner, ECG-gated images (eight bins) were obtained at rest and 4 min after dipyridamole infusion, 90 s after infusion of 1,480-2,220 MBq of (82)Rb. Summed rest, stress, and difference scores (SRS, SSS, and SDS) were determined using a five-point scoring system and 20-segment model. Ejection fraction was calculated using automated QGS software.

RESULTS

Significant reversibility (SDS > or = 4) was found in 23 patients (21%). Mean LVEF in all patients was 47 +/- 13% at rest and 53 +/- 13% during dipyridamole. LVEF increased in 89 patients, and decreased in 17 patients during vasodilation. The change in LVEF was inversely correlated with SDS (r = -0.26; p = 0.007). Additionally, it was inversely correlated with resting LVEF (r = -0.20; p = 0.03) and SSS (r = -0.25; p = 0.009). No significant correlations were observed with SRS, heart rate, blood pressure, age, hypertension, hypercholesterolemia, or pretest likelihood of disease. At multivariate regression analysis, SDS was an independent predictor of the change in LVEF.

CONCLUSIONS

Gated (82)Rb PET during pharmacologic stress allows for assessment of the functional response to vasodilation. The magnitude of LVEF increase is determined by stress perfusion/reversible perfusion defects. Functional response to hyperemia may thus be incorporated in future evaluations of diagnostic and prognostic algorithms based on (82)Rb PET.

CT-based attenuation correction in 82Rb-myocardial perfusion PET–CT: incidence of misalignment and effect on regional tracer distribution

PURPOSE

Misalignment of low-dose-CT used for attenuation correction (AC) may cause artifacts in cardiac-PET-CT. The aim was to evaluate incidence and severity of misalignment and its quantitative effects on regional myocardial (82)Rb-distribution.

METHODS

Rest/dipyridamole (82)Rb-perfusion-PET-CT studies of 92 consecutive patients were analyzed for misalignment. Two different scanning protocols were employed: the first 57 patients had separate CTs for rest and stress PET. The following 35 patients had one CT at rest, used for AC of rest and stress PET. Misalignment was visually scored on a five-point scale (0 = no, 1 = minimal, 2 = mild, 3 = moderate, and 4 = severe). In five representative patients with normal perfusion and low probability of disease, 95 polarmaps were created by shifting CT vs PET prior to reconstruction of attenuation-corrected data sets using dedicated software (three dimensions of space; magnitude of shifts, 5, 10, 14 mm).

RESULTS

PET/CT -misalignment was detected in 60% of rest and 67% of stress studies. Alignment for rest was better than that for stress (0.7 +/- 0.7 vs 1.0 +/- 0.9, P = 0.03). Comparison of the two protocols revealed no effect on the alignment of the stress study (1.0 +/- 0.9 vs 1.0 +/- 0.9, P = 0.9). Quantitatively, the largest individual effect of any artificial misalignment was a 25% reduction of relative (82)Rb uptake. With a shift of 1 cm, the largest effect in an individual was a 19% decrease. Anterior wall was most frequently influenced by misalignment, but changes of uptake also occurred in all other segments.

CONCLUSIONS

Misalignment between CT and PET in cardiac-PET-CT influences regional tracer distribution in multiple segments. Repeated CT imaging after dipyridamole does not improve alignment. These results emphasize the need for strategies to improve coregistration in clinical imaging protocols.