Progression of atypical parkinsonian syndromes: PROSPECT-M-UK study implications for clinical trials

The advent of clinical trials of disease-modifying agents for neurodegenerative disease highlights the need for evidence-based end point selection. Here we report the longitudinal PROSPECT-M-UK study of progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), multiple system atrophy (MSA) and related disorders, to compare candidate clinical trial end points. In this multicentre UK study, participants were assessed with serial questionnaires, motor examination, neuropsychiatric and MRI assessments at baseline, 6 and 12 months. Participants were classified by diagnosis at baseline and study end, into Richardson syndrome, PSP-subcortical (PSP-parkinsonism and progressive gait freezing subtypes), PSP-cortical (PSP-frontal, PSP-speech and language and PSP-CBS subtypes), MSA-parkinsonism, MSA-cerebellar, CBS with and without evidence of Alzheimer's disease pathology and indeterminate syndromes. We calculated annual rate of change, with linear mixed modelling and sample sizes for clinical trials of disease-modifying agents, according to group and assessment type. Two hundred forty-three people were recruited [117 PSP, 68 CBS, 42 MSA and 16 indeterminate; 138 (56.8%) male; age at recruitment 68.7 ± 8.61 years]. One hundred and fifty-nine completed the 6-month assessment (82 PSP, 27 CBS, 40 MSA and 10 indeterminate) and 153 completed the 12-month assessment (80 PSP, 29 CBS, 35 MSA and nine indeterminate). Questionnaire, motor examination, neuropsychiatric and neuroimaging measures declined in all groups, with differences in longitudinal change between groups. Neuroimaging metrics would enable lower sample sizes to achieve equivalent power for clinical trials than cognitive and functional measures, often achieving N < 100 required for 1-year two-arm trials (with 80% power to detect 50% slowing). However, optimal outcome measures were disease-specific. In conclusion, phenotypic variance within PSP, CBS and MSA is a major challenge to clinical trial design. Our findings provide an evidence base for selection of clinical trial end points, from potential functional, cognitive, clinical or neuroimaging measures of disease progression.

Annotation and quality assessment of left ventricular filling and relaxation pattern using one-dimensional convolutional neural network

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institute For Health Research (NIHR), UK

Introduction

Aberrations in left ventricular (LV) filling or relaxation – known as diastolic dysfunction – occur in heart failure with preserved ejection fraction. CMR is the reference modality for the assessment of ventricular systolic function, however, its role in evaluation of diastolic function is limited at present. One promising technique to assess diastolic function by CMR is the derivation of LV filling and emptying rates from the volume-time curves of cine images.

Purpose

To automatically assess the quality of LV filling-rate curves and annotate the peak emptying and filling rates.

Methods

A previously-described deep-learning network was used to automatically segment the entire cardiac cycle captured by short-axis SSFP cine images from the UK Biobank1. The LV filling-rate curves derived from the volume-time data were smoothed with Savitzky–Golay filter. The peak emptying rate (PER), early peak filling rate (PFR-E) and late peak filling rate (PFR-A) were first annotated by a simple peak finding algorithm from Python Scipy signal module. The preliminary annotated curves were reviewed by five human experts (i) to check for peak-annotation errors and (ii) to provide the curve quality score ranging from 1 to 3 for each peak (score 1 denotes good quality, score 2 represents moderate quality and score 3 indicates poor quality). Higher total score (minimum = 3, maximum = 9), therefore, represents poorer overall curve quality. This expert-annotated dataset was used to train two separate one-dimensional convolutional neural networks (1D-CNN) (Figure 1) for peak annotation and curve quality assessment (QA) using Tensorflow library in Python.

Results

The data from 6,328 LV filling-rate curves were split into the training and testing sets (80:20). The fine-tuned 1D-CNN comprising six hidden layers with two residual connections annotated the PER, PFR-E and PFR-A with the test-set accuracy of 95%, 95% and 98%, respectively. A second trained 1D-CNN for QA based on similar architecture predicted the overall curve quality score with a small error rate (mean absolute error: 0.46, mean squared error: 0.68). These two networks were used to quality check and label 19,409 UK Biobank CMR studies (See Figure 2 for exemplary results). After removing data from poor-quality curves (quality score ≥ 5), 18,735 studies remained. The mean±standard deviation of PER, PFR-E and PFR-A are 461±110 ml/s, 359±117 ml/s and 336±120 ml/s, respectively. Ageing is associated with lower PFR-E (−58.4 ml/s, 95% confidence interval [CI]: −56.1 to −60.7 ml/s per decade increment) and higher PFR-A (18.3 ml/s, 95% CI: 15.8 to 20.8 ml/s per decade increment).

Conclusion

The 1D-CNN models can be used to automatically grade the quality of LV filling rate curves and label important diastolic parameters with a high level of accuracy. The derived data recapitulate impaired LV relaxation pattern associated with ageing and can be used as surrogate indices of diastology by CMR. Figure 1Figure 2

Left atrial strain predicts subclinical atrial fibrillation detected by long-term continuous rhythm monitoring in elderly high-risk individuals

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): he Innovation Fund Denmark (grant no.: 12-135225), The Research Foundation for the Capital Region of Denmark, The Danish Heart Foundation (grant no.: 11-04-R83-A3363-22625 and 18-R125-A8534-22083), Aalborg University Talent Management Programme, Arvid Nilssons Fond, Skibsreder Per Henriksen, R. og Hustrus Fond, and Medtronic

Background

Left atrial (LA) speckle tracking is a novel technique that provides detailed information on atrial function. Its utility for predicting subclinical atrial fibrillation (SCAF) is, however, not well-established.

Purpose

To investigate whether LA speckle tracking measures are associated with SCAF as detected by long-term continuous rhythm monitoring.

Methods

This was an echocardiographic substudy of a randomized controlled clinical trial that enrolled elderly individuals (≥70 years) with a CHADS2-score≥2 to either no intervention or implantation of a loop recorder (Reveal LINQ) to detect SCAF (≥6 minutes). A subset of the participants receiving a loop recorder was included in this analysis. An echocardiographic examination was performed, which included conventional measurements and LA speckle tracking. LA speckle tracking allowed for assessment of reservoir, conduit, and contraction strain. Multivariable proportional hazards Cox regression was applied to adjust for the clinical risk score (CHARGE-AF) and net reclassification index (NRI) was used to assess prognostic improvement of this score. Incidence rate curves were constructed using Poisson models.

Results

Overall, 976 participants were eligible for analysis. Median follow-up time was 3 years (interquartile range: 1.7-4.0 years), during which 284 (29%) were diagnosed with SCAF. The mean age was 74 years, 56% were male, median CHA2DS2-VASc-score was 4. A dilated LA (LA volume≥34ml/m2) was observed in 152 (16%).

LA speckle tracking revealed that both LA reservoir strain and contraction strain were univariable predictors of SCAF (HR = 1.05 (1.03-1.06) and HR = 1.07 (1.05-1.10), p &lt; 0.001, per 1% decrease), such that decreasing reservoir and contraction strain were linearly associated with an increased risk of SCAF (figure). LA conduit strain was not a predictor of SCAF. These findings were unchanged after adjusting for the CHARGE-AF score, and both LA strain measures significantly improved the NRI when added to the CHARGE-AF score by 23% and 33%, respectively.

Even in participants with normal LA size, both reservoir and contraction strain were independent predictors of SCAF after multivariable adjustment (HR = 1.03 (1.01-1.05), p = 0.001 and HR = 1.06 (1.04-1.09), p &lt; 0.001, per 1% decrease).

Conclusion

Decreasing left atrial reservoir and contraction strain are independently associated with an increased risk of SCAF as detected by long-term continuous monitoring and provide incremental prognostic value in addition to clinical risk score.

Abstract Figure.

3080Postsystolic shortening yields novel and independent prognostic information on cardiovascular events and mortality in patients with type 2 diabetes

Background

Cardiovascular disease is the leading cause of death and disability in patients with type 2 diabetes. We aimed to evaluate if postsystolic shortening, a marker of impaired myocardial function, may provide prognostic information on cardiovascular events and mortality in patients with type 2 diabetes.

Method

We prospectively studied 783 patients with diabetes type 2 (63% male, age 65 [58, 70] years; HbA1c 54 [48, 65] mmol/mol; diabetes duration 11 [6, 17] years) who underwent speckle tracking echocardiography. Patients with left bundle branch block, atrial fibrillation and a history of heart failure and myocardial infarction were excluded. The primary endpoint was the composite of incident heart failure, myocardial infarction and cardiovascular death. The secondary endpoint was all-cause death. We defined the postsystolic index (PSI) as: [100x (maximum strain in cardiac cycle – peak systolic strain)/ (maximum strain in cardiac cycle)].

Results

During the median follow-up of 4.9 years [4.2, 5.3], 87 patients (11%) reached the primary endpoint and 80 (10%) died from any cause. Each 1% increase in the PSI was associated with the primary (HR 1.07 95% CI 1.02–1.13, P<0.001, Fig A) and secondary endpoint (HR 1.09 95% CI 1.04–1.14, P<0.001, Fig B). After adjusting for age, sex, hypertension, smoking, duration of diabetes, cholesterol, eGFR, left ventricular ejection fraction and mass index, E/A-ratio, deceleration time and left atrial volume index, the PSI remained an independent predictor of both endpoints; primary (HR 1.07 per 1% increase 95% CI 1.01–1.14, P=0.028) and secondary endpoint (HR 1.07 per 1% increase, 95% CI 1.01–1.14, P=0.022).

PSI and the endpoints

Conclusion

In patients with type 2 diabetes, assessment of PSI yields novel and independent prognostic information on cardiovascular events and mortality. Hence, PSI may offer guidance on risk stratification in patients with type 2 diabetes.

P2487Echocardiography and NT-ProBNP both provide independent and improved prediction of prognosis in a type 1 diabetes population without heart disease and with preserved ejection fraction

Background

Cardiovascular disease is the most common comorbidity in type 1 diabetes (T1D). Current guidelines, however, do not include routine echocardiography or cardiac biomarkers in T1D.

Objectives

To investigate if echocardiography and NT-proBNP provide incremental prognostic information in individuals with T1D without heart disease and with preserved left ventricular ejection fraction (LVEF).

Methods

A prospective cohort of individuals with T1D without heart disease and with preserved LVEF (≥45%) from the outpatient clinic were included. Follow-up was performed through Danish national registers. The association between E/e', a marker of diastolic function, from echocardiography and NT-proBNP with major adverse cardiovascular events (MACE) was tested. MACE was defined as death from all-causes, acute coronary syndromes, cardiac revascularization, incident heart failure, or stroke. Additionally, the incremental prognostic value when adding E/e' and NT-proBNP to the clinical Steno T1D Risk Engine score (including age, sex, duration of diabetes, systolic blood pressure, LDL, HbA1c, presence of albuminuria (micro-or macroalbuminuria), eGFR, smoking status, and physical activity [low, medium, high]), was examined. Follow-up was 100% complete.

Results

Of 964 individuals (mean (SD)) age 49.7 (14.5) years, 51% men, HbA1c 66 (14) mmol/mol, BMI 25.6 (4.0) kg/m2, and diabetes duration 26.1 (14.5) years), 121 (12.6%) experienced MACE during 7.5 years of follow-up. In the full multivariable model, E/e' significantly and independently predicted MACE: (HR (95%)) E/'e <8 (n=639) vs. 8–12 (n=248): 2.00 (1.23; 3.25), p=0.005, E/'e <8 vs E/e'≥12 (n=77): 3.36 (1.8; 6.1), p<0.001. Also, NT-proBNP significantly predicted outcome: NT-proBNP <150 pg/ml (n=435) vs. 150–450 pg/ml (n=386): 1.52 (0.9; 2.5), p=0.11, NT-proBNP <150 pg/ml vs NT-proBNP >450 pg/ml (n=143): 2.78 (1.6; 4.9), p<0.001. Adding both (log)E/e' and (log)NT-proBNP to the Steno T1D Risk Engine score significantly and incrementally improved risk prediction: Harrell's C-index: Steno T1D Risk Engine (AUC 0.783 (0.747; 0.818)) vs. Steno T1D Risk Engine + (log)E/e' (AUC 0.805 (0.773; 0.837)): p<0.001 and Steno T1D Risk Engine + (log)E/e' + (log) NT-proBNP (AUC 0.816 (0.783; 0.848)): p=0.002. The risk of MACE by groups of E/e' and NT-proBNP is shown in the figure.

Figure 1

Conclusion

In individuals with T1D without heart disease and with preserved LVEF, E/e' and NT-proBNP significantly improved risk prediction of cardiovascular events beyond clinical risk factors alone. Echocardiography and NT-proBNP could have a role in clinical care.

P4989Peripheral neuropathy and diastolic function are associated with adverse cardiovascular outcome in patients with type 1 diabetes mellitus: results from the thousand & 1 study

Background

Peripheral neuropathy (PN) is a highly prevalent and feared microvascular complication in patients with type 1 diabetes (T1D). Cardiovascular disease (CVD) is the most common cause of mortality in patients with T1D. PN may act as an early indicator of CVD and can potentially contribute to the propagation of atherosclerosis and cause the disease to remain clinically silent into advanced stages. Therefore, identification of T1D patients at risk of CVD is important in assuring timely prevention and treatment.

Purpose

The purpose of this study was to evaluate the risk of major adverse cardiovascular events (MACE) associated with measures of PN and diastolic function (DF) in patients with T1D and no known heart disease. Furthermore, we tested the additional prognostic value of including PN and DF both alone and in combination, in the validated Steno T1D Risk Engine.

Methods

Patients with T1D without known heart disease were included from the Steno Diabetes Center Copenhagen. Echocardiography and quantitative testing for PN using biothesiometry to determine sensory vibration threshold were performed. The patients were divided into three categories according to sensory threshold: <20mV, 20–49 mV, and ≥50mV. DF was divided into three categories of E/e': <8, 8–12, and >12. Endpoints was first occurring MACE. Using multivariable Cox regression models adjusting for age, sex, blood pressure, BMI, HbA1c, smoking, alcohol consumption, family history of CVD, eGFR, albuminuria, and duration of diabetes, the association between PN and/or DF and the risk of MACE was analysed. Improvement in prediction of prognosis was assessed with Harrell's C-statistics and compared to Steno T1D Risk Engine.

Results

A total of 946 patients (51.5% males) with T1D were included. Mean age was 48.4 (SD 14.4) years and mean duration of diabetes was 25 (SD 14.3) years. In the adjusted analysis, which was mutually adjusted for measures of PN and DF, both PN and DF were associated with increased risk of MACE: Sensory threshold ≥50mV vs. <20mV: Hazard Ratio (HR) 2.18 (95% confidence interval [CI]: 1.02–4.64, p=0.044). Threshold 20–49mV vs. <20mV: HR 1.33 (95% CI: 0.77–2.30, p=0.31). Diastolic measurement E/e' >12 vs. E/e' <8: HR 2.31 (95% CI: 1.16–4.59, p=0.017), and E/e' 8–12 vs. E/e' <8: HR 1.70 (95% CI: 1.03–2.82, p=0.038). In combination, a threshold ≥50mV and E/e' >12 vs. <20mV and E7e' <8 was associated with a marked increased risk of MACE: HR 8.59 (95% CI: 2.60–28.4, p<0.001). The addition of E/e' to the Steno T1D Risk Engine improved the prediction of outcome: C-statistic 0.797, (95% CI: 0.758–0.835) vs. 0.785 (95% CI: 0.744–0.825), p<0.001.

Conclusion

In patients with T1D without known heart disease and with preserved ejection fraction, PN and DF are independently associated with an increased risk of MACE. However, only measures of DF improved the prediction of prognosis when added to clinical risk factors.

Acknowledgement/Funding

None

P2442Myocardial performance index predicts mortality in people with obstructive lung function from the general population

Background

Forced expiratory volume in one second (FEV1) is a significant predictor of mortality in patients with obstructive lung function (OL). Whether echocardiography can be used to identify patients at high risk, and whether it provides incremental prognostic information on mortality in patients with OL, remains unknown.

Methods

In a large, low-risk general population study, 1873 participants underwent a health examination with spirometry and echocardiography, including tissue Doppler imaging (TDI). The myocardial performance index (MPI) was calculated as the sum of the isovolumic contraction time (IVCT) and the isovolumic relaxation time (IVRT) divided by the left ventricle ejection time (LVET). Spirometry included measurements of (FEV1) and the forced vital capacity (FVC). OL was defined as FEV1/FVC <0.70. The primary endpoint was all-cause mortality.

Results

The mean age was 59±16 years, 57% were women, 43% had hypertension, 11% had diabetes, and 6% had ischemic heart disease. Of the 1873 included participants, 288 (15%) were classified as having OL at baseline. During follow up (median 13.7 years (IQR 13.2–16.2)), 584 (31%) persons died, hereof 178 (62%) in the subgroup of participants with OL and 406 (26%) in the subgroup of participants with normal lung function.

OL was associated with presence of left ventricular hypertrophy (higher left ventricular mass index), impaired diastolic function (lower E, higher A, lower E/A ratio, longer deceleration time, lower e' and higher E/e'), lower global longitudinal strain, and higher MPI.

In unadjusted analysis, higher MPI was associated with all-cause mortality for participants with OL (HR=1.18 (1.11–1.26), p<0.001, per 0.1 increase) and for participants with normal lung function (HR=1.42 (1.34–1.50), p<0.001, per 0.1 increase). The predictive value of MPI was significantly modified by the presence of obstructive lung function (p<0.001).

After multivariable adjustment for age, sex, FEV1/FVC, heart rate, systolic blood pressure, smoking status, body mass index (BMI), hypertension, diabetes, ischemic heart disease, ischemic stroke and heart failure at baseline, MPI remained an independent predictor of all-cause mortality (HR=1.19 (1.06–1.34), p=0.004, per 0.1 increase) for participants with OL but not for participants with normal lung function (HR=1.02 (0.94–1.11), p=0.598, per 0.1 increase).

When adding the MPI to the updated Age, Dyspnea and Obstruction (ADO) index, MPI provided incremental prognostic information beyond the updated ADO index, as determined from a significant increase in the Harrell's C-statistics (0.785 to 0.792, p=0.003).

Conclusion

Presence of OL is associated with subtle impairment of left ventricular systolic function, impaired left ventricular diastolic function, and higher MPI. MPI is an independent predictor of mortality in people with OL and provides incremental prognostic information regarding all-cause mortality in this population.

Acknowledgement/Funding

Herlev & Gentofte University Hospital PhD fund

P3427Prognostic performance of echocardiography, electrocardiogram, albuminuria, plasma proBNP and hs-TnI in patients with type 2 diabetes

Background

A range of diagnostic tests including echocardiography, albuminuria, electrocardiogram (ECG), plasma measurement of high sensitivity troponin T (hs-TnI) and pro-brain natriuretic peptide (proBNP) have been suggested as cardiovascular (CV) risk predictors in patients with type 2 diabetes. In this study we examined prognostic yield from these risk markers.

Methods

A total of 1,030 out-patients followed at a large secondary care diabetes clinic were recruited. Echocardiography was considered feasible in patients in sinus rhythm with adequate image quality (n=886). Abnormal echocardiography was defined as a left ventricular ejection fraction (LVEF) <50%; a ratio of early diastolic mitral inflow velocity to early diastolic septal annular velocity (E/e'septal) ≥15; increased left ventricular mass index (>95 g/m2 for women and >115 g/m2 for men) or left atrial volume index >34 ml/m2. ECG was performed in 983 patients and was considered abnormal in the presence of abnormal Q-waves; ST-T segment deviation or bundle branch block. We measured urine albumin (n=1,009) and proBNP/hs-TnI (n=933). The end-point of CV event was a composite of CV death and hospitalization with myocardial infarction/revascularization, stroke, peripheral artery disease or heart failure.

Results

The median follow-up was 4.7 years (interquartile range: 4.0 to 5.3) and 174 patients suffered an CVD event. All markers except hs-TnI were significantly (p<0.001) associated with the composite outcome: Abnormal echocardiogram: Hazard ratio (95% confidence interval): 2.39 (1.69–3.37); albuminuria 2.01 (1.47–2.76); abnormal ECG 2.35 (1.72–3.21); log2(proBNP) 1.60 (1.47–1.75) and hs-TnI 1.05 (0.92–1.19). The findings persisted after adjusting for clinical variables, but after adjusting for the other markers, only log2(proBNP) remained associated with the composite outcome (1.50 (0.20–1.73), p<0.001), figure. Measured by C-index model performance was highest with proBNP (0.70 (0.65–0.75)) and similar to clinical variables (0.71 (0.67–0.76)). Combining risk markers only resulted in very limited increase in C-index (echocardiogram, albuminuria, ECG and proBNP: 0.71 (0.66–0.76)).

Uni- and multivariables

Conclusions

This study identifies proBNP measurement in plasma over echocardiography, ECG and albuminuria for risk prediction in patients with type 2 diabetes. The diagnostic yield in considering more than one risk marker was limited in this population.

P4449Incident cardiovascular disease in patients with type 2 diabetes: Established cardiovascular disease versus traditional risk markers

Background/Introduction

It is well established that patients with both T2D and established cardiovascular disease (CVD) are at high-risk of a re-event and should be treated with either a glucagon-like peptide-1 (GLP-1) analogue or a sodium-glucose transporter-2 (SGLT-2) inhibitor. Other high-risk patients with T2D may also benefit from these treatments. Whether traditional risk markers can identify patients with T2D without CVD with a similar incidence of CVD events as patients with T2D with established CVD is unknown.

Purpose

To compare the CVD incidence in patients with T2D with and without established CVD, stratified according to mid-regional pro-atrial natriuretic peptide (MR-proANP), albuminuria, electrogardiogram (ECG), echocardiography and age, to identify patients without established CVD who are at high risk of a CVD event.

Methods

In this prospective cohort study, patients with T2D (n=921) from a specialized diabetes clinic were examined at baseline regarding the different risk markers. Increasing cut-offs for MR-proANP were analysed to identify high-risk patients. Albuminuria included both micro- and macroalbuminuria. An abnormal ECG was defined as the presence of ST-/T-changes, bundle branch block or atrial fibrillation, and an abnormal echocardiography was defined as either heart failure with preserved (HFpEF) or reduced (HFrEF) ejection fraction. Established CVD was reported at baseline as prior myocardial infarction, coronary revascularization, cerebrovascular disease or peripheral artery disease. Information regarding CVD events was retrieved through national registers and a CVD event was similarly defined as established CVD, but in addition also included hospitalisation for heart failure and CVD death.

Results

In total, 224 (24%) patients had established CVD at baseline. Median [interquartile range] of follow-up was 4.7 [4.0–5.3] years. The incidence of CVD events among patients with established CVD was 95.7 per 1000-person years. Using a cut-off for MR-proANP of 190 pmol/l revealed that patients with a value above had similar incidence (93.9 per 1000-person years) and was found in 47 of 697 (6.7%) patients without CVD. In contrast, patients without CVD and with albuminuria (146 of 685 (21.3%) patients) or abnormal ECG (147 of 679 (21.6%)) or abnormal echocardiography (221 of 618 (35.7%)) or an age>65 years (335 of 697 (35.7%)) had substantial lower incidence (47.1, 35.1, 32.7 and 33.7 per 1000-person years, respectively).

Kaplan-Meier curves

Conclusion(s)

In patients with T2D without established CVD, using a range of traditional risk markers, we were only able to identify a subgroup of patients with MR-proANP values above 190 pmol/l who had a similar high incidence of CVD as T2D patients with established CVD. This subgroup may benefit from treatment with a GLP-1 analog or a SGLT-2 inhibitor. In contrast, the presence of other traditional risk markers in T2D was not associated with risk of incident CVD similar to patients with established CVD.

Acknowledgement/Funding

Thermo Fisher Scientific (Germany) funded the MR-proANP kits

Cardiac repolarization and depolarization in people with Type 1 diabetes with normal ejection fraction and without known heart disease: a case-control study

AIMS

To investigate depolarization and repolarization durations in people with Type 1 diabetes, including the relationship to age.

METHODS

855 persons with Type 1 diabetes without known heart disease were included and matched with 1710 participants from a general population study. Clinical examinations, questionnaires and biochemistry were assessed. A 10-second 12-lead ECG was performed and analysed digitally.

RESULTS

QT_c was longer in people with Type 1 diabetes compared to controls (414±16 vs. 411±19 ms, P <0.001), and particularly so in young people with Type 1 diabetes. The fully adjusted increase was 13.8 ms (95% confidence interval (CI): 8.6-19.0 ms, P <0.001) at age 20 years and 3.4 ms (CI: 1.5-5.3 ms, P<0.001) at age 40 years. The rate-corrected QRS_c was increased in people with Type 1 diabetes (97±11 vs. 95±11 ms, P <0.001) and was age-independent (P =0.5). JT_c was increased in the young people with Type 1 diabetes (10.7 ms (CI: 5.4-16.0 ms, P <0.001) at age 20 years), but not in older people with Type 1 diabetes (interaction age-diabetes, P <0.01).

CONCLUSIONS

For people with Type 1 diabetes, cardiac depolarization is increased at all ages, whereas repolarization is increased only relatively in young people with Type 1 diabetes. Hence, young people with Type 1 diabetes may be more prone to ventricular arrhythmias. The findings contribute to the understanding of sudden cardiac death in young people with Type 1 diabetes.

Glycated haemoglobin and the risk of cardiovascular disease, diabetes and all-cause mortality in the Copenhagen City Heart Study

OBJECTIVE

Individuals with diabetes mellitus (DM) have a considerably elevated risk of developing serious health problems including cardiovascular disease (CVD). Long-term elevated levels of blood glucose in nondiabetic individuals may also be associated with increased risk of CVD. The aim of this study was to investigate the relationships between glycated haemoglobin A(1c) (HbA(1c) ) and CVD, DM and all-cause mortality.

SUBJECTS AND DESIGN

The Copenhagen City Heart Study is a prospective study of individuals from the Danish general population. The cohort was followed for 10 years via national registers with respect to incident CVD, DM and all-cause mortality. Follow-up was 100% complete.

RESULTS

A total of 5127 subjects were included, of whom 597 had DM. In the nondiabetic population, HbA(1c) was significantly associated with incident CVD events in both univariate [hazard ratio (HR) 1.38, 95% CI 1.11-1.71] and multivariate analyses (HR 1.31, 95% CI 1.05-1.64). In the nondiabetic population, increased levels of HbA(1c) were correlated with developing DM. There was a threefold increase in risk of incident DM per unit increase in HbA(1c) with a univariate HR of 3.83 (95% CI 1.96-7.51). This relationship was essentially unchanged after multivariate adjustments (HR 4.19, 95% CI 2.01-8.71). Furthermore, we found that net reclassification improvement for diagnosed DM and CVD was significantly improved with the addition of HbA(1c) in the analyses. Although not statistically significant, we found a strong trend towards an association between HbA(1c) and all-cause mortality (HR 1.21, 95% CI 0.99-1.47). We did not find the same associations amongst the population with DM.

CONCLUSION

In the Danish general population, HbA(1c) was strongly associated with CVD in individuals without DM.

A comparison of warmed-over flavour in pork by sensory analysis, GC/MS and the electronic nose

Pork muscle samples (M. longissimus dorsi and M. psoas major) were obtained from pigs given one of 4 dietary treatments, (i) control diet, (ii) supplemental iron (300 mg iron (II) sulphate/kg feed), (iii) supplemental vitamin E (200 mg dl-α-tocopheryl acetate/kg of feed) and (iv) supplemental vitamin E+supplemental iron. Warmed-over flavour (WOF) was evaluated by a trained sensory panel (n=8) for the four treatments cooked and refrigerated at 4 °C for up to 5 days. Gas chromatography mass spectrometry (GC/MS) and Electronic nose analysis was performed on a subset of the full design which included samples of M. longissimus dorsi, treatments (ii) and (iii) and M. psoas major with treatment (i) for 0 days of WOF development. Day 5 of WOF development was included in the subset and represented by samples of M. longissimus dorsi, treatment (iv) and M. psoas major, treatments (ii) and (iii). Bi-linear modeling was used to determine the correlation of GC/MS and electronic nose data to sensory data. Also, the reproducibility and reliability of electronic nose data was evaluated by repeating the analysis of samples in a different laboratory and with a time difference of approximately 11 months. Mean-centring was used to normalise the data from these two different electronic noise data sets. GC/MS data correlated to sensory data with specific compounds (e.g., pentanal, 2-pentylfuran, octanal, nonanal, 1-octen-3-ol and hexanal), proving to be good indices of oxidation in cooked samples of M. longissimus dorsi and M. psoas major. Electronic nose data correlated to sensory data and separated the sensory variation. The reproducibility of this data was high with the second set of samples being predictive of the first set.

Abstract P3-15-04: The Clinical Course of Metastatic Breast Cancer Patients with a Congestive Heart Failure after an Epirubicin-Based Treatment

Background. Patients treated with epirubicin are at risk for the development of congestive heart failure (CHF). However, only limited data are available, which is describing the outcome for these patients. Materials and methods. The patients were recruited consecutively from 1,097 anthracycline-naïve patients with metastatic breast cancer, who were admitted to Herlev Hospital from November 1983 - November 2003 for an epirubicin-based chemotherapy. No patients had a history of heart disease. The outcome of 125 metastatic breast cancer patients, with a CHF Class ≥ II according to New York Heart Association (NYHA) guidelines after an epirubicin-based treatment, was performed retrospectively. Univariate ordinal logistic regression was used to study the association between NYHA class at time of CHF (II, III or IV) and possible risk factors. Two multiple Cox regression analyses (events: mortality of cardiotoxicity and mortality of other causes) were performed to evaluate the risk of cardiac death.

Results. CHF was developed within a median time from cessation of epirubicin on 3 months (range 0 to 66.7 months). The distribution of patients in the NYHA class II, III, IV and NYHA class ≥2 was; 35 patients (28%), 38 patients (30.4%), 39 patients (31.2%) and 13 patients (10.4%), respectively. No predictive factors, including increasing cumulative dose of epirubicin, co-morbidities and age had an influence on the severity of CHF. The median survival of all patients was 7.3 months (range 0.01 to +121.1 months). Deaths caused by CHF occurred in 27 patients (21.6%) in a median time on 1.2 months (range 0 - 77 months), including 6 patients (4.8%) dying of cardiac failure &lt; 10 days after the diagnosis. Only the NYHA class patient had was the only risk factor for dying of CHF (p = 0.0003). Compared to patients in NYHA class II and III, the risk of cardiac death in patients with NYHA class IV was increased with 93% and 74%, respectively.

Survival in patients with stable CHF was comparable to other patients with metastatic breast cancer.

Discussion. Although the information is obtained retrospectively during a period of twenty years; the study is important, as only limited information is available on the course of CHF patients. The study showed that the risk of cardiac death were closely related to the degree of cardiac toxicity as the risk of cardiac death was 93% or 74% higher for patients in NYHA class IV than for patients in NYHA class II or III. Moreover, the outcome for the patients when CHF is stabilized can be expected to be as patients without CHF. Furthermore, no predictive factors were identified, including increasing cumulative dose of epirubicin for the severity of cardiotoxicity developed.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-15-04.

A diet high in omega-3 fatty acids does not improve or protect cognitive performance in Alzheimer’s transgenic mice

Although a number of epidemiologic studies reported that higher intake of omega-3 fatty acids (largely associated with fish consumption) is protective against Alzheimer's disease (AD), other human studies reported no such effect. Because retrospective human studies are problematic and controlled longitudinal studies over decades are impractical, the present study utilized Alzheimer's transgenic mice (Tg) in a highly controlled study to determine whether a diet high in omega-3 fatty acid, equivalent to the 13% omega-3 fatty acid diet of Greenland Eskimos, can improve cognitive performance or protect against cognitive impairment. Amyloid precursor protein (APP)-sw+PS1 double transgenic mice, as well as nontransgenic (NT) normal littermates, were given a high omega-3 supplemented diet or a standard diet from 2 through 9 months of age, with a comprehensive behavioral test battery administered during the final 6 weeks. For both Tg and NT mice, long-term n-3 supplementation resulted in cognitive performance that was no better than that of mice fed a standard diet. In NT mice, the high omega-3 diet increased cortical levels of omega-3 fatty acids while decreasing omega-6 levels. However, the high omega-3 diet had no effect on cortical fatty acid levels in Tg mice. Irrespective of diet, no correlations existed between brain omega-3 levels and cognitive performance for individual NT or Tg mice. In contrast, brain levels of omega-6 fatty acids were strongly correlated with cognitive impairment for both genotypes. Thus, elevated brain levels of omega-3 fatty acids were not relevant to cognitive function, whereas high brain levels of omega-6 were associated with impaired cognitive function. In Tg mice, the omega-3 supplemental diet did not induce significant changes in soluble/insoluble Abeta within the hippocampus, although strong correlations were evident between hippocampal Abeta(1-40) levels and cognitive impairment. While these studies involved a genetically manipulated mouse model of AD, our results suggest that diets high in omega-3 fatty acids, or use of fish oil supplements (DHA+EPA), will not protect against AD, at least in high-risk individuals. However, normal individuals conceivably could derive cognitive benefits from high omega-3 intake if it corrects an elevation in the brain level of n-6 fatty acids as a result. Alternatively, dietary fish may contain nutrients, other than DHA and EPA, that could provide some protection against AD.

Lifelong immunization with human beta-amyloid (1-42) protects Alzheimer's transgenic mice against cognitive impairment throughout aging

Although both active and passive beta-amyloid (Abeta) immunotherapy have been shown to protect against or lessen cognitive impairment in various Alzheimer's transgenic mouse lines, these studies have focused on a single task and involved standard statistical analysis. Because Alzheimer's disease impacts multiple cognitive domains, the current study employed an extensive behavioral battery and multimetric analysis therein to determine the impact of Abeta immunization given throughout most of adult life (from 2-16 1/2 months of age) to APP+PS1 transgenic mice. At both adult (4 1/2-6 month) and aged (15-16 1/2 month) test points, the same 6-week behavioral battery was administered. Results indicate that Abeta immunotherapy partially or completely protected APP+PS1 mice at both test points from otherwise impaired performance in a variety of tasks spanning multiple cognitive domains (reference learning/memory, working memory, search/recognition). At both adult and aged test points, the cognitive benefits of Abeta immunotherapy were evident even when behavioral measures were analyzed collectively (as "overall" performance) through discriminant function analysis. Since behavioral protection at the 15-16 1/2 month test point occurred without a decrease in (or correlation to) Abeta deposition, the mechanism of Abeta immunotherapy's action most likely involves neutralization/removal of small Abeta oligomers from the brain. However, in factor analysis performed at this aged test point, brain Abeta deposition measures loaded heavily with key cognitive measures. Collectively, our results suggest that the entire process of Abeta deposition deleteriously impacts cognitive performance and that Abeta-based preventative strategies can provide long-term cognitive benefits extending well into older age.

Synthesis of nitrogen analogues of salacinol and their evaluation as glycosidase inhibitors

The syntheses of two nitrogen analogues (11 and 12) of the naturally occurring sulfonium ion, salacinol (7) are described. The latter compound is one of the active principles in the aqueous extracts of Salacia reticulata that are traditionally used in Sri Lanka and India for the treatment of diabetes. The synthetic strategy relies on the nucleophilic attack of a 1,4-dideoxy-1,4-imino-D- or L-arabinitol at the least hindered carbon of 2,4-O-benzylidene D- or L-erythritol-1,3-cyclic sulfate. The nitrogen analogues bear a permanent positive charge and serve as mimics of the sulfonium ion. We reasoned that these ammonium derivatives should function in a manner similar to that of known glycosidase inhibitors of the alkaloid class such as castanospermine (4) and deoxynojirimycin (5). Enzyme inhibition assays indicate that salacinol (7) is a weak (K(i) = 1.7 mM) inhibitor of glucoamylase, whereas compounds 11 and 12 inhibit glucoamylase with K(i) values in the range approximately 10-fold higher. The nitrogen analogues 11 and 12 showed no significant inhibitory effect of either barley alpha-amylase (AMY1) or porcine pancreatic alpha-amylase (PPA) at concentrations of 5 mM. In contrast, salacinol (7) inhibited AMY1 and PPA in the micromolar range, with K(i) values of 15 +/- 1 and 10 +/- 2 microM, respectively.

3-Methylindole (skatole) and indole production by mixed populations of pig fecal bacteria

Pig fecal slurries converted added L-tryptophan either to indole without detectable intermediates or to 3-methylindole (skatole) via indole-3-acetate. The initial rate of production of 3-methylindole was greatest at pH 6.5 and less at pH 5.0 and 8.0; the initial rates of indole production were similar at pH 6.5 and 8.0. More than 80% of the tryptophan added was converted to 3-methylindole at pH 5.0; at pH 8.0 85% was converted to indole. Both pathways had similar Km values for tryptophan and similar maximum rates. Indole-3-carbinol and indole-3-acetonitrile completely inhibited the production of 3-methylindole from indole-3-acetate but had no effect on the reactions involving L-tryptophan.

Gas chromatographic determination of indole and 3-methylindole (skatole) in bacterial culture media, intestinal contents and faeces

A simple, rapid and inexpensive gas chromatographic method was developed for the determination of indole and 3-methylindole (skatole) in faeces, intestinal contents and bacterial cultures. It involves a simple homogenization and extraction with chloroform. The extract is injected onto a gas chromatograph equipped with a 12.5-m fused-silica capillary column coated with BP20 and a film thickness of 0.5 micron. To simplify the chromatograms and to get a higher sensitivity a nitrogen-phosphorus-sensitive detector is applied. The detection limit for indole and 3-methylindole under the conditions employed is 20 micrograms/kg, which is well below the values typically found in intestinal contents (up to 100 mg/kg). Recovery for both compounds was close to 100%, and the mean coefficients of variation were 3.5% for indole and 3.0% for 3-methylindole. The method has demonstrated its practical value in the analysis of more than 50,000 samples in our laboratory. More than 100 samples can be analyzed per day.

Serum antibody responses of neonatal and young adult pigs to transmissible gastroenteritis coronavirus

Serum titers of virus-neutralizing (VN) antibody were 10 to 16 times higher in neonatal pigs than in young adult pigs, after single oral doses of virulent transmissible gastroenteritis virus (TGEV). To determine the reason for this higher response, sera from neonatal and young adult pigs, 18 to 21 days after exposure to TGEV, were collected and assayed for VN antibody by plaque reduction. In addition, sera of VN-positive and VN-negative neonatal pigs were analyzed for immunoglobulin classes by radial immunodiffusion technique. The competence of neonatal pigs to produce VN antibody with increased IgG levels was demonstrated. The higher antibody response seen in neonatal pigs, when compared to sera of young adult pigs, may be attributed to the increased replication of TGEV in the intestinal tracts of neonatal pigs or to the lack of other immunogens that may interfere or compete with the production of specific antibody.

Partial characterization of procomplementary activity of porcine serum and its relationship to the fifth component of complement

The procomplementary factor (PCF) of porcine serum, a component that enhances the hemolytic activity of guinea pig complement, was purified by precipitation with methanol and then by diethylaminoethyl-cellulose chromatography. The PCF substituted for the 5th complement component (C5) in the complement cascade in tests with functionally purified guinea pig complement components. In contrast to human C5, PCF is heat stable at 56 C.

Direct immunoelectron microscopy of transmissible gastroenteritis virus with immunoglobulins G and A and guinea pig complement

Porcine colostral immunoglobulin (Ig)G and IgA, isolated from transmissible gastroenteritis virus-infected sows, were compared by direct immunoelectron microscopy. It was estimated, using antibodies with a less than a twofold difference in virus-neutralizing activity, that IgG was 500 times more efficient than was IgA for coating transmissible gastroenteritis virions. Guinea pig complement enhanced the antibody coating with IgG, but did not increase virus-neutralizing activity of IgG or IgA.

Methanol precipitation of transmissible gastroenteritis virus

Methanol precipitation of transmissible gastroenteritis virus was tested at Ph 4.0, 5.0, 6.0, and 7.0 and at methanol concentrations of 15%, 25%, and 30%. Supernatant and precipitate fractions were tested for complement-fixing and agar-diffusion soluble antigens and plaque-forming units, and were examined by electron microscopy. Virus could be obtained free of detectable agar-diffusion antigens and most of the complement-fixing antigens. Most of the virions were without peplomers after methanol treatment but they retained infectivity.

Efficacy of isolated colostral IgA, IgG, and IgM(A) to protect neonatal pigs against the coronavirus of transmissible gastroenteritis

To ascertain what class of immunoglobulin (Ig; IgA, IgG, or IgM) is most efficacious in protection, a large quantity of colostrum from sows immunized with virulent transmissible gastroenteritis (TGE) virus was fractionated by chromatographic and gel filtration methods. The isolated IgG, IgA, and IgM(A) had specific virus-neutralizing activities of 1:7.6, 1:342, and 1:302 per milligram of protein, respectively. Each Ig was fed to groups of hysterectomy-derived colostrum-deprived neonatal pigs before and after exposure (challenge) with virulent TGE virus. The 7 pigs fed IgG survived the challenge exposure, but 2 of 7 fed IgA and 1 of 7 fed IgM(A) died of TGE. Three of the survivor pigs that had been fed IgG and 2 of the survivor pigs that had been fed IgA had increased serum antibody titers between 8 and 19 days after challenge exposure, but none of the survivor pigs fed IgM(A) had TGE antibody. In contrast, 12 of 14 virus-control pigs died of TGE and the 2 survivors had antibody conversion. The data show that all 3 Ig classes in immune colostrum will protect neonatal pigs against exposure with virulent TGE virus.

Chromatographic separation of gram quantities of immunoglobulins from porcine colostrium against transmissible gastroenteritis virus

Similar immunoglobulin (Ig) classes were obtained from porcine colodtral whey by either column or batch chromatographic procedures; a stepwise buffer elution technique was used. Specific transmissible gastroenteritis virus neutralizing antibody was found in the 4 major fractions eluted comprising of IgG1, IgG2, IgA, and IgM. The IgG1, and IgG2 were essentially homogeneous, and the IgA- AND IgM-rich fractions had to be recycled several times through Sephadex G-200 to obtain pure IgA and IgM that had specific virus neutralizing activities per mg of protein of 342.1 and 302. 4, compared with 7.6 for IgG. By a combination of the batch chromatographic procedures and gel filtration, gram amounts of specific Ig could be fractionated from the same colostrum.

Partial characterization of the principal soluble antigens associated with the coronavirus of transmissible gastroenteritis by complement fixation and immunodiffusion

A microtiter complement fixation (CF) test to detect transmissible gastroenteritis (TGE) viral antigen was developed, using TGE hyperimmune pig serum as an antibody source. Sera from TGE covalescent pigs did not fix complement by this test. Maximal virus and soluble antigen (SA) titers were obtained 36 to 48 h after inoculation of swine testes cells. Cell-associated virus and SA titers were higher than those in the culture fluid, which had to be concentrated 20X before use as antigen in agar immunodiffusion tests (ID). By sucrose density-gradient centrifugation, the SA had a buoyant density of 1.10 g/ml and could be separated from the virus that banded in the 1.19-g/ml region. Virus and SA from three different isolates of TGE had the same buoyant densities. Heating and proteolytic enzyme digestion established the protein nature of the SA. As assayed by CF and ID, there were stability differences between crude and purified preparations of SA. Antibody prepared in rabbits against the SA neutralized the TGE virus.