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Biomedical subjects

R Senior

Publications and source records attributed to R Senior.

At least 19 recordsLinked to original sources
PubMed2006

Diagnostic and prognostic role of cardiac troponin I (cTnI) measured on the DPC Immulite.

OBJECTIVE: To evaluate the diagnostic and prognostic role of the Immulite cTnI assay for the detection of acute coronary syndromes (ACS). POPULATION: 150 males and 63 females with a median age of 63 years, range 28 to 88, and an interquartile range of 18 years were admitted within 24 h of chest pain and non-ST segment elevation ACS were studied. The median onset of symptoms was 3 h (range 0-23). METHODS: Venous samples were taken on admission (t = 0) and at 24 h (t = 24). The serum samples were assayed for CK, CK-MB and cTnT on an Elecsys 1010 (Roche Diagnostics, Lewes, UK). The cTnT assay CV was 5.5% at 0.32 microg/l and 5.4% at 6.0 microg/l, and the detection limit was 0.01 microg/l with an upper limit of 25 microg/l. For cTnI using the Immulite (DPC, Gwynedd, Wales), the detection limit was 0.1 microg/l, and the upper limit was 180 microg/l. Final diagnostic categorization was performed by both WHO and European Society of Cardiology criteria using cTnT as the diagnostic cardiac biomarker. Patients were followed for the major adverse cardiac events (MACE), endpoints cardiac death, AMI or need for urgent revascularization. ROC curves were constructed using final diagnosis. Outcome prediction was assessed by ROC curves and Kaplan-Meier survival curves. RESULTS: Both methods had equivalent diagnostic efficiency using WHO criteria for AMI. When ESC criteria were used the AUC for admission and 24 h cTnT and cTnI values were 0.945 vs. 0.910, P = 0.20 and 0.998 vs. 0.937, P = 0.005, respectively. Both methods predicted outcome as either death or MI or MACE and were not significantly different. CONCLUSION: The Immulite cTnI assay can be used for diagnosis and risk stratification in patients admitted with non-ST segment elevation acute coronary syndromes.

Adult↗
PubMed2005

Myocardial viability assessed by dobutamine stress echocardiography predicts reduced mortality early after acute myocardial infarction: determining the risk of events after myocardial infarction (DREAM) study.

OBJECTIVE: To establish further the role of dobutamine stress echocardiography (DSE) in prognostication of outcome early after acute myocardial infarction (AMI) METHODS: Consecutive patients presenting with AMI were screened for inclusion into the study. 212 stable consenting patients underwent DSE a mean (SD) of 4.8 (1.5) days after AMI. Patients were then followed up for 803 (297) days. RESULTS: The mean (SD) resting systolic wall thickening index (SWTI) was 1.6 (0.4), 44% patients had evidence of viability at low dose, and 38% had evidence of ischaemia. During the follow up period 27 (13%) patients died and 16 (8%) had a non-fatal AMI. Independent predictors of both mortality and combined mortality and non-fatal AMI were age (hazard ratio (HR) 1.04/year, p = 0.01, and HR 1.03/year, p = 0.04, respectively) and SWTI at low dose (HR 3.6, p < 0.01, and HR 2.5, p = 0.02, respectively). Low dose DSE provided incremental information over clinical and resting left ventricular function data for predicting death and non-fatal AMI. For patients who were not revascularised SWTI at peak dose dobutamine was the only independent predictor of mortality. CONCLUSION: DSE is a powerful predictor of outcome in stable survivors of AMI. The presence of myocardial viability has a positive impact on survival.

Echocardiography, Stress↗
PubMed2005

Ethnic differences in the prevalence and aetiology of left ventricular systolic dysfunction in the community: the Harrow heart failure watch.

OBJECTIVE: To assess ethnic differences in the prevalence and aetiology of left ventricular systolic dysfunction (LVSD) in the community. DESIGN: Community cohort study. All patients underwent echocardiography and those found to have LVSD underwent myocardial perfusion imaging with or without coronary angiography to diagnose underlying coronary artery disease (CAD). SETTING: Seven representative general practices in Harrow, UK, a community hospital, and a local district general hospital. PATIENTS: 1392 patients >or= 45 years old randomly selected from the computer records of seven general practices. MAIN OUTCOME MEASURES: The prevalence and aetiology of LVSD in the community, assessing differences between white and non-white populations, and the proportion of patients with LVSD with undiagnosed CAD. RESULTS: 734 patients (53%) attended, 518 (71%) white and 216 (29%) non-white, the majority South Asian. Thirty nine patients (5.5%) had probable LVSD and 25 (3.5%) definite LVSD. No significant differences in prevalence were seen with ethnicity. CAD underlay most cases of LVSD. Non-white patients had a higher prevalence of CAD as the underlying aetiology of significant LVSD than white patients (100% v 56%, p = 0.04) and a trend towards less alcoholic cardiomyopathy. 8% of patients with LVSD had undiagnosed CAD. CONCLUSIONS: LVSD is common. White and non-white patients have a similar overall prevalence of LVSD. Non-white patients, the majority South Asians in this study, have a higher prevalence of CAD as the underlying cause for LVSD than white patients. CAD underlies most cases of LVSD in the community, although it may be undiagnosed unless formally assessed.

Aged↗
PubMed2005

Stress echocardiography for the diagnosis and risk stratification of patients with suspected or known coronary artery disease: a critical appraisal. Supported by the British Society of Echocardiography.

Stress echocardiography today has matured into a robust and reliable technique not only for the diagnosis of suspected coronary artery disease (CAD) but also for the accurate risk stratification of patients with suspected and established CAD. This is mainly because of rapid advances in image acquisition, digital display, and the development of harmonic and contrast imaging. Stress echocardiography today is also utilised in patients with heart failure both for assessing the cause of heart failure and determining the extent of hibernating myocardium. With advances in myocardial perfusion imaging, stress echocardiography now allows simultaneous assessment of myocardial function and perfusion. Tissue Doppler imaging allows quantitation of wall motion. Ready availability and reliability makes stress echocardiography a cost effective technique for the assessment of CAD.

Aged↗
PubMed2005

Early experiences and their relationship to maternal eating disorder symptoms, both lifetime and during pregnancy.

BACKGROUND: There is some evidence that early sexual abuse is an aetiological factor for eating disorder. However, there is sparse information from large-scale, non-clinical studies. AIMS: This study was designed to explore which early experiences, recalled during pregnancy, were associated with both lifetime and antenatal eating disorder symptoms in a community sample. METHOD: Univariate and multivariate analyses were conducted of data from questionnaires administered during pregnancy to a community sample of pregnant women. RESULTS: Recall of parental mental health problems and of early unwanted sexual experiences were independently associated with both lifetime eating problems, laxative use and vomiting during pregnancy, and marked concern during pregnancy over shape and weight. CONCLUSIONS: There are public health implications for these results. Eating disorders in mothers represent a risk for child development. It may be important to enquire during pregnancy about a history of eating problems and to provide the opportunity for early experiences to be discussed.

Adolescent↗
PubMed2004

The upper limit of physiological cardiac hypertrophy in elite male and female athletes: the British experience.

Establishment of upper normal limits of physiological hypertrophy in response to physical training is important in the differentiation of physiological and pathological left ventricular hypertrophy. The genetic differences that exist in the adaptive response of the heart to physical training and the causes of sudden cardiac death in young athletes indicate the need for population-specific normal values. Between September 1994 and December 2001, 442 (306 male, 136 female) elite British athletes from 13 sports were profiled. Standard two-dimensional guided M-mode and Doppler echocardiography were employed to evaluate left ventricular morphology and function. Eleven (2.5%) athletes, competing in a range of sports including judo, skiing, cycling, triathlon, rugby and tennis, presented with a wall thickness >13 mm, commensurate with a diagnosis of hypertrophic cardiomyopathy. Eighteen (5.8%) male athletes presented with a left ventricular internal diameter during diastole (LVIDd) >60 mm, with an upper limit of 65 mm. Of the 136 female athletes, none where found to have a maximum wall thickness >11 mm. Left ventricular internal diameter was <60 mm in all female athletes. Systolic and diastolic function were within normal limits for all athletes. Upper normal limits for left ventricular wall thickness and LVIDd are 14 mm and 65 mm for elite male British athletes, and 11 mm and 60 mm for elite female British athletes. Values in excess of these should be viewed with caution and should prompt further investigation to identify the underlying mechanism.

Adolescent↗
PubMed2004

Analytical performance of the N terminal pro B type natriuretic peptide (NT-proBNP) assay on the Elecsys 1010 and 2010 analysers.

The Elecsys NT-proBNP assay is based on two polyclonal antibodies directed at residues 1-21 and 39-50 of the NT-proBNP molecule. Analytical performance was assessed using NCCLS protocol EP-5A using three serum pools in a preliminary study then as part of a multicentre evaluation (16 instruments in 8 hospitals). Using pools of 350 pg/l, 8700 pg/l and 13000 pg/l single site within run %CV was 0.7-1.6 (1010) and 1.2-1.5 (2010) and between run CV 5.3-6.7 (1010) and 4.4-5.0 (2010). In the multicentre evaluation within run CV was 1.0-2.5% with total imprecision 1.5-2.5% and between labs imprecision 3.8-4.0%. Functional sensitivity of <50 pg/l and measuring range to 35000 pg/l. There was excellent agreement between instrument platforms, y=0.97x+2.6; r=1.00 (n=215) for Elecsys 2010 (x) vs. Elecsys 1010 (y) and y=1.02x-0.3; r=1.00 (n=99) for Elecsys 2010 (x) vs. E 170 (y). Serum and heparin plasma samples showed good agreement but lower values were seen in EDTA plasma. Samples were stable for 7 days at room temperature; 21 days at 4 degrees C and for 5 freeze thaw cycles. Samples were obtained from a population of 1205 (671 male, 534 female) apparently healthy individuals screened by echocardiography and symptom questionnaire. There was poor correlation with NT-proANP (ELISA) (rs 0.33) and modest correlation with BNP (rs 0.89) with NT-proBNP values approximately 5 times greater than BNP (Biosite Triage). In a subset of 320 with normal ejection fraction (>50%) and no risk factors, NT-proBNP values increased with age and were higher in women than men.

Aged↗
PubMed2004

Improved interpretation of dobutamine stress echocardiography following 4 months of systematic training in patients following acute myocardial infarction.

OBJECTIVES: Interpretation of stress echocardiography is subjective, and highly dependent on the experience of the interpreter. We sought to evaluate whether a cardiologist without any previous experience in stress echocardiography could adequately learn the skills of interpreting dobutamine stress echocardiograms (DSE) in post-infarct patients, after a period of systematic training. METHODS: A trainee in cardiology blindly reported 51 consecutive DSEs from a database of post-infarction studies, after 2 and 4 months of systematic training. We compared his interpretation with that of an expert. RESULTS: Agreement between the trainee and the expert improved significantly from 2 to 4 months of training in the left anterior descending artery territory for the overall scan interpretation (from kappa = 0.58 to kappa = 0.73; p = 0.03), wall thickening assessment in individual segments (from kappa = 0.40 to kappa = 0.55; p < 0.01) and the diagnosis of viable myocardium (from kappa = 0.11 to kappa = 0.43; p = 0.01). Similar improvement was observed in left circumflex, but not in the right coronary artery territory. Agreement in identifying inducible ischaemia also remained poor. CONCLUSION: This study suggests that systematic training can significantly reduce interobserver variability in a short time frame (4 months) and may improve the interpretation of DSE by a trainee. But improvements in image quality and use of predefined reading criteria are necessary to improve interobserver agreement further in myocardial regions where conformity in dobutamine stress echocardiographic interpretation is low.

Adult↗
PubMed2004

Wall thickening assessment with tissue harmonic echocardiography results in improved risk stratification for patients with non-ST-segment elevation acute chest pain.

OBJECTIVES: To demonstrate whether the improved imaging quality gained by using tissue harmonic echocardiography in place of fundamental echocardiography results in the improved risk stratification of patients presenting with non-ST-elevation acute chest pain. METHODS AND RESULTS: Eighty patients with over 30 min of non-ST-elevation chest pain that had lasted less than 6 h were recruited. All patients underwent resting tissue harmonic and fundamental echocardiographic scans. Diagnosis for acute myocardial infarction was made on a 24 h creatine kinase-MB sample. Echocardiographic images were reported by two experienced blinded observers. Patients were followed up at least 4 months after admission. Endpoints included all-cause mortality, non-fatal myocardial infarction and revascularisation procedures. Tissue harmonic echocardiography allowed assessment of all myocardial segments in all patients compared to 43/78 patients ( p<0.001 ) with fundamental echocardiography. A wall thickening abnormality demonstrated on tissue harmonic echocardiography and not fundamental echocardiography was a significant predictor of index myocardial infarction on admission ( p<0.007 ) and for an adverse cardiac event during follow up ( p=0.002 ). CONCLUSIONS: Tissue harmonic echocardiography is superior to fundamental echocardiography for accurate assessment of systolic wall thickening and hence risk stratification for patients presenting with acute chest pain and non-diagnostic electrocardiogram changes.

Acute Disease↗
PubMed2004

Is echocardiography a valid tool to screen for left ventricular systolic dysfunction in chronic survivors of acute myocardial infarction? A comparison with radionuclide ventriculography.

OBJECTIVE: To assess the accuracy of echocardiography with Simpson's apical biplane method in screening for left ventricular systolic dysfunction (LVSD) in patients six months after acute myocardial infarction (AMI) as compared with radionuclide ventriculography by assessing the proportion of clinically significant errors that occur with echocardiography. DESIGN: Comparison of results of echocardiography and radionuclide ventriculography in assessing left ventricular ejection fraction among patients six months after AMI. SETTING: District general hospital. PATIENTS: 86 patients thrombolysed for AMI at six month follow up. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Correlation coefficients, mean differences, 95% limits of agreement, and differences of clinical significance between left ventricular ejection fraction on echocardiography and on radionuclide ventriculography. RESULTS: The correlation coefficient between techniques was 0.90, mean difference 1% (p = 0.04), and 95% limits of agreement -13.0% to 10.3%. Only one patient (1.2%, 0.0% to 6.3%) was classified as having normal systolic function on one imaging modality but significant LVSD on the other. Overall accuracy between the two techniques was 86%, kappa value of agreement 0.78. CONCLUSION: Echocardiography is a valid tool to screen for LVSD in patients six months after AMI, accurately differentiating normal from abnormal systolic function and showing excellent agreement with radionuclide ventriculography. This study supports the use of echocardiography in screening for LVSD in chronic stable patients after AMI or alternative high risk patients, with few differences of major clinical significance likely to occur.

Adult↗
PubMed2004

Evaluation of N-terminal pro-B type natriuretic peptide analysis on the Elecsys 1010 and 2010 analysers.

BACKGROUND: N-terminal pro-B type natriuretic peptide (NTpBNP) is a potential marker of cardiac failure. METHODS: The Roche Elecsys(trade mark) 1010 and 2010 assays for NTpBNP were evaluated for precision, sample stability, and correlation between sample types and with other natriuretic peptides. Samples from 290 individuals aged 45-89 years with no cardiovascular risk factors, renal failure, electrocardiogram changes, evidence of structural abnormalities, or wall motion abnormalities on echocardiography and with an ejection fraction >50% were used to provide reference NTpBNP ranges. RESULTS: The intra-assay imprecision was <10% across the analytical range and >3% at all concentrations analysed <30 ng/L. Inter-assay imprecision was 5.3-6.7% on the Elecsys 1010 and 4.4-5.0% on the Elecsys 2010, in the range 380-13000 ng/L. There was no statistically significant change in NTpBNP following storage in whole-blood samples at room temperature for 24 h before centrifugation; serum samples at room temperature for 7 days, at 4 degrees C for up to 11 days on clot-activation gel or 22 days separated from the gel. NTpBNP concentrations were stable throughout five freeze-thaw cycles. There was a close correlation between NTpBNP concentrations in matched serum, EDTA plasma and lithium-heparin plasma samples. NTpBNP and BNP were more closely associated than were N-terminal proatrial natriuretic peptide and NTpBNP. This association was stronger at lower concentrations. NTpBNP concentrations increased with age, with values higher in women than men. CONCLUSIONS: NTpBNP is a stable molecule that can be measured easily and precisely using the Roche Elecsys 1010 or 2010 immunoassay analysers.

Aged↗
PubMed2003

The heart failure revascularisation trial (HEART): rationale, design and methodology.

BACKGROUND: Most patients with heart failure due to left ventricular systolic dysfunction (LVSD) secondary to coronary artery disease (CAD) have evidence of myocardium in jeopardy (reversible ischaemia and/or stunning hibernation). It is not known whether revascularisation in such cases is safe or beneficial. AIMS: To determine whether revascularisation will improve the survival of patients with LVSD and heart failure secondary to CAD and myocardium in jeopardy. METHODS: This is a randomised controlled trial comparing revascularisation or not, in addition to optimal medical therapy with ACE inhibitors, beta-blockers, aldosterone antagonists and an anti-thrombotic agent. Patients must have heart failure requiring treatment with diuretics, a left ventricular ejection fraction <35% and evidence of coronary disease. Myocardial viability and ischaemia are assessed by a broad range of techniques including stress echocardiography and nuclear imaging. All imaging tests are reviewed in core laboratories to ensure uniform reporting. Any conventional revascularisation technique is permitted. The primary outcome measure is all cause mortality. Symptoms, quality of life and health economic issues will also be explored. Assuming an annual mortality of 10% in the control group and allowing for substantial cross-over rates, a study of 800 patients followed for 5 years has 80% power with an alpha of 0.05 (two-sided) to show a 25% reduction in mortality with revascularisation. RESULTS: At the time of writing 180 patients have been screened for inclusion, 111 have consented to participate and 70 have been randomised. The results of viability testing are awaited in 22 patients. Twenty-six patients had been investigated for myocardial viability and/or by angiography prior to consent, as part of the routine practice in that cardiology department. Of 68 patients who have completed assessment only after consent, 47 (69%) were included. The principal reason for drop-out between consent and randomisation was lack of evidence of myocardial ischaemia or hibernation. CONCLUSION: The HEART trial will help to determine whether investigation of myocardial ischaemia and/or viability with a view to revascularisation should become part of the routine care of patients with heart failure due to LVSD and CAD.

Coronary Artery Disease↗
PubMed2003

Portable echocardiography: an innovative tool in screening for cardiac abnormalities in the community.

AIMS: Heart failure is placing an increasing burden on society. This has led to calls for echocardiographic-based programmes to screen for left ventricular systolic dysfunction and other cardiac abnormalities. Echocardiography using new fully portable echocardiography devices would allow community-based cost-effective screening programmes once validated. This study was undertaken to evaluate this further in both high and low-risk subjects. METHODS AND RESULTS: 562 consecutive subjects attending a community-based heart failure screening programme, some at high-risk and some at low-risk of cardiac abnormalities, underwent echocardiography by both portable and traditional echocardiography machines. An 'eyeball' estimate of left ventricular ejection fraction was made on the portable device and compared to a quantitative measure of ejection fraction on the traditional machine. Qualitative measures of valvular regurgitation and quantitative measures of left ventricular hypertrophy were also compared. An estimate of ejection fraction was possible in 97% of cases using portable echocardiography. It gave a sensitivity, specificity and negative predictive value in diagnosing left ventricular systolic dysfunction of 96%, 98% and 99.6%, respectively. Inter-observer variability gave a mean difference in ejection fraction of 2%, and 95% limits of agreement of -8% to +12%. All cases of moderate or severe valvular regurgitation and 29 of 31 cases of significant left ventricular hypertrophy were correctly identified as abnormal on the portable device. CONCLUSIONS: Thus, echocardiography performed by experienced sonographers using these new fully portable devices is an accurate and reproducible technique for detecting left ventricular systolic dysfunction, left ventricular hypertrophy and valvular regurgitation in both high-risk and low-risk members of the community. Its very high negative predictive values would allow their use in future community-based screening programmes.

Adult↗
PubMed2003

Myocardial contrast echocardiography is superior to other known modalities for assessing myocardial reperfusion after acute myocardial infarction.

BACKGROUND: Angiographic flow measurements do not define perfusion accurately at a microvascular level, so other techniques which assess flow at a tissue level are to be preferred. OBJECTIVES: To compare intravenous myocardial contrast echocardiography (MCE) with other methods of assessing microvascular reperfusion for their ability to predict left ventricular function at one month after acute myocardial infarction. DESIGN: 15 patients underwent primary percutaneous coronary angioplasty for acute myocardial infarction, with restoration of TIMI grade 3 flow. Corrected TIMI frame count (cTFC), myocardial blush grade (MBG), and percentage ST segment resolution at 90 and 180 minutes were recorded. Baseline regional wall motion score index (WMSI) and regional contrast score index (RCSI) were obtained 12-24 hours after the procedure, with a final regional WMSI assessment at one month. RESULTS: Mean (SD) cTFC was 27 (9.4), and ST segment resolution was 69 (22)% at 90 minutes and 77 (20)% at 180 minutes. MBG values were 0 in six patients, 2 in two, and 3 in seven. Baseline regional WMSI, RCSI, and follow up WMSI were 2.7 (0.71), 1.5 (0.71), and 1.6 (0.73), respectively. The correlation coefficient between RCSI and follow up WMSI was 0.82 (p = 0.0012). Peak CK correlated with follow up WMSI (R = 0.80). None of the other reperfusion assessment techniques correlated significantly with follow up WMSI. Multiple regression analysis showed that a perfused hypokinetic or akinetic segment was 50 times more likely to recover function than a non-perfused segment. MCE predicted segmental myocardial recovery with a sensitivity of 88%, a specificity of 74%, and positive and negative predictive values of 83% and 81%, respectively. CONCLUSIONS: MCE is currently the best and most accurate measure of reperfusion at a microvascular level and an excellent predictor of left ventricular function at one month following acute myocardial infarction.

Angioplasty, Balloon, Coronary↗
PubMed2003

Myocardial contrast echocardiography for the assessment of left ventricular function.

Assessment of regional and global left ventricular (LV) function is important in the management of patients with known or suspected cardiovascular disease. Echocardiography is widely used to provide vital parameters of LV function such as ejection fraction, wall motion score indices, LV volumes and regional wall motion assessment. Despite advances in image quality some images may still be inadequate for accurate assessment of LV function. The advent of intravenous contrast agents consisting of microbubbles have allowed improved endocardial definition leading to better assessment of global and regional function. This together with advances in low power imaging techniques allow less microbubble destruction and hence smaller doses of contrast agent. Improved endocardial definition has also lead to advances in techniques for the automated quantification of LV function. As a result contrast enhanced echocardiography may become the gold-standard in the assessment of wall motion and LV function.

Contrast Media↗