Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Joan E. Davies is active.

Publication


Featured researches published by Joan E. Davies.


Circulation | 2007

C-Terminal Provasopressin (Copeptin) as a Novel and Prognostic Marker in Acute Myocardial Infarction. Leicester Acute Myocardial Infarction Peptide (LAMP) Study

Sohail Q. Khan; Onkar S. Dhillon; Russell J. O’Brien; Joachim Struck; Paulene A. Quinn; Nils G. Morgenthaler; Iain B. Squire; Joan E. Davies; Andreas Bergmann; Leong L. Ng

Background— The role of the vasopressin system after acute myocardial infarction is unclear. Copeptin, the C-terminal part of the vasopressin prohormone, is secreted stoichiometrically with vasopressin. We compared the prognostic value of copeptin and an established marker, N-terminal pro-B-type natriuretic peptide (NTproBNP), after acute myocardial infarction. Methods and Results— In this prospective single-hospital study, we recruited 980 consecutive post–acute myocardial infarction patients (718 men, median [range] age 66 [24 to 95] years), with follow-up over 342 (range 0 to 764) days. Plasma copeptin was highest on admission (n=132, P<0.001, day 1 versus days 2 to 5) and reached a plateau at days 3 to 5. In the 980 patients, copeptin (measured at days 3 to 5) was elevated in patients who died (n=101) or were readmitted with heart failure (n=49) compared with survivors (median [range] 18.5 [0.6 to 441.0] versus 6.5 [0.3 to 267.0] pmol/L, P<0.0005). With logistic regression analysis, copeptin (odds ratio, 4.14, P<0.0005) and NTproBNP (odds ratio, 2.26, P<0.003) were significant independent predictors of death or heart failure at 60 days. The area under the receiver operating characteristic curves for copeptin (0.75) and NTproBNP (0.76) were similar. The logistic model with both markers yielded a larger area under the curve (0.84) than for NTproBNP (P<0.013) or copeptin (P<0.003) alone, respectively. Cox modeling predicted death or heart failure with both biomarkers (log copeptin [hazard ratio, 2.33], log NTproBNP [hazard ratio, 2.70]). In patients stratified by NTproBNP (above the median of ≈900 pmol/L), copeptin above the median (≈7 pmol/L) was associated with poorer outcome (P<0.0005). Findings were similar for death and heart failure as individual end points. Conclusions— The vasopressin system is activated after acute myocardial infarction. Copeptin may predict adverse outcome, especially in those with an elevated NTproBNP (more than ≈900 pmol/L).


Circulation | 2002

Plasma Urotensin in Human Systolic Heart Failure

Leong L. Ng; Ian Loke; Russell J. O'brien; Iain B. Squire; Joan E. Davies

Background—Human urotensin II (UTN) has potent vasoactive and cardiostimulatory effects, acting on the G protein–linked receptor GPR14. Myocardial UTN expression is upregulated in heart failure, and UTN stimulates myocardial expression of the natriuretic peptides. We investigated plasma UTN levels in heart failure (HF; left ventricular systolic dysfunction) in comparison with plasma N-terminal pro-brain natriuretic peptide (N-BNP) levels. Methods and Results—N-BNP and UTN were measured in plasma from 126 patients with HF and 220 age- and sex-matched controls. Both peptides were elevated in plasma of HF patients and were correlated (rs=0.35, P <0.001). In contrast to N-BNP, there was no relationship of plasma UTN with New York Heart Association (NYHA) class. Although plasma N-BNP showed a positive relationship with age and female sex, there was no such age-dependent change in plasma UTN, and control women had lower levels compared with control men. Receiver operating characteristic curves for the diagnosis of HF had areas of 0.90 and 0.86 for N-BNP and UTN, respectively (P <0.001 for both). Receiver operating characteristic curve area for diagnosis of NYHA class I HF with UTN was better than that with N-BNP. Conclusions—Plasma UTN is elevated in HF, which suggests a pathophysiological role for this peptide. Plasma UTN may be a useful alternative to N-BNP in the diagnosis of HF, inasmuch as its levels are elevated irrespective of age, sex, or NYHA class.


Cell Transplantation | 2004

Autotransplantation of unmanipulated bone marrow into scarred myocardium is safe and enhances cardiac function in humans.

Manuel Galiñanes; Mahmoud Loubani; Joan E. Davies; Derek Chin; John Pasi; Peter R.F. Bell

Stem cell transplants into damaged myocardium may have the potential to improve cardiac function. We investigated the safety of transplanting unmanipulated autologous bone marrow into infarcted myocardium of patients undergoing coronary bypass surgery and assessed its efficacy to improve cardiac function. Fourteen patients with one or more areas of transmural myocardial infarction were studied. Autologous bone marrow was obtained by sternal bone aspirate at the time of surgery, diluted in autologous serum at a ratio of 1:2, and then injected 1 cm apart into the mid-depth of the left ventricular scar. There were no deaths, no perioperative myocardial infarctions, and no significant ventricular arrhythmias. Dobutamine stress echocardiography demonstrated overall improvement in the global and regional left ventricular function 6 weeks and 10 months after surgery. Of 34 infarcted left ventricular segments, 11 were injected with bone marrow alone, 13 were revascularized with a bypass graft alone, and 10 received bone marrow transplantation and a bypass graft in combination. Only the left ventricle segmental wall motion score of the areas injected with bone marrow and receiving a bypass graft in combination improved at low dose and at peak dobutamine stress. These findings suggest that transplantation of unmanipulated autologous bone marrow into scar tissue of the human heart is safe and enhances cardiac function only when used in combination with myocardial revascularization. This benefit can be seen after 6 weeks of the bone marrow transplant and is maintained after 10 months of follow-up.


Heart | 2000

Plasma N terminal pro-brain natriuretic peptide and cardiotrophin 1 are raised in unstable angina

S Talwar; Iain B. Squire; P F Downie; Joan E. Davies; Leong L. Ng

OBJECTIVE To compare circulating concentrations of N terminal pro-brain natriuretic peptide (N-BNP) and cardiotrophin 1 in stable and unstable angina. DESIGN AND SETTING Observational study in a teaching hospital. PATIENTS 15 patients with unstable angina, 10 patients with stable angina, and 15 controls. MAIN OUTCOME MEASURES Resting plasma N-BNP and cardiotrophin 1 concentrations. RESULTS N-BNP concentration (median (range)) was 714 fmol/ml (177–3217 fmol/ml) in unstable angina, 169.5 fmol/ml (105.7–399.5 fmol/ml) in stable angina (p = 0.005v unstable angina), and 150.5 fmol/ml (104.7–236.9 fmol/ml) in controls (p < 0.0001v unstable angina; NSv stable angina). Cardiotrophin 1 concentration was 142.5 fmol/ml (42.2–527.4 fmol/ml) in unstable angina, 73.2 fmol/ml (41.5–102.1 fmol/ml) in stable angina (p < 0.05 v unstable angina), and 27 fmol/ml (6.9–54.1 fmol/ml) in controls (p < 0.0005v stable angina; p < 0.0001v unstable angina). Log cardiotrophin 1 correlated with log N-BNP in unstable angina (r = 0.93, p < 0.0001). CONCLUSIONS Both circulating N-BNP and cardiotrophin 1 are raised in unstable angina, while cardiotrophin 1 alone is raised in stable angina. The role of cardiotrophin 1 and the relation between cardiotrophin 1 and N-BNP in myocardial ischaemia remain to be defined.


European Journal of Heart Failure | 2003

Reference ranges for natriuretic peptides for diagnostic use are dependent on age, gender and heart rate

Ian Loke; Iain B. Squire; Joan E. Davies; Leong L. Ng

Plasma natriuretic peptide levels may be useful in the diagnosis of heart failure. The available natriuretic peptide assays differ markedly in their performance characteristics. In addition, plasma levels are influenced by a number of factors including age and gender.


Clinical Science | 2009

Gender and renal function influence plasma levels of copeptin in healthy individuals.

Sanjay S. Bhandari; Ian Loke; Joan E. Davies; Iain B. Squire; Joachim Struck; Leong L. Ng

The present study sought to identify confounding factors for the interpretation of copeptin levels in healthy individuals. The natriuretic peptides are recognized as diagnostic and prognostic tools in HF (heart failure). Interpretation of BNP (brain natriuretic peptide) and NTproBNP (N-terminal pro-BNP) levels is multifaceted as their secretion is influenced by many variables. A newly identified glycopeptide called copeptin is comparable with the natriuretic peptides in the diagnosis and prognosis of HF and as a prognostic biomarker after AMI (acute myocardial infarction). Copeptin, derived from the C-terminal portion of the precursor to AVP (arginine vasopressin), is secreted stoichiometrically with vasopressin, hence it can be used as a surrogate marker of the AVP system. In the present study, 706 healthy volunteers were recruited from a local HF screening study. Participants with a history of cardiovascular disease and those with echocardiographic abnormalities were excluded from the study. Copeptin and NTproBNP levels were assayed using in-house immunoluminometric assays. Median copeptin levels were significantly higher in the male volunteers compared with the females [median (range): 4.3 (0.4-44.3) compared with 3.2 (1.0-14.8) pmol/l; P<0.001]. In males, copeptin was correlated with eGFR (estimated glomerular filtration rate; r(s)=-0.186, P<0.001). In females, the correlation of copeptin with eGFR was weak (r(s)=-0.097, P=0.095). DT (deceleration time) and left atrial size correlated with higher copeptin levels (r(s)=0.085, P=0.029 and r(s)=0.206, P<0.001 respectively). Only gender (P<0.001), eGFR (P<0.001), left atrial size (P=0.04) and DT (P=0.02) remained independently predictive of plasma copeptin. The present study suggests that gender and renal function specific partition values should be used to interpret copeptin values in future studies of this biomarker in HF or ischaemic heart disease.


European Journal of Heart Failure | 2003

Pre‐discharge, but not admission, levels of NT‐proBNP predict adverse prognosis following acute LVF

Russell J. O'brien; Iain B. Squire; Bettina Demme; Joan E. Davies; Leong L. Ng

Circulating natriuretic peptide levels provide prognostic information following acute coronary syndromes and in chronic heart failure. Little evidence exists of their utility following hospitalisation with acute left ventricular failure (LVF).


Journal of Cardiac Failure | 2008

C-Terminal Provasopressin (Copeptin) is Associated With Left Ventricular Dysfunction, Remodeling, and Clinical Heart Failure in Survivors of Myocardial Infarction

Dominic Kelly; Iain B. Squire; Sohail Q. Khan; Paulene A. Quinn; Joachim Struck; Nils G. Morgenthaler; Joan E. Davies; Leong L. Ng

BACKGROUND Acute myocardial infarction (AMI) is associated with left ventricular (LV) dysfunction and clinical heart failure. Arginine vasopressin is elevated in heart failure and the C-terminal of provasopressin (Copeptin) is associated with adverse outcome post-AMI. The aim of this study was to describe the association between Copeptin with LV dysfunction, volumes, and remodeling and clinical heart failure post-AMI. METHODS AND RESULTS We studied 274 subjects with AMI. Copeptin was measured from plasma at discharge and subjects underwent echocardiography at discharge and follow-up (median 155 days). Subjects were followed for clinical heart failure for a median of 381 days. Remodeling was assessed as the change (Delta) in LV volumes between echo examinations. Copeptin correlated directly with wall motion index score (WMIS) and inversely with LV ejection fraction (LVEF) at discharge (WMIS, r=0.276, P < .001; LVEF, r=-0.188, P=.03) and follow-up (WMIS, r=0.244, P < .001; LVEF, r=-0.270, P < .001) and with ventricular volumes at follow-up (LVEDV, r=0.215, P=.002; LVESV, r=0.299, P < .001). Copeptin was associated with ventricular remodeling; DeltaEDV; r=0.171, P=0.015, DeltaESV; r=0.186, P=.008. Subjects with increasing LVESV had higher levels of Copeptin (median 6.30 vs. 5.75 pmol/L, P=.012). Subjects with clinical heart failure (n=30) during follow-up had higher Copeptin before discharge (median 13.55 vs. 5.80, P < .001). In a Cox proportional hazards model, Copeptin retained association with clinical heart failure. Kaplan-Meier assessment revealed increased risk in subjects with Copeptin >6.31 pmol/L. CONCLUSIONS Copeptin is associated with LV dysfunction, volumes, and remodeling and clinical heart failure post-AMI. Measurement of Copeptin may provide prognostic information and the AVP system may be a therapeutic target in post-MI LV dysfunction.


European Journal of Heart Failure | 2001

Plasma N-terminal pro BNP and cardiotrophin-1 are elevated in aortic stenosis

S. Talwar; Paul F. Downie; Iain B. Squire; Joan E. Davies; David B. Barnett; Leong L. Ng

Echocardiography with Doppler examination of the aortic valve provides a very accurate assessment of the transvalvular gradient and is used to monitor progression of aortic stenosis (AS). Plasma brain natriuretic peptide (BNP) has been shown to correlate with end‐systolic wall stress in patients with AS.


Clinical Science | 2004

Plasma urocortin in human systolic heart failure.

Leong L. Ng; Ian W. Loke; Russell J. O'brien; Iain B. Squire; Joan E. Davies

Urocortin (UCN), a member of the corticotrophin-releasing factor family, is expressed in heart, brain and gut. UCN has potent cardiostimulatory, cardioprotective, vasodilator and diuretic/natriuretic effects, and cardiac UCN expression is increased in heart failure (HF). In the present study, we investigated plasma levels of UCN in 119 patients with HF and 212 age- and gender-matched controls to clarify its relationship with gender and disease severity. UCN was elevated in HF [normal males, 19.5 (3.9-68.8) pmol/l and HF males, 50.2 (6.9-108.2) pmol/l, P < 0.0005; normal females, 14.2 (3.9-53.5) pmol/l and HF females, 21.8 (3.9-112.5) pmol/l, P < 0.001; values are medians (range)]. The relative increase was greater in males than females ( P < 0.03). UCN fell with increasing age, especially in HF patients ( r(s) = -0.56, P < 0.0005) and with increasing New York Heart Association (NYHA) class ( r(s) = -0.55, P < 0.0005). The fall in UCN levels with increasing NYHA class was reinforced by a significant correlation between UCN and ejection fraction ( r(s) = 0.45, P < 0.0005) in HF patients. Although receiver operating characteristic (ROC) curves for diagnosis of all HF cases yielded an area under the curve (AUC) of 0.76, ROC AUCs for patients with early HF (NYHA class I and II) were better (0.91). ROC AUCs for logistic models incorporating N-terminal probrain natriuretic peptide (N-BNP) and UCN were better than either peptide alone. In conclusion, plasma UCN is elevated in HF, especially in its early stages. Its decline with increasing HF severity may expedite disease progression due to diminished cardioprotective/anti-inflammatory effects. UCN measurement may also complement N-BNP in the diagnosis of early HF.

Collaboration


Dive into the Joan E. Davies's collaboration.

Top Co-Authors

Avatar

Leong L. Ng

University of Leicester

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Sohail Q. Khan

Leicester Royal Infirmary

View shared research outputs
Top Co-Authors

Avatar

Joachim Struck

Thermo Fisher Scientific

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Andreas Bergmann

University of Massachusetts Medical School

View shared research outputs
Top Co-Authors

Avatar

Dominic Kelly

Leicester Royal Infirmary

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge