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A D Struthers

Publications and source records attributed to A D Struthers.

At least 19 recordsLinked to original sources
PubMed2006

Effect of social deprivation on mortality and the duration of hospital stay after a stroke.

BACKGROUND: We aim to assess whether social deprivation independently predicts case fatality after a stroke patient has been admitted to hospital, and to assess whether social deprivation affected duration of hospital stay. METHODS: Cohort study in a tertiary teaching hospital included consecutive patients admitted to hospital within 48 h of their stroke between 1988 and 1994. Outcome measures were case fatality at 1 year and length of hospital stay. The socioeconomic category was derived from the postcode sector of residence for the patients (Carstairs index). Cause of death was determined by data linkage to the Registrar General data for Scotland. RESULTS: 2,042 stroke patients were included. A significant age difference existed between the deprivation categories (76.0 +/- 10.9 years in the affluent cohort vs. 71.4 +/- 10.7 years in the deprived cohort). Smoking was more common in the deprived group. ECG findings and neurological score on admission were similar between the groups. No difference existed between groups for length of hospital stay (p = 0.793), and in the proportions remaining alive at 1 year (p = 0.416). When entered into a multivariate Cox regression analysis, the deprivation categories did not predict mortality. Age, sex, Philadelphia Geriatric Center Instrumental Activities of Daily Living (IADL) Scale Score, Orgogozo neurological score on admission, and ECG abnormalities were the significant predictors. CONCLUSIONS: Stroke patients living in more socially deprived areas had their strokes at an earlier age but were not at a greater risk of dying or longer hospital stay once they had been admitted to hospital.

Aged↗
PubMed2005

Angiotensin blockade or aldosterone blockade as the third neuroendocrine-blocking drug in mild but symptomatic heart failure patients.

Recent clinical trials have explored whether angiotensin receptor blockers (ARBs) or aldosterone blockade should be added to standard angiotensin-converting enzyme (ACE) inhibitor/beta blocker treatment in heart failure. Both strategies are of some value but it is unclear which strategy should be used first in patients with mild but symptomatic heart failure. The arguments for and against each strategy are discussed. The strongest argument for aldosterone blockade is the consistency in the results of the RALES (Randomized Aldactone Evaluation Study) and EPHESUS (Eplerenone Post-acute Myocardial Infarction Heart Failure Efficacy and Survival Study) studies, but what is lacking is a trial of aldosterone blockade in patients with mild, symptomatic heart failure as such. The strongest argument for ARBs is that the CHARM (Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity) Added trial result was positive in the precise patient population of interest (mild, symptomatic heart failure). The strength of this argument is diminished by the somewhat different results in Val-HeFT (Valsartan Heart Failure Trial). A third possibility is to use neither an ARB nor an aldosterone blocker and arguments can be marshalled for this position also. Clinicians should now assess these various arguments to select what they believe would be best for their patients.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2005

B-type natriuretic peptide can detect silent myocardial ischaemia in asymptomatic type 2 diabetes.

OBJECTIVE: To find out whether B-type natriuretic peptide (BNP) detects silent myocardial ischaemia in patients with type 2 diabetes, since many of these patients have silent ischaemia leading to unexpected cardiac deaths. DESIGN: Prospective cross-sectional study with consecutive recruitment of patients. SETTING: Outpatient, single centre. PATIENTS: 219 patients with type 2 diabetes. Patients were excluded if they had a history or evidence of cardiac failure. OUTCOME MEASURES: BNP, echocardiography and exercise tolerance test (ETT). BNP was compared with the ETT result in all patients and specifically in those who had no apparent ischaemic heart disease (IHD). RESULTS: 121 patients had no history of IHD or cardiac failure and of these patients 85 had a clearly abnormal or normal ETT result. BNP was higher in patients with an abnormal than with a normal ETT (mean 58.2 (SD 46.3) v 24.4 (SD 15.7) pg/ml, p < 0.001). In univariate analysis BNP was an independent predictor of an abnormal ETT (p < 0.001). In multivariate analysis BNP remained an independent predictor of the ETT result. BNP concentration over 20 pg/ml predicted an abnormal ETT result with a sensitivity of 87% and specificity of 37%, and BNP over 40 pg/ml had a sensitivity of 63% and a specificity of 81%. CONCLUSION: BNP is of value in predicting silent ischaemia on exercise testing in asymptomatic patients with type 2 diabetes.

Area Under Curve↗
PubMed2005

B-type natriuretic peptide identifies silent myocardial ischaemia in stroke survivors.

OBJECTIVE: To test the hypothesis that B-type natriuretic peptide (BNP) predicts reversible myocardial ischaemia in stroke survivors who do not have chest pain or previous myocardial infarction. METHODS: 56 stroke survivors (mean (SE) age 68 (8) years) underwent tetrofosmin myocardial perfusion scanning with dipyridamole as the stressor. The degree of ischaemia was assessed by a scoring system (out of 64) by an experienced observer blinded to the results of BNP. RESULTS: In the whole cohort, BNP was significantly correlated with the degree of myocardial ischaemia on stress scanning (Spearman's r = -0.475, p < 0.001). BNP also correlated with the degree of reversible ischaemia (stress score - rest score; Spearman's r = 0.28, two tailed p = 0.049). In the cohort who did not have left ventricular systolic dysfunction (n = 44), BNP remained higher in patients with relevant myocardial ischaemia (mean (SE) BNP 20.9 pg/ml, 95% confidence interval (CI) 15.2 to 26.5 v 12.2 pg/ml, 95% CI 5.95 to 18.5; p = 0.046); 33 of the 44 patients had no chest pain or history of myocardial infarction. The relation between resting BNP and both inducible ischaemia and dipyridamole stress score remained significant (Spearman's r = 0.37 and -0.38, respectively). CONCLUSIONS: BNP correlates with the degree of reversible myocardial ischaemia in patients who do not have chest pain or a history of myocardial infarction or evidence of left ventricular systolic dysfunction. Stroke survivors with a high BNP deserve further investigations to rule out significant reversible myocardial ischaemia, in order to reduce their risk of cardiac death.

Aged↗
PubMed2005

The epidemiology of left ventricular hypertrophy in type 2 diabetes mellitus.

AIMS/HYPOTHESIS: Patients with type 2 diabetes mellitus are at greater cardiovascular risk than the general population. Although it is widely acknowledged that diabetes is a risk factor for coronary artery disease, the increased prevalence of potentially lethal left ventricular abnormalities in this population is less well appreciated. METHODS: We carried out an echocardiographic study of 500 subjects with type 2 diabetes mellitus to assess the prevalence of left ventricular hypertrophy (LVH) and left ventricular systolic dysfunction (LVSD). We also assessed whether abnormalities in diastolic filling parameters were present. RESULTS: Of the 371 patients in whom left ventricular mass could be successfully assessed, 264 had LVH (71%). Left ventricular systolic dysfunction was much less common, being present in 16/385 patients (4.2%). Long axis contraction was abnormal in 29/429 patients (6.8%). Diastolic filling abnormalities were present in 178/435 (41%) of patients who could be classified using the selected criteria. CONCLUSIONS: We conclude that left ventricular abnormalities are common in type 2 diabetic patients. As medical therapy is available for both LVH and LVSD and has been demonstrated to reduce cardiovascular death, these left ventricular abnormalities could be ideal targets for screening, followed by selective therapeutic intervention.

Aged↗
PubMed2005

B-type natriuretic peptide: a simple new test to identify coronary artery disease?

A common key question in clinical medicine is whether coronary artery disease (CAD) is present in a patient. This applies not only to patients with symptomatic chest pain, but also to those at high risk of sudden unexpected death due to asymptomatic CAD, such as diabetics. In both groups of patients, it would be of great benefit if a simple blood test could identify those most likely to have CAD. Such individuals could then be selected for more definitive but more invasive tests for CAD, such as angiography, exercise testing, etc. In addition to its established role in diagnosing heart failure, it appears that BNP may fulfil this function of pre-screening for both symptomatic and asymptomatic CAD. We review the evidence for this new prospect, which has the potential to reduce cardiac deaths by using a simple blood test to better target cardioprotective strategies to those who most need them.

Biomarkers↗
PubMed2005

QT interval abnormalities are often present at diagnosis in diabetes and are better predictors of cardiac death than ankle brachial pressure index and autonomic function tests.

OBJECTIVES: To study serial measures of maximum QT interval corrected for heart rate (QTc) and QT dispersion (QTD) and their association with cardiac mortality patients with non-insulin dependent diabetes and to compare QT abnormalities with other mortality predictors (ankle brachial pressure index (ABPI) and autonomic function tests) in their ability to predict cardiac death. SETTING: Teaching hospital. METHODS AND PATIENTS: QT interval analysis, heart rate (RR) variation in response to deep breathing and standing, and ABPI were analysed in 192 patients with non-insulin dependent diabetes. Cardiac death was the primary end point. RESULTS: Mean (SD) follow up was 12.7 (3.2) years (range 1.2-17.1 years). There were 48 deaths, of which 26 were cardiac. QTc and QTD were individually significant predictors of cardiac mortality throughout the follow up period (p < 0.001). The predictability of QT parameters was superior to the predictability of ABPI and RR interval analysis. Temporal changes in QT parameters showed that the mean absolute QT parameter was a significant predictor of cardiac death (p < 0.001), whereas an intraindividual change in QT parameter over time was not predictive. CONCLUSION: QT abnormalities seem to exist at the point of diagnosis of diabetes and do not appear to change between then and the subsequent cardiac death. Furthermore, the analysis of QT interval is superior to ABPI and the RR interval in identifying diabetic patients at high risk of cardiac death.

Adult↗
PubMed2005

Allopurinol reduces B-type natriuretic peptide concentrations and haemoglobin but does not alter exercise capacity in chronic heart failure.

OBJECTIVE: To study whether the effect of allopurinol on improvement of endothelial dysfunction in chronic heart failure (CHF) translates into improved exercise capacity and to examine whether allopurinol also improves B-type natriuretic peptide (BNP), the other important prognostic marker of CHF. DESIGN: Randomised, double blind, placebo controlled crossover trial. SETTING: Teaching hospital. PATIENTS: 50 patients with CHF (New York Heart Association functional classes II and III) were recruited. INTERVENTIONS: 50 patients with CHF were randomly assigned to three months' treatment with allopurinol (300 mg/day) or placebo. At two and three months into treatment, they underwent a modified Bruce exercise protocol and a six minute walk test. Blood was taken for BNP and haemoglobin analysis. RESULTS: Neither exercise test was altered by allopurinol. However, plasma BNP concentrations fell significantly (p = 0.035) with allopurinol (11.9 pmol/l) versus placebo (14.4 pmol/l). Haemoglobin concentrations also fell highly significantly with allopurinol (p = 0.001). CONCLUSIONS: An important negative finding is that despite high hopes for it, allopurinol had no effect on exercise capacity in CHF. On the other hand, allopurinol did reduce BNP, which is the best available surrogate marker for prognosis in CHF.

Aged↗
PubMed2005

Spectrum of cardiac abnormalities associated with long QT in stroke survivors.

OBJECTIVES: To find out what spectrum of cardiac abnormalities are found in those stroke survivors who can be deemed to be at high cardiac risk by their having long QT. METHODS: 202 patients with good recovery from a cerebrovascular event occurring at least one month previously were recruited into a prospective epidemiological study. These stroke survivors underwent a battery of cardiac investigations including 12 lead ECG, echocardiography, myocardial perfusion scanning, and heart rate variability assessment. The ECGs were digitised by a single observer blinded to the blood pressure and other investigations of the patients. The maximum heart rate corrected QT interval (QTc max) in the 12 lead ECG was derived by Bazett's formula. RESULTS: Prolonged QTc max significantly correlated with increasing blood pressure, left ventricular mass index, and depressed heart rate variability. As the number of cardiac abnormalities increased, QTc max became more prolonged. CONCLUSIONS: Long QT is significantly associated with left ventricular mass index even after adjustment for both systolic and diastolic blood pressures. Long QT was also associated with the total cardiac disease burden. These two observations may explain why stroke survivors with long QTc max were at greater risk of cardiac death.

Adult↗
PubMed2005

Pathophysiology of heart failure following myocardial infarction.

The structural and functional abnormalities that lead to cardiac death are coronary artery disease and left ventricular abnormalities related to remodelling (left ventricular hypertrophy, left ventricular systolic dysfunction, and left ventricular fibrosis). Aldosterone adversely affects all of these processes. It produces both a vasculopathy and left ventricular dysfunction and fibrosis. Endothelial dysfunction in the coronary arteries can lead to acute coronary events. Left ventricular dysfunction will cause the progression of heart failure, and left ventricular fibrosis and dysfunction provide an arrhythmic substrate. The combination of acute coronary events and arrhythmias can lead to sudden cardiac deaths, while acceleration of the heart failure disease process can lead to deaths from progressive heart failure. The increased understanding of the mechanistic role of aldosterone in cardiovascular disease provides a rationale for the positive results that have been seen in clinical trials of aldosterone blockade.

Aldosterone↗
PubMed2005

Agreement between community echocardiography and hospital echocardiography in patients suspected of having left ventricular systolic dysfunction.

BACKGROUND: Smaller echocardiography machines, when used in hospitals, are accurate for detecting left ventricular dysfunction and valvular disease. This paper assessed the detection of left ventricular dysfunction and of valvular disease in the community setting by a smaller machine. AIMS: To measure the agreement in patients with suspected heart failure between community echocardiography and traditional echocardiography in the hospital in detecting left ventricular dysfunction and significant valve disease. METHODS: Suspected heart failure patients were referred to one of the authors (SJ) for community echocardiography using a Siemens Cypress machine. The patients had a second echocardiogram in the hospital by another sonographer who was blinded to the results of the first echocardiogram. The reports of the two sonographers were assessed for agreement using kappa statistics. RESULTS: 458 patients had a community echocardiogram and 136 agreed to a second echocardiogram in the hospital. There was excellent agreement, kappa = 0.87 (0.06 SE), for the detection of left ventricular dysfunction between community echocardiography and the hospital machine. The detection of significant valvular disease was good, kappa = 0.75 (0.06) between the community echocardiogram and hospital machines. CONCLUSIONS: In suspected heart failure patients, community echocardiography gives comparable results to traditional hospital echocardiography for left ventricular dysfunction detection and for significant valvular disease detection.

Aged↗
PubMed2004

Spironolactone impairs endothelial function and heart rate variability in patients with type 2 diabetes.

AIMS/HYPOTHESIS: Aldosterone blockade has followed in the footsteps of ACE inhibition in reducing mortality in patients with heart failure. This is associated with its beneficial effects on endothelial function and heart rate variability. Diabetes is another area, where angiotensin II withdrawal has proven to be of particular value. We postulated that aldosterone blockade with spironolactone might also have beneficial effects on the prognostic markers of endothelial function and heart rate variability in diabetic patients. METHODS: We assessed endothelial function by forearm venous occlusion plethysmography in 42 patients with type 2 diabetes mellitus after 1 month of treatment with spironolactone or placebo allocated in a randomised double-blind trial. Of the 42 patients, 20 were on ACE inhibitor therapy. We also assessed heart rate variability, HbA1c and plasma angiotensin II levels at the end of each treatment period. RESULTS: Compared to placebo, spironolactone decreased forearm blood flow response to acetylcholine by 44.56+/-14.56% (p=0.003) in the group as a whole and by 57.61+/-15.56% (p<0.001) in the 20 patients on ACE inhibition. Spironolactone also worsened heart rate variability parameters, with root mean squared standard deviation decreased by 1.99+/-0.93 ms (p=0.03), low-frequency normalised power increased by 2.00+/-0.91 normalised units (nu) (p=0.03), high-frequency normalised power decreased by 1.98+/-0.94 nu (p=0.04) and the low frequency : high frequency ratio increased by 0.40+/-0.19 (p=0.04). HbA1c and angiotensin II increased during treatment with spironolactone by 0.26+/-0.07% (p=0.001) and 8.12+/-1.94 pg/ml (p=0.001) respectively. CONCLUSIONS/INTERPRETATION: Spironolactone worsened endothelial function and heart rate variability in patients with type 2 diabetes. These findings are possibly due to the worsening of glycaemic control and increase in plasma angiotensin II that were seen with spironolactone treatment. Thus the prescription of spironolactone to diabetic patients without heart failure does not seem to be justified.

Adult↗
PubMed2004

Cardiovascular autonomic function in patients with hemodynamic instability at induction of capnoperitoneum: a case-control study.

BACKGROUND: This study hypothesized that patients in whom bradycardia and hypotension develop with induction of positive-pressure capnoperitoneum have an underlying autonomic cardiovascular dysfunction. METHODS: A case-control study was conducted to examine the baseline autonomic function of patients in whom bradycardia and hypotension develop with induction of positive-pressure capnoperitoneum. The control group consisted of patients who maintained normal cardiac rhythm and blood pressure during the same procedure. Two groups of tests were performed: bedside stress tests of cardiovascular autonomic function (response graded 1 (normal) to 4 (severely abnormal) and heart rate variability analysis (spectral and time domain components). RESULTS: The study evaluated 6 patients in the bradycardia group and 10 in the control group. The group in whom bradycardia had developed scored significantly worse on the bedside stress tests than the control group (for grades I to IV: chi2 = 6.5, p = 0.022; for trend: chi2 = 5.6, p = 0.018). In contrast, both groups had similar baseline autonomic tone, as measured by heart rate variability. CONCLUSIONS: Patients in whom bradycardia and hypotension develop with induction of positive-pressure capnoperitoneum have cardiovascular autonomic dysfunction, which is identifiable by bedside stress tests of autonomic function.

Autonomic Nervous System↗
PubMed2004

Hypothetical economic analysis of screening for left ventricular hypertrophy in high-risk normotensive populations.

BACKGROUND: Left ventricular hypertrophy (LVH) measured by echocardiography is a powerful independent marker of increased cardiovascular risk. The prevalence of echocardiographic LVH in patients with high cardiovascular risk appears to be high, even in patients currently considered normotensive. AIM: To ascertain the likely costs of screening for and treating echocardiographic LVH in normotensive patients at high risk of cardiovascular events. DESIGN: Hypothetical economic analysis. METHODS: Cost analyses were based on known costs of echocardiography, costs of selected cardiovascular medications and prevalence of normotensive LVH in at-risk populations, combined with treatment effect data from studies of hypertensive patients with echocardiographic LVH. RESULTS: Screening costs per case for echocardiographic LVH are likely to be low, because of the high prevalence of the condition and the low unit cost of echocardiography. Treatment costs are likely to be comparable to those currently deemed acceptable in treating high-risk cardiovascular populations, e.g. the HOPE study population. DISCUSSION: The costs of screening for and treating LVH in normotensive patients at risk of cardiovascular events do not appear to be prohibitively high. Trials of screening and treatment for normotensive LVH seem therefore to be warranted.

Antihypertensive Agents↗
PubMed2004

Angiotensin converting enzyme activity in infancy is related to birth weight.

AIMS: (a) To measure infant angiotensin converting enzyme (ACE) activity in healthy term infants at birth and during the first three months of life. (b) To determine the relation between serum ACE activity and infant feeding practice during this period. (c) To investigate the relation between serum ACE activity and birth weight and other potential contributing factors including acid-base status at birth, gestation, and maternal ACE genotype. METHODS: Prospective study of term infants, with clinical and feeding data collected from parents and medical records, and serum ACE measured in the infant at birth and 1 and 3 months of age, and in the mother at the time of birth and one to three months after birth. RESULTS: At birth and 1 and 3 months of age, infant serum ACE activity was twice that of maternal ACE activity. Infant ACE activity at birth and 1 and 3 months did not significantly differ between breast and formula fed infants. There was a highly significant negative correlation between infant ACE activity at 3 months and birth weight (r = -0.52; p < 0.001). This persisted after the conversion of birth weights to z scores (r = -0.34; p = 0.03). ACE activity at 3 months was also related to placental weight (r = -0.30; p = 0.02) and maternal age (r = -0.30; p = 0.05). The strong correlation between serum ACE activity and birth weight z score persisted after adjustment for maternal age and placental weight (r = -0.34; p = 0.03). CONCLUSION: As ACE is increasingly identified as a risk factor for cardiovascular disease, serum ACE activity in infancy may contribute to the link between low birth weight and later cardiovascular events.

Aging↗
PubMed2004

Effects of spironolactone on endothelial function, vascular angiotensin converting enzyme activity, and other prognostic markers in patients with mild heart failure already taking optimal treatment.

OBJECTIVES: To examine whether the favourable effects on endothelial function, vascular angiotensin converting enzyme (ACE) activity, cardiac remodelling, autonomic function, and QT intervals of spironolactone in combination with ACE inhibitor also occur in patients with New York Heart Association class I-II congestive heart failure (CHF) taking optimal treatment (including beta blockers). METHODS: Double blind, crossover study comparing 12.5-50 mg/24 hours spironolactone (three months) with placebo in 43 patients with class I-II CHF taking ACE inhibitors and beta blockers. RESULTS: Acetylcholine induced vasodilatation improved with spironolactone (p = 0.044). Vascular ACE activity fell (p = 0.006). QTc and QTd fell (mean (SD) QTc 473 (43.1) ms with placebo, 455 (35.4) ms with spironolactone, p = 0.002; QTd 84.5 (41.3) ms with placebo, 72.1 (32.3) ms with spironolactone, p = 0.037). beta-Type natriuretic peptide (BNP) and procollagen III N-terminal peptide (PIIINP) concentrations were also reduced by spironolactone (mean (SD) BNP 48.5 (29.6) pg/ml with placebo, 36.8 (28.5) pg/ml with spironolactone, p = 0.039; PIIINP 3.767 (1.157) microg/ml with placebo, 3.156 (1.123) microg/ml with spironolactone, p = 0.000). CONCLUSIONS: Spironolactone improves vascular function (endothelial function, vascular ACE activity) and other markers of prognosis (BNP, collagen markers, and QT interval length) in asymptomatic or mild CHF when added to optimal treatment including beta blockade. This gives support to the hypothesis that the prognostic benefit seen in RALES (randomised aldactone evaluation study) and EPHESUS (eplerenone postacute myocardial infarction heart failure efficacy and survival study) may also occur in patients with milder CHF already taking standard optimal treatment.

Adrenergic beta-Antagonists↗
PubMed2004

Sudden unexpected death in heart failure may be preceded by short term, intraindividual increases in inflammation and in autonomic dysfunction: a pilot study.

OBJECTIVE: To see whether sudden unexpected death in chronic heart failure is preceded by intraindividual worsening in inflammation and in ECG criteria. DESIGN AND SETTING: Prospective cohort study conducted in the community. PATIENTS: 34 patients with chronic heart failure were studied. Their mean (SD) age was 68 (8) years, 29 were men, mean (SD) left ventricular ejection fraction was 29 (9)%, and they were in New York Heart Association functional class II (n = 20), III (n = 11), and IV (n = 3). The patients were examined monthly over 24 months, with sequential measurement of C reactive protein and neutrophil counts and 24 hour ambulatory ECG monitoring measuring heart rate variability, mean heart rate, and arrhythmias. Intraindividual changes in these parameters were related to subsequent cardiac deaths. RESULTS: During follow up, nine patients died: five patients had a sudden unexpected death (SUD) and four died of progressive heart failure (PHF). There were significant intraindividual changes in neutrophil counts (p = 0.02), C reactive protein (p = 0.039), and heart rate variability (p < or = 0.018) in those who died of SUD and PHF. In contrast no significant changes were seen in ventricular extrasystoles, ventricular tachycardia episodes, brain natriuretic peptide, or aldosterone in the SUD group, but all of these parameters did increase as expected in those who died of PHF. CONCLUSIONS: This is preliminary evidence that SUD may be preceded by intraindividual increases in both inflammation and autonomic dysfunction. Both may be causal in genesis but, even if they are not, intraindividual increases in either may be convenient markers to identify patients at high risk of impending SUD. Larger studies are needed to confirm the observation from this pilot study.

Aged↗