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Allan Gaw

Publications and source records attributed to Allan Gaw.

At least 19 recordsLinked to original sources
PubMed2006

Increased soluble Fas plasma levels in subjects at high cardiovascular risk: Atorvastatin on Inflammatory Markers (AIM) study, a substudy of ACTFAST.

OBJECTIVE: Increasing evidence indicates that the Fas/Fas ligand interaction is involved in atherogenesis. We sought to analyze soluble Fas (sFas) and soluble Fas ligand (sFasL) concentrations in subjects at high cardiovascular risk and their modulation by atorvastatin treatment. METHODS AND RESULTS: ACTFAST was a 12-week, prospective, multicenter, open-label trial which enrolled subjects (statin-free or statin-treated at baseline) with coronary heart disease (CHD), CHD-equivalent, or 10-year CHD risk > 20%. Subjects with LDL-C between 100 to 220 mg/dL (2.6 to 5.7 mmol/L) and triglycerides < or = 600 mg/dL (6.8 mmol/L) were assigned to a starting dose of atorvastatin (10 to 80 mg/d) based on LDL-C at screening. Of the 2117 subjects enrolled in ACTFAST, AIM sub-study included the 1078 statin-free patients. At study end, 85% of these subjects reached LDL-C target. Mean sFas levels were increased and sFasL were reduced in subjects at high cardiovascular risk compared with healthy subjects. Atorvastatin reduced sFas in the whole population as well as in patients with metabolic syndrome or diabetes. Minimal changes were observed in sFasL. CONCLUSIONS: sFas concentrations are increased and sFasL are decreased in subjects at high cardiovascular risk, suggesting that these proteins may be novel markers of vascular injury. Atorvastatin reduces sFas, indicating that short-term treatment with atorvastatin exhibits antiinflammatory effects in these subjects.

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PubMed2005

Plasma lipoproteins and apolipoproteins as predictors of cardiovascular risk and treatment benefit in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER).

BACKGROUND: Statins are important in vascular disease prevention in the elderly. However, the best method of selecting older patients for treatment is uncertain. We assessed the role of plasma lipoproteins as predictors of risk and of treatment benefit in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). METHOD AND RESULTS: The association of LDLc and HDLc with risk was examined in the 5804 70- to 82-year-old subjects of PROSPER. Baseline LDLc showed no relation to risk of the primary end point in the placebo group (P=0.27), nor did on-treatment LDLc in the pravastatin group (P=0.12). HDLc was inversely associated with risk in subjects on placebo (P=0.0019) but not in those on pravastatin (P=0.24). Risk reduction on pravastatin treatment was unrelated to baseline LDLc (P=0.38) but exhibited a significant interaction with HDLc (P=0.012). Subjects in the lowest 2 quintiles of HDLc (<1.15 mmol/L) had a risk reduction of 33% (hazard ratio, 0.67; 95% confidence limits, 0.55, 0.81; P<0.0001), whereas those with higher HDLc showed no benefit (RR, 1.06; 95% confidence limits, 0.88, 1.27; P=0.53). During follow-up, there was no relation between achieved level of LDLc or HDLc and risk. However, the change in the LDLc/HDLc ratio on statin treatment appeared to account for the effects of therapy. CONCLUSIONS: In people >70 years old, HDLc appears to be a key predictor of risk and of treatment benefit. Findings in PROSPER suggest that statin therapy could usefully be targeted to those with HDLc <1.15 mmol/L or an LDLc/HDLc ratio >3.3.

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PubMed2005

Plasma lipoprotein(a) [Lp(a)] concentrations and cardiovascular events in the elderly: evidence from the prospective study of pravastatin in the elderly at risk (PROSPER).

Using analyses of the large cohort (n=5732) from the prospective study of pravastatin in the elderly at risk (PROSPER), we tested the hypothesis that Lp(a) concentration is an independent predictor of major vascular events and cognitive impairment in the elderly. Baseline Lp(a) levels were measured on fresh samples from 5732 subjects aged 70-82, who were followed for 3.2 years on average. Lp(a) levels were not significantly different across the age range in PROSPER, but were significantly higher in women (geometric mean 14.8 versus 12.4 mg/dl, P<0.0001). Those with a history of vascular disease had significantly higher Lp(a) levels, which remained after adjustment (P<0.0001). There was no statistically significant association between baseline Lp(a) and the risk of the primary endpoint (CHD death, non-fatal MI and fatal or non-fatal stroke) (hazard ratio 1.05, 95% CI 1.00-1.11, P=0.077), but after adjustment for baseline risk factors this did achieve statistical significance (1.06, 1.005-1.12, P=0.032). Finally, there was no statistically or clinically significant association between any adjusted baseline or dynamic cognition variables and Lp(a), and nor was there any significant association between Lp(a) and indices of disability throughout the study. This is the first study of the association between Lp(a) and a range of cardiovascular endpoints including cognitive and disability indices in the elderly. The main finding is that Lp(a) level, while influenced by a number of baseline characteristics, is not a significant predictor of cognitive function or levels of disability, but is a predictor of combined cardiovascular events over an average 3.2 year follow-up.

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PubMed2005

Unblinding of trial participants to their treatment allocation: lessons from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER).

BACKGROUND: The gold standard clinical trial design is the double-blind, randomized, controlled trial. No standard practice exists for the "unblinding" of trial participants and no legal obligation is placed on investigators to inform participants of their treatment allocation or study results at the end of a trial. Here we document our experiences of unblinding the 2520 Scottish participants in the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). METHODS: The objectives of the PROSPER unblinding process were to provide all study participants with their study medication status and on-trial cholesterol levels and to respect the rights of participants not to be unblinded. It was considered imperative by the study executive that the blind was maintained until the presentation and publication of the results. Staff therefore remained "blinded" throughout the unblinding process. Inappropriate contact with the PROSPER participants was avoided by confirming their current vital status and health status. RESULTS: To coincide with the presentation of the PROSPER results, all participants, for whom it was deemed appropriate, were sent a summary of the results and were offered the opportunity to be advised of their treatment allocation and on-trial lipid profiles. The majority of participants opted for telephone unblinding. All primary care physicians who had patients randomised to the study were also sent a summary of the study results and sealed documents detailing the treatment allocation and lipid profiles for each patient. Relocated patients were traced and the information forwarded to their new primary care physicians. CONCLUSION: The dissemination of study results and treatment allocation to study participants is an integral part of the research process and should be included in the design of any clinical trial.

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PubMed2004

Understanding why older people participate in clinical trials: the experience of the Scottish PROSPER participants.

BACKGROUND: over the next 20 years it is anticipated that there will be a significant increase in those aged 75 and over, and a consequent increase in cardiovascular disease, cancer and chronic illness. As this shift takes effect, there will be an increased need for treatment strategies that are of known benefit to this age group and a consequent rise in demand for clinical trials that are conducted specifically with the older population. Because factors that motivate older individuals to participate in clinical trials may differ from those that influence younger adults, it is important to evaluate the strategies used to encourage recruitment and retention and to determine how appropriate these are. AIM: evaluation of the reasons why subjects agree to participate in a controlled clinical trial of vascular disease prevention and the strategies used to improve compliance and protocol adherence. SETTING: Scotland. SUBJECTS: 2,520 Prospective Study of Pravastatin in the Elderly at Risk participants, aged 70-82 with either pre-existing vascular disease or at least one major vascular risk factor (hypertension, cigarette smoking, or diabetes mellitus). DESIGN OF STUDY: two-stage iterative survey. Stage I was exploratory. RESULTS: curiosity, or an interest in finding out more about the study, 'a desire to support research', and anticipated personal benefits, such as health screening, were the most important motivators for generating initial interest in the trial. Ongoing health monitoring was the most important recruitment and retention motivator (P = 0.001). CONCLUSIONS: curiosity, self interest and altruism may act as motivators at different points in the study time-line. However, fostering positive relationships between staff and recruits, and keeping recruits informed about the progress of the study are likely to maximise the retention of older subjects to long-term trials.

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PubMed2004

Statin therapy in the elderly.

PURPOSE OF REVIEW: The clinical efficacy and safety of statin therapy have been well established from a series of large-scale, randomized controlled trials. These trials, however, have predominantly recruited patients under the age of 70 years. As a consequence, the use of statins in older patients has remained controversial. RECENT FINDINGS: The results of the first trial to look exclusively at the elderly--the Prospective Study of Pravastatin in the Elderly at Risk--have added enormously to our understanding of the use of statins in the elderly. These findings, together with those from the large elderly cohort within the Heart Protection Study and the smaller elderly subgroups within the other major statin trials, have forced us to re-evaluate any systematic exclusion of elderly patients from statin therapy. SUMMARY: The collective evidence now strongly supports the use of statins in the at-risk elderly population.

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PubMed2004

Closing out a large clinical trial: lessons from the prospective study of pravastatin in the elderly at risk (PROSPER).

Relatively little has been written about the practicalities of the closeout of large, multi-centre clinical trials, but this aspect of trial conduct and design is both important and requires careful planning in order to be accomplished in a timely and orderly fashion. Here, we document our recent experiences of closing down the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER). This five-year study with over 5800 subjects was closed down and published in 2002. We describe the methods used to ensure the speedy progression from the start of the closeout period through data lock to publication and presentation of the results. We discuss the strategic planning of all aspects of the closeout process, the training of staff for final visits, the methods used to follow-up all study participants including those used in dealing with "difficult to contact" and defaulted patients, and the strategies employed to ensure that study participants were left with positive feelings about the study. We also detail the methods employed to expedite the throughput of study paperwork and endpoints and the cleaning of data in preparation for data lock and subsequent publication and presentation of the results. Based on our experiences we summarize the most important aspects of closeout design and make recommendations for future studies, the most important of which is that a well-planned and well-managed closeout is a key feature of any large scale clinical trial and a coherent and practicable closeout strategy should be an integral part of the design.

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PubMed2003

Metabolic syndrome with and without C-reactive protein as a predictor of coronary heart disease and diabetes in the West of Scotland Coronary Prevention Study.

BACKGROUND: The National Cholesterol Education Program (NCEP) recently proposed a simple definition for metabolic syndrome. Information on the prospective association of this definition for coronary heart disease (CHD) and type 2 diabetes is currently limited. METHODS AND RESULTS: We used a modified NCEP definition with body mass index in place of waist circumference. Baseline assessments in the West of Scotland Coronary Prevention Study were available for 6447 men to predict CHD risk and for 5974 men to predict incident diabetes over 4.9 years of follow-up. Mean LDL cholesterol was similar but C-reactive protein was higher (P<0.0001) in the 26% of men with the syndrome compared with those without. Metabolic syndrome increased the risk for a CHD event [univariate hazard ratio (HR)=1.76 (95% CI, 1.44 to 2.15)] and for diabetes [univariate HR=3.50 (95% CI 2.51 to 4.90)]. Metabolic syndrome continued to predict CHD events (HR=1.30, 95% CI, 1.00 to 1.67, P=0.045) in a multivariate model incorporating conventional risk factors. Men with 4 or 5 features of the syndrome had a 3.7-fold increase in risk for CHD and a 24.5-fold increase for diabetes compared with men with none (both P<0.0001). C-reactive protein enhanced prognostic information for both outcomes. With pravastatin, men with the syndrome had similar risk reduction for CHD as compared with those without (HR, 0.73 and 0.69; pravastatin versus placebo). CONCLUSIONS: A modified NCEP metabolic syndrome definition predicts CHD events, and, more strikingly, new-onset diabetes, and thus helps identify individuals who may receive particular benefit from lifestyle measures to prevent these diseases.

Body Mass Index↗
PubMed2003

Patients' perspectives on statin therapy for treatment of hypercholesterolaemia: a qualitative study.

BACKGROUND: Health Care Practitioners' attempts to implement secondary prevention targets for coronary heart disease (CHD) may be restricted by low rates of persistence with statin therapy. There is a need to understand why some patients, despite having established CHD and elevated cholesterol, do not comply with their prescribed statin regimen. AIM: To explore patients' perspectives on compliance with statin therapy. SETTING: Primary care, West of Scotland. METHODS: The research approach was qualitative. Thirty-three patients prescribed statin therapy and identified as having different patterns of compliance (poor moderate and good) were interviewed. The in-depth interviews were conducted on a one to one basis. Patients prescribed statin therapy for less than three months were excluded. Data were analysed thematically with the assistance of QSR Nudist. FINDINGS: From analysis of the narrative data, two broad categories, i.e. 'Patient-health care provider communication' and 'Health beliefs' were identified. These categories encompassed six main themes: 'Initiation of therapy'; 'Subsequent feedback'; 'Sources of misconceptions'; 'Unconditional acceptance'; 'Conditional acceptance'; 'Deferment and Rejection'. Acceptance of and compliance with statin therapy appeared to be associated with the provision, interpretation and feedback of information during patient-practitioner consultations, and patients' beliefs about personal health status, cholesterol, and recommended cholesterol-lowering strategies. CONCLUSIONS: Patients' beliefs and understanding about cholesterol, and the role of cholesterol modifying strategies should be determined prior to the initiation of therapy and at appropriate intervals thereafter.

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PubMed2003

HDL-C and triglyceride levels: relationship to coronary heart disease and treatment with statins.

The association between low-density lipoprotein cholesterol (LDL-C) levels and risk of coronary heart disease (CHD) is well established and LDL-C-lowering is currently the primary target for the treatment of dyslipidemia. However, low levels of high-density lipoprotein cholesterol (HDL-C), and high levels of triglycerides (TG) are also risk factors for CHD and modifying levels of these lipid subfractions, in addition to LDL-C lowering, may have clinical benefits in many patients. Statins are the first-line drug therapy for the treatment of dyslipidemia because of their efficacy in lowering LDL-C and good tolerability. Statins also have beneficial effects on TG and HDL-C levels although they differ in the degree to which they modify the levels of these lipoproteins. Improvements across the atherogenic components of the lipid profile may be optimized by the co-administration of a statin with a fibrate, niacin or omega-3 fatty acids; however, particular combination therapies have been associated with side effects and may be poorly tolerated. Newer combinations with better tolerability, or new statins with improved efficacy on non-LDL-C lipid subfractions, would be welcome additions to the currently available therapies for the treatment of dyslipidemia.

Cholesterol, HDL↗
PubMed2003

Statin therapy in the elderly: does it make good clinical and economic sense?

HMG-CoA reductase inhibitors (statins) have been established as the dominant treatment for coronary heart disease (CHD). This dominance is based on an impressive body of clinical trial evidence showing significant benefits in primary prevention of cardiovascular events in individuals at risk for CHD and in secondary prevention of such events in patients with CHD and high or normal plasma cholesterol levels. There is, however, significant room for improvement in the treatment of CHD with respect both to drug efficacy and to the disparity between evidence-based medicine and actual clinical practice particularly in relation to treatment strategies for the elderly. Current statins fall short of requirements for 'ideal' lipid-lowering treatment in several respects; 'super' statins and other agents currently in development may satisfy more of these requirements. Moreover, available therapies are not applied optimally, because of physician nonacceptance and/or patient noncompliance; thus, the majority of patients with CHD or its risk factors still have cholesterol levels that exceed guideline targets. There is also evidence that older patients with CHD, or at high risk of CHD, are undertreated - possibly because of concerns regarding the increased likelihood of adverse events or drug interactions or doubts regarding the cost effectiveness of statin therapy in this population. This group is of particular clinical relevance, since it is showing a proportionate rapid expansion in most national populations. To address their potential healthcare needs, the ongoing Pravastatin in the Elderly at Risk (PROSPER) study is assessing the effects of pravastatin in elderly patients (5804 men and women aged 70-82 years) who either have pre-existing vascular disease or are at significant risk for developing it, with the central hypothesis that statin therapy (pravastatin 40 mg/day) will diminish the risk of subsequent major vascular events compared with placebo. After a 3.2-year treatment period, a primary assessment will be made of the influence of statin treatment on major cardiovascular events (a combination of CHD death, nonfatal myocardial infarction, and fatal or nonfatal stroke). Optimal deployment of the currently available agents and of newer agents (no matter how well they satisfy requirements for ideal treatment) ultimately depends on the establishment of an evidence base and may require far-reaching educational programmes that change the way risk factor management is viewed by caregivers and patients alike.

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PubMed2002

Pravastatin in elderly individuals at risk of vascular disease (PROSPER): a randomised controlled trial.

BACKGROUND: Although statins reduce coronary and cerebrovascular morbidity and mortality in middle-aged individuals, their efficacy and safety in elderly people is not fully established. Our aim was to test the benefits of pravastatin treatment in an elderly cohort of men and women with, or at high risk of developing, cardiovascular disease and stroke. METHODS: We did a randomised controlled trial in which we assigned 5804 men (n=2804) and women (n=3000) aged 70-82 years with a history of, or risk factors for, vascular disease to pravastatin (40 mg per day; n=2891) or placebo (n=2913). Baseline cholesterol concentrations ranged from 4.0 mmol/L to 9.0 mmol/L. Follow-up was 3.2 years on average and our primary endpoint was a composite of coronary death, non-fatal myocardial infarction, and fatal or non-fatal stroke. Analysis was by intention-to-treat. FINDINGS: Pravastatin lowered LDL cholesterol concentrations by 34% and reduced the incidence of the primary endpoint to 408 events compared with 473 on placebo (hazard ratio 0.85, 95% CI 0.74-0.97, p=0.014). Coronary heart disease death and non-fatal myocardial infarction risk was also reduced (0.81, 0.69-0.94, p=0.006). Stroke risk was unaffected (1.03, 0.81-1.31, p=0.8), but the hazard ratio for transient ischaemic attack was 0.75 (0.55-1.00, p=0.051). New cancer diagnoses were more frequent on pravastatin than on placebo (1.25, 1.04-1.51, p=0.020). However, incorporation of this finding in a meta-analysis of all pravastatin and all statin trials showed no overall increase in risk. Mortality from coronary disease fell by 24% (p=0.043) in the pravastatin group. Pravastatin had no significant effect on cognitive function or disability. INTERPRETATION: Pravastatin given for 3 years reduced the risk of coronary disease in elderly individuals. PROSPER therefore extends to elderly individuals the treatment strategy currently used in middle aged people.

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PubMed2002

A Prospective Study of Pravastatin in the Elderly at Risk (PROSPER): Screening Experience and Baseline Characteristics.

BACKGROUND: PROSPER was designed to investigate the benefits of treatment with pravastatin in elderly patients for whom a typical doctor might consider the prescription of statin therapy to be a realistic option. METHODS: The PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) is a randomised, double blind, placebo-controlled trial to test the hypothesis that treatment with pravastatin (40 mg/day) will reduce the risk of coronary heart disease death, non-fatal myocardial infarction, and fatal or non-fatal stroke in elderly men and women with pre-existing vascular disease or with significant risk of developing this condition. RESULTS: In Scotland, Ireland, and the Netherlands, 23,770 individuals were screened, and 5,804 subjects (2,804 men and 3,000 women), aged 70 to 82 years (average 75 years) and with baseline cholesterol 4.0-9.0 mmol/l, were randomised. Randomised subjects had similar distributions with respect to age, blood pressure, and body mass index when compared to the entire group of screenees, but had a higher prevalence of smoking, diabetes, hypertension, and a history of vascular disease. The average total cholesterol level at baseline was 5.4 mmol/l (men) and 6.0 mmol/l (women). CONCLUSIONS: Compared with previous prevention trials of cholesterol-lowering drugs, the PROSPER cohort is significantly older and for the first time includes a majority of women. The study, having achieved its initial goal of recruiting more than 5,500 elderly high-risk men and women, aims to complete all final subject follow-up visits in the first half of 2002 with the main results being available in the fourth quarter of 2002.

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