Summary Background The benefits of blood pressure lowering treatment for prevention of cardiovascular disease are well established. However, the extent to which these effects differ by baseline blood ...pressure, presence of comorbidities, or drug class is less clear. We therefore performed a systematic review and meta-analysis to clarify these differences. Method For this systematic review and meta-analysis, we searched MEDLINE for large-scale blood pressure lowering trials, published between Jan 1, 1966, and July 7, 2015, and we searched the medical literature to identify trials up to Nov 9, 2015. All randomised controlled trials of blood pressure lowering treatment were eligible for inclusion if they included a minimum of 1000 patient-years of follow-up in each study arm. No trials were excluded because of presence of baseline comorbidities, and trials of antihypertensive drugs for indications other than hypertension were eligible. We extracted summary-level data about study characteristics and the outcomes of major cardiovascular disease events, coronary heart disease, stroke, heart failure, renal failure, and all-cause mortality. We used inverse variance weighted fixed-effects meta-analyses to pool the estimates. Results We identified 123 studies with 613 815 participants for the tabular meta-analysis. Meta-regression analyses showed relative risk reductions proportional to the magnitude of the blood pressure reductions achieved. Every 10 mm Hg reduction in systolic blood pressure significantly reduced the risk of major cardiovascular disease events (relative risk RR 0·80, 95% CI 0·77–0·83), coronary heart disease (0·83, 0·78–0·88), stroke (0·73, 0·68–0·77), and heart failure (0·72, 0·67–0·78), which, in the populations studied, led to a significant 13% reduction in all-cause mortality (0·87, 0·84–0·91). However, the effect on renal failure was not significant (0·95, 0·84–1·07). Similar proportional risk reductions (per 10 mm Hg lower systolic blood pressure) were noted in trials with higher mean baseline systolic blood pressure and trials with lower mean baseline systolic blood pressure (all ptrend >0·05). There was no clear evidence that proportional risk reductions in major cardiovascular disease differed by baseline disease history, except for diabetes and chronic kidney disease, for which smaller, but significant, risk reductions were detected. β blockers were inferior to other drugs for the prevention of major cardiovascular disease events, stroke, and renal failure. Calcium channel blockers were superior to other drugs for the prevention of stroke. For the prevention of heart failure, calcium channel blockers were inferior and diuretics were superior to other drug classes. Risk of bias was judged to be low for 113 trials and unclear for 10 trials. Heterogeneity for outcomes was low to moderate; the I2 statistic for heterogeneity for major cardiovascular disease events was 41%, for coronary heart disease 25%, for stroke 26%, for heart failure 37%, for renal failure 28%, and for all-cause mortality 35%. Interpretation Blood pressure lowering significantly reduces vascular risk across various baseline blood pressure levels and comorbidities. Our results provide strong support for lowering blood pressure to systolic blood pressures less than 130 mm Hg and providing blood pressure lowering treatment to individuals with a history of cardiovascular disease, coronary heart disease, stroke, diabetes, heart failure, and chronic kidney disease. Funding National Institute for Health Research and Oxford Martin School.
Summary Background End-stage kidney disease is a leading cause of morbidity and mortality worldwide. Prevalence of the disease and worldwide use of renal replacement therapy (RRT) are expected to ...rise sharply in the next decade. We aimed to quantify estimates of this burden. Methods We systematically searched Medline for observational studies and renal registries, and contacted national experts to obtain RRT prevalence data. We used Poisson regression to estimate the prevalence of RRT for countries without reported data. We estimated the gap between needed and actual RRT, and projected needs to 2030. Findings In 2010, 2·618 million people received RRT worldwide. We estimated the number of patients needing RRT to be between 4·902 million (95% CI 4·438–5·431 million) in our conservative model and 9·701 million (8·544–11·021 million) in our high-estimate model, suggesting that at least 2·284 million people might have died prematurely because RRT could not be accessed. We noted the largest treatment gaps in low-income countries, particularly Asia (1·907 million people needing but not receiving RRT; conservative model) and Africa (432 000 people; conservative model). Worldwide use of RRT is projected to more than double to 5·439 million (3·899–7·640 million) people by 2030, with the most growth in Asia (0·968 million to a projected 2·162 million 1·571–3·014 million). Interpretation The large number of people receiving RRT and the substantial number without access to it show the need to both develop low-cost treatments and implement effective population-based prevention strategies. Funding Australian National Health and Medical Research Council.
Summary Background Recent hypertension guidelines have reversed previous recommendations for lower blood pressure targets in high-risk patients, such as those with cardiovascular disease, renal ...disease, or diabetes. This change represents uncertainty about whether more intensive blood pressure-lowering strategies are associated with greater reductions in risk of major cardiovascular and renal events. We aimed to assess the efficacy and safety of intensive blood pressure-lowering strategies. Methods For this updated systematic review and meta-analysis, we systematically searched MEDLINE, Embase, and the Cochrane Library for trials published between Jan 1, 1950, and Nov 3, 2015. We included randomised controlled trials with at least 6 months' follow-up that randomly assigned participants to more intensive versus less intensive blood pressure-lowering treatment, with different blood pressure targets or different blood pressure changes from baseline. We did not use any age or language restrictions. We did a meta-analysis of blood pressure reductions on relative risk (RR) of major cardiovascular events (myocardial infarction, stroke, heart failure, or cardiovascular death, separately and combined), and non-vascular and all-cause mortality, end-stage kidney disease, and adverse events, as well as albuminuria and progression of retinopathy in trials done in patients with diabetes. Findings We identified 19 trials including 44 989 participants, in whom 2496 major cardiovascular events were recorded during a mean 3·8 years of follow-up (range 1·0–8·4 years). Our meta-analysis showed that after randomisation, patients in the more intensive blood pressure-lowering treatment group had mean blood pressure levels of 133/76 mm Hg, compared with 140/81 mm Hg in the less intensive treatment group. Intensive blood pressure-lowering treatment achieved RR reductions for major cardiovascular events (14% 95% CI 4–22), myocardial infarction (13% 0–24), stroke (22% 10–32), albuminuria (10% 3–16), and retinopathy progression (19% 0–34). However, more intensive treatment had no clear effects on heart failure (15% 95% CI −11 to 34), cardiovascular death (9% –11 to 26), total mortality (9% –3 to 19), or end-stage kidney disease (10% –6 to 23). The reduction in major cardiovascular events was consistent across patient groups, and additional blood pressure lowering had a clear benefit even in patients with systolic blood pressure lower than 140 mm Hg. The absolute benefits were greatest in trials in which all enrolled patients had vascular disease, renal disease, or diabetes. Serious adverse events associated with blood pressure lowering were only reported by six trials and had an event rate of 1·2% per year in intensive blood pressure-lowering group participants, compared with 0·9% in the less intensive treatment group (RR 1·35 95% CI 0·93–1·97). Severe hypotension was more frequent in the more intensive treatment regimen (RR 2·68 1·21–5·89, p=0·015), but the absolute excess was small (0·3% vs 0·1% per person-year for the duration of follow-up). Interpretation Intensive blood pressure lowering provided greater vascular protection than standard regimens. In high-risk patients, there are additional benefits from more intensive blood pressure lowering, including for those with systolic blood pressure below 140 mmHg. The net absolute benefits of intensive blood pressure lowering in high-risk individuals are large. Funding National Health and Medical Research Council of Australia.
This paper reviews the application of intrinsically conducting polymers (ICPs) in drug delivery. ICPs are organic polymers with electrical, magnetic and optical properties usually associated with ...metals, whilst retaining the advantageous mechanical properties and ease of processing usually associated with polymers. Due to the inherent properties of these unique materials, electrical stimulation can be used to alter the redox state of ICPs, which in turn can modify the release rate of drug. The controlled release of drugs from ICPs has been reported in the literature since the 1980s. Following continued development, clinical applications of ICP-based drug delivery systems (DDS) have been reported recently. The next generation of controlled release technologies could utilise the biosensing properties of ICPs combined with their drug delivering abilities to develop an intelligent drug delivery system from a single material where the release rate of drug self adjusts in response to a sensed change in local body environment. This article provides an overview of ICP synthesis and properties relevant to their use as DDS, including biodegradability and biocompatibility, followed by literature on ICP-based DDS examining different methods of drug incorporation and release. The pharmaceutical applications of these systems have also been discussed. It is concluded that ICPs hold great promise in drug delivering implants where the dose can be adjusted through application of external stimulus, thus optimising benefit to side effect ratio while simultaneously ensuring patient adherence.
The application of intrinsically conducting polymers (ICPs) in drug delivery has been reviewed. Electrical stimulation can alter the redox state of ICPs, which in turn can modify the release rate of incorporated drug. ICPs hold great promise in drug delivering implants where the dose can be adjusted to optimise patient benefit to side effect ratio while simultaneously ensuring adherence.
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Summary This Review is intended to help clinicians, patients, and the public make informed decisions about statin therapy for the prevention of heart attacks and strokes. It explains how the evidence ...that is available from randomised controlled trials yields reliable information about both the efficacy and safety of statin therapy. In addition, it discusses how claims that statins commonly cause adverse effects reflect a failure to recognise the limitations of other sources of evidence about the effects of treatment. Large-scale evidence from randomised trials shows that statin therapy reduces the risk of major vascular events (ie, coronary deaths or myocardial infarctions, strokes, and coronary revascularisation procedures) by about one-quarter for each mmol/L reduction in LDL cholesterol during each year (after the first) that it continues to be taken. The absolute benefits of statin therapy depend on an individual's absolute risk of occlusive vascular events and the absolute reduction in LDL cholesterol that is achieved. For example, lowering LDL cholesterol by 2 mmol/L (77 mg/dL) with an effective low-cost statin regimen (eg, atorvastatin 40 mg daily, costing about £2 per month) for 5 years in 10 000 patients would typically prevent major vascular events from occurring in about 1000 patients (ie, 10% absolute benefit) with pre-existing occlusive vascular disease (secondary prevention) and in 500 patients (ie, 5% absolute benefit) who are at increased risk but have not yet had a vascular event (primary prevention). Statin therapy has been shown to reduce vascular disease risk during each year it continues to be taken, so larger absolute benefits would accrue with more prolonged therapy, and these benefits persist long term. The only serious adverse events that have been shown to be caused by long-term statin therapy—ie, adverse effects of the statin—are myopathy (defined as muscle pain or weakness combined with large increases in blood concentrations of creatine kinase), new-onset diabetes mellitus, and, probably, haemorrhagic stroke. Typically, treatment of 10 000 patients for 5 years with an effective regimen (eg, atorvastatin 40 mg daily) would cause about 5 cases of myopathy (one of which might progress, if the statin therapy is not stopped, to the more severe condition of rhabdomyolysis), 50–100 new cases of diabetes, and 5–10 haemorrhagic strokes. However, any adverse impact of these side-effects on major vascular events has already been taken into account in the estimates of the absolute benefits. Statin therapy may cause symptomatic adverse events (eg, muscle pain or weakness) in up to about 50–100 patients (ie, 0·5–1·0% absolute harm) per 10 000 treated for 5 years. However, placebo-controlled randomised trials have shown definitively that almost all of the symptomatic adverse events that are attributed to statin therapy in routine practice are not actually caused by it (ie, they represent misattribution). The large-scale evidence available from randomised trials also indicates that it is unlikely that large absolute excesses in other serious adverse events still await discovery. Consequently, any further findings that emerge about the effects of statin therapy would not be expected to alter materially the balance of benefits and harms. It is, therefore, of concern that exaggerated claims about side-effect rates with statin therapy may be responsible for its under-use among individuals at increased risk of cardiovascular events. For, whereas the rare cases of myopathy and any muscle-related symptoms that are attributed to statin therapy generally resolve rapidly when treatment is stopped, the heart attacks or strokes that may occur if statin therapy is stopped unnecessarily can be devastating.
The impact of elevated systolic blood pressure (SBP) and low-density lipoprotein cholesterol (LDL-C) on the risk of coronary heart disease (CHD) at different stages of life is unclear. We aimed to ...investigate whether genetically mediated SBP/LDL-C is associated with the risk of CHD throughout life.
We conducted a three-sample Mendelian randomization analysis using data from the UK Biobank including 136,648 participants for LDL-C, 135,431 participants for SBP, and 24,052 cases for CHD to assess the effect of duration of exposure to the risk factors on risk of CHD. Analyses were stratified by age at enrolment. In univariable analyses, there was a consistent association between exposure to higher LDL-C and SBP with increased odds of incident CHD in individuals aged ≤55 years, ≤60 years, and ≤65 years (p-value for heterogeneity = 1.00 for LDL-C and 0.67 for SBP, respectively). In multivariable Mendelian randomization analyses, exposure to elevated LDL-C/SBP early in life (age ≤55 years) was associated with a higher risk of CHD independent of later life levels (age >55 years) (odds ratio 1.68, 95% CI 1.20-2.34 per 1 mmol/L LDL-C, and odds ratio 1.33, 95% CI 1.18-1.51 per 10 mmHg SBP).
Genetically predicted SBP and LDL-C increase the risk of CHD independent of age. Elevated SBP and LDL-C in early to middle life is associated with increased CHD risk independent of later-life SBP and LDL-C levels. These findings support the importance of lifelong risk factor control in young individuals, whose risk of CHD accumulates throughout life.
In the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) factorial trial, the combination of perindopril and indapamide reduced ...mortality among patients with type 2 diabetes, but intensive glucose control, targeting a glycated hemoglobin level of less than 6.5%, did not. We now report results of the 6-year post-trial follow-up.
We invited surviving participants, who had previously been assigned to perindopril-indapamide or placebo and to intensive or standard glucose control (with the glucose-control comparison extending for an additional 6 months), to participate in a post-trial follow-up evaluation. The primary end points were death from any cause and major macrovascular events.
The baseline characteristics were similar among the 11,140 patients who originally underwent randomization and the 8494 patients who participated in the post-trial follow-up for a median of 5.9 years (blood-pressure-lowering comparison) or 5.4 years (glucose-control comparison). Between-group differences in blood pressure and glycated hemoglobin levels during the trial were no longer evident by the first post-trial visit. The reductions in the risk of death from any cause and of death from cardiovascular causes that had been observed in the group receiving active blood-pressure-lowering treatment during the trial were attenuated but significant at the end of the post-trial follow-up; the hazard ratios were 0.91 (95% confidence interval CI, 0.84 to 0.99; P=0.03) and 0.88 (95% CI, 0.77 to 0.99; P=0.04), respectively. No differences were observed during follow-up in the risk of death from any cause or major macrovascular events between the intensive-glucose-control group and the standard-glucose-control group; the hazard ratios were 1.00 (95% CI, 0.92 to 1.08) and 1.00 (95% CI, 0.92 to 1.08), respectively.
The benefits with respect to mortality that had been observed among patients originally assigned to blood-pressure-lowering therapy were attenuated but still evident at the end of follow-up. There was no evidence that intensive glucose control during the trial led to long-term benefits with respect to mortality or macrovascular events. (Funded by the National Health and Medical Research Council of Australia and others; ADVANCE-ON ClinicalTrials.gov number, NCT00949286.).
Summary Background Few studies have assessed the extent and distribution of the blood-pressure burden worldwide. The aim of this study was to quantify the global burden of disease related to high ...blood pressure. Methods Worldwide burden of disease attributable to high blood pressure (≥115 mm Hg systolic) was estimated for groups according to age (≥30 years), sex, and World Bank region in the year 2001. Population impact fractions were calculated with data for mean systolic blood pressure, burden of deaths and disability-adjusted life years (DALYs), and relative risk corrected for regression dilution bias. Findings Worldwide, 7·6 million premature deaths (about 13·5% of the global total) and 92 million DALYs (6·0% of the global total) were attributed to high blood pressure. About 54% of stroke and 47% of ischaemic heart disease worldwide were attributable to high blood pressure. About half this burden was in people with hypertension; the remainder was in those with lesser degrees of high blood pressure. Overall, about 80% of the attributable burden occurred in low-income and middle-income economies, and over half occurred in people aged 45–69 years. Interpretation Most of the disease burden caused by high blood pressure is borne by low-income and middle-income countries, by people in middle age, and by people with prehypertension. Prevention and treatment strategies restricted to individuals with hypertension will miss much blood-pressure-related disease.
The effects of pharmacological blood-pressure-lowering on cardiovascular outcomes in individuals aged 70 years and older, particularly when blood pressure is not substantially increased, is ...uncertain. We compared the effects of blood-pressure-lowering treatment on the risk of major cardiovascular events in groups of patients stratified by age and blood pressure at baseline.
We did a meta-analysis using individual participant-level data from randomised controlled trials of pharmacological blood-pressure-lowering versus placebo or other classes of blood-pressure-lowering medications, or between more versus less intensive treatment strategies, which had at least 1000 persons-years of follow-up in each treatment group. Participants with previous history of heart failure were excluded. Data were obtained from the Blood Pressure Lowering Treatment Triallists' Collaboration. We pooled the data and categorised participants into baseline age groups (<55 years, 55–64 years, 65–74 years, 75–84 years, and ≥85 years) and blood pressure categories (in 10 mm Hg increments from <120 mm Hg to ≥170 mm Hg systolic blood pressure and from <70 mm Hg to ≥110 mm Hg diastolic). We used a fixed effects one-stage approach and applied Cox proportional hazard models, stratified by trial, to analyse the data. The primary outcome was defined as either a composite of fatal or non-fatal stroke, fatal or non-fatal myocardial infarction or ischaemic heart disease, or heart failure causing death or requiring hospital admission.
We included data from 358 707 participants from 51 randomised clinical trials. The age of participants at randomisation ranged from 21 years to 105 years (median 65 years IQR 59–75), with 42 960 (12·0%) participants younger than 55 years, 128 437 (35·8%) aged 55–64 years, 128 506 (35·8%) 65–74 years, 54 016 (15·1%) 75–84 years, and 4788 (1·3%) 85 years and older. The hazard ratios for the risk of major cardiovascular events per 5 mm Hg reduction in systolic blood pressure for each age group were 0·82 (95% CI 0·76–0·88) in individuals younger than 55 years, 0·91 (0·88–0·95) in those aged 55–64 years, 0·91 (0·88–0·95) in those aged 65–74 years, 0·91 (0·87–0·96) in those aged 75–84 years, and 0·99 (0·87–1·12) in those aged 85 years and older (adjusted pinteraction=0·050). Similar patterns of proportional risk reductions were observed for a 3 mm Hg reduction in diastolic blood pressure. Absolute risk reductions for major cardiovascular events varied by age and were larger in older groups (adjusted pinteraction=0·024). We did not find evidence for any clinically meaningful heterogeneity of relative treatment effects across different baseline blood pressure categories in any age group.
Pharmacological blood pressure reduction is effective into old age, with no evidence that relative risk reductions for prevention of major cardiovascular events vary by systolic or diastolic blood pressure levels at randomisation, down to less than 120/70 mm Hg. Pharmacological blood pressure reduction should, therefore, be considered an important treatment option regardless of age, with the removal of age-related blood-pressure thresholds from international guidelines.
British Heart Foundation, National Institute of Health Research Oxford Biomedical Research Centre, Oxford Martin School.
The Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) trial reported that intensive glucose control prevents end-stage kidney disease (ESKD) in ...patients with type 2 diabetes, but uncertainty about the balance between risks and benefits exists. Here, we examine the long-term effects of intensive glucose control on risk of ESKD and other outcomes.
Survivors, previously randomized to intensive or standard glucose control, were invited to participate in post-trial follow-up. ESKD, defined as the need for dialysis or kidney transplantation, or death due to kidney disease, was documented overall and by baseline CKD stage, along with hypoglycemic episodes, major cardiovascular events, and death from other causes.
A total of 8,494 ADVANCE participants were followed for a median of 5.4 additional years. In-trial HbA1c differences disappeared by the first post-trial visit. The in-trial reductions in the risk of ESKD (7 vs. 20 events, hazard ratio HR 0.35, P = 0.02) persisted after 9.9 years of overall follow-up (29 vs. 53 events, HR 0.54, P < 0.01). These effects were greater in earlier-stage CKD (P = 0.04) and at lower baseline systolic blood pressure levels (P = 0.01). The effects of glucose lowering on the risks of death, cardiovascular death, or major cardiovascular events did not differ by levels of kidney function (P > 0.26).
Intensive glucose control was associated with a long-term reduction in ESKD, without evidence of any increased risk of cardiovascular events or death. These benefits were greater with preserved kidney function and with well-controlled blood pressure.
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