Influence of gender and age on preventing cardiovascular disease by antihypertensive treatment and acetylsalicylic acid. The HOT study. Hypertension Optimal Treatment

Aspirin Use to Prevent Cardiovascular Disease and Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Low-dose aspirin is used for primary cardiovascular disease prevention and may have benefits for colorectal cancer prevention.

OBJECTIVE

To review the benefits and harms of aspirin in primary cardiovascular disease prevention and colorectal cancer prevention to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, Embase, and the Cochrane Central Register of Controlled Trials through January 2021; literature surveillance through January 21, 2022.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of low-dose aspirin (≤100 mg/d) compared with placebo or no intervention in primary prevention populations.

DATA EXTRACTION AND SYNTHESIS

Single extraction, verified by a second reviewer. Quantitative synthesis using Peto fixed-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Cardiovascular disease events and mortality, all-cause mortality, colorectal cancer incidence and mortality, major bleeding, and hemorrhagic stroke.

RESULTS

Eleven RCTs (N = 134 470) and 1 pilot trial (N = 400) of low-dose aspirin for primary cardiovascular disease prevention were included. Low-dose aspirin was associated with a significant decrease in major cardiovascular disease events (odds ratio [OR], 0.90 [95% CI, 0.85-0.95]; 11 RCTs [n = 134 470]; I2 = 0%; range in absolute effects, -2.5% to 0.1%). Results for individual cardiovascular disease outcomes were significant, with similar magnitude of benefit. Aspirin was not significantly associated with reductions in cardiovascular disease mortality or all-cause mortality. There was limited trial evidence on benefits for colorectal cancer, with the findings highly variable by length of follow-up and statistically significant only when considering long-term observational follow-up beyond randomized trial periods. Low-dose aspirin was associated with significant increases in total major bleeding (OR, 1.44 [95% CI, 1.32-1.57]; 10 RCTs [n = 133 194]; I2 = 4.7%; range in absolute effects, 0.1% to 1.0%) and in site-specific bleeding, with similar magnitude.

CONCLUSIONS AND RELEVANCE

Low-dose aspirin was associated with small absolute risk reductions in major cardiovascular disease events and small absolute increases in major bleeding. Colorectal cancer results were less robust and highly variable.

Sex Differences in the Prevalence, Outcomes and Management of Hypertension

PURPOSE OF REVIEW

To review recent data on sex differences in the prevalence, outcomes and management of hypertension.

RECENT FINDINGS

Although hypertension is overall more common in males, females experience a much sharper incline in blood pressure from the third decade of life and consequently the prevalence of hypertension accelerates comparatively with age. Mechanisms responsible for these blood pressure trajectories may include the sustained vascular influence of hypertensive disorders of pregnancy, interactions between the renin-angiotensin-aldosterone system and sex hormones or even psychosocial gendered factors such as socioeconomic deprivation. Moreover, the impact of hypertension is not uniform and females are at higher risk of developing a multitude of adverse cardiovascular outcomes at lower blood pressure thresholds. Blood pressure is a sexually dimorphic trait and although significant differences exist in the prevalence, pathophysiology and outcomes of hypertension in males and females, limited data exist to support sex-specific blood pressure targets.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

An aspirin a day? Clinical utility of aspirin therapy for the primary prevention of cardiovascular disease

Introduction: Cardiovascular disease remains a leading cause of morbidity and mortality. Since the description of its therapeutic potential, aspirin has been a cornerstone of therapy following vascular events. However, aspirin in the primary prevention setting is controversial and major guideline groups provide inconsistent recommendations. Thus, there is variability in practice as providers are faced with a balance of therapeutic benefit and drug-induced harm. Areas covered: This article provides a critical appraisal of both past and present data for aspirin in the primary prevention setting. PubMed and Cochrane Central Register databases were searched from inception to May 1^st, 2019. Expert opinion: The decision to initiate or withdraw aspirin for primary prevention requires an understanding of the equilibrium between efficacy and safety. In adults greater than 70 years of age, low to moderate cardiovascular risk, controlled diabetes, or at high risk of bleeding, initiation of aspirin for primary prevention should generally be avoided. Instead, risk factor modification should be prioritized. The net benefit of aspirin in those at high risk for cardiovascular disease and in those with uncontrolled diabetes is largely unknown. Ultimately, initiation or withdrawal of aspirin therapy must involve discussion of the patient's wishes and treatment expectations.

Effects of blood pressure-lowering treatment on cardiovascular outcomes and mortality: 13 - benefits and adverse events in older and younger patients with hypertension: overview, meta-analyses and meta-regression analyses of randomized trials

BACKGROUND

There is overwhelming evidence that blood pressure (BP)-lowering treatment can reduce cardiovascular outcomes also in the elderly, but some important aspects influencing medical practice are controversial as sufficient evidence has not been provided by single randomized controlled trials (RCTs), whereas evidence may result from a systematic search and meta-analysis of all available data.

OBJECTIVES

The following clinically relevant issues concerning the effects of BP lowering in older and younger individuals have been investigated: differences in benefits; the oldest and the youngest age range for which evidence of BP-lowering effects is available; the SBP level at which BP-lowering treatment should be initiated; the SBP and DBP levels treatment should be aimed at; differences in treatment burdens and harms.

METHODS

A database we previously identified of 72 BP-lowering RCTs in 260 210 patients was searched for separately reported data on older and younger individuals [cutoffs of 65 (primary analyses), 70, 75, 80, 60 and 55 years). The data were further stratified according to the levels of baseline (untreated) BP, and of on-treatment achieved SBP or DBP. Seven fatal and nonfatal outcomes were considered for benefits. Burdens and harms were investigated as permanent treatment discontinuations for adverse events, and hypotension/syncope. Risk ratios and absolute risk changes were calculated by a random effects model. Effects at older and younger ages were compared by heterogeneity test.

RESULTS

Thirty-two RCTs provided data on 96 549 patients older than 65 years, and 31 RCTs on 114 009 patients younger than 65 years. All cardiovascular outcomes were significantly reduced by treatment both in older and younger individuals, without significant age-dependent differences in relative risk reduction but with significantly higher absolute risk reductions in older individuals. The extreme age ranges for which evidence of significant benefits of treatment were available was greater than 80 and less than 55 years. Only one RCT provided data on benefits of BP-lowering at age greater than 65 when treatment was initiated at SBP values in the grade 1 range, but more consistent evidence was provided when age was greater than 60 years. Both in patients older and younger than 65 years, significant reductions of cardiovascular outcomes were found at on-treatment SBP less than 140 mmHg and DBP less than 80 mmHg. There was no evidence that treatment discontinuations for adverse events or hypotension/syncope were more frequent at age greater than 65.

CONCLUSION

Antihypertensive treatment should be recommended to all individuals with elevated BP, independent of age. The prudent recommendation to initiate treatment at SBP values 140-159 mmHg is supported at older age defined as greater than 60 years. SBP and DBP values lower than 140 mmHg and, respectively, 80 mmHg can be aimed at with incremental benefits without disproportionate burdens until age 80 years, above which available evidence is for benefits at on-treatment SBP 140-149 mmHg.

The rise and fall of aspirin in the primary prevention of cardiovascular disease

Aspirin is one of the most frequently used drugs worldwide and is generally considered effective for the secondary prevention of cardiovascular disease. By contrast, the role of aspirin in primary prevention of cardiovascular disease is controversial. Early trials evaluating aspirin for primary prevention, done before the turn of the millennium, suggested reductions in myocardial infarction and stroke (although not mortality), and an increased risk of bleeding. In an effort to balance the risks and benefits of aspirin, international guidelines on primary prevention of cardiovascular disease have typically recommended aspirin only when a substantial 10-year risk of cardiovascular events exists. However, in 2018, three large randomised clinical trials of aspirin for the primary prevention of cardiovascular disease showed little or no benefit and have even suggested net harm. In this narrative Review, we reappraise the role of aspirin in primary prevention of cardiovascular disease, contextualising data from historical and contemporary trials.

Antithrombotic Treatment May Reduce Mortality Among New-Onset Atrial Fibrillation Patients with Gray-Zone Risk of Stroke

In clinical practice, some atrial fibrillation (AF) patients were classified as having low and moderate stroke risk by the CHADS₂ score (≤ 1) in 2001 but in 2012 they were not truly classified as low risk of stroke according to the CHA₂DS₂-VASc score (≥ 2) (defined gray zone). Therefore, a treatment gap exists in gray zone AF patients. This study aimed to evaluate whether gray zone AF patients could benefit from reduced all-cause mortality under antithrombotic treatment. This was a longitudinal cohort study performed using data from claim forms submitted to the Taiwan Bureau of National Health Insurance from January 2000 to December 2011. The new-onset AF patients consisted of a gray zone cohort with a total of 1237 patients being enrolled. The primary outcome was all-cause mortality between 2001 and 2011. Patients in the gray zone receiving antithrombotic treatment had a significant reduction in all-cause mortality [hazard ratio (HR): 0.21; 95% confidence interval (CI): 0.16-0.28] compared with the no treatment group [warfarin only: HR, 0.28 (95% CI, 0.15-0.52); warfarin + Aspirin: HR, 0.21 (95% CI, 0.15-0.30); and Aspirin only: HR, 0.22 (95% CI, 0.16-0.29) ]. All-cause mortality was notably increased when any of the following risk factors were present: age 65-74 years, age ≥ 75 years, chronic kidney disease, and vascular disease. We concluded that AF patients in the gray zone must receive either anticoagulant and/or antiplatelet treatment and there is a lower mortality in these groups during long-term follow-up. Further investigation is needed to observe whether the antithrombotic drugs have benefits for patients with AF with a CHA₂DS₂-VASc score < 2.

Achieved systolic blood pressure in older people: a systematic review and meta-analysis

BACKGROUND

It remains unclear into which level the systolic blood pressure (SBP) should be lowered in order to provide the best cardiovascular protection among older people. Hypertension guidelines recommendation on attaining SBP levels <150 mmHg in this population is currently based on experts' opinion. To clarify this issue, we systematically reviewed and quantified available evidence on the impact of achieving different SBP levels <150 mmHg on various adverse outcomes in subjects aged ≥60 years old receiving antihypertensive drug treatment.

METHODS

We searched 8 databases to identify randomized controlled trials (RCTs) and post-hoc analyses or subanalyses of RCTs reporting the effects of attaining different SBP levels <150 mmHg on the risk of stroke, acute myocardial infarction, heart failure, cardiovascular mortality and all-cause mortality in participants aged ≥60 years. We performed random-effects meta-analyses stratified by study design.

RESULTS

Eleven studies (> 33,600 participants) were included. Compared with attaining SBP levels ≥140 mmHg, levels of 130 to <140 mmHg were not associated with lower risk of outcomes in the meta-analysis of RCTs, whereas there was an associated reduction of cardiovascular mortality (RR 0.72, 95% CI 0.59-0.88) and all-cause mortality (RR 0.86, 95% CI 0.75-0.99) in the meta-analysis of post-hoc analyses or subanalyses of RCTs. Limited and conflicting data were available for the SBP levels of <130 mmHg and 140 to <150 mmHg.

CONCLUSIONS

Among older people, there is suggestive evidence that achieving SBP levels of 130 to <140 mmHg is associated with lower risks of cardiovascular and all-cause mortality. Future trials are required to confirm these findings and to provide additional evidence regarding the <130 and 140 to <150 mmHg SBP levels.

Effectiveness and patient safety of platelet aggregation inhibitors in the prevention of cardiovascular disease and ischemic stroke in older adults - a systematic review

BACKGROUND

Platelet aggregation inhibitors (PAI) are among the most frequently prescribed drugs in older people, though evidence about risks and benefits of their use in older adults is scarce. The objectives of this systematic review are firstly to identify the risks and benefits of their use in the prevention and treatment of vascular events in older adults, and secondly to develop recommendations on discontinuing PAI in this population if risks outweigh benefits.

METHODS

Staged systematic review consisting of three searches. Searches 1 and 2 identified systematic reviews and meta-analyses. Search 3 included controlled intervention and observational studies from review-articles not included in searches 1 and 2. All articles were assessed by two independent reviewers regarding the type of study, age of participants, type of intervention, and clinically relevant outcomes. After data extraction and quality appraisal we developed recommendations to stop the prescribing of specific drugs in older adults following the Grading of Recommendations Assessment Development and Evaluation (GRADE) methodology.

RESULTS

Overall, 2385 records were screened leading to an inclusion of 35 articles reporting on 22 systematic reviews and meta-analyses, 11 randomised controlled trials, and two observational studies. Mean ages ranged from 57.0 to 84.6 years. Ten studies included a subgroup analysis by age. Overall, based on the evaluated evidence, three recommendations were formulated. First, the use of acetylsalicylic acid (ASA) for primary prevention of cardiovascular disease (CVD) in older people cannot be recommended due to an uncertainty in the risk-benefit ratio (weak recommendation; low quality of evidence). Secondly, the combination of ASA and clopidogrel in patients without specific indications should be avoided (strong recommendation; moderate quality of evidence). Lastly, to improve the effectiveness and reduce the risks of stroke prevention therapy in older people with atrial fibrillation (AF) and a CHA₂DS₂-VASc score of ≥ 2, the use of ASA for the primary prevention of stroke should be discontinued in preference for the use of oral anticoagulants (weak recommendation; low quality of evidence).

CONCLUSIONS

The use of ASA for the primary prevention of CVD and the combination therapy of ASA and clopidogrel for the secondary prevention of vascular events in older people may not be justified. The use of oral anticoagulants instead of ASA in older people with atrial fibrillation may be recommended. Further high quality studies with older adults are needed.

Gender related issues in thrombosis and hemostasis

INTRODUCTION

Many aspects of hemostasis, both primary and secondary, as well as fibrinolysis display sex differences. From a clinical viewpoint, certain differential phenotypic presentations clearly arise within various disorders of thrombosis and hemostasis. Areas covered: The present mini-review summarizes selected clinical entities where sex differences are reflected in both frequency and clinical presentation of hemostasis disorders. Sex differences are discussed within the settings of cardiovascular disease, including coronary artery disease and ischemic stroke, venous thromboembolism and inherited bleeding disorders. Moreover, pregnancy and labor present particular challenges in terms of increased thromboembolic and bleeding risk, and this is also summarized. Expert commentary: Available knowledge on sex differences in risk factors and clinical presentation of disorders within thrombosis and hemostasis is increasing. However, more evidence is needed to further clarify different risk factors and treatment effect in men and women, both as regards to cardiovascular disease and venous thromboembolism. This should facilitate improved gender guided risk stratification, and prevention and treatment of these diseases. Finally, risk assessment during pregnancy remains a challenge; this applies both to thromboembolic risk assessment during normal pregnancy and special care of women with inherited bleeding disorders during labor.

Aspirin for Primary Prevention

Aspirin reduces the risk of nonfatal myocardial infarction and stroke, and the risk of colorectal cancer. Aspirin increases the risk of gastrointestinal and intracranial bleeding. The best available evidence supports initiating aspirin in select populations. In 2016, the US Preventive Services Task Force recommended initiating aspirin for the primary prevention of both cardiovascular disease and colorectal cancer among adults ages 50 to 59 who are at increased risk for cardiovascular disease. Adults 60 to 69 who are at increased cardiovascular disease risk may also benefit. There remains considerable uncertainty about whether younger and older patients may benefit.

Cardiology: Aspirin Resistance in Patients with Stable Coronary Artery Disease with and without a History of Myocardial Infarction

Background:

Aspirin therapy is a cornerstone in the prevention of atherothrombotic events, but recurrent vascular events are estimated to occur in 8-18% of patients taking aspirin for secondary prevention after 2 years. Estimates of biologic aspirin resistance vary from 5% to 60%, depending on the assay used. However, the relationship between biologic measurements of aspirin resistance and adverse clinical events remains unclear.

Objective:

To determine whether patients with documented myocardial infarction (Ml) while on aspirin therapy (cases) were more likely to be aspirin resistant than were patients with coronary artery disease (CAD) who had no history of Ml (controls) and to assess clinical predictors of aspirin resistance in patients with stable CAD.

Methods:

This case-control study examined aspirin responses using the VerifyNow Aspirin Assay system in 50 cases and 50 controls who had taken a dose of aspirin within 48 hours of presentation to the clinic visit. Odds ratios were estimated to determine the association between aspirin resistance and MI, Independent predictors of aspirin resistance were determined using univariate and multivariate analyses.

Results:

An increase in the prevalence of aspirin resistance among cases (16% vs 12% in controls) was not observed (OR 1.40; 95% CI 0.45 to 4.37; p = 0.566). In the overall CAD population, female sex was independently associated with aspirin resistance (OR 4.01; 95% CI 1.15 to 13.92; p = 0.029).

Conclusions:

Additional large studies are required to understand whether biologically defined aspirin resistance is associated with increased risk for cardiovascular events, with special attention paid to sex differences.

"Mind the gap" acute coronary syndrome in women: A contemporary review of current clinical evidence

The incidence and prevalence of coronary artery disease in women has exceeded that in men over the past four decades, and although a significant decline in mortality has occurred in the past two decades, there is a growing body of evidence suggesting that there are gender differences between the clinical manifestations and course of coronary artery disease, as well as differences in treatment and treatment response. This review article considers the current literature regarding the gender-specific manifestation of acute coronary syndromes. Through the review of basic science articles, subsets of trial data, and meta-analyses, the gender-specific differences in within acute coronary syndromes are considered in terms of diagnostic dilemmas, pathophysiology, and treatment options (including pharmacological, percutaneous and surgical methods). Finally, acute coronary syndromes and their management in the special circumstance of pregnancy are also reviewed.

A Case for Less Intensive Blood Pressure Control: It Matters to Achieve Target Blood Pressure Early and Sustained Below 140/90mmHg

Although high blood pressure (BP) is the leading risk factors for cardiovascular (CV) disease, the optimal BP treatment target in order to reduce CV risk is unclear in the aftermath of the SPRINT study. The aim of this review is to assess large, randomized, and controlled trials on BP targets, as well as review selected observational analyses from other large randomized BP trials in order to evaluate the benefit of intense vs. standard BP control. None of the studies, except SPRINT, favored intense BP treatment. Some of the studies suggested favorable effects of lowering treatment target in patients with diabetes or high risk of stroke. In SPRINT, a new BP measurement method was introduced, and the results must be interpreted in light of this. The results of the observational analyses indicated the best preventive effect when achieving early and sustained BP control rather than low targets. In conclusion, today's guidelines' recommended treatment target of <140/90mmHg seems sufficient for most patients. Early and sustained BP control should be the main focus.

Primary Prevention of Coronary Heart Disease in the Elderly

OBJECTIVE:

To review relevant literature supporting the use of antihypertensive agents, lipid-lowering agents (i.e., statins), and aspirin therapy for the primary prevention of coronary heart disease (CHD) in an elderly patient population (age ≥65 y).

DATA SOURCES:

A MEDLINE search (1988–January 2003) was conducted.

STUDY SELECTION AND DATA EXTRACTION:

Primary and tertiary literature involving the uses of antihypertensives, statins, and aspirin therapy in the elderly were reviewed.

DATA SYNTHESIS:

Mortality due to CHD in the US population has decreased 40–50% over the last 30 years; however, CHD remains the leading cause of morbidity and mortality in elderly persons. As the population continues to age, the number of older adults eligible for primary prevention will rise. The American Heart Association clinical practice guidelines for the primary prevention of CHD were updated in 2002; however, they are based on findings from clinical trials that enrolled predominantly middle-aged white men. The recommendations for elderly individuals are predominantly extrapolated from subgroup analyses of randomized clinical trials or cohort studies. This literature suggests that elderly persons are candidates for primary prevention measures and experience reductions in coronary events when treated with appropriate therapies.

CONCLUSIONS:

Data suggest that use of antihypertensives, statins, and aspirin therapy in the elderly appears effective to an extent similar to, and often greater than, that observed in younger patients. We believe these agents should be prescribed to all appropriate high-risk elderly patients. Ongoing and future studies will more clearly elucidate the benefits of primary prevention therapy, particularly in persons ≥75 years of age.

Statins and aspirin: do they really work in women?

Cardiovascular disease continues to be the most common cause of mortality in women in the USA. As a result, greater emphasis has been placed on preventive measures. Studies examining the role of aspirin and HMG-CoA reductase inhibitors (statins) have shown important clinical differences in men versus women in the preventive realm. This has led to inconsistent recommendations by guideline committees and clinicians alike. This review presents a summary of the past and current guidelines. In addition, important clinical trials influencing current era practice are also discussed. Both strengths and limitations of these studies are described in detail, along with recommendations regarding future directions and the scope of aspirin and statin use for primary and secondary prevention of cardiovascular disease.

Pharmacogenomics, pharmacokinetics and pharmacodynamics: interaction with biological differences between men and women

Pharmacological response depends on multiple factors and one of them is sex-gender. Data on the specific effects of sex-gender on pharmacokinetics, as well as the safety and efficacy of numerous medications, are beginning to emerge. Nevertheless, the recruitment of women for clinical research is inadequate, especially during the first phases. In general, pharmacokinetic differences between males and females are more numerous and consistent than disparities in pharmacodynamics. However, sex-gender pharmacodynamic differences are now increasingly being identified at the molecular level. It is now even becoming apparent that sex-gender influences pharmacogenomics and pharmacogenetics. Sex-related differences have been reported for several parameters, and it is consistently shown that women have a worse safety profile, with drug adverse reactions being more frequent and severe in women than in men. Overall, the pharmacological status of women is less well studied than that of men and deserves much more attention. The design of clinical and preclinical studies should have a sex-gender-based approach with the aim of tailoring therapies to an individual's needs and concerns.

Antiplatelet and Lipid-lowering Drugs in Hypertension

Antiplatelet therapy, and low-dose acetylsalicylic acid (ASA) in particular, is recommended in hypertensive patients with previous cardiovascular events and is considered in hypertensive patients with reduced renal function or a high cardiovascular (CV) risk, provided blood pressure is well-controlled. Acetylsalicylic acid is not recommended in low-to-moderate risk hypertensive patients in whom absolute benefit and harm are equivalent. Further trials evaluating antithrombotic therapy including newer agents in hypertension are needed. Women at high and moderate risk of pre-eclampsia are advised to take a low dose of ASA daily from 12 weeks of gestation until delivery. In addition to their lipid-lowering effects, statins induce a small blood pressure reduction. The 2013 European Society of Hypertension (ESH)/European Society of Cardiology (ESC) guidelines recommend using statin therapy in hypertensive patients at moderate-to-high CV risk to achieve the target low-density lipoprotein (LDL) cholesterol value <3 mmol/l (115 mg/dl). For individuals with manifest CV disease or at very high CV risk, a more aggressive LDL target of <1.8 mmol/l (70 mg/dl) is recommended.

Effect of low-dose aspirin on functional outcome from cerebral vascular events in women

BACKGROUND AND PURPOSE

Although aspirin is effective in prevention of stroke, fewer studies have examined the impact of aspirin on stroke morbidity.

METHODS

The Women's Health Study is a completed randomized, placebo-controlled trial designed to test the effect of low-dose aspirin and vitamin E in the primary prevention of cardiovascular disease and cancer, which enrolled 39 876 women. We used multinomial logistic regression to evaluate the relationship between randomized aspirin assignment and functional outcomes from stroke. Possible functional outcomes were neither stroke nor transient ischemic attack (TIA), modified Rankin scale (mRS) score 0 to 1, 2 to 3, and 4 to 6.

RESULTS

After a mean of 9.9 years of follow-up, 460 confirmed strokes (366 ischemic, 90 hemorrhagic, and 4 unknown type) and 405 confirmed TIAs occurred. With regard to total and ischemic stroke, women who were randomized to aspirin had a nonsignificant decrease in risk of any outcome compared to women not randomized to aspirin. This decrease in risk only reached statistical significance for those experiencing TIA compared to participants without stroke or TIA (odds ratio=0.77; 95% confidence interval, 0.63-0.94). For hemorrhagic stroke, a nonsignificant increase in the risk of achieving an mRS score 2 to 3 or 4 to 6 compared with no stroke or TIA was observed for the women randomized to aspirin compared to those randomized to placebo.

CONCLUSIONS

Results from this large randomized clinical trial provide evidence that 100 mg of aspirin every other day may reduce the risk of ischemic cerebral vascular events but does not have differential effects on functional outcomes from stroke.

Aspirin resistance: current status and role of tailored therapy

Aspirin is integral in the primary and secondary prevention of coronary artery disease and acute coronary syndrome. Given the high clinical importance of aspirin in the management of coronary artery disease, much attention has been directed towards the concept of "aspirin resistance." Unfortunately, the term aspirin resistance is ill-defined in the literature, leading to a large variance in the reported prevalence of this phenomenon. In this review, the current understanding of aspirin resistance is discussed. Commonly used functional and diagnostic tests of platelet function, including their strengths and weakness, are reviewed. We next discuss several proposed mechanisms of aspirin resistance and special high-risk groups at risk for aspirin treatment failure. We then discuss optimal dosing and diagnostic strategies for those populations at risk for aspirin resistance with a focus on tailored aspirin therapy for high-risk groups. Finally, future topics of interest in the field of aspirin resistance are considered.

What should be the optimal levels of blood pressure: Does the J-curve phenomenon really exist?

INTRODUCTION

The blood pressure (BP) J-curve debate has lasted for over 30 years and we still cannot definitively answer all the questions. However, recent studies suggest that BP should be reduced carefully in patients with hypertension and coronary artery disease. BP should not fall below 110 - 115/70 - 75 mmHg, because this may be associated with more cardiovascular events.

AREAS COVERED

A retrospective analysis of the INVEST Trial and the results of the BP arm of the ACCORD Trial shows that care is needed in patients with hypertension and diabetes. Although the ACCORD BP Trial suggests important benefits connected with the significant reduction of stroke in patients being treated intensively, it also shows the lack of advantage of such therapy on each main and other additional endpoints. The ACCORD Trial also confirmed the increased risk of adverse events that might appear when intensive treatment was used in this group of patients.

EXPERT OPINION

Most available studies were observational and randomized trials (BBB, HOT, ACCORD BP), do not have or have lost their statistical power and were inconclusive. Further studies are therefore needed to provide definitive conclusions on the subject. In the meantime, it seems that in high-risk patients with hypertension, it is necessary to carefully select those who might suffer adverse events and those who may benefit from intensive BP lowering.

Why is cardiovascular health important in menopausal women?

Since endogenous estrogen shows some preventative benefits against cardiovascular risk factors in premenopausal women, cardiovascular disease (CVD) is often considered a male disease. However, CVD is the biggest cause of death in women, especially after menopause when endogenous estrogen withdrawal has detrimental effects on cardiovascular physiology and whole-body metabolism. Despite this, awareness of the risk of CVD is low in both women and in doctors; this needs rectifying. Women are under-represented in most clinical studies of CVD. Following diagnosis of CVD, the prognosis for women is not systematically similar to that for men. Furthermore, from the few comparisons conducted, gender differences in response to pharmacological interventions are evident, so that results obtained in wholly or largely male-based studies cannot be systematically extrapolated to women. Women with CVD should be afforded equivalent investigations and treatment to men, and it is vital that women be included in clinical trials in sufficient numbers to allow sub-group analyses and subsequent development of appropriate therapies. Since CVD is usually advanced by the time symptoms appear, prevention is the key; health management advice might include smoking cessation, adoption of a healthy diet, and incorporation of physical activity into the lifestyle.

Thrombosis and antithrombotic therapy in women

Sex-based differences in the prevalence and presentation of arterial and venous thrombosis exist, and emerging data indicate that men and women do not accrue equal benefit from antithrombotic therapy. Sex hormones alter procoagulant protein expression and the function of blood and vascular cells. Sex-based differences in platelet function have been reported, and in animal models, sex-based differences in thrombosis have been noted. Here we review plausible mechanisms that may explain how sex functions as a modifier of thrombosis and summarize clinical data on the interaction between sex and response to antithrombotic therapy.

Postmenopausal hormone therapy and cardiovascular disease in perspective

The totality of data indicate that the window of opportunity for reducing mortality and coronary heart disease is initiation of hormone therapy (HT) within 6 years of menopause and/or by 60 years of age and continued for 6 years or more. Additionally, the risks of HT are rare (<1/1000) especially in younger postmenopausal women and comparable with other primary prevention therapies. In fact, as randomized controlled trial results accumulate, the more they look like the consistent observational data. These studies showed that young postmenopausal women with menopausal symptoms who use HT for long periods of time have lower rates of mortality and coronary heart disease than comparable postmenopausal women who do not use HT.

Prevalence of cardiovascular risk factors among elderly Brazilians over eighty with ischemic stroke

INTRODUCTION: An ischemic stroke is usually a catastrophic event, mostly in the elderly. Cardiovascular involvement is the leading cause of ischemic stroke in this age population and hence the knowledge about its risk factors is important for the definition of specific policies of prevention. PURPOSE: To evaluate the prevalence of cardiovascular risk factors in patients with age equal to or above 80 in a hospital population with ischemic stroke. METHOD: Retrospective study of consecutive patients diagnosed with ischemic stroke admitted to a tertiary health facility. RESULTS: From September 2004 to March 2006, 215 patients were studied. There was a female preponderance (p<0.01). Among patients over eighty, 72% had hypertension and atrial fibrillation was more common among the oldest old (p<0.01). CONCLUSION: Hypertension and atrial fibrillation should be treated aggressively in the elderly. Anticoagulants should be considered more often in these patients.

Secondary stroke prevention: inside the vessels and beyond

Cerebral ischaemic stroke is frequently a relapsing, if not chronic, disease. Its incidence is age-dependent, and with the ageing of society the need for effective therapies increases. This review considers current and alternative hypotheses underlying secondary prevention of stroke. Currently, secondary stroke prevention is widely practiced with aspirin (acetylsalicylic acid), a drug that has been in use for more than 100 years. Newer drugs such as ticlopidine and clopidogrel have subsequently been developed, but their efficacy barely surpasses that of aspirin. Other drugs used in secondary stroke prevention include HMG-CoA reductase inhibitors and antihypertensive agents. The endovascular paradigm has shaped the thinking of secondary stroke prevention, and aspirin, ticlopidine and clopidogrel are known as 'platelet inhibitors'; however, their pharmacological and clinical effects are not fully explained within the platelet paradigm. Moreover, in recent years, reduction of stroke incidence has also been observed with HMG-CoA reductase inhibitors, regardless of their lipid-lowering effects. Hence, current understanding needs to be supplemented by considering mechanisms beyond platelet inhibition. Evidence has shown that aspirin, ticlopidine and clopidogrel share neuroprotective properties not explained by the platelet paradigm and that are reminiscent of a preconditioning effect. This neuroprotective mechanism is also shared with HMG-CoA reductase inhibitors.

Postmenopausal hormone therapy in clinical perspective

Although many of the risks and benefits of postmenopausal hormone therapy are known, only recently has the magnitude of these effects and their perspective to other therapies become more fully understood. Careful review of randomized controlled trials indicates that the risks of postmenopausal hormone therapy including breast cancer, stroke and venous thromboembolism are similar to other commonly used agents. Overall, these risks are rare (less than 1 event per 1,000 women) and even rarer when initiated in women less than 60 years of age or within 10 years of menopause. In addition, the literature indicates similar benefit of postmenopausal hormone therapy, in women who initiate hormone therapy in close proximity to menopause, to other medications used for the primary prevention of coronory heart disease in women.

Sex Difference in the Antiplatelet Effect of Aspirin in Patients with Stroke

Background:

There is substantial interpatient variability in response to aspirin after an ischemic stroke or transient ischemic attack (TIA), as assessed by ex vivo effects of aspirin on platelet aggregation. The factors contributing to this variability are not well defined.

Objective:

To determine whether demographic, social, or clinical characteristics are associated with ex vivo response to aspirin in patients with a history of stroke or TIA.

Methods:

Eighty-one patients who were taking aspirin for secondary stroke prevention and underwent ex vivo platelet aggregation studies were identified. The medical records of eligible patients were reviewed by clinicians who specialize in the management of stroke patients. Characteristics were compared between 45 patients who had a complete response to aspirin and 36 patients who exhibited an incomplete (partial) response to aspirin based on the results of platelet aggregation testing.

Results:

The median (range) aspirin dose was similar in complete (325; 81–1950 mg/day) and partial (325; 81–1300 mg/day) responders. There was no association between aspirin response and age, race, body mass index, medical history, smoking status, or use of statin or hormone replacement therapy. However, sex was significantly associated with response to aspirin, with more women in the partial versus complete responder group (75% vs 49%; p = 0.02).

Conclusions:

Our data suggest that aspirin may be less effective at inhibiting platelet aggregation in women compared with men who have a history of ischemic stroke or TIA.

Aspirin to prevent heart attack and stroke: what's the right dose?

Despite hundreds of clinical trials, the appropriate dose of aspirin to prevent myocardial infarction (MI) and stroke is uncertain. In the US, the doses most frequently recommended are 80, 160, or 325 mg per day. Because aspirin can cause major bleeding, the appropriate dose is the lowest dose that is effective in preventing both MI and stroke because these two diseases frequently co-exist. Five randomized clinical trials have compared aspirin with placebo or no therapy for the prevention of stroke and MI. These trials varied with regard to the dose of aspirin, the duration of treatment, and, most important, the populations selected for study varied in their baseline risk of stroke and MI. In men, 160 mg/day consistently lowered the risk of MI. In women, doses of 50 mg, 75, and 100 mg/day did not significantly decrease the risk of MI; therefore, the appropriate dose in women must exceed 100 mg/day. The appropriate dose for the primary prevention of stroke in men and women has not been established. Doses of 75 and 100 mg/day have been ineffective in men and women. The appropriate dose must be at least 160 mg/day. The lowest dose to prevent recurrent MI or death in patients with stable coronary artery disease (CAD) is 75 mg/day. In acute MI the lowest dose is 160 mg/day. In patients with a history of stroke or transient ischemic attack (TIA), 50 mg/day has been shown to be effective in men and women. In acute stroke, 160 mg/day is effective in preventing recurrent stroke or death. The risk of major bleeding with 160 mg/day is the same as with 80 mg/day: 1 to 2 cases per 1000 patient years of treatment, and the risk of fatal bleeding is the same with 80 and 160 mg/day. These studies indicate that the most appropriate dose for the primary and secondary prevention of stroke and MI is 160 mg/day.

Antiplatelet agents and arterial thrombosis

There is an increase in arterial thrombotic events in the elderly. Elderly patients are more likely to have associated diseases, such as diabetes, hypertension and hypercholesterolemia, and when age is confounded by these other predisposing factors, the risk of an arterial ischemic event increases disproportionately. Antithrombotic therapy for geriatric patients is underused, even when one adjusts for potential drug contraindications. This article focuses on the action of the currently available antiplatelet agents--aspirin, clopidogrel, and glycoprotein IIb/IIIa (GPIIb/IIIa) receptor antagonists, and assesses their effects in different disease states, with special attention to data that examine the geriatric population.

Aspirin under fire: aspirin use in the primary prevention of coronary heart disease

The issue of aspirin use in the primary prevention of cardiovascular disease is still debated because of conflicting opinions on risks versus benefits. Recently, a United States Food and Drug Administration (FDA) panel rejected the approval of aspirin in the setting of primary prevention in moderate-risk patients. However, the United States Preventive Services Task Force recommends that clinicians discuss aspirin therapy with patients at increased risk for having a future coronary event. During the past 15 years, many large randomized trials have specifically addressed this issue and helped shape the decisions of the FDA panel and the Preventive Services Task Force. These trials lend a handful of experiences and results, with no clear recommendations for antiplatelet therapy in the setting of primary prevention of coronary heart disease (CHD). Recently, trial results have been assimilated into practical tools for risk stratification to guide aspirin use in this setting. An overview and critical evaluation of the work performed thus far is provided in order to lend insight into the ongoing debate and, through use of the Framingham CHD risk prediction score sheets, to better equip practitioners faced with the decision of giving aspirin to "relatively" healthy individuals for CHD primary prevention.

Female-specific aspects in the pharmacotherapy of chronic cardiovascular diseases

Differences in pharmacokinetics, pharmacodynamics, and physiology contribute to the phenomenon that women and men frequently respond differently to cardiovascular drugs. Hormonal influences, in addition, can play an important role: for example, the menstrual cycle, menopause, and pregnancy--as a result of fluctuations in concentrations of sexual steroids, and of changes in total body water--can be associated with gender-specific differences in the plasma levels of cardiovascular drugs. Clinical relevance accordingly results, especially for substances with a narrow therapeutic margin. This review treats the most important pharmacodynamic gender-relevant differences in this context, and surveys available evidence on the benefits of therapy of chronic cardiovascular diseases in women. On the whole, the study situation for women is appreciably less favourable than for men: owing to the fact that women are under-represented in most studies, and that few gender-specific analyses have been conducted.

Improved posthypoxic recovery in vitro on treatment with drugs used for secondary stroke prevention

Besides aspirin several new drugs for inhibition of platelet aggregation and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibition are used in secondary stroke prevention. Pharmacology and clinical effects, however, are not fully explained by current understanding of underlying mechanisms. Population spike amplitude (PSAP), an established marker of slice integrity, was measured during hypoxia and recovery thereof in hippocampal slices from control CD1 mice (25-35 g) and animals pretreated in vivo with a single i.p. injection of clopidogrel, ticlopidine, or atorvastatine at different time intervals and dosages. Posthypoxic recovery of PSAP was 20 +/- 35% in control CD1 mice. Upon pretreatment with clopidogrel (1-24 h, 0.5-2 mg/kg body weight) an increase up to 81 +/- 20% (p < 0.01 to control) was observed at 1h interval and 1mg/kg. Application of ticlopidine (1-24 h, 1-4 mg/kg body weight) resulted in an improvement of posthypoxic recovery to 61 +/- 41% (p < 0.05 to control) while administration of atorvastatine (1-24 h, 1-4 mg/kg body weight) caused an increase up to 87 +/- 31% (p < 0.01 to control) at 1h interval and 2 mg/kg. On application of these substances in vitro the NADH autofluorescence spectrum in hippocampal slices is blue-shifted suggesting an alteration of oxidative metabolism. The present data demonstrate a shared neuroprotective effect of agents known to inhibit platelets (acetylsalicylic acid, clopidogrel, and ticlopidine) and HMG-CoA reductase (atorvastatine). The time course of this neuroprotective action in the current experimental study (onset within an hour, duration of several hours in contrast to several days) resembles clinical practice in dosing these substances. We hypothesize that an increase of hypoxic tolerance resulting from mild mitochondrial inhibition by these substances is a principal constituent of the effectiveness of these drugs.

A randomized trial of low-dose aspirin in the primary prevention of cardiovascular disease in women

BACKGROUND

Randomized trials have shown that low-dose aspirin decreases the risk of a first myocardial infarction in men, with little effect on the risk of ischemic stroke. There are few similar data in women.

METHODS

We randomly assigned 39,876 initially healthy women 45 years of age or older to receive 100 mg of aspirin on alternate days or placebo and then monitored them for 10 years for a first major cardiovascular event (i.e., nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes).

RESULTS

During follow-up, 477 major cardiovascular events were confirmed in the aspirin group, as compared with 522 in the placebo group, for a nonsignificant reduction in risk with aspirin of 9 percent (relative risk, 0.91; 95 percent confidence interval, 0.80 to 1.03; P=0.13). With regard to individual end points, there was a 17 percent reduction in the risk of stroke in the aspirin group, as compared with the placebo group (relative risk, 0.83; 95 percent confidence interval, 0.69 to 0.99; P=0.04), owing to a 24 percent reduction in the risk of ischemic stroke (relative risk, 0.76; 95 percent confidence interval, 0.63 to 0.93; P=0.009) and a nonsignificant increase in the risk of hemorrhagic stroke (relative risk, 1.24; 95 percent confidence interval, 0.82 to 1.87; P=0.31). As compared with placebo, aspirin had no significant effect on the risk of fatal or nonfatal myocardial infarction (relative risk, 1.02; 95 percent confidence interval, 0.84 to 1.25; P=0.83) or death from cardiovascular causes (relative risk, 0.95; 95 percent confidence interval, 0.74 to 1.22; P=0.68). Gastrointestinal bleeding requiring transfusion was more frequent in the aspirin group than in the placebo group (relative risk, 1.40; 95 percent confidence interval, 1.07 to 1.83; P=0.02). Subgroup analyses showed that aspirin significantly reduced the risk of major cardiovascular events, ischemic stroke, and myocardial infarction among women 65 years of age or older.

CONCLUSIONS

In this large, primary-prevention trial among women, aspirin lowered the risk of stroke without affecting the risk of myocardial infarction or death from cardiovascular causes, leading to a nonsignificant finding with respect to the primary end point.