Treating hypertension - what are we to believe?

Genetics of Human Primary Hypertension: Focus on Hormonal Mechanisms

Increasingly, primary hypertension is being considered a syndrome and not a disease, with the individual causes (diseases) having a common sign-an elevated blood pressure. To determine these causes, genetic tools are increasingly employed. This review identified 62 proposed genes. However, only 21 of them met our inclusion criteria: (i) primary hypertension, (ii) two or more supporting cohorts from different publications or within a single publication or one supporting cohort with a confirmatory genetically modified animal study, and (iii) 600 or more subjects in the primary cohort; when including our exclusion criteria: (i) meta-analyses or reviews, (ii) secondary and monogenic hypertension, (iii) only hypertensive complications, (iv) genes related to blood pressure but not hypertension per se, (v) nonsupporting studies more common than supporting ones, and (vi) studies that did not perform a Bonferroni or similar multiassessment correction. These 21 genes were organized in a four-tiered structure: distant phenotype (hypertension); intermediate phenotype [salt-sensitive (18) or salt-resistant (0)]; subintermediate phenotypes under salt-sensitive hypertension [normal renin (4), low renin (8), and unclassified renin (6)]; and proximate phenotypes (specific genetically driven hypertensive subgroup). Many proximate hypertensive phenotypes had a substantial endocrine component. In conclusion, primary hypertension is a syndrome; many proposed genes are likely to be false positives; and deep phenotyping will be required to determine the utility of genetics in the treatment of hypertension. However, to date, the positive genes are associated with nearly 50% of primary hypertensives, suggesting that in the near term precise, mechanistically driven treatment and prevention strategies for the specific primary hypertension subgroups are feasible.

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.

Primary and secondary prevention of stroke by antihypertensive drug treatment

Hypertension is the most powerful risk factor for stroke. Antihypertensive drug treatment reduces the incidence of stroke. In a meta-analysis of actively controlled trials, calcium-channel blockers, including (-8%; p = 0.07) or excluding verapamil (-10%; p = 0.02), as well as angiotensin Type 1 receptor blockers (-24%; p = 0.0002) resulted in better stroke prevention than the old drugs (diuretics or beta-blockers), whereas the opposite trend was observed for angiotensin-converting enzyme inhibitors (+10%; p = 0.03). An overview of six trials conducted in patients with a history of cerebrovascular disease demonstrated that blood pressure-lowering therapy reduced stroke recurrence by 25% (p = 0.004). A meta-regression analysis showed that within-trial differences in systolic blood pressure accounted for the prevention of stroke in most trials. This finding was corroborated by the recently published Valsartan Antihypertensive Long-term Use Evaluation trial.

Ramipril-based versus diuretic-based antihypertensive primary treatment in patients with pre-diabetes (ADaPT) study

Background

Previous randomized controlled trials demonstrated a protective effect of renin angiotensin system blocking agents for the development of type-2 diabetes in patients with pre-diabetes. However, there are no real-world data available to illustrate the relevance for clinical practice.

Methods

Open, prospective, parallel group study comparing patients with an ACE inhibitor versus a diuretic based treatment. The principal aim was to document the first manifestation of type-2 diabetes in either group.

Results

A total of 2,011 patients were enrolled (mean age 69.1 ± 10.3 years; 51.6% female). 1,507 patients were available for the per-protocol analysis (1,029 ramipril, 478 diuretic group). New-onset diabetes was less frequent in the ramipril than in the diuretic group over 4 years. Differences were statistically different at a median duration of 3 years (24.4% vs 29.5%; p < 0.05). Both treatments were equally effective in reducing BP (14.7 ± 18.0/8.5 ± 8.2 mmHg and 12.7 ± 18.1/7.0 ± 8.3 mmHg) at the 4 year follow-up (p < 0.001 vs. baseline; p = n.s. between groups). In 38.6% and 39.7% of patients BP was below 130/80 mmHg (median time-to-target 3 months). There was a significant reduction of cardiovascular morbidity and mortality in favour of ramipril (p = 0.033). No significant differences were found for a change in HbA1c as well as for fasting blood glucose levels during follow-up. The rate of adverse events was higher in diuretic treated patients (SAE 15.4 vs. 12.4%; p < 0.05; AE 26.6 vs. 25.6%; p = n.s).

Conclusions

Ramipril treatment is preferable over diuretic based treatment regimens for the treatment of hypertension in pre-diabetic patients, because new-onset diabetes is delayed.

Association of hypertension treatment and control with all-cause and cardiovascular disease mortality among US adults with hypertension

BACKGROUND

Clinical trials have provided convincing evidence that blood pressure (BP) lowering treatment reduces the risk of cardiovascular disease (CVD) and total mortality. The objective of this study was to examine the association of hypertension treatment, control, and BP indexes with all-cause and cardiovascular mortality among US adults with hypertension.

METHODS

Persons aged > or =18 years from the Third National Health and Nutrition Examination Survey (NHANES III) were identified as hypertensives based on a BP > or =140/90 mm Hg or current treatment for hypertension. Vital status in 2006 was ascertained by passive follow-up using the National Death Index. Cox regression models were used to assess correlates of survival.

RESULTS

At baseline, 52% of hypertensive adults reported currently taking prescription medicine for high BP and 38% of treated persons had BP controlled. Compared to treated controlled hypertensives, treated uncontrolled hypertensives had a 1.57-fold (95% confidence interval (CI) 1.28-1.91) and 1.74-fold (95% CI 1.36-2.22) risk of all-cause and cardiovascular mortality; untreated hypertensives had a 1.34-fold (95% CI 1.12-1.62) and 1.37-fold (95% CI 1.04-1.81) risk of all-cause and cardiovascular mortality, respectively. The association persisted after further excluding persons with pre-existing hypertension comorbidities. Mortality risk was linearly increased with systolic BP (SBP), pulse pressure (PP), and mean arterial pressure (MBP), whereas diastolic BP (DBP) was not a significant predictor of cardiovascular mortality overall. No significant associations were observed between drug classes and mortality risk.

CONCLUSIONS

This study indicates that uncontrolled and untreated hypertension was associated with increased risk of total and cardiovascular mortality among the general hypertensive population.

Antihypertensive prescriptions for newly treated patients before and after the main antihypertensive and lipid-lowering treatment to prevent heart attack trial results and seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure guidelines

Main results of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial were published in December 2002. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, published in May 2003, recommended thiazide-type diuretics as initial pharmacological treatment alone or in combination with another drug in most patients with hypertension. To assess changes from before to after these publications, we compared antihypertensive medication prescriptions filled by patients who initiated pharmacological antihypertensive treatment in a large managed care organization during 3 time periods: (1) July 1, 2001, to June 30, 2002 (before these publications; n=1354); (2) July 1, 2003, to June 30, 2004 (to assess short-term changes; n=1542); and (3) July 1, 2004, to June 30, 2005 (to assess extended changes; n=1865). The percentage of patients initiating antihypertensive treatment with a thiazide-type diuretic increased from 30.6% to 39.4% (P<0.001) between 2001-2002 and 2003-2004, and the increase was maintained at 36.5% in 2004-2005 (P<0.001 compared with 2001-2002 and P=0.33 compared with 2003-2004). Among patients without diabetes mellitus, renal disease, a history of myocardial infarction, or heart failure, the percentage initiating pharmacological antihypertensive treatment with a thiazide-type diuretic increased from 33.1% in 2001-2002 to 43.4% in 2003-2004 (P<0.001) and remained increased (41.0%) in 2004-2005 (P<0.001 and P=0.23 compared with 2001-2002 and 2003-2004, respectively). Despite a sustained increase in the use of thiazide-type diuretics, this study indicates that an opportunity exists to increase adherence to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure guidelines.

First-line antihypertensive treatment in patients with pre-diabetes: rationale, design and baseline results of the ADaPT investigation

BACKGROUND

Recent clinical trials reported conflicting results on the reduction of new-onset diabetes using RAS blocking agents. Therefore the role of these agents in preventing diabetes is still not well defined. Ramipril is an ACE inhibitor (ACEi), that has been shown to reduce cardiovascular events in high risk patients and post-hoc analyses of the HOPE trial have provided evidence for its beneficial action in the prevention of diabetes.

METHODS

The ADaPT investigation ("ACE inhibitor-based versus diuretic-based antihypertensive primary treatment in patients with pre-diabetes") is a 4-year open, prospective, parallel group phase IV study. It compares an antihypertensive treatment regimen based on ramipril versus a treatment based on diuretics or betablockers. The primary evaluation criterion is the first manifestation of type 2 diabetes. The study is conducted in primary care to allow the broadest possible application of its results. The present article provides an outline of the rationale, the design and baseline characteristics of AdaPT and compares these to previous studies including ASCOT-BLPA, VALUE and DREAM.

RESULTS

Until March 2006 a total of 2,015 patients in 150 general practices (general physicians and internists) throughout Germany were enrolled. The average age of patients enrolled was 67.1 +/- 10.3 years, with 47% being male and a BMI of 29.9 +/- 5.0 kg/m2. Dyslipidemia was present in 56.5%. 37.8% reported a family history of diabetes, 57.8% were previously diagnosed with hypertension (usually long standing). The HbA1c value at baseline was 5.6 %. Compared to the DREAM study patients were older, had more frequently hypertension and patients with cardiovascular disease were not excluded.

CONCLUSION

Comparing the ADaPT design and baseline data to previous randomized controlled trial it can be acknowledged that AdaPT included patients with a high risk for diabetes development. Results are expected to be available in 2010. Data will be highly valuable for clinical practice due to the observational study design.

Determinants for the adoption of angiotensin II receptor blockers by general practitioners

Results of studies conducted 10-20 years ago show the prominence of commercial information sources in the adoption process of new drugs. Over the past decade, there has been a growing emphasis on practicing evidence-based medicine in drug prescribing. This raises the question whether professional information sources currently counterbalance the influence of commercial information sources in the adoption process. The aim of this study was to identify determinants influencing the adoption of a new drug class, the angiotensin II receptor blockers (ARBs), by general practitioners (GPs) in The Netherlands. A retrospective study was conducted to assess prevalent ARB prescribing for hypertensive patients using the Integrated Primary Care Information (IPCI) database. We conducted a survey among all GPs who participated in the IPCI project in 2003 to assess their exposure to commercial and professional information sources, perceived benefits and risks of ARBs, perceived influences of the professional network, and general characteristics. Multilevel logistic regression was applied to identify determinants of ARB adoption while adjusting for patient characteristics. Data were obtained from 70 GPs and 9470 treated hypertensive patients. A total of 1093 patients received ARBs (12%). GPs who reported frequent use of commercial information sources were more likely to prescribe ARBs routinely in preference to other antihypertensives, whereas GPs who used a prescribing decision support system and those who were involved in pharmacotherapy education were less likely to prescribe ARBs. Other factors that were associated with higher levels of ARB adoption included a more positive perception of ARBs regarding their effectiveness in lowering blood pressure, and working in single-handed practices or in rural areas. Aside from determinants related to the patient population, adoption of a new drug class among Dutch GPs is still determined more by their reliance on promotional information than by their use of professional information sources.

Does comorbidity explain trends in prescribing of newer antihypertensive agents?

OBJECTIVE

Concerns exist about heavily prescribing of new drugs when the evidence on hard outcomes is still limited. This has been the case for the newer classes of antihypertensives, especially in hypertensive patients without additional comorbidity. The association between comorbidity and trends in prescribing of angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARBs) was examined for the period 1996-2000.

DESIGN AND METHODS

Data were obtained from the Integrated Primary Care Information database, which contains medical records from more than 100 general practitioners in the Netherlands. Prevalent drug use in hypertensive patients was determined per calendar year. As initial treatment, the first antihypertensive drug prescribed within 1 year after diagnosis of hypertension was considered. Logistic regression was used to estimate the likelihood of receiving either ACE-I or ARBs.

RESULTS

The overall prevalent ACE-I use remained stable (31%), but it increased from 33 to 41% in hypertensive patients with diabetes, heart failure, proteinuria and/or renal insufficiency. ARB use increased significantly from 2 to 12%; this trend did not differ between patients with or without specific comorbidities. Initial ACE-I use slightly decreased (from 29% to 24%), whereas initial ARB use significantly increased (from 4% to 12%). ACE-I were more likely to be the first treatment in patients with diabetes [odds ratio (OR)=3.9; 95% confidence interval (CI) 3.2-4.9] or hypercholesterolemia (OR=1.4; 95% CI 1.1-1.8). ARBs were more likely to be the initial treatment in patients with asthma/chronic obstructive pulmonary disease (OR=1.6; 1.2-2.3), diabetes (OR=2.1; 1.5-2.9) or hypercholesterolemia (OR=1.7; 1.2-2.4).

CONCLUSIONS

The increased use of ACE-I is mostly restricted to hypertensive patients with comorbidities for which their use has been recommended. Trends in prescribing of ARBs are not related to relevant comorbidities.

Does Aspirin Attenuate the Beneficial Effect of ACE Inhibitors in Elderly People with Heart Failure?

BACKGROUND

Several studies have raised concerns over a possible reduction in the beneficial effects of ACE inhibitors on mortality in people also taking aspirin (acetylsalicylic acid).

OBJECTIVE

We performed this study to determine whether there is a reduction in the beneficial effects of ACE inhibitors on mortality in elderly people with heart failure also taking aspirin.

PARTICIPANTS

822 patients discharged from hospital wards with a diagnosis of heart failure participated in the GIFA (Italian Group of Pharmacoepidemiology in the Elderly) study.

MEASUREMENTS

We analysed the characteristics of the participants according to the type of therapy prescribed (no ACE inhibitor/no aspirin, ACE inhibitor/no aspirin, no ACE inhibitor/aspirin and ACE inhibitor/aspirin). We calculated the hazard ratios (HRs) for dying associated with each of these treatments, and calculated the synergy index to identify any negative interaction between ACE inhibitor and aspirin.

RESULTS

The mean age of study participants was 79 +/- 7.3 (SD) years. Of the 629 (76.5%) patients discharged on ACE inhibitor and/or aspirin therapy, 31.0% were taking both drugs. Compared with no therapy with ACE inhibitor or aspirin, the HR for death was 0.65 (95% CI 0.31, 1.36) for aspirin users, 0.45 (95% CI 0.27, 0.74) for ACE inhibitor users and 0.37 (95% CI 0.19, 0.70) for ACE inhibitor/aspirin users. The synergy index was 0.98 (95% CI 0.34, 2.80), suggesting no interaction between the drugs.

CONCLUSIONS

Our data do not support the existence of a negative interaction between ACE inhibitors and aspirin in elderly patients with heart failure.

Retrospective longitudinal cohort study comparing the effects of angiotensin-converting enzyme inhibitors and long-acting calcium channel blockers on total and cardiovascular mortality in patients with hypertension

BACKGROUND

There is controversy regarding the impact that different antihypertensive regimens, including modern combination therapy, have on the incidence of myocardial infarction, other cardiovascular events, and mortality.

OBJECTIVE

The objective of this study was to determine and compare the effects of treatment strategies based on angiotensin-converting enzyme (ACE) inhibitors and long-acting calcium channel blockers (CCBs) on total and cardiovascular mortality in hypertensive patients in a usual-care setting.

METHODS

This retrospective, longitudinal cohort study used integrated medical and pharmacy claims data from a geographically diverse administrative database of >8 million persons in the United States. Patients aged > or = 18 years with hypertension were eligible if they had filled a prescription for either an ACE inhibitor or a long-acting CCB between January 1, 1995, and June 30, 1999 (the index prescription). Patients who had a prescription for any antihypertensive agents before the index prescription were excluded, as were eligible ACE inhibitor-treated patients who used CCBs or CCB-treated patients who used ACE inhibitors during the follow-up period. Use of all other antihypertensive medications was permitted. Patients were matched using a propensity score generated from a logistic regression model. A survival-analysis approach was used to compare mortality between groups. The final cohorts were assessed through June 30, 2002.

RESULTS

A total of 18,199 patients met the study inclusion criteria; 12,608 (69.3%) used an ACE inhibitor and 5,591 (30.7%) used a CCB. The mean follow-up was approximately 4.4 years. After cohort matching using the propensity score, the study population consisted of 10,926 patients, 5,463 matched patients in each group. The adjusted hazard ratios (95% CIs) for all-cause, cardiovascular, congestive heart disease, and congestive heart failure mortality in the ACE-inhibitor group compared with the CCB group for the entire follow-up period were 0.70 (0.63-0.79), 0.65 (0.53-0.80), 0.47 (0.32-0.70), and 0.74 (0.49-1.12), respectively.

CONCLUSION

Analysis of a large medical and pharmacy database suggests that an ACE inhibitor-based treatment strategy is associated with reduced mortality compared with a CCB-based strategy in patients with hypertension in a managed care setting.

Prior convictions

Large, randomized clinical trials ("megatrials") are key drivers of modern cardiovascular practice, since they are cited frequently as the authoritative foundation for evidence-based management policies. Nevertheless, fundamental limitations in the conventional approach to statistical hypothesis testing undermine the scientific basis of the conclusions drawn from these trials. This review describes the conventional approach to statistical inference, highlights its limitations, and proposes an alternative approach based on Bayes' theorem. Despite its inherent subjectivity, the Bayesian approach possesses a number of practical advantages over the conventional approach: 1). it allows the explicit integration of previous knowledge with new empirical data; 2). it avoids the inevitable misinterpretations of p values derived from megatrial populations; and 3). it replaces the misleading p value with a summary statistic having a natural, clinically relevant interpretation-the probability that the study hypothesis is true given the observations. This posterior probability thereby quantifies the likelihood of various magnitudes of therapeutic benefit rather than the single null magnitude to which the p value refers, and it lends itself to graphical sensitivity analyses with respect to its underlying assumptions. Accordingly, the Bayesian approach should be employed more widely in the design, analysis, and interpretation of clinical megatrials.

Diuretics: drugs of choice for the initial management of patients with hypertension

The optimal first-line treatment of hypertension has been a contentious issue. Despite the probable advantage of diuretics, which was demonstrated in early clinical trials, concern about their metabolic effects meant that therapy was often commenced with drugs of other types. The results of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), which compared agents of three groups of new antihypertensive drugs with a diuretic, demonstrated the equivalence between these drugs and chlorthalidone (Tenoretic AstraZeneca) in the prevention of incident fatal coronary heart disease and nonfatal myocardial infarction. The diuretic was superior to other drugs in preventing some major secondary end-points, such as cerebrovascular disease and heart failure. These findings, together with other very practical reasons, such as easy administration, few side effects and low cost, demonstrate that diuretics are the first option for drug management of hypertension.

The role of renin-angiotensin-aldosterone system inhibition in chronic kidney disease

Chronic kidney disease (CKD) is emerging as a new health pandemic. Underlying the global rise in CKD is an increase in diabetes, hypertension and other cardiovascular risk factors leading to progressive renal dysfunction. Emerging evidence strongly suggests that achieving target blood pressure goals via inhibition of the renin-angiotensin-aldosterone system confers significant renal and cardioprotection for patients with CKD. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) lower blood pressure, reduce proteinuria and reduce both the progression of CKD and adverse cardiovascular events. The role of aldosterone inhibition and combination therapy, such as ACEI/ARB, in CKD are under investigation. As our understanding of the basic mechanisms underlying CKD progression advances, novel therapies targeting post-translational endothelial and mesangial messengers downstream from angiotensin II and aldosterone may become available for clinical use.

Residual coronary risk in men aged 50–59 years treated for hypertension and hyperlipidaemia in the population

OBJECTIVE

Since the proportion of subjects taking antihypertensive and lipid-lowering drugs is currently increasing in industrialized countries, it is important to evaluate, at the population level, coronary risk of treated individuals, while taking into account the achieved level of their risk factors (i.e. their 'residual coronary risk').

DESIGN AND METHODS

We used the data from the Prospective Study of Myocardial Infarction (PRIME), which involved populations from France (three centres) and Northern Ireland (one centre) (in each centre, 2500 men, aged 50-59 years, free of coronary heart disease, with a 5-year follow-up), to analyse the relationships between cardiovascular drug use and subsequent coronary risk.

RESULTS

Antihypertensive drug use was significantly positively associated (relative risk = 1.60; 95% confidence interval, 1.18-2.16) with total coronary risk, but not lipid-lowering drug use (relative risk = 1.15; 95% confidence interval, 0.77-1.73), while adjusting on classical risk factor levels (age, smoking, total cholesterol, high-density lipoprotein-cholesterol and systolic blood pressure). Subgroup analysis showed that these results applied to beta-blockers and calcium channel antagonists, but not to diuretics and angiotensin-converting enzyme inhibitors, to both angina pectoris and hard coronary event risk, but in the French population only and not in Belfast. Although the PRIME study was not designed to test the ability of different drugs to prevent coronary heart disease, this analysis raises the hypothesis that antihypertensive drugs could be associated with a sizeable residual coronary risk in middle-aged men.

CONCLUSION

Treatment with antihypertensive agents, beta-blockers and calcium channel antagonists in particular, was associated with a sizeable residual coronary risk. It seems, therefore, important to consider antihypertensive treatment in the cardiovascular risk assessment of individuals.

Antihypertensive therapy and incidence of type 2 diabetes: a systematic review

OBJECTIVE

To systematically review the available evidence examining the effects of the major antihypertensive drug classes on the incidence of type 2 diabetes.

RESEARCH DESIGN AND METHODS

The Cochrane Controlled Trials Register, Medline, and Embase were searched for English-language case-control, cohort, and randomized controlled trials involving the major antihypertensive classes and reporting type 2 diabetes as an end point. Reference lists of original studies and narrative reviews were also hand searched. One reviewer (R.P.) performed the electronic searches. Both reviewers independently extracted data and assessed all potentially relevant studies for inclusion and methodological quality. Abstracts were not included, and unpublished studies were not sought.

RESULTS

One case-control study, 8 cohort studies, and 14 randomized controlled trials met inclusion criteria. No study examined diabetes incidence as a primary end point. Poor methodological quality limits the conclusions that can be drawn from most nonrandomized trials. Evidence from randomized studies is also potentially limited by several sources of bias, including treatment contamination and bias inherent in post hoc analyses. Data from the highest-quality studies suggest that diabetes incidence is unchanged or increased by thiazide diuretics and beta-blockers and unchanged or decreased by ACE inhibitors, calcium channel blockers, and angiotensin receptor blockers.

CONCLUSIONS

The major antihypertensive classes may exert differential effects on diabetes incidence, although current data are far from conclusive. Ongoing placebo-controlled randomized trials involving potentially beneficial drug classes and examining diabetes incidence as a primary end point should provide more definitive evidence.

New evidence on the importance of the renin-angiotensin system in the treatment of higher-risk patients with hypertension

We reviewed the drug treatment of hypertension in the light of recent trials. beta-Blockers and diuretics clearly reduce mortality, strokes, and coronary heart disease (CHD) in hypertension. Recent trials assessed whether newer agents that block the renin-angiotensin-aldosterone system, or calcium blockers, offer any additional advantage, or have benefits in high-risk individuals with conventionally 'normal' blood pressure. The recent ALLHAT study claimed no differences in CHD or mortality when chlorthalidone, amlodipine, and lisinopril were compared. However, the decrease in blood pressure was not the same with the three agents, and a substantial proportion of patients enrolled did not have clinical disease. In contrast, the LIFE study (comparing losartan and a beta-blocker) and the ANBP-2 study [comparing angiotensin-converting enzyme (ACE) inhibition and a diuretic] reduced blood pressure similarly, yet demonstrated benefits in favour of angiotensin II type 1 receptor blockers (ARBs) and ACE inhibitors. Other trials indicated similar advantages of ACE inhibitors or ARBs in patients with diabetic nephropathy. Among high-risk patients with initial blood pressure in the 'normal' range, ACE inhibitors significantly reduce clinical events (mortality, strokes, and myocardial infarction), despite modest decreases in blood pressure, suggesting that additional mechanisms are responsible. Recent results of the Prospective Studies Collaboration show lower risk, even in the normal blood pressure range; high-risk patients will benefit further from ACE inhibitors and ARBs (and beta-blockers after myocardial infarction). Data for other blood pressure decreasing agents are unavailable in such populations. We conclude that blood pressure decreasing per se is of clinical benefit, but drugs that block the renin-angiotensin system offer additional advantages. Drug choice is best determined by the patient's clinical condition.

Management of diabetic and hypertensive cardiovascular disease

The simultaneous occurrence of essential hypertension and diabetes mellitus is exceedingly common. In recent years the treatment of the cardiovascular and renal complications has not only become more specific but more effective. The evidence-based medicine data have been provided through many large multicenter studies and strongly support the promise not only of effective treatment in retarding the progression of target-organ involvement, but also the potential of reversal. These dramatic therapeutic improvements have been made possible by wedding the involved pathophysiologic disease mechanisms with the actions of pharmacologic agents. Inherent in this concept is the promise of retarding the development of the cardiovascular and renal morbid events and also reducing their associated mortal endpoints.

Microalbuminuria and hypertension with focus on type 1 and type 2 diabetes

Microalbuminuria and hypertension with Over the past decade, there has been considerable focus on the concept of microalbuminuria, not only because it predicts renal disease in type 1 and type 2 diabetes, but also because it relates to premature mortality in the diabetic and in the general population. More importantly, intervention at this stage is now possible with the perspective of preserving glomerular filtration rate (GFR) and ameliorating cardiovascular disease and ensuing strong end-points. INITIAL STUDIES: The concept of microalbuminuria was introduced about 20 years ago and since then there has been a multitude of studies and papers on this subject using the original definition, but not always, in the US. Before that time it was suggested, mainly from the US, that diabetic renal disease was an untreatable relentlessly progressive condition.

GENETIC STUDIES

There is an overwhelming number of studies on genetics and diabetes and also covering the genetics of diabetic complications including nephropathy. However, so far the results are extremely disappointing. Patients at risk cannot be identified and genetic analyses are of no value as a guide to treatment. The notion that the development of complications is controlled mainly by a special genetic pattern is increasingly doubtful. In genetic studies, it is rather phenotypic well-accepted risk factors that dominate. STRUCTURAL BASIS OF MICROALBUMINURIA: Patients with microalbuminuria have significant abnormalities in the kidney, including glomeruli. This is quite clear in patients with type 1 diabetes, but is also seen in type 2 diabetes, where on the other hand, other risk factors such as hypertension and dyslipidaemia also seem to be of importance, including loss of autoregulation. Renal biopsies are generally not indicated in the management of diabetic patients. MICROALBUMINURIA AND EARLY MORTALITY: It is quite clear that microalbuminuria predicts early mortality both in type 1 and type 2 diabetes. The association to other risk factors may partly explain this--but this does not account for the whole picture. Endothelial dysfunction as well as inflammatory and arteriosclerotic abnormalities in blood vessels may be a relevant hypothesis that needs to be further explored along with other possibilities. CLINICAL COURSE AND ASSOCIATED ABNORMALITIES: The risk factor for progression in normoalbuminuric patients to microalbuminuria is higher than normal albumin excretion (strongest factor), poor glycaemic control, elevated blood pressure, and to some extent smoking. The clinical course of microalbuminuria is usually progressive, but with the more effective intervention now available we encounter that the so-called natural history (without intervention) is increasingly difficult to study. Microalbuminuria is clearly associated with a number of abnormalities, almost in all organs, but GFR is generally well preserved in spite of more advanced structural lesions. Therefore, microalbuminuria is an important marker for more pronounced diabetic vascular disease in general as well as for nephropathy. Regression to normoalbuminuria only rarely occurs during standard unchanged nonintensive treatment. TREATMENT STRATEGIES: The best possible glycaemic control is important in preventing and ameliorating the course of normo- and micro-albuminuria. Another major treatment strategy, especially in microalbuminuric patients, is antihypertensive treatment including inhibition of the renal angiotensin aldosterone system. Numerous new studies are available, both in type 1 and type 2 diabetes, documenting that not only microalbuminuria but also renal and cardiovascular complications in these patient are also far better controlled by early detection and treatment. Therefore, screening for microalbuminuria should be a strategy in all diabetes management followed by effective intervention as outlined in this paper.

Drug Therapy for Hypertension: Does ALLHAT Alter our Approach?

This continuing feature will update readers on recent developments in cardiovascular pharmacotherapy. Cardiovascular disease remains the number one killer in the US, and more clinical outcome trials have been conducted in cardiology than in any other field of medicine. Given this rapidly expanding knowledge base, pharmacists can have a significant impact on prevention and treatment — if they keep current with developments in drug therapy.