Identification of risk factors in hypertensive patients: contribution of randomized controlled trials through an individual patient database

The Minnesota attributable risk of kidney donation (MARKD) study: a retrospective cohort study of long-term (> 50 year) outcomes after kidney donation compared to well-matched healthy controls

BACKGROUND

There is uncertainty about the long-term risks of living kidney donation. Well-designed studies with controls well-matched on risk factors for kidney disease are needed to understand the attributable risks of kidney donation.

METHODS

The goal of the Minnesota Attributable Risk of Kidney Donation (MARKD) study is to compare the long-term (> 50 years) outcomes of living donors (LDs) to contemporary and geographically similar controls that are well-matched on health status. University of Minnesota (n = 4022; 1st transplant: 1963) and Mayo Clinic LDs (n = 3035; 1st transplant: 1963) will be matched to Rochester Epidemiology Project (REP) controls (approximately 4 controls to 1 donor) on the basis of age, sex, and race/ethnicity. The REP controls are a well-defined population, with detailed medical record data linked between all providers in Olmsted and surrounding counties, that come from the same geographic region and era (early 1960s to present) as the donors. Controls will be carefully selected to have health status acceptable for donation on the index date (date their matched donor donated). Further refinement of the control group will include confirmed kidney health (e.g., normal serum creatinine and/or no proteinuria) and matching (on index date) of body mass index, smoking history, family history of chronic kidney disease, and blood pressure. Outcomes will be ascertained from national registries (National Death Index and United States Renal Data System) and a new survey administered to both donors and controls; the data will be supplemented by prior surveys and medical record review of donors and REP controls. The outcomes to be compared are all-cause mortality, end-stage kidney disease, cardiovascular disease and mortality, estimated glomerular filtration rate (eGFR) trajectory and chronic kidney disease, pregnancy risks, and development of diseases that frequently lead to chronic kidney disease (e.g. hypertension, diabetes, and obesity). We will additionally evaluate whether the risk of donation differs based on baseline characteristics.

DISCUSSION

Our study will provide a comprehensive assessment of long-term living donor risk to inform candidate living donors, and to inform the follow-up and care of current living donors.

Blood Pressure Changes After a Health Promotion Program Among Mexican Workers

Background: Cardiovascular disease is becoming increasingly prevalent in low and middle-income countries (LMIC), and high blood pressure (BP) is one of the main risk factors. The efficacy and sustainability of worksite health promotion (WHP) programs for BP reduction in LMIC have yet to be determined. Methods: This non-randomized company-based trial evaluated 6- and 12-months effects of a WHP intervention on BP among 2,002 participating workers from seven Mexican companies. Intervention and control groups were assigned at the company level. The intervention included nutrition counseling, physical exercise, and stress management components. Mixed models assessed differences in BP change between intervention and control companies in intent-to-treat (ITT), per-protocol (PerP), and as-treated (AsTr) analyses, and also within-group changes stratified by company, intervention component, and baseline cardiovascular risk factor levels. All analyses were adjusted for potential confounders. We accounted for missing data and loss to follow-up using inverse probability of censoring weighting. Results: ITT analyses revealed mean BP change differences of -1.1 mmHg at 12 months (95% CI: -2.9; 0.6) in intervention companies relative to control companies. PerP and AsTr analyses confirmed this finding. Within-group analyses showed consistent BP reductions at both 6 and 12 months. Substantial differences in BP changes ranging from diastolic -6.1 mmHg, (95% CI: -11.2; -1.2) to systolic -13.0 mmHg (95% CI: -16.0; -10.1) were found among individuals with diabetes at baseline in intervention companies relative to control companies. Conclusion: After 1 year, WHP was associated with modest but uncertain BP reductions. Substantial reductions were mainly observed among diabetic workers.

INSAF-HAS: a tool to select patients with hypertension for pharmaceutical care

OBJECTIVE

To develop and validate the content of a tool aimed to select patients with hypertension for pharmaceutical care, based on identification of individuals in greater need of attention.

METHODS

The tool was developed and assessed for face and content validity, which was carried out in three stages. Phase I consisted of comprehensive literature review, which prompted the development of the first version of the tool. Phase II consisted of validation by an expert panel. Phase III consisted of a pilot study with hypertensive patients and preparation of the final version of the instrument.

RESULTS

Literature review yielded 30 studies, out of which 13 factors associated with hypertension and cardiovascular disease control and complications were selected. Once the initial version of the tool named INSAF-HAS was obtained, four expert meetings were held, each leading to instrument improvement until a final consensus was reached. In the pilot study, INSAF-HAS was applied to 30 patients with a diagnosis of hypertension for applicability pretest; adjustments were made and the final version of INSAF-HAS obtained.

CONCLUSION

The INSAF-HAS tool developed in this study has face and content validity, and may contribute to the selection of patients with hypertension in greater need of pharmaceutical care services.

Optimized Collection Protocol for Plasma MicroRNA Measurement in Patients with Cardiovascular Disease

Background. Various microRNAs (miRNAs) are used as markers of acute coronary syndrome, in which heparinization is considered mandatory therapy. Nevertheless, a standard method of handling plasma samples has not been proposed, and the effects of heparin treatment on miRNA detection are rarely discussed. Materials and Method. This study used quantitative polymerase chain reaction (qPCR) analysis to investigate how storage temperature, standby time, hemolysis, and heparin treatment affect miRNA measurement in plasma samples from 25 patients undergoing cardiac catheterization. Results. For most miRNAs, the qPCR results remained consistent during the first 2 hours. The miRNA signals did not significantly differ between samples stored at 4°C before processing and samples stored at room temperature (RT) before processing. miR-451a/miR-23a ratio < 60 indicated < 0.12% hemolysis with 100% sensitivity and 100% specificity. Pretreatment with 0.25 U heparinase I recovered qPCR signals that were reduced by in vivo heparinization. Conclusions. For miRNA measurement, blood samples stored at RT should be processed into plasma within 2 hours after withdrawal and should be pretreated with 0.25 U heparinase I to overcome heparin-attenuated miRNA signals. The miR-451a/miR-23a ratio is a reliable indicator of significant hemolysis.

Effect of a pharmacist intervention in Spanish community pharmacies on blood pressure control in hypertensive patients

PURPOSE

The effect of a protocol-based pharmacist intervention on blood pressure (BP) control among treated hypertensive patients who use community pharmacies was studied.

METHODS

A quasi-experimental study with a control group was conducted at 13 community pharmacies in Jaén and Granada in Spain. Hypertensive patients over age 18 years who were receiving antihypertensive treatment were eligible for participation. The protocol-based intervention consisted of three components: (1) patient education about hypertension, (2) home blood pressure monitoring (HBPM), and (3) referral to a physician through personalized reports when necessary. The control group received the standard of care. BP control was assessed at the beginning and end of the study. Results Data were collected from 176 patients. In the intervention group (n = 87), significant baseline-to-endpoint reductions in systolic blood pressure (SBP) and diastolic blood pressure (DBP) were observed: 6.8 mm Hg (p < 0.001) and 2.1 mm Hg (p = 0.032), respectively. The changes in SBP and DBP in the intervention group at the end of the study were significantly greater than those in the control group (difference between adjusted mean change, 5.7 mm Hg for SBP [p = 0.001] and 2.6 mm Hg for DBP [p = 0.013]). The odds of achieving BP control in the intervention group was 2.46 times higher than in the control group (95% confidence interval, 1.15-5.24; p = 0.020).

CONCLUSION

A protocol-based community pharmacist intervention in combination with HBPM significantly reduced SBP and DBP and increased the percentage of patients with controlled BP compared with patients receiving the standard of care.

Individual patient data meta-analysis of survival data using Poisson regression models

Background

An Individual Patient Data (IPD) meta-analysis is often considered the gold-standard for synthesising survival data from clinical trials. An IPD meta-analysis can be achieved by either a two-stage or a one-stage approach, depending on whether the trials are analysed separately or simultaneously. A range of one-stage hierarchical Cox models have been previously proposed, but these are known to be computationally intensive and are not currently available in all standard statistical software. We describe an alternative approach using Poisson based Generalised Linear Models (GLMs).

Methods

We illustrate, through application and simulation, the Poisson approach both classically and in a Bayesian framework, in two-stage and one-stage approaches. We outline the benefits of our one-stage approach through extension to modelling treatment-covariate interactions and non-proportional hazards. Ten trials of hypertension treatment, with all-cause death the outcome of interest, are used to apply and assess the approach.

Results

We show that the Poisson approach obtains almost identical estimates to the Cox model, is additionally computationally efficient and directly estimates the baseline hazard. Some downward bias is observed in classical estimates of the heterogeneity in the treatment effect, with improved performance from the Bayesian approach.

Conclusion

Our approach provides a highly flexible and computationally efficient framework, available in all standard statistical software, to the investigation of not only heterogeneity, but the presence of non-proportional hazards and treatment effect modifiers.

Management of hypertension in the facelift patient: results of a national consensus survey

INTRODUCTION

In the facelift patient, uncontrolled perioperative hypertension is a difficult, acute condition that can lead to significant complications. Although the treatment of hypertension in the ambulatory medical setting has been standardized, its management in the cosmetic surgery setting has been ambiguous.

OBJECTIVES

The authors evaluate the results of a survey to assess current national trends in perioperative facelift hypertension management.

METHODS

A 13-question survey regarding perioperative hypertension management was sent by postal mail to 1776 members of the American Society for Aesthetic Plastic Surgery (ASAPS). Respondents were queried about their geographic location, caseload volume, facelift method, and hematoma rate.

RESULTS

A 35.4% response rate was attained (629 respondents). Superficial musculoaponeurotic system (SMAS) plication performed under general anesthesia as an outpatient procedure was the most common facelift technique. Perioperative blood pressure management was consistent among all respondents. Beta-blockers were commonly utilized throughout the preoperative period. Administration of alpha agonists was reported more frequently by surgeons with higher-volume caseloads and more years in practice. Reported hematoma rates did not vary with medication. Medical treatment at an intraoperative systolic blood pressure (SBP) threshold below 100 (p < .04) and a postoperative SBP of greater than 139 (p < .05) significantly increased reported hematoma rates.

CONCLUSIONS

The data generated from the survey suggest that the timing of treating hypertension deserves more attention than the actual medication administered. Proper perioperative care of the facelift patient is paramount in the reduction of hematoma rates. Preexisting hypertension correlates with a higher hematoma rate, though this study also suggests that normotensive anesthesia, as well as strict postoperative blood pressure control did contribute to a reduction in hematoma rate.

The positive effect of an intervention program on the hypertension knowledge and lifestyles of rural residents over the age of 35 years in an area of China

Hypertension (HTN) is a leading cause of cardiovascular and cerebrovascular diseases. Lifestyle modification may be the preferential approach to prevent and control HTN. The purpose of this study was to evaluate the effects of a community intervention program, which focused on improving the HTN knowledge, diets and lifestyles in a rural Chinese area. The study was carried out in a rural area of the Hubei Province from May 2003 to April 2006. A total of 1632 participants were recruited. Of the participants, 826 from the town of Xiaoxita and 806 from the town of Fenxiang were assigned to the intervention group (group I) and to the control group (group C), respectively. Group I participants underwent an intervention that included HTN education and dietary and lifestyle guidance. Group C participants were not subjected to an intervention. The outcome measures included HTN knowledge, dietary and lifestyle behaviors, and prevalence, awareness, treatment and control rates of HTN. Along with the changes in HTN education (P<0.05), the participants in group I exhibited a significantly greater improvement in dietary habits and lifestyle behaviors, including reducing salty food intake (13.6%), fat intake (22.9%) and alcohol consumption (9.6%), after 3 years in comparison with those in group C (21.7, 31.9 and 18%, respectively). The prevalence of HTN was significantly lower in group I (22.5%) than in group C (36%) after the intervention strategies. The study showed that the implementation of a community intervention program involving HTN education and lifestyle modifications for rural residents is a powerful approach to reduce HTN prevalence and improve long-term health outcomes.

Effects of individual risk factors on the residual risk of cardiovascular events in a population of treated Chinese patients with hypertension: data from the Felodipine Event Reduction (FEVER) study

BACKGROUND AND OBJECTIVES

The added cardiovascular risk conferred by risk factors or diseases accompanying hypertension has been investigated in Caucasian patients, and much less is known in Chinese patients. Furthermore, the residual risk persisting in hypertensive patients, despite blood pressure (BP) reduction, due to accompanying conditions has never been explored in Chinese, and whether they differ from Caucasians under this respect is unknown.

METHODS

Felodipine Event Reduction (FEVER) study randomized 9711 Chinese hypertensive patients to more or less intense antihypertensive treatment for 40 months, with outcome monitoring. The present analyses provide information on the role that baseline presence of individual risk factors has in increasing outcome probability despite BP control. Risk ratios were calculated using Cox proportional hazard models, adjusted for a large number of baseline variables, except the one under examination, and also adjusted for on-treatment systolic and diastolic BP.

RESULTS

Male sex, older age, diabetes and cardiovascular disease were accompanied by a significantly higher incidence of cardiovascular events (risk ratios 1.41-1.86 according to risk factor), stroke (risk ratios 1.42-1.72), cardiac events (risk ratios 1.40-2.70), all-cause death (risk ratios 1.51-2.16) and cardiovascular death (risk ratios 1.61-2.02). Higher baseline systolic BP and smoking conferred a significantly increased risk of cardiovascular events and strokes. Higher cholesterol was not found to increase any cardiovascular outcome. The same was the case for electrocardiographic left-ventricular hypertrophy and isolated systolic hypertension.

CONCLUSIONS

A number of additional risk factors increased the residual risk of Chinese hypertensive patients despite effective antihypertensive treatment as much as described in Caucasians. High serum cholesterol was an exception: whether this is a Chinese characteristic or a more general phenomenon remains to be investigated.

The new Sheffield risk and benefit tables for the elderly

Several charts or tables are used to guide treatment in primary prevention of cardiovascular disease (CVD). These usually relate to patients up to 75 years of age, leaving older patients without guidance. Most also present this information as risk, leaving patients to estimate the benefit of treatment and decide whether it is worthwhile. We present tables to display both CVD risk and benefit from treatment in the elderly. A systematic review identified CVD risk functions for the elderly. The Dubbo study of older patients' 5-year CVD risk equation was deemed most appropriate, due to the population studied, endpoints observed and risk factors recorded. By dichotomizing most risk factors, we produced a new risk table in the form of the original 'Sheffield table'. Risk is calculated by selecting the appropriate table for gender and the appropriate cell from the rows and columns, representing age and risk factor contributors, respectively. Total cholesterol above a cell value corresponds to a 20 or 40% 10-year CVD risk. A simple risk scoring system was then derived from the Dubbo equation. Calculation of risk score requires knowledge of a patient's simple demographics, systolic blood pressure and total and high-density lipoprotein cholesterol. Positive integers corresponding to level of risk for each contributing factor are then added together to give a final risk score. A Markov chain model was produced based on the Dubbo derived risk and relative risk reductions from published meta-analyses of 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins) and anti-hypertensive treatment. Using this model, individual scores were mapped to likely benefit from treatment in terms of disease free years. Our risk table provides a simple means for calculating risk in the elderly, to two major thresholds, while the benefit table explores the concept of presenting benefit of taking CVD-preventing medication.

Evaluating the risk of hypertension using an artificial neural network method in rural residents over the age of 35 years in a Chinese area

Hypertension (HTN) has been proven to be associated with an increased risk of cardiovascular diseases. The purpose of the study was to examine risk factors for HTN and to develop a prediction model to estimate HTN risk for rural residents over the age of 35 years. This study was based on a cross-sectional survey of 3054 rural community residents (N=3054). Participants were divided into two groups: a training set (N1=2438) and a validation set (N2=616). The differences between the training set and validation set were not statistically significant. The predictors of HTN risk were identified from the training set using logistic regression analysis. Some risk factors were significantly associated with HTN, such as a high educational level (EL) (odds ratio (OR)=0.744), a predominantly sedentary job (OR=1.090), a positive family history of HTN (OR=1.614), being overweight (OR=1.525), dysarteriotony (OR=1.101), alcohol intake (OR=0.760), a salty diet (OR=1.146), more vegetable and fruit intake (OR=0.882), meat consumption (OR=0.787) and regular physical exercise (OR=0.866). We established the predictive models using logistic regression model (LRM) and artificial neural network (ANN). The accuracy of the models was compared by receiver operating characteristic (ROC) when the models were applied to the validation set. The ANN model (area under the curve (AUC)=0.900+/-0.014) proved better than the LRM (AUC=0.732+/-0.026) in terms of evaluating the HTN risk because it had a larger area under the ROC curve.

Predictors of cardiovascular events in patients with hypertension and left ventricular hypertrophy: the Losartan Intervention for Endpoint reduction in hypertension study

OBJECTIVE

We assessed readily available patient characteristics, including albuminuria (not included in traditional cardiovascular risk scores), as predictors of cardiovascular events in hypertension with left ventricular hypertrophy (LVH) and developed risk algorithms/scores for outcomes.

METHODS

The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study compared effects of losartan-based versus atenolol-based therapy on cardiovascular events in 9193 patients with hypertension and LVH. Univariate and multivariate analyses identified baseline variables with significant impact on development of the primary composite endpoint (cardiovascular death, stroke and myocardial infarction) and its components. Multivariate analysis used a Cox regression model with stepwise selection process. Risk scores were developed from coefficients of risk factors from the multivariate analysis, validated internally using naïve and jack-knife procedures, checked for discrimination and calibration, and compared with Framingham coronary heart disease and other risk scores.

RESULTS

LIFE risk scores showed increasing endpoint rates with increasing quintile (first to fifth quintile, composite endpoint 2.8-26.7%, cardiovascular death 0.5-14.4%, stroke 1.2-11.3%, myocardial infarction 1.4-8.1%) and were confirmed with a jack-knife approach that adjusts for potentially optimistic bias. The Framingham coronary heart disease and other risk scores overestimated risk in lower risk patients and underestimated risk in higher risk patients, except for myocardial infarction.

CONCLUSION

A number of patient characteristics predicted cardiovascular events in patients with hypertension and LVH. Risk scores developed from these patient characteristics, including albuminuria, strongly predicted outcomes and may improve risk assessment of patients with hypertension and LVH and planning of clinical trials.

Prognostic value of lipoprotein fractions in essential hypertension

BACKGROUND

To evaluate distribution and prognostic value of total cholesterol and lipoprotein fractions in essential hypertension.

METHODS

In a prospective cohort study, 2649 initially untreated subjects with essential hypertension (aged 51, 46.5% women) were investigated at entry and followed for a mean of 5.6 years (range: 1-16).

RESULTS

At entry, subjects with total cholesterol (TC) > or =240 mg/dl (> or =6.22 mmol/l) or high-density lipoprotein (HDL) cholesterol (HDL-C) <40 mg/dl (1.05 mmol/l) or low-density lipoprotein (LDL) cholesterol (LDL-C) > or =160 mg/dl (4.13 mmol/l) or TC/HDL-C ratio >6 were 47.7%. TC, HDL-C, LDL-C and triglycerides (TG) did not show any association with office or 24-h ambulatory blood pressure (BP). During follow-up there were 167 first cardiac events and 122 first cerebrovascular events. TC, HDL-C, LDL-C and TC/HDL-C ratio showed an association with cardiac events, but not with cerebrovascular events. TG did not show any association with cardiac or cerebrovascular events. After adjustment for age, sex, diabetes, smoking, left ventricular (LV) hypertrophy and 24-h pulse pressure, the hazard ratio for cardiac events was 1.83 (95% CI 1.23-2.71) in association with a TC > or =6.22 mmol/l, 2.23 with a HDL-C <1.05 mmol/l (95% CI 1.06-4.70), 2.83 with a LDL-C > or =4.91 mmol/l (95% CI 1.48-5.42) and 3.90 with a TC/HDL-C ratio >6.0 (95% CI 2.23-6.81). When forced in the same model, HDL-C and LDL-C showed an independent association with cardiac events.

CONCLUSIONS

Abnormalities of TC and lipoproteins are common in essential hypertension. HDL-C and LDL-C independently predict the risk of cardiac, but not cerebrovascular, events. Their predictive value is independent of several confounding factors including LV hypertrophy and ambulatory BP.

Topography and severity of coronary artery disease in white-coat hypertension

BACKGROUND

White-coat hypertension (WCH) has been evaluated as a risk factor for cardiovascular disease. In this study, the role of WCH is evaluated in a cohort of patients with suspected coronary artery disease with both coronary angiography and non-invasive techniques.

METHODS

One hundred patients with suspected coronary artery disease underwent coronary angiography, 24-h ambulatory blood pressure monitoring (ABPM), and ultrasound imaging of the myocardium and carotids. The lesions in percentage of stenosis in the left coronary artery stem (LM), left anterior descending ramus (LAD), left circumflex artery (LCX), diagonal artery (D1), and right coronary artery (RCA), along with the Gensini score (GS), were recorded. After a series of manual blood pressure measurements, the patients were divided into two groups (patients with and patients without WCH).

RESULTS

GS was higher in the WCH group (P=0.042), a difference that could be attributed to lesions in the LAD (P=0.007). GS correlated significantly with left ventricular end-diastolic diameter (LVEDD - P=0.041), left ventricular end-systolic diameter (LVESD - P=0.005), end-diastolic volume (EDV - P=0.042), end-systolic volume (ESV - P=0.004), LvMass/BSA (P=0.012), right internal carotid artery intima-media thickness (RICA - P=0.018), left internal carotid artery intima-media thickness (LICA - P=0.021), and their mean (MICA - P=0.005) in the WCH group but not in normotensives.

CONCLUSIONS

Coronary disease may be more severe among patients with WCH than among those without. In this group, data from myocardial and carotid ultrasound may help to estimate coronary artery disease.

Evaluation of the dose response with valsartan and valsartan/hydrochlorothiazide in patients with essential hypertension

This patient data meta-analysis included 9 randomized, double-blind, placebo-controlled trials (N=4278) of once-daily valsartan 80, 160, or 320 mg or valsartan/hydrochlorothiazide 80/12.5, 160/12.5, 160/25, 320/12.5, or 320/25 mg given for 4 to 8 weeks. Efficacy variables included: (1) mean change in systolic blood pressure (BP) and diastolic BP; and (2) proportion of patients reaching BP goal (<140/90 mm Hg) at the end of the study. Results showed that incremental systolic and diastolic BP reductions were achieved with increasing doses. Starting doses of valsartan 160 mg provided greater BP reductions and a higher proportion of patients reaching goal than 80 mg; combination therapy was more effective than monotherapy. BP goal rates increased incrementally with higher doses. With valsartan/hydrochlorothiazide 320/25 mg, 74.9% overall, 88.8% of stage 1, and 62.1% of stage 2 patients reached BP goal. The rate of discontinuation due to adverse events was low with both monotherapy and combination treatment. Higher starting doses may enable patients to achieve greater initial BP reductions and reach BP goal more rapidly.

Serum uric acid as a risk factor for cardiovascular and renal disease: an old controversy revived

Hyperuricemia is commonly associated with traditional risk factors such as abnormalities in glucose metabolism, dyslipidemia, and hypertension. Recent studies have revived the controversy over the role of serum uric acid as an independent prognostic factor for cardiovascular mortality. The authors review clinical and experimental evidence concerning the role of serum uric acid in the development of cardiovascular and renal damage. Results of trials suggesting that serum uric acid variations over time may have a prognostic impact are also discussed.

Determination of risk factors for hypertension through the classification tree method

Most current statistical strategies for determining risk factors for hypertension (HT) among certain populations have proved inconclusive. In this study, the classification tree method, which is more practical and easy to understand than other statistical methods, was used to determine the risk for HT among outpatients in a clinic in Denizli province, western Turkey, between January 2002 and July 2004. The effects of 14 risk factors (body mass index, waist-to-hip ratio, age, serum total cholesterol, serum triglycerides, sex, HT in first-degree relatives, diabetes mellitus, smoking, stress factors, alcohol consumption, dyslipidemia in first-degree relatives, dyslipidemia [previously diagnosed], and saturated fat consumption) on HT were evaluated in this population. In all, 1761 adults at the outpatient clinic were recruited for lipid and HT measurements. The classification tree method revealed 7 main risk factors (body mass index, waist-to-hip ratio, sex, serum triglycerides, serum total cholesterol, HT in first-degree relatives, and saturated fat consumption) for HT. The findings of the present study suggest that the classification tree is a valuable statistical method for evaluating multiple risk factors for HT.

Arterial stiffness and stroke in hypertension: therapeutic implications for stroke prevention

Stroke is the second leading cause of mortality worldwide, and the leading cause of death in China and Japan. Its prevention represents a major goal. Identification of primary stroke risk, particularly through newly individualised risk factors including biomarkers of large artery damage such as arterial stiffening, is necessary for determining the appropriate level of intervention. The purpose of this review is to focus on the pathophysiology of arterial stiffness, its predictive value for stroke and the therapeutic implications of this risk factor for stroke prevention. The predictive value of arterial stiffness for stroke was demonstrated in a longitudinal study that included 1715 patients with essential hypertension and measurements of carotid-femoral pulse wave velocity (PWV) [an indicator of arterial stiffness] at entry. Over a mean follow-up period of 7.9 years, during which 25 fatal strokes occurred, PWV significantly predicted stroke (relative risk = 1.39 [(95% CI 1.08, 1.72]; p = 0.02 for each 4 m/sec increase) independently of classical cardiovascular risk factors, including age, cholesterol level, diabetes mellitus, smoking and mean blood pressure. Additional longitudinal studies are needed to confirm the predictive value of aortic stiffness on primary and secondary events, in low- and high-risk populations, in various countries, and using different methodologies of arterial stiffness measurement. Drug treatment could prevent stroke through a reduction in arterial stiffness in parallel with correction of cardiovascular risk factors such as hypertension, dyslipidaemia, diabetes mellitus and smoking, all of which are associated with arterial stiffening. In view of the important local actions of angiotensin II on arterial stiffening, drugs interfering with the renin-angiotensin-aldosterone system should be particularly effective. Promising therapeutic strategies to reduce arterial stiffness include taking advantage of the non-lipid-lowering effects of statins and directly targeting the molecular events leading to arterial stiffening, such as formation of advanced glycation end products.

Usefulness of QT-interval parameters for cardiovascular risk stratification in type 2 diabetic patients with arterial hypertension

QT-interval parameters are potential indicators of increased cardiovascular risk. We evaluated prospectively their prognostic value, in relation to other risk markers, for cardiovascular fatal and nonfatal events in a cohort of 271 hypertensive type 2 diabetic outpatients. QT intervals were measured from 12-lead standard ECGs obtained on admission and maximum rate-corrected QT-interval duration and QT-interval dispersion (QTd) calculated. Clinical and laboratory data and 2-D echocardiograms (available in 126 patients) were recorded. Survival analyses included Kaplan-Meier survival curves, uni and multivariate Cox proportional-hazards models. After a median follow-up of 55 months (range 2-84), 68 total fatal or nonfatal cardiovascular events and 34 cardiovascular deaths (24 of them from cardiac causes) were observed. In multivariate Cox analysis, QTd was an independent predictor for total cardiovascular events (HR: 1.16, 95% CI: 1.01-1.34, for each 10 ms increments) and for cardiac deaths (HR: 1.28, 95% CI: 1.01-1.60). Other independent risk indicators for cardiovascular morbidity and mortality were echocardiographic left ventricular hypertrophy (Echo-LVH), serum triglycerides, presence of pre-existing cardiac and peripheral arterial disease, age, diabetes duration, heart rate and the presence of frequent ventricular premature contractions on ECG. The combination of QTd and Echo-LVH improved cardiovascular risk stratification compared with either alone, the presence of both prolonged QTd (>65 ms) and Echo-LVH was associated with a 3.2-fold (95% CI: 1.7-6.1) increased risk of a first cardiovascular event and a 5.9-fold (95% CI: 2.1-16.4) increased risk of cardiovascular death. Thus, QT provided additive prognostic information for cardiovascular morbidity and mortality beyond that obtained from conventional risk markers, including Echo-LVH, in type 2 diabetic patients with arterial hypertension.

Accelerated coronary artery calcification in mildly reduced renal function of high-risk hypertensives

OBJECTIVE

To examine the effect of mild renal dysfunction on coronary artery calcifications.

METHODS

We examined the progression of coronary atherosclerosis, as measured by dual-section spiral computed tomography, using the total coronary artery calcium score as a quantitative measure of the burden of atherosclerosis. Of 547 high-risk Israeli hypertensive patients, who were participants of the prospective calcification study (a side-arm of the international INSIGHT study), 313 patients completed the 3-year follow-up. Subjects were studied upon entry (on placebo) and again after 3 years of treatment (nifedipine or thiazide). Patients were divided into two groups depending on their creatinine clearance: (i) </= 60 ml/min, renal dysfunction (RD) (n = 53) and (ii) > 60 ml/min, normal renal function group (n = 263).

RESULTS

Blood pressure, hypercholesterolemia, and smoking did not differ between the groups. After 3 years of treatment, blood pressure control was similar, whereas the total coronary artery calcium score progression was two-fold greater in the RD than the normal group (156 +/- 32 versus 64 +/- 8, respectively) (P = 0.006). In a multiple logistic regression analysis, the odds ratio (OR) for total coronary artery calcium score progression was higher for the RD group (2.1) [95% confidence interval (CI) 1.2-3.7]. Gender, body mass index, smoking, cholesterol, family history of ischaemic heart disease and diabetes were not significant predictors. Thiazide-based antihypertensive therapy predicted a faster progression compared to nifedipine (OR 1.66, 95% CI 1.09-2.51).

CONCLUSIONS

Mild renal dysfunction accelerates coronary artery calcifications, above and beyond conventional risk factors.

Left ventricular mass and cardiovascular morbidity in essential hypertension: the MAVI study

OBJECTIVES

This study investigated the prognostic value of left ventricular (LV) mass at echocardiography in uncomplicated subjects with essential hypertension.

BACKGROUND

Only a few single-center studies support the prognostic value of LV mass in uncomplicated hypertension.

METHODS

The MAssa Ventricolare sinistra nell'Ipertensione study was a multicenter (45 centers) prospective study. The prespecified aim was to explore the prognostic value of LV mass in hypertension. Admission criteria included essential hypertension, no previous cardiovascular events, and age > or =50. There was central reading of echocardiographic tracings. Treatment was tailored to the single subject.

RESULTS

Overall, 1,033 subjects (396 men) were followed for 0 to 4 years (median, 3 years). Mean age at entry was 60 years, and systolic/diastolic blood pressure was 154/92 mm Hg. The rate of cardiovascular events (x100 patient-years) was 1.3 in the group with normal LV mass and 3.2 in the group (28.5% of total sample) with LV mass > or =125 g/body surface area (p = 0.005). After adjustment for age (p < 0.01), diabetes (p < 0.01), cigarette smoking (p < 0.01) and serum creatinine (p = 0.03), LV hypertrophy was associated with an increased risk of events (RR [relative risk] 2.08; 95% CI [confidence interval]: 1.22 to 3.57). For each 39 g/m(2) (1 SD) increase in LV mass there was an independent 40% rise in the risk of major cardiovascular events (95% CI: 14 to 72; p = 0.0013).

CONCLUSIONS

Our findings show a strong, continuous and independent relationship of LV mass to subsequent cardiovascular morbidity. This is the first study to extend such demonstration to a large nationwide multicenter sample of uncomplicated subjects with essential hypertension.

Hypertensive left ventricular hypertrophy: relation to peripheral sympathetic drive

OBJECTIVES

This study was designed to examine whether the occurrence of left ventricular hypertrophy (LVH) in moderate to severe essential hypertension (EHT) was associated with alteration in peripheral sympathetic drive.

BACKGROUND

In hypertension, LVH is an independent predictor of increased morbidity and mortality. The reported mechanisms leading to LVH remain unclear but include hemodynamic and humoral factors. The sympathetic nervous system may be important, particularly as catecholamines have been shown to have trophic properties. We tested the hypothesis that sympathetic activity measured using microneurography could be different in patients with hypertension depending on the presence of LVH.

METHODS

We examined 28 subjects with moderate to severe EHT (stages 2 to 3; Joint National Committee [JNC]-VI classification). Fourteen had echocardiographic evidence of LVH (EHT + LVH), while the other 14 subjects (EHT) did not. Subjects were matched in terms of age, body mass index and levels of arterial blood pressure. Peripheral muscle sympathetic nerve activity was measured from both multiunit bursts (MSNA) and single unit (s-MSNA) vasoconstrictor impulses via the peroneal nerve.

RESULTS

The mean frequency of s-MSNA and MSNA was greater in the EHT + LVH group than it was in the EHT group (mean +/- SEM; 75.9 +/- 6.9 impulses/100 beats vs. 52.1 +/- 2.9 impulses/100 beats, p < 0.001 and 64.2 +/- 5.7 bursts/100 beats vs. 48.9 +/- 2.8 bursts/100 beats, p < 0.05).

CONCLUSIONS

These results indicate that, in subjects with moderate to severe hypertension, the presence of LVH is associated with higher sympathetic discharge, evidenced by an increase in unitary firing frequency and also by fiber recruitment.

Effects of individual risk factors on the incidence of cardiovascular events in the treated hypertensive patients of the Hypertension Optimal Treatment Study. HOT Study Group

BACKGROUND

The Hypertension Optimal Treatment (HOT) Study has provided information about cardiovascular events in 18790 hypertensives, subjected to pronounced blood pressure (BP) lowering for a mean of 3.8 years. The HOT study data have subsequently been analysed after stratification of the patients according to global cardiovascular risk, and it has been found that, despite intensive blood pressure lowering in all risk strata, morbid event rates increased with increasing risk stratum.

OBJECTIVES

Previously analysed global risk strata were based on combinations of risk factors. The analyses presented here were intended to provide information on the relative role that the presence of each individual factor may have in increasing cardiovascular risk, despite good BP control.

METHODS

Risk ratios (RR) for patients with and those without a risk factor were calculated with 95% confidence intervals (CI) using a Cox proportional hazard model, and adjusted for all variables except the one under examination.

RESULTS

For all risk factors considered and for all types of event, RR were always greater than 1, indicating a greater risk in the presence, compared with that in the absence of each factor. The male gender was a statistically significant risk for cardiovascular (CV) events, CV and total mortality and particularly for myocardial infarction (MI); age > or = 65 years for CV events, stroke, CV and particularly total mortality; smoking for all events analysed, but particularly for total mortality (twice higher in smokers than in non-smokers); high serum cholesterol (> 6.8 mmol/l) for CV events, MI and CV mortality; high serum creatinine (> 155 micromol/l) for CV events, stroke, CV and total mortality; diabetes for CV events, stroke, total mortality and particularly CV mortality; and ischaemic heart disease for all events analysed. Adjusted RR were often close to or greater than 2.

CONCLUSIONS

Each of the risk factors considered was found to be an important cause of residual risk, despite good BP control. These findings emphasize the importance of addressing other correctable risk factors, e.g. smoking, hypercholesterolaemia and diabetes, as well as rigorous control of blood pressure, and of initiating antihypertensive therapy before cardiovascular and renal damage becomes manifest.