Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) Trial of Cardiovascular Events in High-Risk Hypertensive Patients: Rationale, Design, and Methods

Calcium channel blockers versus other classes of drugs for hypertension

BACKGROUND

This is the first update of a review published in 2010. While calcium channel blockers (CCBs) are often recommended as a first-line drug to treat hypertension, the effect of CCBs on the prevention of cardiovascular events, as compared with other antihypertensive drug classes, is still debated.

OBJECTIVES

To determine whether CCBs used as first-line therapy for hypertension are different from other classes of antihypertensive drugs in reducing the incidence of major adverse cardiovascular events.

SEARCH METHODS

For this updated review, the Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials (RCTs) up to 1 September 2020: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL 2020, Issue 1), Ovid MEDLINE, Ovid Embase, the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted the authors of relevant papers regarding further published and unpublished work and checked the references of published studies to identify additional trials. The searches had no language restrictions.

SELECTION CRITERIA

Randomised controlled trials comparing first-line CCBs with other antihypertensive classes, with at least 100 randomised hypertensive participants and a follow-up of at least two years.

DATA COLLECTION AND ANALYSIS

Three review authors independently selected the included trials, evaluated the risk of bias, and entered the data for analysis. Any disagreements were resolved through discussion. We contacted study authors for additional information.

MAIN RESULTS

This update contains five new trials. We included a total of 23 RCTs (18 dihydropyridines, 4 non-dihydropyridines, 1 not specified) with 153,849 participants with hypertension. All-cause mortality was not different between first-line CCBs and any other antihypertensive classes. As compared to diuretics, CCBs probably increased  major cardiovascular events (risk ratio (RR) 1.05, 95% confidence interval (CI) 1.00 to 1.09, P = 0.03) and increased congestive heart failure events (RR 1.37, 95% CI 1.25 to 1.51, moderate-certainty evidence). As compared to beta-blockers, CCBs reduced the following outcomes: major cardiovascular events (RR 0.84, 95% CI 0.77 to 0.92), stroke (RR 0.77, 95% CI 0.67 to 0.88, moderate-certainty evidence), and cardiovascular mortality (RR 0.90, 95% CI 0.81 to 0.99, low-certainty evidence). As compared to angiotensin-converting enzyme (ACE) inhibitors, CCBs reduced stroke (RR 0.90, 95% CI 0.81 to 0.99, low-certainty evidence) and increased congestive heart failure (RR 1.16, 95% CI 1.06 to 1.28, low-certainty evidence). As compared to angiotensin receptor blockers (ARBs), CCBs reduced myocardial infarction (RR 0.82, 95% CI 0.72 to 0.94, moderate-certainty evidence) and increased congestive heart failure (RR 1.20, 95% CI 1.06 to 1.36, low-certainty evidence).

AUTHORS' CONCLUSIONS

For the treatment of hypertension, there is moderate certainty evidence that diuretics reduce major cardiovascular events and congestive heart failure more than CCBs. There is low to moderate certainty evidence that CCBs probably reduce major cardiovascular events more than beta-blockers. There is low to moderate certainty evidence that CCBs reduced stroke when compared to angiotensin-converting enzyme (ACE) inhibitors and reduced myocardial infarction when compared to angiotensin receptor blockers (ARBs), but increased congestive heart failure when compared to ACE inhibitors and ARBs. Many of the differences found in the current review are not robust, and further trials might change the conclusions. More well-designed RCTs studying the mortality and morbidity of individuals taking CCBs as compared with other antihypertensive drug classes are needed for patients with different stages of hypertension, different ages, and with different comorbidities such as diabetes.

Calcium channel blockers versus other classes of drugs for hypertension

BACKGROUND

This is the first update of a review published in 2010. While calcium channel blockers (CCBs) are often recommended as a first-line drug to treat hypertension, the effect of CCBs on the prevention of cardiovascular events, as compared with other antihypertensive drug classes, is still debated.

OBJECTIVES

To determine whether CCBs used as first-line therapy for hypertension are different from other classes of antihypertensive drugs in reducing the incidence of major adverse cardiovascular events.

SEARCH METHODS

For this updated review, the Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials (RCTs) up to 1 September 2020: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL 2020, Issue 1), Ovid MEDLINE, Ovid Embase, the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted the authors of relevant papers regarding further published and unpublished work and checked the references of published studies to identify additional trials. The searches had no language restrictions.

SELECTION CRITERIA

Randomised controlled trials comparing first-line CCBs with other antihypertensive classes, with at least 100 randomised hypertensive participants and a follow-up of at least two years.

DATA COLLECTION AND ANALYSIS

Three review authors independently selected the included trials, evaluated the risk of bias, and entered the data for analysis. Any disagreements were resolved through discussion. We contacted study authors for additional information.

MAIN RESULTS

This update contains five new trials. We included a total of 23 RCTs (18 dihydropyridines, 4 non-dihydropyridines, 1 not specified) with 153,849 participants with hypertension. All-cause mortality was not different between first-line CCBs and any other antihypertensive classes. As compared to diuretics, CCBs probably increased  major cardiovascular events (risk ratio (RR) 1.05, 95% confidence interval (CI) 1.00 to 1.09, P = 0.03) and increased congestive heart failure events (RR 1.37, 95% CI 1.25 to 1.51, moderate-certainty evidence). As compared to beta-blockers, CCBs reduced the following outcomes: major cardiovascular events (RR 0.84, 95% CI 0.77 to 0.92), stroke (RR 0.77, 95% CI 0.67 to 0.88, moderate-certainty evidence), and cardiovascular mortality (RR 0.90, 95% CI 0.81 to 0.99, low-certainty evidence). As compared to angiotensin-converting enzyme (ACE) inhibitors, CCBs reduced stroke (RR 0.90, 95% CI 0.81 to 0.99, low-certainty evidence) and increased congestive heart failure (RR 1.16, 95% CI 1.06 to 1.28, low-certainty evidence). As compared to angiotensin receptor blockers (ARBs), CCBs reduced myocardial infarction (RR 0.82, 95% CI 0.72 to 0.94, moderate-certainty evidence) and increased congestive heart failure (RR 1.20, 95% CI 1.06 to 1.36, low-certainty evidence).

AUTHORS' CONCLUSIONS

For the treatment of hypertension, there is moderate certainty evidence that diuretics reduce major cardiovascular events and congestive heart failure more than CCBs. There is low to moderate certainty evidence that CCBs probably reduce major cardiovascular events more than beta-blockers. There is low to moderate certainty evidence that CCBs reduced stroke when compared to angiotensin-converting enzyme (ACE) inhibitors and reduced myocardial infarction when compared to angiotensin receptor blockers (ARBs), but increased congestive heart failure when compared to ACE inhibitors and ARBs. Many of the differences found in the current review are not robust, and further trials might change the conclusions. More well-designed RCTs studying the mortality and morbidity of individuals taking CCBs as compared with other antihypertensive drug classes are needed for patients with different stages of hypertension, different ages, and with different comorbidities such as diabetes.

Antihypertensive treatment and risk of cancer: an individual participant data meta-analysis

BACKGROUND

Some studies have suggested a link between antihypertensive medication and cancer, but the evidence is so far inconclusive. Thus, we aimed to investigate this association in a large individual patient data meta-analysis of randomised clinical trials.

METHODS

We searched PubMed, MEDLINE, The Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from Jan 1, 1966, to Sept 1, 2019, to identify potentially eligible randomised controlled trials. Eligible studies were randomised controlled trials comparing one blood pressure lowering drug class with a placebo, inactive control, or other blood pressure lowering drug. We also required that trials had at least 1000 participant years of follow-up in each treatment group. Trials without cancer event information were excluded. We requested individual participant data from the authors of eligible trials. We pooled individual participant-level data from eligible trials and assessed the effects of angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), β blockers, calcium channel blockers, and thiazide diuretics on cancer risk in one-stage individual participant data and network meta-analyses. Cause-specific fixed-effects Cox regression models, stratified by trial, were used to calculate hazard ratios (HRs). The primary outcome was any cancer event, defined as the first occurrence of any cancer diagnosed after randomisation. This study is registered with PROSPERO (CRD42018099283).

FINDINGS

33 trials met the inclusion criteria, and included 260 447 participants with 15 012 cancer events. Median follow-up of included participants was 4·2 years (IQR 3·0-5·0). In the individual participant data meta-analysis comparing each drug class with all other comparators, no associations were identified between any antihypertensive drug class and risk of any cancer (HR 0·99 [95% CI 0·95-1·04] for ACEIs; 0·96 [0·92-1·01] for ARBs; 0·98 [0·89-1·07] for β blockers; 1·01 [0·95-1·07] for thiazides), with the exception of calcium channel blockers (1·06 [1·01-1·11]). In the network meta-analysis comparing drug classes against placebo, we found no excess cancer risk with any drug class (HR 1·00 [95% CI 0·93-1·09] for ACEIs; 0·99 [0·92-1·06] for ARBs; 0·99 [0·89-1·11] for β blockers; 1·04 [0·96-1·13] for calcium channel blockers; 1·00 [0·90-1·10] for thiazides).

INTERPRETATION

We found no consistent evidence that antihypertensive medication use had any effect on cancer risk. Although such findings are reassuring, evidence for some comparisons was insufficient to entirely rule out excess risk, in particular for calcium channel blockers.

FUNDING

British Heart Foundation, National Institute for Health Research, Oxford Martin School.

Long-term effects of antihypertensive therapy on cardiovascular events and new-onset diabetes mellitus in high-risk hypertensive patients in Japan

OBJECTIVE

During the Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial, patients with hypertension who received amlodipine had similar cardiovascular risks as those who received candesartan. We conducted a post-trial study, the Candesartan Antihypertensive Survival Evaluation in Japan 10-year follow-up (CASE-J 10). This study aimed to confirm the long-term cardiovascular effects of candesartan and amlodipine.

METHODS

Case report forms were sent to CASE-J investigators who agreed to participate in the CASE-J 10. All the available information was retrospectively collected. The primary endpoint was a time-to-first event for a composite of cerebrovascular, cardiac, renal, and vascular events, and sudden death. Secondary endpoints included new-onset diabetes (NOD), cardiovascular mortality, and all-cause mortality. For each endpoint, treatment effect was compared on an intention-to-treat basis, according to previous randomization categories.

RESULTS

A total of 1313 patients' data have been updated. The 10-year Kaplan-Meier rates of the primary endpoint were 14.7% for candesartan and 14.8% for amlodipine. After adjusting for baseline characteristics, the rates for the primary endpoint were similar between the two treatments (hazards ratioadj = 0.99, 95% CI 0.82-1.20). Candesartan had a lower Kaplan-Meier rate of NOD than amlodipine (8.3 vs. 11.1%), and when adjusted for clinical factors, candesartan remained an independent predictor for NOD prevention (hazard ratioadj = 0.71, 95% CI 0.52-0.98).

CONCLUSION

With more than 28 385 patient-years follow-up, we demonstrated that candesartan and amlodipine were comparable in reducing cardiovascular events in patients with high-risk hypertension. Additionally, our results may support candesartan's superiority in reducing NOD incidence compared with amlodipine even after the long-term follow-up.

Diabetes mellitus as a compelling indication for use of renin angiotensin system blockers: systematic review and meta-analysis of randomized trials

OBJECTIVE

To evaluate the outcomes with use of renin angiotensin system (RAS) blockers compared with other antihypertensive agents in people with diabetes.

DESIGN

Meta-analysis.

DATA SOURCES AND STUDY SELECTION

PubMed, Embase, and the Cochrane central register of controlled trials databases for randomized trials of RAS blockers versus other antihypertensive agents in people with diabetes mellitus. Outcomes were death, cardiovascular death, myocardial infarction, angina, stroke, heart failure, revascularization, and end stage renal disease.

RESULTS

The search yielded 19 randomized controlled trials that enrolled 25,414 participants with diabetes for a total of 95,910 patient years of follow-up. When compared with other antihypertensive agents, RAS blockers were associated with a similar risk of death (relative risk 0.99, 95% confidence interval 0.93 to 1.05), cardiovascular death (1.02, 0.83 to 1.24), myocardial infarction (0.87, 0.64 to 1.18), angina pectoris (0.80, 0.58 to 1.11), stroke (1.04, 0.92 to 1.17), heart failure (0.90, 0.76 to 1.07), and revascularization (0.97, 0.77 to 1.22). There was also no difference in the hard renal outcome of end stage renal disease (0.99, 0.78 to 1.28) (power of 94% to show a 23% reduction in end stage renal disease).

CONCLUSIONS

In people with diabetes, RAS blockers are not superior to other antihypertensive drug classes such as thiazides, calcium channel blockers, and β blockers at reducing the risk of hard cardiovascular and renal endpoints. These findings support the recommendations of the guidelines of the European Society of Cardiology/European Society of Hypertension and eighth Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure to also use other antihypertensive agents in people with diabetes but without kidney disease.

Potential of the angiotensin receptor blockers (ARBs) telmisartan, irbesartan, and candesartan for inhibiting the HMGB1/RAGE axis in prevention and acute treatment of stroke

Stroke is a major cause of mortality and disability worldwide. The main cause of stroke is atherosclerosis, and the most common risk factor for atherosclerosis is hypertension. Therefore, antihypertensive treatments are recommended for the prevention of stroke. Three angiotensin receptor blockers (ARBs), telmisartan, irbesartan and candesartan, inhibit the expression of the receptor for advanced glycation end-products (RAGE), which is one of the pleiotropic effects of these drugs. High mobility group box 1 (HMGB1) is the ligand of RAGE, and has been recently identified as a lethal mediator of severe sepsis. HMGB1 is an intracellular protein, which acts as an inflammatory cytokine when released into the extracellular milieu. Extracellular HMGB1 causes multiple organ failure and contributes to the pathogenesis of hypertension, hyperlipidemia, diabetes mellitus, atherosclerosis, thrombosis, and stroke. This is the first review of the literature evaluating the potential of three ARBs for the HMGB1-RAGE axis on stroke therapy, including prevention and acute treatment. This review covers clinical and experimental studies conducted between 1976 and 2013. We propose that ARBs, which inhibit the HMGB1/RAGE axis, may offer a novel option for prevention and acute treatment of stroke. However, additional clinical studies are necessary to verify the efficacy of ARBs.

Upstream stimulatory factors 1 and 2 mediate the transcription of angiotensin II binding and inhibitory protein

The angiotensin II type 1 receptor (AT1R)-associated protein (ATRAP/Agtrap) promotes constitutive internalization of the AT1R so as to specifically inhibit the pathological activation of its downstream signaling yet preserve the base-line physiological signaling activity of the AT1R. Thus, tissue-specific regulation of Agtrap expression is relevant to the pathophysiology of cardiovascular and renal disease. However, the regulatory mechanism of Agtrap gene expression has not yet been fully elucidated. In this study, we show that the proximal promoter region from −150 to +72 of the mouse Agtrap promoter, which contains the X-box, E-box, and GC-box consensus motifs, is able to elicit substantial transcription of the Agtrap gene. Among these binding motifs, we showed that the E-box specifically binds upstream stimulatory factor (Usf) 1 and Usf2, which are known E-box-binding transcription factors. It is indicated that the E-box-Usf1/Usf2 binding regulates Agtrap expression because of the following: 1) mutation of the E-box to prevent Usf1/Usf2 binding reduces Agtrap promoter activity; 2) knockdown of Usf1 or Usf2 affects both endogenous Agtrap mRNA and Agtrap protein expression, and 3) the decrease in Agtrap mRNA expression in the afflicted kidney by unilateral ureteral obstruction is accompanied by changes in Usf1 and Usf2 mRNA. Furthermore, the results of siRNA transfection in mouse distal convoluted tubule cells and those of unilateral ureteral obstruction in the afflicted mouse kidney suggest that Usf1 decreases but Usf2 increases the Agtrap gene expression by binding to the E-box. The results also demonstrate a functional E-box-USF1/USF2 interaction in the human AGTRAP promoter, thereby suggesting that a strategy of modulating the E-box-USF1/USF2 binding has novel therapeutic potential.

The effects of calcium channel blockers in the prevention of stroke in adults with hypertension: a meta-analysis of data from 273,543 participants in 31 randomized controlled trials

BACKGROUND

Hypertension is a major risk factor for the development of stroke. It is well known that lowering blood pressure decreases the risk of stroke in people with moderate to severe hypertension. However, the specific effects of calcium channel blockers (CCBs) against stroke in patients with hypertension as compared to no treatment and other antihypertensive drug classes are not known.

METHODS AND FINDINGS

This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated CCBs effect on stroke in patients with hypertension in studies of CCBs versus placebo, angiotensin-converting-enzyme inhibitors (ACEIs), β-adrenergic blockers, and diuretics. The PUBMED, MEDLINE, EMBASE, OVID, CNKI, MEDCH, and WANFANG databases were searched for trials published in English or Chinese during the period January 1, 1996 to July 31, 2012. A total of 177 reports were collected, among them 31 RCTs with 273,543 participants (including 130,466 experimental subjects and 143,077 controls) met the inclusion criteria. In these trials a total of 9,550 stroke events (4,145 in experimental group and 5,405 in control group) were reported. CCBs significantly decreased the incidence of stroke compared with placebo (OR = 0.68, 95% CI 0.61-0.75, p<1×10(-5)), β-adrenergic blockers combined with diuretics (OR = 0.89, 95% CI 0.83-0.95, p = 7×10(-5)) and β-adrenergic blockers (OR = 0.79, 95% CI 0.72-0.87, p<1×10(-5)), statistically significant difference was not found between CCBs and ACEIs (OR = 0.92, 95% CI 0.8-1.02, p = 0.12) or diuretics (OR = 0.95, 95% CI 0.84-1.07, p = 0.39).

CONCLUSION

In a pooled analysis of data of 31 RCTs measuring the effect of CCBs on stroke, CCBs reduced stroke more than placebo and β-adrenergic blockers, but were not different than ACEIs and diuretics. More head to head RCTs are warranted.

The central mechanism underlying hypertension: a review of the roles of sodium ions, epithelial sodium channels, the renin-angiotensin-aldosterone system, oxidative stress and endogenous digitalis in the brain

The central nervous system has a key role in regulating the circulatory system by modulating the sympathetic and parasympathetic nervous systems, pituitary hormone release, and the baroreceptor reflex. Digoxin- and ouabain-like immunoreactive materials were found >20 years ago in the hypothalamic nuclei. These factors appeared to localize to the paraventricular and supraoptic nuclei and the nerve fibers at the circumventricular organs and supposed to affect electrolyte balance and blood pressure. The turnover rate of these materials increases with increasing sodium intake. As intracerebroventricular injection of ouabain increases blood pressure via sympathetic activation, an endogenous digitalis-like factor (EDLF) was thought to regulate cardiovascular system-related functions in the brain, particularly after sodium loading. Experiments conducted mainly in rats revealed that the mechanism of action of ouabain in the brain involves sodium ions, epithelial sodium channels (ENaCs) and the renin-angiotensin-aldosterone system (RAAS), all of which are affected by sodium loading. Rats fed a high-sodium diet develop elevated sodium levels in their cerebrospinal fluid, which activates ENaCs. Activated ENaCs and/or increased intracellular sodium in neurons activate the RAAS; this releases EDLF in the brain, activating the sympathetic nervous system. The RAAS promotes oxidative stress in the brain, further activating the RAAS and augmenting sympathetic outflow. Angiotensin II and aldosterone of peripheral origin act in the brain to activate this cascade, increasing sympathetic outflow and leading to hypertension. Thus, the brain Na(+)-ENaC-RAAS-EDLF axis activates sympathetic outflow and has a crucial role in essential and secondary hypertension. This report provides an overview of the central mechanism underlying hypertension and discusses the use of antihypertensive agents.

Oxidative stress as pathogenesis of cardiovascular risk associated with metabolic syndrome

Metabolic syndrome (MetS) is characterized by accumulation of visceral fat associated with the clustering of metabolic and pathophysiological cardiovascular risk factors: impaired glucose tolerance, dyslipidemia, and hypertension. Although the definition of MetS is different among countries, visceral obesity is an indispensable component of MetS. A growing body of evidence suggests that increased oxidative stress to adipocytes is central to the pathogenesis of cardiovascular disease in MetS. Increased oxidative stress to adipocytes causes dysregulated expression of inflammation-related adipocytokines in MetS, which contributes to obesity-associated vasculopathy and cardiovascular risk primarily through endothelial dysfunction. The purpose of present review is to unravel the mechanistic link between oxidative stress and cardiovascular risk in MetS, focusing on insulin resistance, hypertension, and atherosclerosis. Then, therapeutic opportunities translated from the bench to bedside will be provided to develop novel strategies to cardiovascular risk factors in MetS.

How to use marginal structural models in randomized trials to estimate the natural direct and indirect effects of therapies mediated by causal intermediates

Background Although intention-to-treat analysis is a standard approach, additional supplemental analyses are often required to evaluate the biological relationship among interventions, intermediates, and outcomes. Therefore, we need to evaluate whether the effect of an intervention on a particular outcome is mediated by a hypothesized intermediate variable.

Purpose To evaluate the size of the direct effect in the total effect, we applied the marginal structural model to estimate the average natural direct and indirect effects in a large-scale randomized controlled trial (RCT).

Method The average natural direct effect is defined as the difference in the probability of a counterfactual outcome between the experimental and control arms, with the intermediate set to what it would have been, had the intervention been a control treatment. We considered two marginal structural models to estimate the average natural direct and indirect effects introduced by VanderWeele ( Epidemiology 2009) and applied them in a large-scale RCT – the Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J trial) – that compared angiotensin receptor blockers and calcium-channel blockers in high-risk hypertensive patients.

Results There were no strong blood pressure-independent or dependent effects; however, a systolic blood pressure reduction of about 1.9 mmHg suppressed all events. Compared to the blood pressure-independent effects of calcium channel blockers, those of angiotensin receptor blockers contributed positively to cardiovascular and cardiac events, but negatively to cerebrovascular events.

Limitations There is a particular condition for estimating the average natural direct effect. It is impossible to check whether this condition is satisfied with the available data.

Conclusion We estimated the average natural direct and indirect effects through the achieved systolic blood pressure in the CASE-J trial. This first application of estimating the average natural effects in an RCT can be useful for obtaining an in-depth understanding of the results and further development of similar interventions.

Impact of left ventricular hypertrophy on the time-course of renal function in hypertensive patients – a subanalysis of the CASE-J trial –

BACKGROUND

In this subanalysis of the CASE-J, which was conducted to compare the effects of candesartan and amlodipine in Japanese high-risk hypertensive patients, THE ASSOCIATION OF LEFT VENTRICULAR HYPERTROPHY (LVH) WITH RENAL FUNCTION IS CLARIFIED.

METHODS AND RESULTS

Patients were divided into 2 groups: 1,082 patients with LVH and 2,119 patients without LVH. The primary endpoint was the change in the estimated glomerular filtration rate (eGFR). The eGFRs were increased from 63.6 to 65.1 ml · min(-1) · 1.73 m(-2) in patients with LVH and from 63.6 to 68.5 ml · min(-1) · 1.73 m(-2) in those without LVH. The improvement in the eGFR was greater in patients without LVH than in those with LVH (P=0.004). In patients with chronic kidney disease (CKD) patients, the eGFR increased from 52.7 to 60.5 ml · min(-1) · 1.73 m(-2) in patients without LVH, but from 53.1 to 57.2 ml · min(-1) · 1.73 m(-2) in those with LVH (P<0.001, patients without LVH vs patients with LVH). Furthermore, because the eGFR changed from 76.5 to 75.4 ml · min(-1) · 1.73 m(-2) in patients without CKD but with LVH, and from 76.5 to 77.5 ml · min(-1) · 1.73 m(-2) in those without either CKD or LVH, the final eGFR was higher in patients without LVH than in those with LVH (P=0.048).

CONCLUSIONS

LVH related to the time-course of renal function in Japanese hypertensive patients.

Is pulse pressure a predictor of new-onset diabetes in high-risk hypertensive patients?: a subanalysis of the Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial

OBJECTIVE

Hypertensive patients have an increased risk of developing diabetes. Accumulating evidence suggests a close relation between metabolic disturbance and increased arterial stiffness. Here, we examined the association between pulse pressure and the risk of new-onset diabetes in high-risk Japanese hypertensive patients.

RESEARCH DESIGN AND METHODS

The Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial examined the effects of candesartan and amlodipine on the incidence of cardiovascular events in 4,728 high-risk Japanese hypertensive patients. In the present study, we analyzed the relationship between pulse pressure at baseline and new-onset diabetes in 2,685 patients without diabetes at baseline (male 1,471; mean age 63.7 years; mean BMI 24.8 kg/m(2)) as a subanalysis of the CASE-J trial.

RESULTS

During 3.3 +/- 0.8 years of follow-up, 97 patients (3.6%) developed diabetes. In multiple Cox regression analysis, pulse pressure was an independent predictor for new-onset diabetes (hazard ratio [HR] per 1 SD increase 1.44 [95% CI 1.15-1.79]) as were male sex, BMI, and additional use of diuretics, whereas age and heart rate were not. Plots of HRs for new-onset diabetes considering both systolic and diastolic blood pressure (DBP) revealed that a higher pulse pressure with a lower DBP, indicating that the increased pulse pressure was largely due to increased arterial stiffness, was strongly associated with the risk of new-onset diabetes.

CONCLUSIONS

Pulse pressure is an independent predictor of new-onset diabetes in high-risk Japanese hypertensive patients. Increased arterial stiffness may be involved in the development of diabetes.

Relationship between the achieved blood pressure and the incidence of cardiovascular events in Japanese hypertensive patients with complications: a sub-analysis of the CASE-J trial

Various guidelines for hypertension specify that the target blood pressure (BP) should be below 140/90 mm Hg and that strict control is recommended for patients with cardiovascular risk factors. We examined the relationship between the achieved BP and the incidence of cardiovascular events in hypertensive patients with complications as a sub-analysis of the Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial. A total of 4703 patients were evaluated for efficacy in the CASE-J trial. In this sub-analysis, 4553 patients had at least one follow-up visit without any cardiovascular events. We examined the relationship between the achieved BP and cardiovascular events in hypertensive patients with type II diabetes mellitus (DM), chronic kidney disease (CKD) or left ventricular hypertrophy (LVH) at baseline. Possible baseline confounders were adjusted by using the multiple Cox regression model. A higher achieved BP was associated with an increased risk of cardiovascular events in hypertensive patients with complications (DM, CKD or LVH). In patients with LVH, who achieved systolic/diastolic BP (SBP/DBP) <130/75-79 mm Hg, the risk of cardiovascular events was reduced to the same level of SBP/DBP <130/75-79 mm Hg in those without LVH. However, the risks of cardiovascular events in patients with DM or CKD, who achieved SBP/DBP <130/75-79 mm Hg, were still significantly higher than in those without DM or CKD. In conclusion, this study extended the significance of BP control in hypertensive patients especially with complications. Further investigation in a large-scale clinical trial is needed to determine the optimal target BP for LVH patients.

ARB candesartan and CCB amlodipine in hypertensive patients: the CASE-J trial

The Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial was a comparative study of the angiotensin II receptor blocker (ARB), candesartan, and a calcium channel blocker (CCB), amlodipine, regarding the incidence of cardiovascular events in high-risk Japanese hypertensive patients. The study design was a prospective, multicenter, randomized, open-label, active-controlled, two-arm, parallel-group comparison study with a response-dependent dose titration and blinded assessment of the end point. The CASE-J trial enrolled 4728 patients, with a mean age of 63.8 years and a mean BMI of 24.6 kg/m(2), who were randomly assigned to either candesartan- or amlodipine-based treatment regimens. Blood pressure was well controlled to the level of less than 140/80 mmHg in both of the treatment regimens. During 3.2 years of follow-up, primary cardiovascular events occurred in 134 patients in each of the two treatment-based regimens, resulting in no significant difference in the incidence of cardiovascular events between them (hazard ratio: 1.01; 95% confidence interval: 0.79-1.28; p = 0.969). In 404 patients with left ventricular hypertrophy, a significantly larger decrease in left ventricular mass index 3 years after enrollment was observed in candesartan-based (n = 205) than amlodipine-based (n = 199) regimens (-22.9 vs -13.4 g/m(2), respectively; p = 0.023). Furthermore, new-onset diabetes occurred in fewer patients taking candesartan than in those taking amlodipine, resulting in a 36% relative risk reduction (p = 0.030). The CASE-J trial demonstrated that both an ARB, candesartan, and a CCB, amlodipine, equally suppressed the incidence of cardiovascular events. The ARB may confer more beneficial effects to hypertensive patients with left ventricular hypertrophy or for those at-risk of diabetes than CCB.

Prevention of stroke and myocardial infarction by amlodipine and Angiotensin receptor blockers: a quantitative overview

In the present quantitative overview of outcome trials, we investigated the efficacy of amlodipine or angiotensin receptor blockers in the prevention of stroke and myocardial infarction in patients with hypertension, coronary artery disease, or diabetic nephropathy. The analysis included 12 trials of 94 338 patients. The analysis of trials involving an amlodipine group showed that amlodipine provided more protection against stroke and myocardial infarction than other antihypertensive drugs, including angiotensin receptor blockers (-19%, P<0.0001 and -7%, P=0.03) and placebo (-37%, P=0.06 and -29%, P=0.04). The analysis of trials involving an angiotensin receptor blocker group showed contrasting results between trials versus amlodipine and trials versus other antihypertensive drugs for stroke (+19% versus -25%; P<0.0001) and myocardial infarction (+21% versus +1%; P=0.03). The results of 3 trials comparing an angiotensin receptor blocker with placebo were neutral (P> or =0.14). The within-trial between-group difference in achieved systolic pressure ranged from -1.1 to +4.7 mm Hg for trials involving an amlodipine group and from -2.8 to +4.0 mm Hg for trials involving an angiotensin receptor blocker group. The metaregression analysis correlating odds ratios with blood pressure differences showed a negative relationship (regression coefficients: -3% to -8%), which reached statistical significance (regression coefficient: -6%; P=0.01) for stroke in trials involving an amlodipine group. In conclusion, blood pressure differences largely accounted for cardiovascular outcome.

Informed consent in the Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial: a survey of collaborating physicians

An anonymous postal survey was conducted among the physicians collaborating in a randomized controlled trial to examine their method of convincing patients, their consent process, the factors related to higher accrual, and the predictors of 100% success in the process of obtaining informed consent (IC). A total of 512 questionnaires were sent out and 448 responses were received, for a response rate of 87.5%. The 448 physicians solicited a total of 5371 eligible patients (12.0 per physician), among which 3763 patients (8.4 per physician) agreed to participate. One-fifth (22.3%) of the physicians were able to obtain IC from 100% of the patients they solicited. Physicians who thought that the information on the IC sheet was sufficient to obtain consent (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.1-3.9; p = 0.03) and those who did not consider that the patient's decision was influenced by relatives and friends (OR = 0.2, CI = 0.1-0.4; p = 0.001), were significantly more likely to obtain IC from 100% of the eligible patients. Three-fourths (73.2%) of the physicians targeted only patients who they perceived would easily provide IC, and 81.2% favored some form of incentives for patients. The results of this study should be useful for efficiently implementing randomized controlled trials in Japan.

National Stroke Association guidelines for the management of transient ischemic attacks

OBJECTIVE

Transient ischemic attacks are common and important harbingers of subsequent stroke. Management varies widely, and most published guidelines have not been updated in several years. We sought to create comprehensive, unbiased, evidence-based guidelines for the management of patients with transient ischemic attacks.

METHODS

Fifteen expert panelists were selected based on objective criteria, using publication metrics that predicted nomination by practitioners in the field. Prior published guidelines were identified through systematic review, and recommendations derived from them were rated independently for quality by the experts. Highest quality recommendations were selected and subsequently edited by the panelists using a modified Delphi approach with multiple iterations of questionnaires to reach consensus on new changes. Experts were provided systematic reviews of recent clinical studies and were asked to justify wording changes based on new evidence and to rate the final recommendations based on level of evidence and quality. No expert was allowed to contribute to recommendations on a topic for which there could be any perception of a conflict of interest.

RESULTS

Of 257 guidelines documents identified by systematic review, 13 documents containing 137 recommendations met all entry criteria. Six iterations of questionnaires were required to reach consensus on wording of 53 final recommendations. Final recommendations covered initial management, evaluation, medical treatment, surgical treatment, and risk factor management.

INTERPRETATION

The final recommendations on the care of patients with transient ischemic attacks emphasize the importance of urgent evaluation and treatment. The novel approach used to develop these guidelines is feasible, allows for rapid updating, and may reduce bias.

Factors associated with compliance and non-compliance by physicians in a large-scale randomized clinical trial

Background

In order to minimize the amount of incomplete follow-up data, reducing the non-compliance of participating physicians is one of the key issues for the data coordinating center in a multi-center trial. Identifying the physicians' non-compliance in advance is considered to be an important strategy for more efficient conduct of trials. In this study, we identified physicians' characteristics and factors associated with the need for individual visits to institutions to collect data or to complete information during two years of follow-up in a large Japanese investigator-initiated trial related to cardiovascular disease.

Methods

We categorized the physicians into two groups, "complier" and "non-complier". Odds ratios and corresponding 95% confidence intervals were calculated for 11 factors related to the characteristics of and compliance by physicians. Multiple logistic regression analysis was also performed. In addition, we evaluated the incremental cost for obtaining additional information of the non-compliant physicians.

Results

Three factors were identified in multiple logistic regression analysis as being significantly associated with compliance status: 1) prior participation in clinical trials (OR = 0.40 95%CI = 0.21–0.74); 2) physician opinion that the support system for case registration and follow-up was well organized (OR = 0.41 95%CI = 0.22–0.75); and 3) number of patients recruited (OR = 2.25 95%CI = 1.01–5.02). The actual incremental cost was about US $112,000 (14.4% of total routine follow-up costs) for the non-compliant physicians during the 2 years, or about US $570 per patient.

Conclusion

Investigator-initiated clinical trials have recently attracted great interest, but they often suffer from insufficient funding. If trial networks are to be well organized, it is important that trials are conducted more efficiently. We believe that our findings will be useful for reducing the additional burden associated with incomplete follow-up data and data lost to follow-up when planning future trials.

Recruitment of patients for a clinical trial: factors on the physician side and reasons on the patient side

OBJECTIVES

To examine the factors related to actual patient recruiters among the physicians who initially agreed to collaborate in a randomized control trial.

METHODS

We conducted a questionnaire survey of 679 physicians (512 actual recruiter and 167 non-recruiters) who had initially agreed to recruit patients for a clinical trial to determine factors to predict who would actually do so.

RESULTS

Response rates among recruiters and non-recruiters were 87.5% and 73.1%, respectively. Multivariate logistic regression model showed that the proportions of regular users of computer [odds ratio (OR) =2.1, 95% confidence intervals (CI)=1.3-3.3] (p=0.002) and current participants in other clinical trials (OR=2.2, CI=1.5-3.4) (p=0.001) were significantly higher among recruiters than non-recruiters. Patients' reasons for non-participation as perceived by the physicians did not differ between recruiters and non-recruiters.

CONCLUSION

Results of this study might be useful in predicting actual recruiters at the outset of clinical trials.

Genetic determinants of blood pressure regulation

Hypertension is a multifactorial disorder that probably results from the inheritance of a number of susceptibility genes and involves multiple environmental determinants. Existing evidence suggests that the genetic contribution to blood pressure variation is about 30-50%. Although a number of candidate genes have been studied in different ethnic populations, results from genetic analysis are still inconsistent and specific causes of hypertension remain unclear. Furthermore, the abundance of data in the literature makes it difficult to piece together the puzzle of hypertension and to define candidate genes involved in the dynamic of blood pressure regulation. In this review, we attempt to highlight the genetic basis of hypertension pathogenesis, focusing on the most important existing genetic variations of candidate genes and their potential role in the development of this disease. Our objective is to review current knowledge and discuss limitations to clinical applications of genotypic information in the diagnosis, evaluation and treatment of hypertension. Finally, some principles of pharmacogenomics are presented here along with future perspectives of hypertension.

Physicians' attitudes towards and reasons for participation in the Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial

BACKGROUND: Physicians’ perception and attitudes towards a research topic and trial management could influence their participation in a randomized controlled trial. The objectives of this study were to determine the reasons for physicians’ participation in and attitudes towards the Candesartan Antihypertensive Survival Evaluation in Japan (CASE-J) trial.

METHODS: CASE-J’s main objective is to compare the effectiveness of an angiotensin II receptor antagonist (candesartan cilexetil) with that of a calcium channel blocker (amlodipine besilate) in terms of the incidence of cardiovascular events among high-risk hypertensive patients. We conducted a questionnaire survey among the physicians (n=512) participating in that trial to determine the reasons behind their participation and to elicit their reactions to the trial management.

RESULTS: Eighty-eight percent of the 512 participating physicians responded to our survey. The main reasons for participation were clear objectives of the trial (85.1%), a simple protocol (61.1%), interest in finding out the inhibiting effects of the drugs on cardiac events (80.2%), and a well-organized support system (59.8%). As for negative factors, case registration and follow-up were considered cumbersome by 28.6% and 10.8%, respectively while 44.2% stated that support by the clinical research coordinators provided by the trial management authority was necessary for case screening, recruitment process, patient registration, and follow-up. Multivariate logistic regression analysis showed that participants who did not use a computer very regularly (odds ratio = 1.9, 95% confidence interval = 1.1-3.6) were more likely to consider the case registration and follow-up procedures as a cumbersome.

CONCLUSION: The information generated by this study could be useful in designing future randomized controlled trials in Japan and abroad.

Redefining efficacy of antihypertensive therapies beyond blood pressure reduction--the role of angiotensin II antagonists

Antihypertensive efficacy must be redefined beyond blood pressure (BP) lowering per se to include reducing the cardiovascular complications of hypertension. Treatment decisions should be based on results from large clinical trials with relevant clinical outcomes. Several recent morbidity and mortality trials with angiotensin II receptor antagonists (AIIAs) provide an evidence-based rationale for the use of AIIAs in patients with hypertension. Studies with AIIAs in comparison to conventional antihypertensive agents showed improved morbidity and mortality outcomes in patients with hypertension and left ventricular hypertrophy (losartan) and diabetes mellitus (losartan and irbesartan). Trials with some members of the AIIA class (candesartan and valsartan) have not demonstrated such benefits in comparison to conventional agents, possibly due to differences in BP control during the trials. The results of these AIIA outcome trials have impacted on recently issued clinical guidelines for management of hypertension.

Interaction between Amlodipine and Simvastatin in Patients with Hypercholesterolemia and Hypertension

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are often prescribed in association with antihypertensive agents, including calcium antagonists. Simvastatin is an HMG-CoA reductase inhibitor that is metabolized by the cytochrome P450 (CYP) 3A4. The calcium antagonist amlodipine is also metabolized by CYP3A4. The purpose of this study was to investigate drug interactions between amlodipine and simvastatin. Eight patients with hypercholesterolemia and hypertension were enrolled. They were given 4 weeks of oral simvastatin (5 mg/day), followed by 4 weeks of oral amlodipine (5 mg/day) co-administered with simvastatin (5 mg/day). Combined treatment with simvastatin and amlodipine increased the peak concentration (C(max)) of HMG-CoA reductase inhibitors from 9.6 +/- 3.7 ng/ml to 13.7 +/- 4.7 ng/ml (p < 0.05) and the area under the concentration-time curve (AUC) from 34.3 +/- 16.5 ng h/ml to 43.9 +/- 16.6 ng h/ml (p < 0.05) without affecting the cholesterol-lowering effect of simvastatin. This study is the first to determine prospectively the pharmacokinetic and pharmacodynamic interaction between amlodipine and simvastatin.

Left Ventricular Remodeling after Myocardial Infarction in Antecedent Hypertensive Patients

Antecedent hypertension adversely affects mortality and heart failure after myocardial infarction (MI). In addition, accelerated ventricular remodeling is a contributor to the increased mortality observed after MI. The purpose of this study was to assess the relationship of antecedent hypertension to ventricular remodeling after MI. Ninety-four patients presenting with a first acute MI who were treated with reperfusion therapy within 12 h of their symptom onset were enrolled in this study. All of them underwent left ventriculography immediately after reperfusion therapy and again at 6 months after the occurrence of MI. Patients were divided into two groups: a hypertensive group and a normotensive group. End-diastolic volume index (EDVI), end-systolic volume index (ESVI), and ejection fraction (EF) values in the acute phase were compared to those at 6 months after acute MI in either group. The hypertensive group showed a significant increase in both EDVI and ESVI after 6 months, whereas the normotensive group did not. In addition, there was no change in EF in the hypertensive group, whereas EF increased significantly after 6 months in the normotensive group. As a result, the percent changes in ESVI and EF were significantly different between the hypertensive group and normotensive group. The results demonstrated that antecedent hypertension interacts with ventricular cavity dilatation after MI.

Physicians' reasons for not entering their patients in a randomized controlled trial in Japan

Physicians' not entering their patients can jeopardize the success of a randomized controlled trial (RCT). We used a survey to investigate the possible reasons why physicians who initially agreed to collaborate did not recruit any patients for an RCT being conducted in Japan. A total of 167 questionnaires were sent out and 122 responses were received. Main reasons for not entering patients were: concern about the detrimental effects on the doctor-patient relationship (51.8%), patients' refusal (47.5%), complicated registration and follow-up procedures (34.9%), and not feeling comfortable recruiting their own patients (32.4%). Multivariate logistic regression made it clear that physicians who thought that registering their own patients would damage the doctor-patient relationship and who expected the RCT would fail were more likely to be uncomfortable entering their own patients. Moreover, physicians aged 50 years or older, who felt uncomfortable recruiting their own patients, and saw no advantage in participating in the trial, were more likely to view the enrolment and follow-up procedures as cumbersome. We conclude that training and a manual for obtaining informed consent and a face-to-face demonstration of patient registration/follow-up procedures for the potential participants are prerequisites for increasing physician participation in RCTs in Japan.

Valsartan in Elderly Isolated Systolic Hypertension (VALISH) Study: Rationale and Design

Although antihypertensive therapy has been proven to reduce cardiovascular morbidity and mortality, it is unclear how much blood pressure should be decreased in elderly patients with hypertension. The Valsartan in Elderly Isolated Systolic Hypertension (VALISH) study is a multicenter parallel-group study comparing the incidence of cardiovascular events between two target systolic blood pressure levels, below 140 mmHg and below 150 mmHg, under treatment with valsartan, an angiotensin II receptor blocker, as an initial antihypertensive drug in elderly patients with isolated systolic hypertension. The number of patients to be recruited is 3,000 and the duration of follow-up is at least 2 years. This 3,000-patient trial was designed with a two-sided alpha level of 0.05 and 80% power to detect the difference in incidence of cardiovascular events between the target blood pressure levels based on estimation of the cardiovascular events ratio as 21.5/1,000 patient-years and 29.1/1,000 patient-years for the two blood pressure levels. The VALISH study, a large-scale investigator-initiated trial in Japan, will determine whether age should be considered in setting target blood pressure in treatment of isolated systolic hypertension in elderly patients.