Prevention of cardiovascular events with calcium channel blocker-based combination therapies in patients with hypertension: a randomized controlled trial

Effects of the T/L-type calcium channel blocker benidipine on albuminuria and plasma aldosterone concentration. A pilot study involving switching from L-type calcium channel blockers to benidipine

Albuminuria and a high plasma aldosterone concentration (PAC) are prognosis factors predicting a poor outcome for cardiovascular disease. We examined here the effects of benidipine, a T/L-type calcium channel blocker (CCB), on albuminuria and PAC.Thirty-one patients with essential hypertension who received an L-type CCB and achieved the target blood pressure (BP) indicated by the Treatment Guidelines of the Japan Society of Hypertension (JSH2009) were investigated. The Ltype CCB under treatment was switched to benidipine at a dose in which equivalent BP reduction was expected. BP and estimated glomerular filtration rate at 6 months after switching to benidipine were not significantly different from those at baseline. The urinary-albumin-creatinine ratio (UACR) decreased significantly by 36.9% (P = 0.001). No significant change was observed in plasma renin activity (P = 0.063). The PAC of all patients decreased significantly by 11.8% (P = 0.002). When analyzed by daily doses of benidipine, the PAC appeared to have decreased in patients who received 4 mg per day of benidipine (n = 14), although statistical significance was not reached (P = 0.096). The PAC in patients who received 8 mg per day of benidipine (n =17) was significantly reduced by 13.2% (P = 0.017).In hypertensive patients whose BP is controlled by L-type CCB, switching to the T/L-type CCB benidipine maintained BP control and reduced UACR. In addition, the high dose of benidipine reduced the PAC independent of BP control. These results suggest the T/L-type CCB benidipine may contribute to cardio-renal protection in addition to lowering BP.

Combination therapy of hypertension in the elderly: a subgroup analysis of the Combination of OLMesartan and a calcium channel blocker or diuretic in Japanese elderly hypertensive patients trial

Combination of OLMesartan and a calcium channel blocker or a diuretic in Japanese elderly hypertensive patients (COLM) trial demonstrated that olmesartan combinations with a CCB or diuretic have similar effects on reducing cardiovascular risk in elderly hypertensive patients. However, the safety profiles suggest that olmesartan combined with CCB may be preferable to olmesartan combined with diuretic. In this subgroup analysis, we further evaluated the effects and safety of these combinations in elderly (65–74 years old (y.o.)) and very elderly (75–84 y.o.) hypertensive patients. In the COLM trial, 5141 patients (2918 elderly and 2223 very elderly) were randomly assigned to receive olmesartan-based therapy with either CCB or diuretic. The hazard ratios and 95% confidence intervals, respectively, in the elderly age group and in the very elderly group were: 1.04 (0.72–1.50; olmesartan plus CCB vs. olmesartan plus diuretic, P=0.85) and 0.71 (0.51–0.99, P=0.045) for the primary composite end point, and 1.07 (0.67–1.72, P=0.77) and 0.64 (0.42–0.98, P=0.036) for the composite of hard end points. The hazard ratios for stroke (fatal and non-fatal) were 1.48 (0.88–2.48; olmesartan plus CCB vs. olmesartan plus diuretic, P=0.13) and 0.63 (0.39–1.02, P=0.059) (interaction-P=0.019). Withdrawal rates from the trial, withdrawal due to serious adverse event and the incidence of any adverse event were higher in the olmesartan plus diuretic group than in the olmesartan plus CCB group in both age groups. In conclusion, angiotensin receptor blocker (ARB) and CCB combination may be preferable to an ARB and diuretic combination in the very elderly hypertensive patients for the reduction of cardiovascular risk, particularly for the reduction in stroke risk.

Comparison of olmesartan combined with a calcium channel blocker or a diuretic in elderly hypertensive patients (COLM Study): safety and tolerability

The cardiovascular effects of combined therapy with the angiotensin receptor blocker (olmesartan) and a dihydropyridine calcium channel blocker (CCB) or a diuretic were compared in high-risk elderly Japanese hypertensive patients by performing a randomized, open label, blinded-endpoint study of morbidity and mortality (the COLM study). Here we report the results obtained with respect to safety and tolerability. High-risk hypertensive patients aged 65–84 years were enrolled and were randomized to receive olmesartan combined with either a CCB (amlodipine or azelnidipine) or a low-dose diuretic for at least 3 years. The primary endpoint was a composite of fatal and non fatal cardiovascular events, whereas adverse events (AEs) and the percentage of patients who discontinued the allocated treatment were evaluated as secondary endpoints. A total of 5141 patients were randomized. Both combination regimens achieved a similar reduction of cardiovascular morbidity and mortality. The incidences of AEs, serious AEs, drug-related serious AEs and discontinuation due to serious AEs were lower in the olmesartan plus CCB group than in the olmesartan plus diuretic group. Serum levels of uric acid and creatinine were significantly higher in the olmesartan plus diuretic group than in the olmesartan plus CCB group. Olmesartan combined with a CCB was significantly superior to olmesartan plus a diuretic with regard to the frequency of AEs and discontinuation of treatment.

Blood pressure control with a single-pill combination of indapamide sustained-release and amlodipine in patients with hypertension: the EFFICIENT study

OBJECTIVE

Despite antihypertensive treatment, most hypertensive patients still have high blood pressure (BP), notably high systolic blood pressure (SBP). The EFFICIENT study examines the efficacy and acceptability of a single-pill combination of sustained-release (SR) indapamide, a thiazide-like diuretic, and amlodipine, a calcium channel blocker (CCB), in the management of hypertension.

METHODS

Patients who were previously uncontrolled on CCB monotherapy (BP≥140/90 mm Hg) or were previously untreated with grade 2 or 3 essential hypertension (BP≥160/100 mm Hg) received a single-pill combination tablet containing indapamide SR 1.5 mg and amlodipine 5 mg daily for 45 days, in this multicenter prospective phase 4 study. The primary outcome was mean change in BP from baseline; percentage of patients achieving BP control (BP<140/90 mm Hg) was a secondary endpoint. SBP reduction (ΔSBP) versus diastolic BP reduction (ΔDBP) was evaluated (ΔSBP/ΔDBP) from baseline to day 45. Safety and tolerability were also assessed.

RESULTS

Mean baseline BP of 196 patients (mean age 52.3 years) was 160.2/97.9 mm Hg. After 45 days, mean SBP decreased by 28.5 mm Hg (95% CI, 26.4 to 30.6), while diastolic BP decreased by 15.6 mm Hg (95% CI, 14.5 to 16.7). BP control (<140/90 mm Hg) was achieved in 85% patients. ΔSBP/ΔDBP was 1.82 in the overall population. Few patients (n = 3 [2%]) reported side effects, and most (n = 194 [99%]) adhered to treatment.

CONCLUSION

In patients who were previously uncontrolled on CCB monotherapy or untreated with grade 2 or 3 hypertension, single-pill combination indapamide SR/amlodipine reduced BP effectively--especially SBP--over 45 days, and was safe and well tolerated.

TRIAL REGISTRATION

Clinical Trial Registry-India CTRI/2010/091/000114.

Review of blood pressure control rates and outcomes

Despite the high prevalence of hypertension and documented benefits of blood pressure (BP) control, >40% of patients with hypertension are not controlled. A majority of uncontrolled hypertensive patients receive two or more antihypertensive drugs. The current review examined the relationship between antihypertensive combination drug therapy, achievement of goal BP, and cardiovascular (CV) outcomes. Articles were selected from a PubMed search using a prespecified search strategy. Randomized, controlled clinical trials of adult human subjects published in English between January 1991 and January 2013 were included. From 2319 identified articles, 28 met inclusion criteria and contained a total of 226,877 subjects. There were seven placebo-controlled studies and 21 treatment comparator and combination therapy studies. The studies included in this review reported a positive association between the degree of BP lowering, number of medications, and CV outcomes. As combination therapy became available, it was increasingly utilized in clinical trials and enabled an increased proportion of patients to achieve a prespecified BP target. Adverse events with monotherapy and combination therapy were as anticipated for the specific classes of antihypertensive therapy. Although many patients reach BP goal, combination antihypertensive therapy is often needed to reach BP goal. Effective BP lowering has been shown to result in improvements in CV outcomes.

Effects of antihypertensive treatment in Asian populations: a meta-analysis of prospective randomized controlled studies (CARdiovascular protectioN group in Asia: CARNA)

To examine the effects of antihypertensive treatment on cardiovascular disease (CVD) in Asian populations, we systematically evaluated prospective randomized studies carried out in Asia (1991-2013). We identified 18 trials with 23,215 and 21,986 hypertensive patients in the intervention (ie, strict blood pressure [BP] lowering or add-on treatment) and reference groups, respectively (mean age, 65 years; follow-up duration, 3.2 years). Analysis was performed through 1) first subgroup: eight trials that compared active antihypertensive treatment with placebo or intensive with less intensive BP control and 2) second subgroup: 10 trials that compared different antihypertensive treatments. In the first subgroup analysis, BP was reduced from 160.3/87.3 mm Hg to 140.2/78.4 mm Hg in the intervention group with a -6.7/-2.2 mm Hg (P < .001) greater BP reduction than the reference group. Compared with the reference group, the intervention group had a lower risk of composite CVD events (odd ratio [OR], 0.73; 95% confidence interval [CI], 0.66-0.81), myocardial infarction (OR, 0.79; 95% CI, 0.63-1.0), stroke (OR, 0.71; 95% CI, 0.63-0.80), and CVD mortality (OR, 0.81; 95% CI, 0.68-0.97; all P ≤ .05). In the second subgroup analysis, no difference was found for any outcome between renin-angiotensin blockers and calcium-channel blockers or diuretics. The meta-regression line among the 18 trials indicated that a 10 mm Hg reduction in systolic BP was associated with a reduced risk for composite CVD events (-39.5%) and stroke (-30.0%). Our meta-analysis shows a benefit when a BP target of less than 140/80 mm Hg is achieved in Asian hypertensives. BP reduction itself, regardless of BP lowering agents, is important for achieving CVD risk reduction.

Effects of a benidipine-based combination therapy on the risk of stroke according to stroke subtype: the COPE trial

The Combination Therapy of Hypertension to Prevent Cardiovascular Events (COPE) trial compared the dihydropyridine T/L-type calcium channel blocker benidipine-based therapies when combined with an angiotensin receptor blocker (ARB), a β-blocker (BB) or a thiazide diuretic (TD). The results suggested that benidipine combined with a BB appeared to be less beneficial in reducing the risk of stroke compared with the benidipine-TD combination (hazard ratio (HR): 2.31, P=0.0109). We further evaluated the treatment effects on different stroke subtypes among the three benidipine-based regimens. The COPE trial was an investigator-initiated, multicenter study with PROBE design. Patients with atrial fibrillation or flutter were excluded from the study. All stroke events were subclassified with the Trial of Org 10,172 in Acute Stroke Treatment (TOAST) criteria. The total incidence of stroke was 4.7, hemorrhagic stroke was 1.6 and ischemic stroke was 2.5 per 1000 person-years. The incidence of lacunar stroke was 1.1, large-artery stroke was 0.6, cardioembolic stroke was 0.3, unknown ischemic type was 0.6 and transient ischemic attack was 0.6 per 1000 person-years. Although few differences in stroke subtypes were observed among the three treatment groups, multi-adjusted HRs for the incidence rates of all types of stroke, hemorrhagic stroke and ischemic stroke were significantly higher with the benidipine-BB regimen than with the benidipine-TD regimen. The incidence of both hemorrhagic and ischemic stroke in the benidipine-ARB regimen was not different compared with the other two treatment regimens. This prespecified sub-analysis suggested that a blood pressure-lowering therapy with a benidipine-TD regimen might be beneficial for hypertensive patients to prevent both hemorrhagic and ischemic stroke.

Combination therapy for hypertension in patients with CKD: a subanalysis of the Combination Therapy of Hypertension to Prevent Cardiovascular Events trial

The Combination Therapy of Hypertension to Prevent Cardiovascular Events (COPE) trial was a multicenter, randomized, three-arm comparative study (N=3293) undertaken to determine the optimal combination therapy, based on the occurrence of cardiovascular events in patients treated with an angiotensin II receptor blocker (ARB), a β-blocker (BB) or a thiazide diuretic (TD) in addition to the calcium antagonist benidipine as baseline medication. This subanalysis was conducted to compare the efficacy of three combination therapies in a subset of 834 patients with chronic kidney disease (CKD) (287 patients treated with benidpine-ARB, 283 patients treated with benidipine-BB and 264 patients treated with benidipine-TD). The incidence of composite cardiovascular events as the primary end point did not differ among these three groups. The incidence of hard end points and cerebrovascular events among these groups did not differ either, although the incidence among all patients in the COPE trial was lower in the benidipine-TD group than in the benidipine-BB group. The incidence of new-onset diabetes mellitus was higher in the benidipine-TD group than in the benidipine-ARB group among patients with CKD. The estimated glomerular filtration rate (eGFR) was maintained even after 12 months of treatment in patients with a baseline eGFR <60 ml min(-1) per 1.73 m(2) regardless of the treatment group, although the eGFR decreased over time in all patients in the three groups. In conclusion, in patients with CKD, all of the tested combination therapies demonstrated comparable efficacy in terms of prevention of cardiovascular events as well as maintenance of eGFR.

Efficacy and effects on lipid metabolism of combination treatment with losartan + hydrochlorothiazide versus losartan + amlodipine: a 48-week prospective, multicenter, randomized, open-label trial

BACKGROUND

Both combination therapies of an angiotensin II receptor blocker (ARB) with the thiazide diuretic hydrochlorothiazide (HCTZ) and an ARB with a calcium channel blocker (CCB) are recommended to achieve blood pressure (BP) goals in antihypertensive treatment. However, although HCTZ is known to have unfavorable effects on lipid metabolism, the effects of HCTZ in the ARB + HCTZ combination on lipid metabolism have not been fully elucidated.

OBJECTIVE

The aim of this study was to compare the effects on lipid metabolism of combination treatment with the ARB losartan + HCTZ and losartan + the CCB amlodipine and to assess the efficacy in BP lowering of these 2 combination therapies. The metabolism of glucose, uric acid (UA), and high-sensitivity C-reactive protein (hs-CRP), an inflammation marker of atherosclerosis, were also assessed in association with lipid metabolism.

METHODS

This 48-week, prospective, randomized, open-label trial was conducted at 2 clinics and 2 hospitals in Tokorozawa City (Saitama, Japan) and Shinjuku-ku Ward (Tokyo, Japan). Eligible patients had a systolic BP (SBP) >140 mm Hg and/or diastolic BP (DBP) >90 mm Hg despite a >1-month history of monotherapy with an ARB. Patients were randomly assigned to receive losartan 50 mg/d + HCTZ 12.5 mg/d (LOS + HCTZ) or losartan 50 mg/d + amlodipine 5 mg/d (LOS + CCB) for 48 weeks. Follow-up visits were scheduled at 4, 8, 12, 24, and 48 weeks. Biochemical measurements were centrally measured at a single institute. Tolerability and treatment compliance were assessed by physicians every 4 weeks.

RESULTS

A total of 112 patients were enrolled; 26 were excluded from the final analysis, leaving 42 and 44 patients in the LOS + HCTZ and LOS + CCB groups, respectively, included in the final analysis. At 48 weeks, SBP and DBP were significantly decreased in the 2 treatment groups (both, P < 0.0001). The decrease in SBP was significantly greater in the LOS + HCTZ group than in the LOS + CCB group (P < 0.001). The difference in the decrease in DBP between the 2 groups was nonsignificant. There were no significant differences in the changes from baseline (Δ) in any of the lipid parameters between the 2 groups. The decreases at 8 and 12 weeks in LDL-C, TC, and apolipoprotein (apo) B were significantly greater in the LOS + CCB group compared with those in the LOS + HCTZ group. The between-group differences in ΔTG, ΔHDL-C, ΔapoA-1, and ΔapoE throughout the study were nonsignificant. Changes in fasting plasma glucose (FPG), hemoglobin A1c, and hs-CRP were not significantly different between the 2 groups. The between-group difference in ΔUA in men was not significant, but a significant difference was found in women (LOS + HCTZ, 0.74 mg/dL; LOS + CCB, 0.28 mg/dL [P = 0.0017]). No clinically significant adverse events were reported with either treatment throughout the study.

CONCLUSIONS

The findings from the present study suggest that LOS + HCTZ was more efficacious in decreasing SBP than was LOS + CCB in the management of hypertension refractory to ARB monotherapy. Unfavorable effects on lipid metabolism were not observed with either combination therapy.

Eplerenone, an aldosterone blocker, is more effective in reducing blood pressure in patients with, than without, metabolic syndrome

BACKGROUND

Recently, the role of aldosterone in metabolic syndrome (MS) has aroused interest and several reports have suggested that aldosterone blockade could be beneficial in reducing blood pressure (BP).

METHODS

To examine the add-on effects of eplerenone (EP) on BP in patients with MS, 54 hypertensive patients with MS and 44 without MS were recruited. Systolic and diastolic BPs in mmHg before the initiation of EP was 144/84 ± 13/12 (MS group) and 147/85 ± 12/14 (non-MS group). Before the start of EP, all patients in both groups were treated with at least one antihypertensive drug. BPs were checked on every visit (at least every 2 months) and serum chemistries were measured every 4 months. The levels of microalbuminuria and aminoterminal pro-brain natriuretic peptide (NT pro-BNP) were determined before the start of and at the end of the study. Patients were followed for 1 year. If adverse effects were reported by patients or found in laboratory studies, EP was withdrawn.

RESULTS

One month after the start of EP, BPs were decreased to 140/80 ± 12/12 mmHg (MS group) versus 142/82 ± 11/12 mmHg (non-MS group) and there was no difference between the two groups. Towards the end of the study, BPs of both groups gradually decreased. At the end of the study, BPs of both groups were 129/76 ± 15/13 mmHg (MS group) versus 133/78 ± 13/11 mmHg (non-MS group). There was a significant difference in reduction of systolic BP between the two groups (p < 0.05). Add-on EP significantly decreased the levels of urinary excretion of albumin in MS patients but not in non-MS patients (p < 0.05). There was a significant correlation between reduction of systolic BP and NT pro-BNP but not microalbuminuria in the MS group (p < 0.05). There were no serious adverse effects in both groups.

CONCLUSION

EP may have some beneficial effects in lowering BP in patients with reduction of microalbuminuria.

Antihypertensive effect of a fixed-dose combination of losartan/hydrochlorothiazide in patients with uncontrolled hypertension: a multicenter study

BACKGROUND

Achieving adequate blood pressure (BP) control often requires more than one antihypertensive agent. The purpose of this study was to determine whether a fixed-dose formulation of losartan (LOS) plus hydrochlorothiazide (HCTZ) (LOS/HCTZ) is effective in achieving a greater BP lowering in patients with uncontrolled hypertension.

METHODS

The study was a prospective, multicenter, observational trial exploring the antihypertensive effect of a single tablet of LOS 50 mg/HCTZ 12.5 mg. A total of 228 patients whose BP had previously been treated with more than one antihypertensive agents without having achieved BP goal below 130/80 mmHg enrolled in the study.

RESULTS

A significant decrease in systolic and diastolic BP was observed in both clinic and home measurement after switching from the previous treatment to LOS/HCTZ. There was a significant decrease in both B-type natriuretic peptide (BNP) and urinary albumin creatinine (Cr) excretion ratio (ACR), especially in patients with elevated values. In contrast, there was a significant increase in serum Cr concentration in conjunction with a decrease in estimated glomerular filtration rate (eGFR). Overall serum uric acid (UA) concentration increased, whereas in patients with hyperuricemia there was a significant reduction in this value.

CONCLUSION

Switching to LOS/HCTZ provides a greater reduction in clinic and home BP in patients with uncontrolled hypertension. This combination therapy may lead to cardio-, reno protection and improve UA metabolism.

Suppression of aldosterone synthesis and secretion by ca(2+) channel antagonists

Aldosterone, a specific mineralocorticoid receptor (MR) agonist and a key player in the development of hypertension, is synthesized as a final product of renin-angiotensin-aldosterone system. Hypertension can be generally treated by negating the effects of angiotensin II through the use of angiotensin-converting enzyme inhibitors (ACE-Is) or angiotensin II type 1 receptor antagonists (ARBs). However, the efficacy of angiotensin II blockade by such drugs is sometimes diminished by the so-called "aldosterone breakthrough" effect, by which ACE-Is or ARBs (renin-angiotensin system (RAS) inhibitors) gradually lose their effectiveness against hypertension due to the overproduction of aldosterone, known as primary aldosteronism. Although MR antagonists are used to antagonize the effects of aldosterone, these drugs may, however, give rise to life-threatening adverse actions, such as hyperkalemia, particularly when used in conjunction with RAS inhibitors. Recently, several groups have reported that some dihydropyridine Ca(2+) channel blockers (CCBs) have inhibitory actions on aldosterone production in in vitro and in the clinical setting. Therefore, the use of such dihydropyridine CCBs to treat aldosterone-related hypertension may prove beneficial to circumvent such therapeutic problems. In this paper, we discuss the mechanism of action of CCBs on aldosterone production and clinical perspectives for CCB use to inhibit MR activity in hypertensive patients.