Improving vascular function in hypertension: potential benefits of combination therapy with amlodipine and renin-angiotensin-aldosterone system blockers

Synergism of amlodipine and candesartan on blood pressure reduction and organ protection in hypertensive rats

This study was designed to investigate the possible synergism of amlodipine and candesartan on the reduction of blood pressure (BP) in hypertensive rats. The end organ protection was also observed. In acute experiment, spontaneously hypertensive rats (SHRs) were treated with intragastric administration of amlodipine (0.5, 1, 2, 3 mg/kg), candesartan (1, 2, 3, 4, 6, 8 mg/kg), and 14 different combinations to find the possible ratio of synergistic interaction. In two kidneys, one clip (2K1C) rats, the effects of amlodipine (1 mg/kg), canderastan (2 mg/kg) and their combination on BP reduction were also observed. In chronic study, SHRs were treated with amlodipine (1 mg/kg), candesartan (2 mg/kg), and their combination for 5 months. Organ damage evaluation was performed after BP recording. The probability sum test (q test) was used to evaluate the synergistic action. There is a synergistic interaction between amlodipine and candesartan on BP reduction. The optimal dose ratio is 1:2. The synergistic effect was also confirmed by 2K1C hypertensive rats. In chronic study, this combination (1:2) possessed an obvious synergism on the reduction of BP and BP variability (BPV) and protection on end organs. Multiple regression analysis showed that heart and aortic hypertrophy indexes and glomerular damage parameters were positively related to BP and BPV. In conclusion, combination of amlodipine and candesartan exhibited a potent antihypertensive effect and possessed an obvious synergism on BP reduction and organ protection in hypertension. The optimal proportion was 1:2. BP and BPV reduction may both importantly contribute to end organ protection.

Comparison of benazepril plus amlodipine or hydrochlorothiazide in high-risk patients with hypertension and coronary artery disease

Combination therapy with benazepril 40 mg and amlodipine 10 mg (B+A) has been shown to be more effective than benazepril 40 mg and hydrochlorothiazide (HCTZ) 25 mg (B+H) in reducing cardiovascular (CV) events in high-risk patients with stage 2 hypertension with similar blood pressure reductions. In the present post hoc analysis, we evaluated whether B+A is more effective than B+H for reducing CV events in patients with known coronary artery disease (CAD) at baseline in a subgroup analysis of the Avoiding Cardiovascular events through COMbination therapy in Patients LIving with Systolic Hypertension (ACCOMPLISH) study. The main trial randomized 11,506 patients. Of those, 5,744 received B+A and 5,762 received B+H. Of the 11,506 patients, 5,314 (46%) were classified as having CAD at baseline. The mean patient follow-up period was 35.7 months for the B+A group and 35.6 months for the B+H group. The primary end point was the interval to the first event of composite CV morbidity and mortality. At baseline, significant differences were present between the 5,314 with CAD and the 6,192 without CAD. The patients with CAD had a lower systolic blood pressure and heart rate, a lower incidence of diabetes, and greater incidence of dyslipidemia. However, no baseline differences were found between the randomized B+A and B+H groups. In the patients with CAD, an 18% reduction occurred in the hazard ratio for CV events (primary end point) with B+A versus B+H (p = 0.0016). In a prespecified secondary analysis of the composite end point, including only CV death, myocardial infarction, and stroke, the hazard ratio in the patients with CAD was reduced by 25% (p = 0.0033) in the B+A group compared with the B+H group. B+A was more effective than B+H at comparable blood pressure reductions for reducing CV events in patients, regardless of the presence of CAD. In conclusion, our findings suggest that the combination of B+A should be preferentially used for older patients with high-risk, stage 2 hypertension.

Efficacy of the combination of amlodipine and candesartan in hypertensive patients with coronary artery disease: a subanalysis of the HIJ-CREATE study

BACKGROUND

The effects of the combination of angiotensin II receptor blocker (ARB) plus dihydropyridine calcium channel blockers (DHP-CCBs), which is known as a potent antihypertensive drug regimen, on cardiovascular events remain unclear.

OBJECTIVE

The purpose of this post hoc subgroup analysis was to compare the incidence of major adverse cardiovascular events (MACE) of patients treated with candesartan and amlodipine with that of those with candesartan and non-amlodipine CCBs in hypertensive patients with coronary artery disease (CAD).

METHODS

HIJ-CREATE was a multicenter, prospective, randomized, controlled study that compared the effects of candesartan-based with those of non-ARB-based standard therapy on MACE in 2049 hypertensive patients with CAD. In the candesartan group, a total of 335 patients were treated with DHP-CCBs (amlodipine: 170 and non-amlodipine-CCBs: 165) at the baseline. In this sub-analysis, we compared, among the participants allocated to candesartan regimen, the long-term effects of amlodipine and non-amlodipine CCBs that were concomitantly given with ARB, although the choice of CCB was not randomized.

RESULTS

The median follow-up was 3.9 years. Treatment using amlodipine with candesartan reduced the risk of MACE by 38% (hazard ratio, 0.62; 95% confidence interval, 0.41-0.94, p=0.025), as compared to patients treated with non-amlodipine-CCBs and candesartan. In a multivariate analysis, combination therapy of candesartan with amlodipine was an independent predictor of reduced risk of MACE.

CONCLUSIONS

The results suggest that the combination of amlodipine and candesartan is more beneficial in reducing MACE in hypertensive patients with CAD compared to non-amlodipine-DHP-CCBs in combination therapy with candesartan. Further investigation in larger-scale prospective randomized studies is required to reach any conclusion as to the superiority of combination therapy of candesartan with amlodipine.

Telmisartan exerts pleiotropic effects in endothelial cells and promotes endothelial cell quiescence and survival

OBJECTIVE

Telmisartan, an angiotensin II type 1 receptor blocker, and amlodipine, a calcium channel blocker, are antihypertensive agents clinically used as monotherapy or in combination. They exert beneficial cardiovascular effects independently of blood pressure lowering and classic mechanisms of action. In this study, we investigate molecular mechanisms responsible for the off-target effects of telmisartan and telmisartan-amlodipine in endothelial cells (ECs), using an unbiased genomic approach.

APPROACH AND RESULTS

In human umbilical vein ECs, microarray analysis of gene expression followed by pathway enrichment analysis and quantitative polymerase chain reaction validation revealed that telmisartan modulates the expression of key genes responsible for cell cycle progression and apoptosis. Amlodipine's effect was similar to control. ECs exposed to telmisartan, but not amlodipine, losartan, or valsartan, exhibited a dose-dependent impairment of cell growth and failed to enter the S-phase of the cell cycle. Similarly, telmisartan inhibited proliferation in COS-7 cells lacking the angiotensin II type 1 receptor. In telmisartan-treated ECs, phosphorylation and activation of Akt, as well as MDM2, were reduced, leading to accumulation of p53 in the nucleus, where it represses the transcription of cell cycle-promoting genes. Phosphorylation of glycogen synthase kinase-3β was also reduced, resulting in rapid proteolytic turnover of CyclinD1. Telmisartan induced downregulation of proapoptotic genes and protected ECs from serum starvation-induced and 7-ketocholesterol-induced apoptosis.

CONCLUSIONS

Telmisartan exerts antiproliferative and antiapoptotic effects in ECs. This may account for the improved endothelial dysfunction observed in the clinical setting.

Prolongation of PR interval is associated with endothelial dysfunction and activation of vascular repair in high-risk cardiovascular patients

PURPOSE

Epidemiological studies showed that PR prolongation is associated with increased risk of adverse cardiovascular outcomes. We investigated the relations of PR interval with indices of vascular function and endothelial repair as the underlying mechanisms.

METHODS

The study comprised 348 high-risk patients with prior coronary artery disease, ischemic stroke, and/or diabetes mellitus recruited from medical outpatient clinics and 150 healthy subjects without such a history. PR interval was considered prolonged if >200 ms, as determined from resting 12-lead electrocardiogram. Vascular function was assessed by brachial flow-meditated dilatation (FMD) using high-resolution ultrasound. Circulating CD133(+)/KDR(+) endothelial progenitor cell (EPC) levels were measured by flow cytometry.

RESULTS

Among healthy subjects, PR interval was inversely associated with FMD (R = -0.20, P = 0.015), but not with the level of circulating CD133(+)/KDR(+) EPC (R = 0.05, P = 0.58). Among high-risk cardiovascular patients, PR prolongation >200 ms was more common compared with healthy subjects (45/348 (13 %) versus 4/150 (3 %), P < 0.001). PR interval was associated inversely with FMD (R = -0.14, P = 0.01) and positively with circulating CD133(+)/KDR(+) EPC level (R = +0.14, P = 0.009). Circulating CD133(+)/KDR(+) EPC level was significantly increased in patients with PR prolongation >200 ms (0.87 ± 0.37 versus 0.68 ± 0.42 (log, ×10(-3)/ml), P = 0.005). Adjusted for potential confounders, increased PR interval remained independently associated with increased CD133(+)/KDR(+) EPC by +0.002 (95 % confidence interval (CI) 0.000 to 0.004 (log, ×10(-3)/ml), P = 0.011) and depressed FMD (B = -0.014 %, 95 % CI -0.027 to -0.002, P = 0.026).

CONCLUSIONS

PR prolongation is associated with endothelial dysfunction and evidence of endothelial repair activation in patients with high cardiovascular risk.

Abnormal vascular function in PR-interval prolongation

BACKGROUND

Underlying mechanisms of PR-interval prolongation leading to increased risk of adverse cardiovascular outcomes, including atrial fibrillation, are unclear. This study aims to investigate the relation between PR interval and changes in vascular function.

HYPOTHESIS

We hypothesize that there exists an intermediate pathological stage between electrocardiographic PR prolongation and adverse cardiovascular outcomes, which could be reflected by changes in surrogate measurements of vascular function.

METHODS

We recruited 88 healthy subjects (mean age 57.5 ± 9.8 y, 46% male) from a community-based health screening program who had no history of cardiovascular disease or diabetes mellitus. PR interval was determined from a resting 12-lead electrocardiogram. Vascular function was noninvasively assessed by flow-mediated dilation (FMD) using high-resolution ultrasound and brachial-ankle pulse wave velocity (PWV) using a vascular profiling system.

RESULTS

Only 3 subjects had a PR-interval length longer than the conventional cutoff of 200 ms. The PR-interval length was associated inversely with FMD (Pearson r = -0.30, P = 0.004) and positively with PWV (r = 0.40, P < 0.001). Adjusting for potential confounders, increased PR-interval length by each 25 ms was independently associated with reduced FMD by -1 unit (absolute %, B = -0.04 [95% confidence interval: -0.080 to -0.002, P = 0.040)] and increased PWV by +103 cm/second (B = +4.1 [95% confidence interval: 0.6-7.6, P = 0.023]).

CONCLUSIONS

This study shows that PR-interval length, even in the conventionally normal range, is independently associated with endothelial dysfunction and increased arterial stiffness in healthy subjects free of atherosclerotic disease. This suggests the presence of a systemic, intermediate pathologic stage of the vasculature in PR prolongation before clinically manifest cardiovascular events, and could represent a mediating mechanism.

The impact of antihypertensive drug therapy on endotoxemia in elderly patients with chronic kidney disease

BACKGROUND AND OBJECTIVES

Endotoxin (ET) is recognized to cause adverse effects on cardiovascular (CV) structure. Circulatory translocation of gut bacterial ET is described in heart failure. Chronic kidney disease (CKD) is common in older people and aggressive BP control is the cornerstone of management. We therefore studied ET after improvement of the overall CV milieu with introduction of optimized antihypertensive therapy (AHT).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We recruited 40 hypertensive nondiabetic patients (≥70 years) with CKD stages 3 and 4 and hypertensive non-CKD matched controls. Assessment was performed after complete AHT washout and repeated after AHT reintroduction to target BP 130/80 mmHg. Pulse wave velocity (PWV) and analysis were assessed by applanation tonometry, central hemodynamics by continuous digital pulse wave analysis, vascular calcification (VC) by superficial femoral artery CT, and serum ET by Limulus Amebocyte assay.

RESULTS

Mean age was 76 ± 5 years, estimated GFR (eGFR) (CKD group) was 40 ± 14 ml/min per 1.73 m(2), and achieved BP was 128/69 mmHg. Washout ET was 0.042 ± 0.011 EU/ml and was independent of renal function, gender, age, BP, VC, arterial stiffness, and high-sensitivity C-reactive protein. ET significantly decreased with AHT (to 0.020 ± 0.028 EU/ml; P < 0.001) and was associated with eGFR (R = -0.38; P = 0.02), arterial wave reflection (Augmentation Index R = -0.42; P = 0.01), and degree of tonic vasodilatation (total peripheral resistance R = -0.37; P = 0.03), but not VC, PWV, gender, age, BP, or high-sensitivity C-reactive protein.

CONCLUSIONS

Elderly patients with hypertension have elevated serum ET. Improvement of their CV status with optimized AHT is associated with a significant reduction in endotoxemia. Further investigation of the potential pathophysiological mechanisms linking CV disease and CKD with this previously unappreciated effect of AHT appears warranted.

Effects of Yinian Jiangya Decoction containing serum on cytokines secretion of vascular endothelium of spontaneously hypertensive rats

OBJECTIVE

To observe the effects of Yinian Jiangya Decoction (YNJYD) on cytokine secretion in spontaneoulsy hypertensive rats (SHRs) vascular endothelium.

METHODS

Aortic endothelial cells (ECs) were primarily cultured from SHRs; male SD rats were treated with different doses (high, medium, and low doses) of YNJYD, the blood was collected on the 21st day, and then, the serum was separated. ECs were cocultured with the serum for different time courses, and the culture supernatant concentrations of endothelin (ET)-1, nitric oxide (NO), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor (PAI-1) were determined by ABC-ELISA methods.

RESULTS

ET-1, NO, t-PA, and PAI-1 levels in endothelial cell culture supernatant were increased in a time-dependent manner; YNJYD could significantly elevate NO and t-PA expressions in ECs, while ET-1 and PAI-1 expressions were dramatically decreased; these effects of YNJYD were in a concentration-dependent manner.

CONCLUSION

The therapeutic effect of YNJYD on hypertension is attributed to its effect on regulating vessel dilation and blood coagulation, in which ET-1/NO and PAI-1/t-PA are two pairs of pivotal mediators.

Amlodipine/Atorvastatin: a review of its use in the treatment of hypertension and dyslipidaemia and the prevention of cardiovascular disease

Amlodipine/atorvastatin (Caduet) is a single-tablet, fixed-dose combination of the dihydropyridine calcium channel antagonist amlodipine and the HMG-CoA reductase inhibitor atorvastatin. The bioavailability of amlodipine and atorvastatin with a single-tablet, fixed-dose amlodipine/atorvastatin combination was not significantly different to that with coadministered separate amlodipine and atorvastatin tablets. In well controlled clinical trials in patients with hypertension and dyslipidaemia, once-daily amlodipine and atorvastatin (administered as the single-tablet, fixed-dose combination or coadministered as two separate tablets) effectively reduced systolic BP (SBP) and low-density lipoprotein cholesterol (LDL-C) levels, and enabled more patients to achieve BP and LDL-C goals than single-agent or placebo therapy. There was no modification of the effect of amlodipine on SBP when administered in combination with atorvastatin and there was no modification of the effect of atorvastatin on LDL-C when administered in combination with amlodipine. In noncomparative, titration-to-goal, open-label 'real-world' trials, the single-tablet, fixed-dose combination of amlodipine/atorvastatin enabled patients with hypertension and dyslipidaemia to achieve both BP and LDL-C goals. Administration of a single tablet of amlodipine/atorvastatin, compared with coadministration of these agents as two separate tablets, improved patient adherence, according to a retrospective study that utilized prescription refill rates from a large US insurance database. Data from the large, randomized, double-blind, placebo-controlled ASCOT-LLA trial also demonstrated that the combination of amlodipine-based therapy and atorvastatin was effective in preventing cardiovascular (CV) endpoints in hypertensive patients at risk of CV disease (CVD). In summary, amlodipine/atorvastatin offers a convenient and effective approach to improving adherence and managing CV risk in hypertensive patients with dyslipidaemia or at risk of CVD.