The Effect of Enalapril and Telmisartan on Clinical and Biochemical Indices of Sympathetic Activity in Hypertensive Patients

Effect of Physical Exercise on Cardiac Autonomic Modulation in Hypertensive Individuals: A Systematic Review and Meta-analysis

BACKGROUND

Cardiac autonomic dysfunction is associated with hypertension and exercise training (ET) in healthy individuals is found to improve cardiac autonomic modulation (CAM). However, the effects of physical exercise on CAM in hypertensive individuals are under debate.

OBJECTIVE

The aim of the review is to systematically evaluate the literature on the effects of physical exercise on CAM in hypertensive individuals and analyse comparative differences in the effects of exercise between hypertensive and normotensive individuals.

METHODS

Electronic databases, such as Pubmed, PEDro, Scopus, and Web of Science, were systematically searched from inception up to February, 2022, evaluating the effect of ET on CAM either by heart rate variability (HRV), baroreflex sensitivity or heart rate recovery. Fifteen studies were included in the review. The risk of bias was assessed using the Cochrane risk of bias tool version 2 and the risk of bias in studies of intervention (ROBINS-I) tool. The overall quality of evidence was assessed using the grading of recommendations, assessment, development, and evaluation approach. Ten studies were included in the quantitative analysis. The meta-analysis and sensitivity analysis were performed using review manager 5.4.1; publication bias was assessed using Jamovi 2.2.5 software.

RESULTS

The qualitative analysis revealed low to moderate certainty of evidence for ET and moderate for aerobic training. For the effect of overall ET, the analysis revealed that the standardized mean differences (SMD) showed a significant effect of ET on HF (SMD 1.76, p = 0.04) and RMSSD (SMD 1.19, p < 0.0001) and a significant decrease in LF (SMD -1.78, p = 0.04). Aerobic training revealed nonsignificant improvement in HRV parameters. In the comparative analysis, ET did not show a significant difference in improvement between hypertensive and normotensive individuals.

CONCLUSION

This review suggests an improvement in CAM with physical exercise in hypertensive individuals, but the overall effect of ET in hypertensive individuals must be interpreted with caution as the robustness of the data is compromised in the sensitivity analysis of the trials. High-quality future trials focusing on different modes of ET interventions are needed to strengthen the findings of the present review.

DPP (Dipeptidyl Peptidase)-4 Inhibition Potentiates the Vasoconstrictor Response to NPY (Neuropeptide Y) in Humans During Renin-Angiotensin-Aldosterone System Inhibition

DPP (dipeptidyl peptidase)-4 inhibitors are antidiabetic drugs that may increase heart failure in high-risk patients. NPY (neuropeptide Y) is coreleased with norepinephrine, causes vasoconstriction via the Y1 receptor, and is degraded by DPP4 to NPY (3-36) in vitro. NPY (3-36) decreases release of norepinephrine via the Y2 receptor. We tested the hypothesis that DPP4 inhibition would potentiate the vasoconstrictor effect of NPY. Eighteen nonsmokers (12 healthy controls and 6 with type 2 diabetes mellitus) participated in 1 of 2 randomized, double-blind, placebo-controlled crossover studies. First, subjects were randomized to order of treatment with sitagliptin 100 mg/d versus placebo for 7 days separated by 4-week washout. On the last day of treatment, NPY was infused by brachial artery and forearm blood flow was measured using plethysmography. Blood samples were collected after each dose. NPY infusions were repeated after 90-minute washout and intra-arterial enalaprilat. Second, 5 healthy subjects were randomized to crossover treatment with sitagliptin 100 mg/d plus valsartan 160 mg/d versus placebo plus valsartan. NPY infusions were performed on the seventh day of treatment. NPY caused dose-dependent vasoconstriction. During enalaprilat, sitagliptin significantly potentiated NPY-induced vasoconstriction in controls and diabetics ( P≤0.02 for forearm blood flow in either group). Baseline norepinephrine release was increased during sitagliptin and enalaprilat, but not further by NPY. Sitagliptin increased the ratio of NPY to NPY (3-36). During valsartan, sitagliptin also significantly potentiated NPY-induced vasoconstriction ( P=0.009 for forearm blood flow). Potentiation of endogenous NPY could contribute to cardiovascular effects of DPP4 inhibitors in patients taking an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker.

Sympathomodulatory Effects of Antihypertensive Drug Treatment

BACKGROUND

An activation of sympathetic neural influences to the heart and peripheral circulation has been shown to represent a hallmark of the essential hypertensive state, adrenergic neural factors participating together with other variables at the development and progression of the high blood pressure state as well as of the hypertension-related target organ damage. This represents the rationale for employing in hypertension treatment drugs which combine the blood pressure-lowering properties with the modulatory effects on the sympathetic neural function.

METHODS AND RESULTS

Several studies published during the past 40 years have investigated the impact of antihypertensive drugs on the sympathetic target as assessed by indirect and direct approaches. In the present paper, the effects of different monotherapies or combination drug treatment used in hypertension to lower elevated blood pressure values on various adrenergic markers will be examined. This will be followed by a discussion of the (i) hemodynamic and nonhemodynamic consequences of employing antihypertensive drugs with sympathomodulatory or sympathoexcitatory properties and (ii) mechanisms potentially responsible for the adrenergic responses to a given antihypertensive drug. The final part of this review will address the questions still open related to the impact of antihypertensive drug treatment on sympathetic function. Two questions in particular will be examined, i.e., whether antihypertensive drugs with sympathomodulatory properties may be capable to fully restore a "normal" adrenergic drive and how far sympathetic activity should be reduced in hypertensive patients.

CONCLUSION

Future investigations aimed at answering these questions will be needed in order to improve cardiovascular protection in treated hypertensive patients.

Renin-angiotensin system inhibitors prevent the recurrence of atrial fibrillation: a meta-analysis of randomized controlled trials

OBJECTIVE

This study was designed to assess whether angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) could prevent the recurrence of atrial fibrillation (AF).

METHODS

A systemic literature search of PubMed, EMBASE, and Cochrane Controlled Trials Register till 2012 was performed to identify randomized controlled trials involving the prevention of recurrence of AF with renin-angiotensin system blockade therapy. Subgroup analysis and meta-regression were performed. Publication bias was checked through funnel plot and Egger's test.

RESULTS

Twenty-one randomized controlled trials including 13,184 patients with AF were identified. Overall, the recurrence of AF was significantly reduced in patients using ACEI/ARBs [odds ratio (OR), 0.43; 95% confidence interval (CI), 0.32-0.56; P < 0.00001], especially both in irbesartan subgroup (OR, 0.38; 95% CI, 0.21-0.68; P = 0.001) and in patients receiving antiarrhythmic drug (AAD) (OR, 0.37; 95% CI, 0.29-0.48; P < 0.00001), and there was no significant difference between ACEIs and ARBs (ACEIs: OR, 0.42; 95% CI, 0.31-0.57 and ARBs: OR, 0.42; 95% CI, 0.31-0.57). Moreover, it was found that the benefits of ACEI/ARBs revealed positive correlation to systolic blood pressure (regression coefficient: -0.0700257, P = 0.000) in no-AAD users.

CONCLUSIONS

ACEI/ARBs are effective on the secondary prevention of AF, especially in patients receiving AAD and suffering from hypertension.

Autonomic dysfunction in essential hypertension: A systematic review

Introduction

Greater sympathetic drive has been established in the early stages of essential hypertension, suggesting that neurohormonal dysregulation may be key to its aetiology and progression. The aims of this review are to discuss evidence of the role of autonomic dysfunction in essential hypertension and proposed mechanisms, and also some applications of this knowledge to current management strategies of essential hypertension.

Methods

A computer search was performed using the PUBMED database for peer reviewed original articles comparing autonomic function tested via heart rate variability (HRV), muscle sympathetic nerve activity (MSNA) or plasma noradrenaline levels in normotensive (mean blood pressure (BP) of ≤140/90 mmHg or ≤135/85 mmHg if measured via home BP measurements) and hypertensive groups (mean resting BP of ≥140/90 mmHg (or ≥135/85 mmHg if measured via home BP measurements). Subjects were excluded with secondary causes of hypertension or autonomic dysfunction.

Results

A total of 17 studies were included for discussion. The main findings of this study include that of reduced baroreflex sensitivity, believed to be secondary to increased arterial stiffness, is hypothesised to be implicated in the pathogenesis of essential hypertension. Also, angiotensin converting enzyme inhibitors were not as effective on markers of autonomic control of blood pressure when compared with alternative anti-hypertensive drugs.

Conclusions

Consistent research is needed to establish the effectiveness of pharmacotherapies at each of stage of hypertension, and on markers of autonomic dysfunction. Consistent study designs will enable more accurate accumulation of data across multiple studies, and appropriate application of such data into clinical practice.

Migraine treated using a prophylactic combination of candesartan and hydrochlorothiazide (ECARD Combination Tablets LD)

We describe the use of the antihypertensive, candesartan, with hydrochlorothiazide (ECARD Combination Tablets LD) as a preventive therapy that decreased the frequency of migraine accompanied by premonitory leg edema. Two women (aged 26 and 50 years) presented to hospital with an increasing frequency of migraine without aura accompanied by leg edema. We prescribed ECARD half tablet (candesartan, 2 mg and hydrochlorothiazide, 3.125 mg), and the migraines and leg edema disappeared. The use of ECARD to treat a series of migraines by controlling premonitory leg edema has not been reported. ECARD, combined with a low-dose diuretic, may have been helpful in these patients with the premonitory migraine symptom of leg edema.

Telmisartan versus angiotension-converting enzyme inhibitors in the treatment of hypertension: a meta-analysis of randomized controlled trials

Telmisartan and angiotensin-converting enzyme inhibitors (ACEIs) are both effective and widely used antihypertensive drugs targeting renin-angiotensin-aldosterone system. The study aimed to estimate the efficacy and tolerability of telmisartan in comparison with different ACEIs as monotherapy in the treatment of hypertension. Cochrane Central Register of Controlled Trials, PubMed and Embase were searched for relevant studies. A meta-analysis of all randomized controlled trials fulfilling the predefined criteria was performed. A random-effect model was used to account for heterogeneity among trials. Twenty-eight randomized controlled trials involving 5157 patients were ultimately identified out of 721 studies. Telmisartan had a greater diastolic blood pressure (DBP) reduction than enalapril (weighted mean difference (WMD) 1.82, 95% confidence interval (CI) 0.66-2.99), ramipril (WMD 3.09, 95% CI 1.94-4.25) and perindopril (WMD 1.48, 95% CI 0.33-2.62). Telmisartan also showed a greater DBP response rate than enalapril (relative risk (RR) 1.15, 95% CI 1.05-1.26), ramipril (RR 1.34, 95% CI 1.11-1.61) and perindopril (RR 1.22, 95% CI 1.05-1.41). There was no statistical difference in DBP reduction or therapeutic response rate between telmisartan and lisinopril (WMD -0.30, 95% CI -0.65 to 0.05; RR 0.99, 95% CI 0.80-1.23, respectively). Telmisartan had fewer drug-related adverse events than enalapril (RR 0.57, 95% CI 0.44-0.74), ramipril (RR 0.44, 95% CI 0.26-0.75), lisinopril (RR 0.70, 95% CI 0.56-0.89) and perindopril (RR 0.52, 95% CI 0.28-0.98). The meta-analysis indicates that telmisartan provides a superior BP control to ACEIs (enalapril, ramipril and perindopril) and has fewer drug-related adverse events and better tolerability in hypertensive patients.