Calcium channel blockers versus other classes of drugs for hypertension

Update of the clinical guideline for hypertension diagnosis and treatment in Iran

BACKGROUND

This article introduces the updated version of the Iranian guideline for the diagnosis and treatment of hypertension in adults. The initial version of the national guideline was developed in 2011 and updated in 2014. Among the reasons necessitating the update of this guideline were the passage of time, the incompleteness of the scopes, the limitation of the target group, and more important is the request of the ministry of health in Iran.

METHOD

The members of the guideline updating group, after reviewing the original version and the new evidence, prepared 10 clinical questions regarding hypertension, and based on the evidence found from the latest scientific documents, provided recommendations or suggestions to answer these questions.

RESULT

According to the updated guideline, the threshold for office prehypertension diagnosis should be considered the systolic blood pressure (SBP) of 130-139 mmHg and/or the diastolic blood pressure (DBP) of 80-89 mmHg, and in adults under 75 years of age without comorbidities, the threshold for office hypertension diagnosis should be SBP ≥ 140 mmHg and or DBP ≥ 90 mmHg. The goal of treatment in adults who lack comorbidities and risk factors is SBP < 140 mmHg and DBP < 90 mmHg. The first-line treatment recommended in people with prehypertension is lifestyle modification, while for those with hypertension, pharmacotherapy along with lifestyle modification. The threshold to start drug therapy is determined at SBP ≥ 140 mmHg and or DBP ≥ 90 mmHg, and the first-line treatment is considered a drug or a combined pill of antihypertensive drugs, including ACEIs, ARBs, thiazide and thiazide-like agents, or CCBs. At the beginning of the pharmacotherapy, the Guideline Updating Group members suggested studying serum electrolytes, creatinine, lipid profile, fasting sugar, urinalysis, and an electrocardiogram. Regarding the visit intervals, monthly visits are suggested at the beginning of the treatment or in case of any change in the type or dosage of the drug until achieving the treatment goal, followed by every 3-to-6-month visits. Moreover, to reduce further complications, it was suggested that healthcare unit employees use telehealth strategies.

CONCLUSIONS

In this guideline, specific recommendations and suggestions have been presented for adults and subgroups like older people or those with cardiovascular disease, diabetes mellitus, chronic kidney disease, and COVID-19.

Calcium channel blockers and clinical outcomes in patients with continuous-flow left ventricular assist devices

AIMS

Current guidelines suggest calcium channel blockers (CCBs) as the second or third option for blood pressure management in patients with left ventricular assist device (LVAD). However, the clinical outcomes of patients with LVAD who receive CCBs remain unclear. Our study aims to analyse the association of CCBs with clinical outcomes in patients after LVAD implantation.

METHODS AND RESULTS

This is a retrospective analysis based on the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) from 2006 to 2017, and adult patients who were alive with LVAD and CCB treatment information at 6 months after implantation were included. Among 10 717 patients, 1369 received CCBs 6 months after implantation, and there was an increasing trend of CCB use after LVAD. Patients receiving CCB therapy at 6 months had a similar 5 year survival rate to those not receiving CCB [49.6%, 95% confidence interval (CI): 47.5-51.7% vs. 51.1%, 95% CI: 45.3-56.7%]. In both Cox and competing risk regressions after adjusting for confounding factors, CCB treatment at 6 months after implantation was not associated with long-term mortality [hazard ratio (HR): 1.03, 95% CI: 0.91-1.17, P = 0.624 and subdistribution HR (SHR): 1.07, 95% CI: 0.95-1.22, P = 0.260]. Consistently, in time-varying models, CCB treatment was not linked to long-term mortality (HR: 0.97, 95% CI: 0.87-1.09, P = 0.682 and SHR: 1.05, 95% CI: 0.94-1.18, P = 0.359). This null association remained in subgroup analysis according to device strategy and propensity-matching analyses. Neurological dysfunction, stroke, bleeding, rehospitalization, and renal dysfunction were more likely to occur among those with CCB when compared with those without CCB treatment.

CONCLUSIONS

In patients with LVAD, CCB therapy fails to show benefits in long-term survival and is associated with increased incidences of neurological dysfunction, bleeding, renal dysfunction, and rehospitalization.

Strategies to prevent, diagnose and treat kidney disease related to systemic arterial hypertension: a narrative review from the Mexican Group of Experts on Arterial Hypertension

This narrative review highlights strategies proposed by the Mexican Group of Experts on Arterial Hypertension endorsed to prevent, diagnose, and treat chronic kidney disease (CKD) related to systemic arterial hypertension (SAH). Given the growing prevalence of CKD in Mexico and Latin America caused by SAH, there is a need for context-specific approaches to address the effects of SAH, given the diverse population and unique challenges faced by the region. This narrative review provides clinical strategies for healthcare providers on preventing, diagnosing, and treating kidney disease related to SAH, focusing on primary prevention, early detection, evidence-based diagnostic approaches, and selecting pharmacological treatments. Key-strategies are focused on six fundamental areas: 1) Strategies to mitigate kidney disease in SAH, 2) early detection of CKD in SAH, 3) diagnosis and monitoring of SAH, 4) blood pressure targets in patients living with CKD, 5) hypertensive treatment in patients with CKD and 6) diuretics and Non-Steroidal Mineralocorticoid Receptor Inhibitors in Patients with CKD. This review aims to provide relevant strategies for the Mexican and Latin American clinical context, highlight the importance of a multidisciplinary approach to managing SAH, and the role of community-based programs in improving the quality of life for affected individuals. This position paper seeks to contribute to reducing the burden of SAH-related CKD and its complications in Mexico and Latin America.

First-line diuretics versus other classes of antihypertensive drugs for hypertension

BACKGROUND

Different first-line drug classes for patients with hypertension are often assumed to have similar effectiveness with respect to reducing mortality and morbidity outcomes, and lowering blood pressure. First-line low-dose thiazide diuretics have been previously shown to have the best mortality and morbidity evidence when compared with placebo or no treatment. Head-to-head comparisons of thiazides with other blood pressure-lowering drug classes would demonstrate whether there are important differences.

OBJECTIVES

To compare the effects of first-line diuretic drugs with other individual first-line classes of antihypertensive drugs on mortality, morbidity, and withdrawals due to adverse effects in patients with hypertension. Secondary objectives included assessments of the need for added drugs, drug switching, and blood pressure-lowering.

SEARCH METHODS

Cochrane Hypertension's Information Specialist searched the Cochrane Hypertension Specialized Register, CENTRAL, MEDLINE, Embase, and trials registers to March 2021. We also checked references and contacted study authors to identify additional studies. A top-up search of the Specialized Register was carried out in June 2022.

SELECTION CRITERIA

Randomized active comparator trials of at least one year's duration were included. Trials had a clearly defined intervention arm of a first-line diuretic (thiazide, thiazide-like, or loop diuretic) compared to another first-line drug class: beta-blockers, calcium channel blockers, alpha adrenergic blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers, direct renin inhibitors, or other antihypertensive drug classes. Studies had to include clearly defined mortality and morbidity outcomes (serious adverse events, total cardiovascular events, stroke, coronary heart disease (CHD), congestive heart failure, and withdrawals due to adverse effects).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

We included 20 trials with 26 comparator arms randomizing over 90,000 participants. The findings are relevant to first-line use of drug classes in older male and female hypertensive patients (aged 50 to 75) with multiple co-morbidities, including type 2 diabetes. First-line thiazide and thiazide-like diuretics were compared with beta-blockers (six trials), calcium channel blockers (eight trials), ACE inhibitors (five trials), and alpha-adrenergic blockers (three trials); other comparators included angiotensin II receptor blockers, aliskiren (a direct renin inhibitor), and clonidine (a centrally acting drug). Only three studies reported data for total serious adverse events: two studies compared diuretics with calcium channel blockers and one with a direct renin inhibitor. Compared to first-line beta-blockers, first-line thiazides probably result in little to no difference in total mortality (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.84 to 1.10; 5 trials, 18,241 participants; moderate-certainty), probably reduce total cardiovascular events (5.4% versus 4.8%; RR 0.88, 95% CI 0.78 to 1.00; 4 trials, 18,135 participants; absolute risk reduction (ARR) 0.6%, moderate-certainty), may result in little to no difference in stroke (RR 0.85, 95% CI 0.66 to 1.09; 4 trials, 18,135 participants; low-certainty), CHD (RR 0.91, 95% CI 0.78 to 1.07; 4 trials, 18,135 participants; low-certainty), or heart failure (RR 0.69, 95% CI 0.40 to 1.19; 1 trial, 6569 participants; low-certainty), and probably reduce withdrawals due to adverse effects (10.1% versus 7.9%; RR 0.78, 95% CI 0.71 to 0.85; 5 trials, 18,501 participants; ARR 2.2%; moderate-certainty). Compared to first-line calcium channel blockers, first-line thiazides probably result in little to no difference in total mortality (RR 1.02, 95% CI 0.96 to 1.08; 7 trials, 35,417 participants; moderate-certainty), may result in little to no difference in serious adverse events (RR 1.09, 95% CI 0.97 to 1.24; 2 trials, 7204 participants; low-certainty), probably reduce total cardiovascular events (14.3% versus 13.3%; RR 0.93, 95% CI 0.89 to 0.98; 6 trials, 35,217 participants; ARR 1.0%; moderate-certainty), probably result in little to no difference in stroke (RR 1.06, 95% CI 0.95 to 1.18; 6 trials, 35,217 participants; moderate-certainty) or CHD (RR 1.00, 95% CI 0.93 to 1.08; 6 trials, 35,217 participants; moderate-certainty), probably reduce heart failure (4.4% versus 3.2%; RR 0.74, 95% CI 0.66 to 0.82; 6 trials, 35,217 participants; ARR 1.2%; moderate-certainty), and may reduce withdrawals due to adverse effects (7.6% versus 6.2%; RR 0.81, 95% CI 0.75 to 0.88; 7 trials, 33,908 participants; ARR 1.4%; low-certainty). Compared to first-line ACE inhibitors, first-line thiazides probably result in little to no difference in total mortality (RR 1.00, 95% CI 0.95 to 1.07; 3 trials, 30,961 participants; moderate-certainty), may result in little to no difference in total cardiovascular events (RR 0.97, 95% CI 0.92 to 1.02; 3 trials, 30,900 participants; low-certainty), probably reduce stroke slightly (4.7% versus 4.1%; RR 0.89, 95% CI 0.80 to 0.99; 3 trials, 30,900 participants; ARR 0.6%; moderate-certainty), probably result in little to no difference in CHD (RR 1.03, 95% CI 0.96 to 1.12; 3 trials, 30,900 participants; moderate-certainty) or heart failure (RR 0.94, 95% CI 0.84 to 1.04; 2 trials, 30,392 participants; moderate-certainty), and probably reduce withdrawals due to adverse effects (3.9% versus 2.9%; RR 0.73, 95% CI 0.64 to 0.84; 3 trials, 25,254 participants; ARR 1.0%; moderate-certainty). Compared to first-line alpha-blockers, first-line thiazides probably result in little to no difference in total mortality (RR 0.98, 95% CI 0.88 to 1.09; 1 trial, 24,316 participants; moderate-certainty), probably reduce total cardiovascular events (12.1% versus 9.0%; RR 0.74, 95% CI 0.69 to 0.80; 2 trials, 24,396 participants; ARR 3.1%; moderate-certainty) and stroke (2.7% versus 2.3%; RR 0.86, 95% CI 0.73 to 1.01; 2 trials, 24,396 participants; ARR 0.4%; moderate-certainty), may result in little to no difference in CHD (RR 0.98, 95% CI 0.86 to 1.11; 2 trials, 24,396 participants; low-certainty), probably reduce heart failure (5.4% versus 2.8%; RR 0.51, 95% CI 0.45 to 0.58; 1 trial, 24,316 participants; ARR 2.6%; moderate-certainty), and may reduce withdrawals due to adverse effects (1.3% versus 0.9%; RR 0.70, 95% CI 0.54 to 0.89; 3 trials, 24,772 participants; ARR 0.4%; low-certainty). For the other drug classes, data were insufficient. No antihypertensive drug class demonstrated any clinically important advantages over first-line thiazides.

AUTHORS' CONCLUSIONS

When used as first-line agents for the treatment of hypertension, thiazides and thiazide-like drugs likely do not change total mortality and likely decrease some morbidity outcomes such as cardiovascular events and withdrawals due to adverse effects, when compared to beta-blockers, calcium channel blockers, ACE inhibitors, and alpha-blockers.

National Heart Center/Saudi Heart Association 2023 Guidelines on the Management of Hypertension

Background

Hypertension is a highly prevalent disease in Saudi Arabia with poor control rates. Updated guidelines are needed to guide the management of hypertension and improve treatment outcomes.

Methodology

A panel of experts representing the National Heart Center (NHC) and the Saudi Heart Association (SHA) reviewed existing evidence and formulated guidance relevant to the local population, clinical practice and the healthcare system. The recommendations were reviewed to ensure scientific and medical accuracy.

Recommendations

Hypertension was defined and a new classification was proposed as relevant to the Saudi population. Recommendations on diagnosis, clinical evaluation, cardiovascular assessment were detailed, along with guidance on measurement modalities and screening/follow-up. Non-pharmacological management is the first line of hypertension treatment. Pharmacological therapy should be used appropriately as needed. Treatment priority is to control blood pressure regardless of the drug class used. The choice of treatment should be tailored to the patient profile in order to achieve treatment targets and ensure patient compliance. Recommendations were provided on pharmacological options available in Saudi Arabia, as well as guidance on the treatment of special conditions.

Conclusion

Hypertension management should be based on appropriate screening, timely diagnosis and lifestyle changes supplemented with pharmacological therapy, as needed. Clinical management should be individualized, and careful consideration should be given to special conditions and patient groups.

Association of Direct-to-Consumer Advertising of Prescription Drugs With Consumer Health-Related Intentions and Beliefs Among Individuals at Risk of Cardiovascular Disease

Importance

Consumers in the US are exposed to unprecedented high levels of direct-to-consumer advertising (DTCA) for prescription drugs, yet there is limited evidence regarding their effect on health-related intentions and beliefs.

Objective

To provide evidence on the association of DTCA for prescription drugs with consumer health-related intentions and beliefs.

Design, Setting, and Participants

This cross-sectional study recruited participants from a nationally representative sample of individuals at high risk of cardiovascular disease. Participants were randomly assigned into 1 of 3 study arms: (1) exposure to DTCA for heart disease medications (treatment 1 [n = 926]), (2) exposure to DTCA for heart disease medications with price disclosure (treatment 2 [n = 921]), (3) and exposure to nonpharmaceutical advertising (control group [n = 902]). Each study arm viewed five 1-minute video advertisements, totaling 5 minutes of advertising exposure. The 2 treatment arms viewed pharmaceutical advertising videos for 4 heart disease medications, and the control arm viewed nonpharmaceutical advertising videos. Participants then completed a survey questionnaire to measure medication- and lifestyle-related intentions and health-related beliefs and perceptions.

Exposures

Direct-to-consumer advertising for heart disease medications (treatment 1), DTCA for heart disease medications with price disclosure (treatment 2), and nonpharmaceutical advertising (control group).

Main Outcomes and Measures

The primary outcomes included ordinal measures of medication- and lifestyle-related intentions, health-related beliefs, and brand perceptions.

Results

Among the 2874 included participants (mean [SD] age, 53.8 [7.1] years; 1549 [54%] male) χ2 tests confirmed that there were no statistically significant differences in baseline demographic characteristics across study arms. There was a positive association between DTCA and medication-related behavioral intentions, including intention to switch medication (marginal effect [ME] = 0.004; P = .002) and engage in information-seeking behaviors (ME = 0.02; P = .01). There was no evidence that pharmaceutical DTCA discouraged use of nonpharmacological lifestyle interventions that can help manage heart disease (eg, diet and exercise), and DTCA exposure also had a positive association with consumers' favorable perceptions of pharmaceutical manufacturers (competence: ME = 0.03; P = .01; innovative: ME = 0.03; P = .008). There was no evidence for differential associations of price disclosures in DTCA.

Conclusions and Relevance

In this cross-sectional study, results showed that brief exposure to pharmaceutical DTCA had a large and positive association with medication-related demand intentions with no offsetting negative spillovers on lifestyle-related intentions. Lack of associations with price disclosure in DTCA suggests that policy makers should consider alternative strategies to promote value-based decision-making for prescription drugs.

Why antidiabetic drugs are potentially neuroprotective during the Sars-CoV-2 pandemic: The focus on astroglial UPR and calcium-binding proteins

We are living in a terrifying pandemic caused by Sars-CoV-2, in which patients with diabetes mellitus have, from the beginning, been identified as having a high risk of hospitalization and mortality. This viral disease is not limited to the respiratory system, but also affects, among other organs, the central nervous system. Furthermore, we already know that individuals with diabetes mellitus exhibit signs of astrocyte dysfunction and are more likely to develop cognitive deficits and even dementia. It is now being realized that COVID-19 incurs long-term effects and that those infected can develop several neurological and psychiatric manifestations. As this virus seriously compromises cell metabolism by triggering several mechanisms leading to the unfolded protein response (UPR), which involves endoplasmic reticulum Ca²⁺ depletion, we review here the basis involved in this response that are intimately associated with the development of neurodegenerative diseases. The discussion aims to highlight two aspects—the role of calcium-binding proteins and the role of astrocytes, glial cells that integrate energy metabolism with neurotransmission and with neuroinflammation. Among the proteins discussed are calpain, calcineurin, and sorcin. These proteins are emphasized as markers of the UPR and are potential therapeutic targets. Finally, we discuss the role of drugs widely prescribed to patients with diabetes mellitus, such as statins, metformin, and calcium channel blockers. The review assesses potential neuroprotection mechanisms, focusing on the UPR and the restoration of reticular Ca²⁺ homeostasis, based on both clinical and experimental data.

1,1′-{[3,5-Bis(dodecyloxycarbonyl)-4-(naphthalen-2-yl)-1,4-dihydropyridine-2,6-diyl]bis(methylene)}bis{4-[(E)-2-(naphthalen-2-yl)vinyl]pyridin-1-ium}dibromide

Synthesis of a double-charged cationic amphiphilic 1,4-dihydropyridine derivative with dodecyl ester groups at positions 3 and 5 of the 1,4-DHP ring was performed starting from Hantzsch type cyclization of dodecyl acetoacetate, 2-naphthaldehyde and ammonium acetate. Bromination of this compound followed by nucleophilic substitution of bromine with (E)-4-(2-(naphthalen-2-yl)vinyl)pyridine gave the desired cationic amphiphilic 1,1′-{[3,5-bis(dodecyloxycarbonyl)-4-(naphthalen-2-yl)-1,4-dihydropyridine-2,6-diyl]bis(methylene)}bis{4-[(E)-2-(naphthalen-2-yl)vinyl]pyridin-1-ium}dibromide. The obtained target compound was fully characterized by IR, UV, 1H-NMR, 13C-NMR, HRMS and microanalysis. The characterization of the cationic 1,4-DHP nanoparticles in an aqueous solution was performed by DLS measurements. The obtained results showed that the compound formed nanoparticles with an average diameter of around 300 nm, a PDI value of around 490 and a zeta-potential of around 20 mV for freshly prepared samples. However, after one week of storage at room temperature, an aggregation of nanoparticles was detected.

Felodipine Determination by a CdTe Quantum Dot-Based Fluorescent Probe

In this work, a CdTe quantum dot-based fluorescent probe was synthesized to determine felodipine (FEL). The synthesis conditions, structure, and interaction conditions with FEL of CdTe quantum dots were analysed by fluorescence spectrophotometry, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV–visible spectroscopy, and TEM. The CdTe QD concentration was 2.0 × 10⁻⁴ mol/L. The amount of quantum dots controlled in the experiment was 0.8 mL. The controlled feeding ratio of N (Cd²⁺):N (Te²⁻):N (TGA) was 2:1:4, the heating temperature was 140 °C, the heating time was 60 min, and the pH of the QD precursor was adjusted to 11 for subsequent experiments. The UV–visible spectrum showed that the emission wavelength of CdTe quantum dots at 545 nm was the strongest and symmetric. The particle size of the synthesized quantum dots was approximately 5 nm. In the interaction of CdTe quantum dots with FEL, the FEL dosage was 1.0 mL, the optimal pH value of Tris-HCl buffer was 8.2, the amount of buffer was 1.5 mL, and the reaction time was 20 min. The standard curve of FEL was determined under the optimal synthesis conditions of CdTe quantum dots and reaction of CdTe quantum dots with FEL. The linear equation was Y = 3.9448x + 50.068, the correlation coefficient R2 was 0.9986, and the linear range was 5 × 10⁻⁶–1.1 × 10⁻⁴ mol/L. A CdTe quantum dot-based fluorescent probe was successfully constructed and could be used to determine the FEL tablet content.

IP3 receptor orchestrates maladaptive vascular responses in heart failure

Patients with heart failure (HF) have augmented vascular tone, which increases cardiac workload, impairing ventricular output and promoting further myocardial dysfunction. The molecular mechanisms underlying the maladaptive vascular responses observed in HF are not fully understood. Vascular smooth muscle cells (VSMCs) control vasoconstriction via a Ca²⁺-dependent process, in which the type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) on the sarcoplasmic reticulum (SR) plays a major role. To dissect the mechanistic contribution of intracellular Ca²⁺ release to the increased vascular tone observed in HF, we analyzed the remodeling of IP3R1 in aortic tissues from patients with HF and from controls. VSMC IP3R1 channels from patients with HF and HF mice were hyperphosphorylated by both serine and tyrosine kinases. VSMCs isolated from IP3R1^VSMC–/– mice exhibited blunted Ca²⁺ responses to angiotensin II (ATII) and norepinephrine compared with control VSMCs. IP3R1^VSMC–/– mice displayed significantly reduced responses to ATII, both in vivo and ex vivo. HF IP3R^1VSMC–/– mice developed significantly less afterload compared with HF IP3R1^fl/fl mice and exhibited significantly attenuated progression toward decompensated HF and reduced interstitial fibrosis. Ca²⁺-dependent phosphorylation of the MLC by MLCK activated VSMC contraction. MLC phosphorylation was markedly increased in VSMCs from patients with HF and HF mice but reduced in VSMCs from HF IP3R1^VSMC–/– mice and HF WT mice treated with ML-7. Taken together, our data indicate that VSMC IP3R1 is a major effector of increased vascular tone, which contributes to increased cardiac afterload and decompensation in HF.

First-line combination therapy versus first-line monotherapy for primary hypertension

BACKGROUND

This is the first update of a review originally published in 2017. Starting with one drug and starting with a combination of two drugs are strategies suggested in clinical guidelines as initial treatment of hypertension. The recommendations are not based on evidence about clinically relevant outcomes. Some antihypertensive combinations have been shown to be harmful. The actual harm-to-benefit balance of each strategy is unknown.

OBJECTIVES

To determine if there are differences in clinical outcomes between monotherapy and combination therapy as initial treatment for primary hypertension.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to April 2019: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 2005), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We used no language restrictions. We also searched clinical studies repositories of pharmaceutical companies, reviews of combination drugs on the US Food and Drug Administration and European Medicines Agency websites, and lists of references in reviews and clinical practice guidelines.

SELECTION CRITERIA

We included randomised, double-blind trials with at least 12 months' follow-up in adults with primary hypertension (systolic blood pressure/diastolic blood pressure 140/90 mmHg or higher, or 130/80 mmHg or higher if participants had diabetes), which compared combination of two first-line antihypertensive drugs with monotherapy as initial treatment. Trials had to include at least 50 participants per group and report mortality, cardiovascular mortality, cardiovascular events, or serious adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, evaluated the risk of bias, and performed data entry. The primary outcomes were mortality, serious adverse events, cardiovascular events, and cardiovascular mortality. Secondary outcomes were withdrawals due to drug-related adverse effects, reaching blood pressure control (as defined in each trial), and blood pressure change from baseline. Analyses were based on the intention-to-treat principle. We summarised data on dichotomous outcomes as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

This update included one new study in which a subgroup of participants met our inclusion criteria. As none of the four included studies focused solely on people initiating antihypertensive treatment, we asked investigators for data for this subgroup. One study (PREVER-treatment 2016) used a combination of thiazide-type diuretic/potassium-sparing diuretic; as the former is not indicated in monotherapy, we analysed this study separately. The three original trials in the main comparison (monotherapy: 335 participants; combination therapy: 233 participants) included outpatients, mostly European and white people. Two trials only included people with type 2 diabetes; the remaining trial excluded people treated with diabetes, hypocholesterolaemia, or cardiovascular drugs. The follow-up was 12 months in two trials and 36 months in one trial. It is very uncertain whether combination therapy versus monotherapy reduces total mortality (RR 1.35, 95% CI 0.08 to 21.72), cardiovascular mortality (zero events reported), cardiovascular events (RR 0.98, 95% CI 0.22 to 4.41), serious adverse events (RR 0.77, 95% CI 0.31 to 1.92), or withdrawals due to adverse effects (RR 0.85, 95% CI 0.53 to 1.35); all outcomes had 568 participants, and the evidence was rated as of very low certainty due to serious imprecision and for using a subgroup that was not defined in advance. The confidence intervals were extremely wide for all important outcomes and included both appreciable harm and benefit. The PREVER-treatment 2016 trial, which used a combination therapy with potassium-sparing diuretic (monotherapy: 84 participants; combination therapy: 116 participants), included outpatients. This trial was conducted in Brazil and had a follow-up of 18 months. The number of events was very low and confidence intervals very wide, with zero events reported for cardiovascular mortality and withdrawals due to adverse events. It is very uncertain if there are differences in clinical outcomes between monotherapy and combination therapy in this trial.

AUTHORS' CONCLUSIONS

The numbers of included participants, and hence the number of events, were too small to draw any conclusion about the relative efficacy of monotherapy versus combination therapy as initial treatment for primary hypertension. There is a need for large clinical trials that address the review question and report clinically relevant endpoints.