Pharmacotherapy for hypertension-induced left ventricular hypertrophy

Zonisamide attenuates pressure overload-induced myocardial hypertrophy in mice through proteasome inhibition

Myocardial hypertrophy is a pathological thickening of the myocardium which ultimately results in heart failure. We previously reported that zonisamide, an antiepileptic drug, attenuated pressure overload-caused myocardial hypertrophy and diabetic cardiomyopathy in murine models. In addition, we have found that the inhibition of proteasome activates glycogen synthesis kinase 3 (GSK-3) thus alleviates myocardial hypertrophy, which is an important anti-hypertrophic strategy. In this study, we investigated whether zonisamide prevented pressure overload-caused myocardial hypertrophy through suppressing proteasome. Pressure overload-caused myocardial hypertrophy was induced in mice by trans-aortic constriction (TAC) surgery. Two days after the surgery, the mice were administered zonisamide (10, 20, 40 mg·kg-1·d-1, i.g.) for four weeks. We showed that zonisamide administration significantly mitigated impaired cardiac function. Furthermore, zonisamide administration significantly inhibited proteasome activity as well as the expression levels of proteasome subunit beta types (PSMB) of the 20 S proteasome (PSMB1, PSMB2 and PSMB5) and proteasome-regulated particles (RPT) of the 19 S proteasome (RPT1, RPT4) in heart tissues of TAC mice. In primary neonatal rat cardiomyocytes (NRCMs), zonisamide (0.3 μM) prevented myocardial hypertrophy triggered by angiotensin II (Ang II), and significantly inhibited proteasome activity, proteasome subunits and proteasome-regulated particles. In Ang II-treated NRCMs, we found that 18α-glycyrrhetinic acid (18α-GA, 2 mg/ml), a proteasome inducer, eliminated the protective effects of zonisamide against myocardial hypertrophy and proteasome. Moreover, zonisamide treatment activated GSK-3 through inhibiting the phosphorylated AKT (protein kinase B, PKB) and phosphorylated liver kinase B1/AMP-activated protein kinase (LKB1/AMPKα), the upstream of GSK-3. Zonisamide treatment also inhibited GSK-3's downstream signaling proteins, including extracellular signal-regulated kinase (ERK) and GATA binding protein 4 (GATA4), both being the hypertrophic factors. Collectively, this study highlights the potential of zonisamide as a new therapeutic agent for myocardial hypertrophy, as it shows potent anti-hypertrophic potential through the suppression of proteasome.

Construction and validation of a nomogram to predict left ventricular hypertrophy in low-risk patients with hypertension

Electrocardiography (ECG) is an accessible diagnostic tool for screening patients with hypertensive left ventricular hypertrophy (LVH). However, its diagnostic sensitivity is low, with a high probability of false-negatives. Thus, this study aimed to establish a clinically useful nomogram to supplement the assessment of LVH in patients with hypertension and without ECG-LVH based on Cornell product criteria (low-risk hypertensive population). A cross-sectional dataset was used for model construction and divided into development (n = 2906) and verification (n = 1447) datasets. A multivariable logistic regression risk model and nomogram were developed after screening for risk factors. Of the 4353 low-risk hypertensive patients, 673 (15.4%) had LVH diagnosed by echocardiography (Echo-LVH). Eleven risk factors were identified: hypertension awareness, duration of hypertension, age, sex, high waist-hip ratio, education level, tea consumption, hypochloremia, and other ECG-LVH diagnostic criteria (including Sokolow-Lyon, Sokolow-Lyon products, and Peguero-Lo Presti). For the development and validation datasets, the areas under the curve were 0.724 (sensitivity = 0.606) and 0.700 (sensitivity = 0.663), respectively. After including blood pressure, the areas under the curve were 0.735 (sensitivity = 0.734) and 0.716 (sensitivity = 0.718), respectively. This novel nomogram had a good predictive ability and may be used to assess the Echo-LVH risk in patients with hypertension and without ECG-LVH based on Cornell product criteria.

Protections of transcription factor BACH2 and natural product myricetin against pathological cardiac hypertrophy and dysfunction

Pathological hypertrophic myocardium under consistent adverse stimuli eventually can cause heart failure. This study aims to explore the role of BACH2, a member of the basic region leucine zipper transcription factor family, in cardiac hypertrophy and failure. Transverse aortic constriction surgery was operated to induce cardiac hypertrophy and failure in mice. BACH2 was overexpressed in mice through tail vein injection of AAV9-Bach2. Mice with systemic or cardiac-specific knockdown of Bach2 were adopted. Neonatal rat ventricular myocytes (NRVMs) were isolated and infected with lentivirus to overexpress Bach2 or transfected with siRNA to knock down Bach2. Our data showed that overexpression of BACH2 ameliorated TAC-induced cardiac hypertrophy and failure in mice and decreased isoproterenol (ISO)-triggered myocyte hypertrophy in NRVMs. Systemic or cardiac-specific knockdown of Bach2 worsened the cardiac hypertrophy and failure phenotype in mice. Further assays showed that BACH2 bound to the promotor region of Akap6 at the -600 to -587 site and repressed its expression, which functioned as a crucial scaffold for cardiac hypertrophy and failure signaling pathways. Small molecular natural product library screening suggested that myricetin could up-regulate expression of Bach2 and simultaneously suppress the transcriptional levels of hypertrophic marker genes Bnp and Myh7. Further studies showed that myricetin exerted a BACH2-dependent protective effect against cardiac hypertrophy in vivo and in vitro. Taken together, our findings demonstrated that BACH2 plays a crucial role in the regulation of cardiac hypertrophy and failure and can be a potential therapeutic target in the future.

Pharmacotherapy for hypertension-induced left ventricular hypertrophy

BACKGROUND

Hypertension is the leading preventable risk factor for cardiovascular disease and premature death worldwide. One of the clinical effects of hypertension is left ventricular hypertrophy (LVH), a process of cardiac remodelling. It is estimated that over 30% of people with hypertension also suffer from LVH, although the prevalence rates vary according to the LVH diagnostic criteria. Severity of LVH is associated with a higher prevalence of cardiovascular disease and an increased risk of death. The role of antihypertensives in the regression of left ventricular mass has been extensively studied. However, uncertainty exists regarding the role of antihypertensive therapy compared to placebo in the morbidity and mortality of individuals with hypertension-induced LVH.

OBJECTIVES

To assess the effect of antihypertensive pharmacotherapy compared to placebo or no treatment on morbidity and mortality of adults with hypertension-induced LVH.

SEARCH METHODS

Cochrane Hypertension's Information Specialist searched the following databases for studies: Cochrane Hypertension Specialised Register (to 26 September 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library; 2020, Issue 9), Ovid MEDLINE (1946 to 22 September 2020), and Ovid Embase (1974 to 22 September 2020). We searched the World Health Organization International Clinical Trials Registry Platform and the ClinicalTrials.gov for ongoing trials. We also searched Epistemonikos (to 19 February 2021), LILACS BIREME (to 19 February 2021), and Clarivate Web of Science (to 26 February 2021), and contacted authors and funders of the identified trials to obtain additional information and individual participant data. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with at least 12 months' follow-up comparing antihypertensive pharmacological therapy (monotherapy or in combination) with placebo or no treatment in adults (18 years of age or older) with hypertension-induced LVH were eligible for inclusion. The trials must have analysed at least one primary outcome (all-cause mortality, cardiovascular events, or total serious adverse events) to be considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors screened the search results, with any disagreements resolved by consensus amongst all review authors. Two review authors carried out the data extraction and analyses. We assessed risk of bias of the included studies following Cochrane methodology. We used the GRADE approach to assess the certainty of the body of evidence.

MAIN RESULTS

We included three multicentre RCTs. We selected 930 participants from the included studies for the analyses, with a mean follow-up of 3.8 years (range 3.5 to 4.3 years). All of the included trials performed an intention-to-treat analysis. We obtained evidence for the review by identifying the population of interest from the trials' total samples. None of the trials provided information on the cause of LVH. The intervention varied amongst the included trials: hydrochlorothiazide plus triamterene with the possibility of adding alpha methyldopa, spironolactone, or olmesartan. Placebo was administered to participants in the control arm in two trials, whereas participants in the control arm of the remaining trial did not receive any add-on treatment. The evidence is very uncertain regarding the effect of additional antihypertensive pharmacological therapy compared to placebo or no treatment on mortality (14.3% intervention versus 13.6% control; risk ratio (RR) 1.02, 95% confidence interval (CI) 0.74 to 1.40; 3 studies; 930 participants; very low-certainty evidence); cardiovascular events (12.6% intervention versus 11.5% control; RR 1.09, 95% CI 0.77 to 1.55; 3 studies; 930 participants; very low-certainty evidence); and hospitalisation for heart failure (10.7% intervention versus 12.5% control; RR 0.82, 95% CI 0.57 to 1.17; 2 studies; 915 participants; very low-certainty evidence). Although both arms yielded similar results for total serious adverse events (48.9% intervention versus 48.1% control; RR 1.02, 95% CI 0.89 to 1.16; 3 studies; 930 participants; very low-certainty evidence) and total adverse events (68.3% intervention versus 67.2% control; RR 1.07, 95% CI 0.86 to 1.34; 2 studies; 915 participants), the incidence of withdrawal due to adverse events may be significantly higher with antihypertensive drug therapy (15.2% intervention versus 4.9% control; RR 3.09, 95% CI 1.69 to 5.66; 1 study; 522 participants; very low-certainty evidence). Sensitivity analyses limited to blinded trials, trials with low risk of bias in core domains, and trials with no funding from the pharmaceutical industry did not change the results of the main analyses. Limited evidence on the change in left ventricular mass index prevented us from drawing any firm conclusions.

AUTHORS' CONCLUSIONS

We are uncertain about the effects of adding additional antihypertensive drug therapy on the morbidity and mortality of participants with LVH and hypertension compared to placebo. Although the incidence of serious adverse events was similar between study arms, additional antihypertensive therapy may be associated with more withdrawals due to adverse events. Limited and low-certainty evidence requires that caution be used when interpreting the findings. High-quality clinical trials addressing the effect of antihypertensives on clinically relevant variables and carried out specifically in individuals with hypertension-induced LVH are warranted.