Myocardial cell damage in human hypertension

Regulation of H9C2 cell hypertrophy by 14-3-3η via inhibiting glycolysis

It has been reported that Ywhah (14-3-3η) reduces glycolysis. However, it remains unclear about the downstream mechanism by which glycolysis is regulated by 14-3-3η in cardiac hypertrophy. As an important regulator, Yes-associated protein (YAP) interacts with 14-3-3η to participate in the initiation and progression of various diseases in vivo. In this study, the model of H9C2 cardiomyocyte hypertrophy was established by triiodothyronine (T3) or rotenone stimulation to probe into the action mechanism of 14-3-3η. Interestingly, the overexpression of 14-3-3η attenuated T3 or rotenone induced cardiomyocyte hypertrophy and decreased glycolysis in H9C2 cardiomyocytes, whereas the knockdown of 14-3-3η had an opposite effect. Mechanistically, 14-3-3η can reduce the expression level of YAP and bind to it to reduce its nuclear translocation. In addition, changing YAP may affect the expression of lactate dehydrogenase A (LDHA), a glycolysis-related protein. Meanwhile, LDHA is also a possible target for 14-3-3η to mediate glycolysis based on changes in pyruvate, a substrate of LDHA. Collectively, 14-3-3η can suppress cardiomyocyte hypertrophy via decreasing the nucleus translocation of YAP and glycolysis, which indicates that 14-3-3η could be a promising target for inhibiting cardiac hypertrophy.

Interpreting High-Sensitive Troponins in Patients with Hypertension

PURPOSE OF REVIEW

As the high-sensitivity cardiac troponin (hs-cTn) becomes more broadly used, physicians must understand the strengths and limitations of using the hs-cTn in the hypertensive population.

RECENT FINDINGS

The most common cause of hs-cTn elevation is cardiac myocyte injury and death; alternate mechanisms for hs-cTn elevation in the absence of cardiac myocyte death are not clearly understood. Hs-cTn elevation has been found in significant proportions of patients with asymptomatic hypertension, in patients with acute hypertensive crisis, and has even been used to predict patients who will go on to develop hypertension. While the mechanisms remain undefined, there is evidence that elevations in hs-cTn are associated with both short- and long-term morbidity and mortality. While ongoing research further defines the relationship between hypertension and hs-cTn, the emergency medicine physician must make clinical decisions today regarding the utility of this increasingly used biomarker. Given the current evidence, clinical context must be utilized including a complete clinical picture, EKGs findings, and importantly serial hs-cTn when needed to establish whether myocardial injury or myocardial infarction is occurring.

Immune system changes in those with hypertension when infected with SARS-CoV-2

The coronavirus disease 2019 (COVID-19) outbreak has become an evolving global health crisis. With an increasing incidence of primary hypertension, there is greater awareness of the relationship between primary hypertension and the immune system [including CD4+, CD8+ T cells, interleukin-17 (IL-17)/T regulatory cells (Treg) balance, macrophages, natural killer (NK) cells, neutrophils, B cells, and cytokines]. Hypertension is associated with an increased risk of various infections, post-infection complications, and increased mortality from severe infections. Despite ongoing reports on the epidemiological and clinical features of COVID-19, no articles have systematically addressed the role of primary hypertension in COVID-19 or how COVID-19 affects hypertension or specific treatment in these high-risk groups. Here, we synthesize recent advances in understanding the relationship between primary hypertension and COVID-19 and its underlying mechanisms and provide specific treatment guidelines for these high-risk groups.

Left ventricular and atrial global strain evaluation within subtypes of ventricular remodeling

BACKGROUND

Left ventricular hypertrophy is associated with poor prognosis and adverse events. Left ventricular and left atrial global strain and left atrial reservoir strain (LV-GS; LA-GS; LA-RS) could be used as markers for myocardial function in different ventricular remodeling forms. This study aimed to evaluate LV-GS and LA-GS scores in different ventricular remodeling variants and identify risk factors for myocardial dysfunction.

METHODS AND RESULTS

This cross-sectional study was divided into four groups of ventricular remodeling: normal geometry, eccentric hypertrophy (EH), concentric hypertrophy (CH), and concentric remodeling (CR). Strain analysis was obtained using standardized protocols. We included 121 subjects, 33 with previous myocardial infarction (MI). We found that EH had the lowest LV-GS and CH, the lowest LA-GS, and LA-RS. Atrial and ventricular dysfunction was present in 40 (33%) and 14 (11.5%) subjects, respectively. Smoking, male sex, and previous MI were associated with LV dysfunction and smoking and dyslipidemia with LA dysfunction; EH was closely associated with LV dysfunction and CH with LA dysfunction.

CONCLUSIONS

We conclude that different ventricular geometry types had echocardiographic profiles associated with different risk factors for dysfunction assessed by strain. The assessment of ventricular remodeling by global strain could be used as a complementary tool in the echocardiographic evaluation of ventricular and atrial function.

Factors associated with global longitudinal strain decline in hypertensive patients with normal left ventricular ejection fraction

Background

Early detection of risk factors for left ventricular (LV) dysfunction may be useful in patients with high blood pressure (HBP).

Methods

Patient from an outpatient HBP clinic underwent a two-dimensional Doppler-coupled echocardiography with determination of LV global longitudinal strain (GLS) by speckle-tracking.

Results

Among 200 patients (mean age 61.7 ± 9.7 years), 155 were overweight, 93 had diabetes, 83 had dyslipidemia, and 109 had uncontrolled HBP. LV hypertrophy (LVH) was found in 136 patients (68%), including concentric (n = 106) and eccentric (n = 30) LVH. Diastolic dysfunction patterns were observed in 178 patients (89%), and increased filling pressures were observed in 37 patients (18.5%). GLS ranged from –25% to –11.6% (mean –16.9 ± 3.2%). Low GLS values (>–17%) were found in 91 patients (45.5%), 68 with and 23 without LVH. In univariate analysis, a reduced GLS was associated with HBP lasting for >10 years (odds ratio (OR) = 3.51, 95% confidence interval (CI) 1.73–7.09; p = 0.002), uncontrolled HBP (OR = 3.55, 95% CI 1.96–6.43; p < 0.0001), overweight (OR = 2.01, 95% CI 0.93–4.31; p = 0.0028), diabetes (OR = 2.21, 95% CI 1.25–3.90; p = 0.006), dyslipidemia (OR = 2.16, 95% CI 1.22–3.84; p = 0.008), renal failure (OR = 4.27, 95% CI 1.80–10.10; p = 0.001), an increased Cornell index (OR = 3.70, 95% CI 1.98–6.90; p < 0.0001), concentric LVH (OR = 9.26, 95% CI 2.62–32.73; p = 0.001), remodeling (OR = 8.51, 95% CI 2.18–33.23; p = 0.002), and filling pressures (OR = 7.1, 95% CI 2.9–17.3; p < 0.0001). In multivariable analysis, duration of HBP (p = 0.038), uncontrolled BP (p = 0.006), diabetes (p = 0.023), LVH (p = 0.001), and increased filling pressures (p = 0.003) remained associated with GLS decline.

Conclusion

Early impairment of LV function, detected by a reduced GLS, is associated with long-lasting, uncontrolled HBP, overweight, related metabolic changes, and is more pronounced in patients with LVH.

Clinical importance of high- sensitivity troponin T in patients without coronary artery disease

Cardiac troponin is the preferred biomarker for the diagnosis of the acute coronary syndrome (ACS), but many other diseases can be identified with elevated troponin levels in the absence of ACS. The recent development of a high-sensitive cardiac troponin T (hs-cTnT) assay permits the detection of very low levels of cTnT. The use of hs-cTnT assay has emerged as a tool for identifying high-risk individuals for primary preventive treatment and can detect subclinical injury in asymptomatic patients. Hs-cTnT analyses are generally related to ischemia in the literature. Thus, we made an evaluation of hs-cTnT analysis in non-coronary patients, which may contribute to the literature.

Accelerated decline in cardiac stem cell efficiency in Spontaneously hypertensive rat compared to normotensive Wistar rat

Cardiac hypertrophy is recognized as an independent risk factor for cardiac failure. Efficient management of hypertensive heart disease requires identification of factors that can possibly mediate the transition from hypertrophy to failure. Resident cardiac stem cells have a prominent role in the maintenance of cardiac tissue homeostasis. Decline in the proportion of healthy cardiac stem cells (CSCs) can affect tissue regeneration. In pathological conditions, apart from natural aging, an adverse microenvironment can lead to decrease in efficiency of CSCs. A systematic analysis of cardiac stem cell characteristics in pathological conditions has not been reported so far. Therefore, this study was designed with the objective of examining the age associated variation in stem cell attributes of Spontaneously hypertensive rat (SHR) in comparison with normotensive Wistar rat. Spontaneously hypertensive rat was used as the experimental model since the cardiac remodeling resembles the clinical course of hypertensive heart disease. CSCs were isolated from atrial explants. Stem cell attributes were assessed in 1-week, 6, 12 and 18-month-old male SHR, in comparison with age matched Wistar rats. In 1-week-old pups, stem cell attributes of SHR and Wistar were comparable. Migration potential, proliferative capacity, TERT expression, telomerase activity and the proportion of c-kit⁺ cells decreased with age, both in SHR and Wistar. DNA damage and the proportion of senescent CSCs increased with age both in SHR and Wistar rats. Age associated increase was observed in the oxidative stress of stem cells, possibly mediated by the enhanced oxidative stress in the microenvironment. The changes were more pronounced in SHR, and as early as six months of age, there was significant decrease in efficiency of CSCs of SHR compared to Wistar. The density of healthy CSCs determined as a fraction of the differentiated cells was remarkably low in 18-month-old SHR. Age associated decrease in functionally efficient CSCs was therefore accelerated in SHR. Considering the vital role of CSCs in the maintenance of a healthy myocardium, decrease in functionally efficient CSCs can be a precipitating factor in pathological cardiac remodeling. Elevated ROS levels in CSCs of SHR lends scope for speculation that decrease in efficiency of CSCs is mediated by oxidative stress; and that modulation of the microenvironment by therapeutic interventions can restore a healthy stem cell population and facilitate maintenance of cardiac homeostasis and prevent cardiac decompensation.

High-Sensitivity Cardiac Troponin T (hs-cTnT) as a Predictor of Incident Diabetes in the Atherosclerosis Risk in Communities Study

OBJECTIVE

Many individuals with prediabetes have evidence of subclinical myocardial damage and are at an increased risk of cardiovascular disease (CVD). If subclinical myocardial damage is independently associated with incident diabetes, this may contribute to the understanding of the association between diabetes and CVD. This study was conducted to determine whether high-sensitivity cardiac troponin T (hs-cTnT) is associated with incident diabetes.

RESEARCH DESIGN AND METHODS

Using Kaplan-Meier curves and Cox models, we prospectively analyzed 8,153 participants without known diabetes or CVD. We used the Harrell C statistic to investigate whether hs-cTnT added incremental prognostic information for diabetes prediction.

RESULTS

During a median of 13 years of follow-up, there were 1,830 incident cases of diagnosed diabetes. After adjustment for demographics and traditional risk factors, participants with a baseline hs-cTnT of 9-13 ng/L or ≥14 ng/L had a significantly increased risk for diabetes compared to those with an hs-cTnT of ≤5 ng/L, with hazard ratios of 1.14 (95% CI 0.99-1.33) and 1.25 (95% CI 1.03-1.53), respectively (P = 0.018 for trend). Linear spline modeling that included adjustment for baseline fasting glucose suggested an increased risk of incident diabetes for participants with hs-cTnT levels >8 ng/L. Furthermore, the addition of hs-cTnT to fully adjusted models that included glucose significantly improved the prediction of incident diabetes from 0.7636 to 0.7644 (P = 0.023).

CONCLUSIONS

Participants with elevated hs-cTnT levels at baseline had an increased risk of incident diabetes, suggesting that the measurement of hs-cTnT may incorporate an underlying pathophysiologic overlap between diabetes and CVD not captured by other traditional risk factors. Measurement of hs-cTnT may be useful to identify individuals at an increased risk for incident diabetes and CVD in order to provide early and more intensive risk factor modification.

Patterns and determinants of temporal change in high-sensitivity cardiac troponin-T: The Atherosclerosis Risk in Communities Cohort Study

BACKGROUND

Patterns and determinants of temporal change in highly-sensitivity troponin-T (hs-cTNT), a novel measure of subclinical myocardial injury, among asymptomatic persons have not been well characterized.

METHODS

We studied 8571 ARIC Study participants, free of cardiovascular disease, who had hs-cTNT measured at two time-points, 6 years apart (1990-1992 and 1996-1998). We examined the association of baseline 10-year atherosclerotic cardiovascular (ASCVD) risk-group (<5%, 5-7.4%, ≥ 7.5%) and individual cardiac risk-factors with change across hs-cTNT categories using Poisson and Multinomial Logistic regression and with mean continuous hs-cTNT change using linear regression.

RESULTS

Mean age was 57 years and 43% were male. Mean (SD) 6-year hs-cTNT change was higher across increasing ASCVD risk-groups; +1.2 (6.1) ng/L [<5%], +2.1 (5.4) ng/L [5-7.4%], and +2.8 (8.8) ng/L [≥ 7.5%]. Major baseline determinants of temporal hs-cTNT increases were: age, male gender, hypertension, diabetes, and obesity. In addition, the relative risk (RR) of incident elevated hs-cTNT (≥ 14 ng/L) was 1.46 (95% CI 1.1-2.0) for persons with sustained hypertension compared to those who remained normotensive. Results for sustained obesity (RR 1.65 [1.19-2.29]) and hyperglycemia (RR 1.76 [1.16-2.67]) were similar. These associations were generally stronger after accounting for survival bias. However, smoking, LDL-cholesterol and triglycerides were not associated with hs-cTNT change. HDL-cholesterol was associated with declining hs-cTNT.

CONCLUSIONS

Persons in higher ASCVD risk-groups were more likely to have increases in hs-cTNT over 6 years of follow-up. The modifiable risk-factors primarily driving this association were diabetes, hypertension, and obesity; particularly when they were persistently elevated over follow-up. Future studies are needed to determine whether modifying these risk factors can prevent progression of subclinical myocardial injury.

Perioperative control of hypertension: when will it adversely affect perioperative outcome?

Much has been published about the impact of treatment on adverse outcomes in patients with cardiovascular diseases. Hypertension is an extremely common condition affecting a significant percentage of the world population. Although care guidelines exist for the medical patient with raised blood pressure, there are no accepted guidelines for the preoperative evaluation and perioperative care of the patient with hypertension who undergoes noncardiac surgery. Of particular importance are defining at-risk groups of patients, and the indications for cancellation to treat and hence reduce this risk. This review examines the interactions between hypertension, drug therapies, anesthesia, and adverse outcomes in these patients. Recommendations for identifying patients at greatest risk of adverse cardiovascular events and cardiac mortality have been developed through evaluation of available data. Based on these findings, the only patients in whom cancellation may be justified and the level of hypertension treated prior to surgery are those with stage 2 hypertension and accompanying target-organ damage, or stage 3 hypertension (blood pressure > 180/> 110 mm Hg).

Effect of the increase in valve area after aortic valve replacement with a 19-mm aortic valve prosthesis on left ventricular mass regression in patients with pure aortic stenosis

OBJECTIVES

Although patients with aortic stenosis, who receive 19-mm valves, are at high risk for prosthesis-patient mismatch, most of them show a significant left ventricular mass (LVM) regression postoperatively. The aim of this study was to identify factors predicting postoperative relative LVM regression in this subgroup of patients.

METHODS

A population of 44 patients operated on for pure aortic stenosis and receiving a 19-mm valve was studied by echocardiography at 1.4 +/- 0.5 years postoperatively.

RESULTS

The mean relative LVM regression was -19.3 +/- 18.9%, the mean gradient drop was -31.6 +/- 13.3 mmHg, and the mean Delta increase in aortic area index (postoperative aortic area index minus preoperative aortic area index) was 0.30 +/- 0.14 cm/m. Thirty-two patients had an indexed effective orifice area of less than 0.8 cm/m. At multivariate analysis (r = 0.63; r = 40%; P < 0.0001) preoperative LVM (P = 0.006), hypertension (P = 0.018) and Delta aortic area index (P = 0.049) were independent predictors of relative LVM regression.

CONCLUSIONS

Our study shows that, at least 1 year postoperatively, in patients receiving a 19-mm valve, LVM regression is influenced by several parameters, in particular preoperative LVM, hypertension and the magnitude of the increase in aortic area.

Non-invasive in vivo imaging of myocardial apoptosis and necrosis

Myocardial necrosis plays an important role in the pathogenesis of various cardiovascular disorders and can result from different myocardial insults. Its non-invasive identification and localisation therefore may help in the diagnosis of these disorders, as well as in prognosis and assessment of treatment response. Apoptosis, or programmed cell death, is important in the spectrum of myocardial damage since it is gradually becoming more apparent that cell death may begin as apoptosis and not as necrosis. First attempts to directly visualise the area of myocardial necrosis were based on recognition of myocardial infarction with "hot spot imaging agents" in patients with chest pain. Since then, the study of myocardial necrosis with gamma imaging agents has gone beyond the detection of myocardial infarction, and attempts have been made to diagnose other cardiovascular disorders associated with cardiac cell death such as heart transplant rejection, myocarditis, cardiotoxicity and cardiomyopathies. Traditionally, two hot spot imaging agents have been used for the detection of myocardial necrosis, (99m)Tc-pyrophosphate and (111)In-antimyosin. In addition, preliminary studies have demonstrated promising results with (99m)Tc-glucarate. Recently, (99m)Tc-annexin V has been successfully used for non-invasive gamma imaging of apoptosis after acute myocardial infarction, acute myocardial ischaemia, acute cardiac allograft rejection and malignant intracardiac tumours. This review article focusses on the characteristics of these different myocardial necrotic and apoptotic markers and compares their role in the assessment of myocardial damage.

Isolated systolic hypertension is associated with adverse outcomes from coronary artery bypass grafting surgery

Isolated systolic blood pressure has not been sufficiently studied in the perioperative setting and may contribute to morbidity and mortality after coronary artery bypass grafting (CABG) surgery. Our objective was to determine the prevalence of isolated systolic hypertension among patients who had CABG surgery and to assess whether isolated systolic hypertension is associated with perioperative and postoperative in-hospital morbidity or mortality. Patients who underwent CABG were selected from a prospective epidemiological study involving 2417 patients in 24 medical centers. Patients were classified as having normal preoperative blood pressure, isolated systolic hypertension (systolic blood pressure >140 mm Hg), diastolic hypertension (diastolic blood pressure >90 mm Hg), or a combination of these. Demographic risk factors (age, sex, and ethnicity), clinical risk factors (diabetes mellitus, increased cholesterol, antihypertensive medications, history of congestive heart failure, myocardial infarction, hypertension, and neurological deficits), and behavioral risk factors (smoking and heavy drinking) were controlled for statistically. Adverse outcomes included left ventricular dysfunction, cerebral vascular dysfunction or events, renal insufficiency or failure, and all-cause mortality. Isolated systolic hypertension was found in 29.6% of patients. Unadjusted isolated systolic hypertension was associated with a 40% increased risk of adverse outcomes (odds ratio, 1.4; confidence interval, 1.1-1.7). After adjusting for other potential risk factors, the increased risk of adverse outcomes with isolated systolic hypertension was 30%. We conclude that isolated systolic hypertension is associated with a 40% increase in the likelihood of cardiovascular morbidity perioperatively in CABG patients. This increase remains present regardless of antihypertensive medications, anesthetic techniques, and other perioperative cardiovascular risk factors (e.g., age older than 60 yr or history of congestive heart failure, myocardial infarction, or diabetes).

IMPLICATIONS

Isolated systolic hypertension is associated with a 40% increase in the likelihood of perioperative cardiovascular morbidity in coronary artery surgery patients.

Left ventricular mass and systolic dysfunction in essential hypertension

A relation between left ventricular (LV) hypertrophy and depressed midwall systolic function has been described in hypertensive subjects. However, a strong confounding factor in this relation is concentric geometry, which is both a powerful determinant of depressed midwall systolic function and a correlate of LV mass in hypertension. To evaluate the independent contribution of LV mass to depressed systolic function, 1827 patients with never-treated essential hypertension (age 48 +/- 12 years, men 58%) underwent M-mode echocardiography under two-dimensional guidance. Relative wall thickness was the strongest determinant of low midwall fractional shortening (r = -0.63, P < 0.0001). The significant inverse relation observed between LV mass and midwall fractional shortening (r = -0.43, P < 0.0001) persisted after taking into account the effect of relative wall thickness (partial r = -0.27, P < 0.0001). Within each sex-specific quintile of relative wall thickness, prevalence of subnormal afterload-corrected midwall systolic function was greater in subjects with, than in subjects without, LV hypertrophy (P < 0.05 for the first, third, fourth and fifth quintile). In a multiple linear regression analysis, both LV mass (P < 0.0001) and relative wall thickness (P < 0.0001) were independent predictors of a reduced midwall fractional shortening. In conclusion, the inverse association between LV mass and midwall systolic function is partly independent from the effect of relative wall thickness. LV hypertrophy is a determinant of subclinical LV dysfunction independently of the concomitant changes in chamber geometry.