Diastolic dysfunction in hypertension

Cardioprotective effect of silicon-built restraint device (ASD), for left ventricular remodeling in rat heart failure model

This study aims to evaluate the feasibility and cardio-protective effects of biocompatible silicon-built restraint device (ASD) in the rat's heart failure (HF) model. The performance and compliance characteristics of the ASD device were assessed in vitro by adopting a pneumatic drive and ball burst test. Sprague-Dawley (SD) rats were divided into four groups (n = 6); control, HF, HF + CSD, and HF + ASD groups, respectively. Heart failure was developed by left anterior descending (LAD) coronary artery ligation in all groups except the control group. The ASD and CSD devices were implanted in the heart of HF + ASD and HF + CSD groups, respectively. The ASD's functional and expansion ability was found to be safe and suitable for attenuating ventricular remodeling. ASD-treated rats showed normal heart rhythm, demonstrated by smooth -ST and asymmetrical T-wave. At the same time, hemodynamic parameters of the HF + ASD group improved systolic and diastolic functions, reducing ventricular wall stress, which indicated reverse remodeling. The BNP values were reduced in the HF + ASD group, which confirmed ASD feasibility and reversed remodeling at a molecular level. Furthermore, the HF + ASD group with no fibrosis suggests that ASD has significant curative effects on the heart muscles. In conclusion, ASD was found to be a promising restraint therapy than the previously standard restraint therapies. Stepwise ASD fabrication process (a) 3D computer model of ASD was generated by using Rhinoceros 5.0 software (b) 3D blue wax model of ASD (c) Silicon was prepared by mixing the solutions (as per manufacturer instruction) (d) Blue wax model of ASD was immersed into liquid Silicon (e) ASD model was put into the oven for 3 hours at 50 °C. (f) Blue wax started melting from the ASD model (g) ASD model was built from pure silicon (h) Two access lines were linked to the ASD device, which was connected with an implantable catheter (Port-a-cath), scale bar 100 µm. (Nikon Ldx 2.0).

Prognostic Impact of Hybrid Comprehensive Telerehabilitation Regarding Diastolic Dysfunction in Patients with Heart Failure with Reduced Ejection Fraction—Subanalysis of the TELEREH-HF Randomized Clinical Trial

Aims: The objective of the study was to evaluate the effects of individually prescribed hybrid comprehensive telerehabilitation (HCTR) implemented at patients’ homes on left ventricular (LV) diastolic function in heart failure (HF) patients. Methods and results: The Telerehabilitation in Heart Failure Patients trial (TELEREH-HF) is a multicenter, prospective, randomized (1:1), open-label, parallel-group, controlled trial involving HF patients assigned either to HCTR involving a remotely monitored home training program in conjunction with usual care (HCTR group) or usual care only (UC group). The patient in the HCTR group underwent a 9-week HCTR program consisting of two stages: an initial stage (1 week) conducted in hospital and the subsequent stage (eight weeks) of home-based HCTR five times weekly. Due to difficulties of proper assessment and differences in the evaluation of diastolic function in patients with atrial fibrillation, we included in our subanalysis only patients with sinus rhythm. Depending on the grade of diastolic dysfunction, patients were assigned to subgroups with mild diastolic (MDD) or severe diastolic dysfunction (SDD), both in HCTR (HCTR-MDD and HCTR-SDD) and UC groups (UC-MDD and UC-SDD). Changes from baseline to 9 weeks in echocardiographic parameters were seen only in A velocities in HCTR-MDD vs. UC-MDD; no significant shifts between groups of different diastolic dysfunction grades were observed after HCTR. All-cause mortality was higher in UC-SDD vs. UC-MDD with no difference between HCTR-SDD and HCTR-MDD. Higher probability of HF hospitalization was observed in HCTR-SDD than HCTR-MDD and in UC-SDD than UC-MDD. No differences in the probability of cardiovascular mortality and hospitalization were found. Conclusions: HCTR did not influence diastolic function in HF patients in a significant manner. The grade of diastolic dysfunction had an impact on mortality only in the UC group and HF hospitalization over a 12–24-month follow-up in HCTR and UC groups.

Efficacy evaluation of serum galectin-3 in hypertension complicated with diastolic dysfunction

Serum galectin-3 (Gal-3) in patients with hypertension complicated with diastolic dysfunction and its predictive value for efficacy were investigated. One hundred patients with hypertension complicated with diastolic dysfunction admitted to the First Affiliated Hospital of Jiamusi University from June 2017 to December 2018 were enrolled as group A, symptomatically treated with conventional drugs. Further 80 individuals undergoing physical examination during the same period were enrolled as group B. Patients in the two groups were subjected to echocardiography to observe mitral valve early peak flow velocity (EPFV), atrial peak flow velocity (APFV), maximum flow velocity ratio of early to atrial diastole (EPFV/APFV) and peak mitral annulus velocity (E/E′). Enzyme-linked immunosorbent assay (ELISA) was used to detect serum Gal-3 concentration. According to efficacy after treatment, patients in group A were divided into the effective group (71 patients) and the invalid group (29 patients). Gal-3 concentration in group A was significantly higher than that in group B (P<0.05). After treatment, the concentration in group A was significantly lower than that before treatment (P<0.05), but significantly higher than that in group B (P<0.05). Gal-3 concentration was significantly higher in patients with cardiac function grades II, III and IV than that in patients with grade I (P<0.05). According to Spearman's test, Gal-3 concentration was positively correlated with cardiac function grading (r=0.569, P<0.001). Compared with before treatment in group A, patients after treatment had significantly higher EPFV and EPFV/APFV (P<0.05), but significantly lower APFV and E/E′ (P<0.05). Before treatment, Gal-3 concentration in the effective group was significantly lower than that in the invalid group (P<0.05). According to the receiver operating characteristic (ROC) curve, the area under curve (AUC) of Gal-3 concentration for evaluating efficacy was 0.792, the sensitivity was 73.24%, and the specificity was 79.31%. In conclusion, Gal-3 may be involved in the development and progression of hypertension complicated with diastolic dysfunction. Its concentration increases with the rise of cardiac function grading but significantly decreases after treatment. Therefore, Gal-3 concentration before treatment can be used as a potential predictor of efficacy.

Na+/H+ exchanger and cardiac hypertrophy

Reactive cardiac hypertrophy (CH) is an increase in heart mass in response to hemodynamic overload. Exercise-induced CH emerges as an adaptive response with improved cardiac function, in contrast to pathological CH that represents a risk factor for cardiovascular health. The Na⁺/H⁺ exchanger (NHE-1) is a membrane transporter that not only regulates intracellular pH but also intracellular Na⁺ concentration. In the scenario of cardiovascular diseases, myocardial NHE-1 is activated by a variety of stimuli, such as neurohumoral factors and mechanical stress, leading to intracellular Na⁺ overload and activation of prohypertrophic cascades. NHE-1 hyperactivity is intimately linked to heart diseases, including ischemia-reperfusion injury, maladaptive CH and heart failure. In this review, we will present evidence to support that the NHE-1 hyperactivity constitutes a "switch on/off" for the pathological phenotype during CH development. We will also discuss some classical and novel strategies to avoid NHE-1 hyperactivity, and that are therefore worthwhile to improve cardiovascular health.

Systolic time ratio measured by impedance cardiography accurately screens left ventricular diastolic dysfunction in patients with arterial hypertension

Background

The use of impedance cardiography (ICG) may play a role in the assessment of cardiac effects of hypertension (HT), especially its hemodynamic features. Hypertensive heart disease involves structural changes and alterations in left ventricular geometry that end up causing systolic and/or diastolic dysfunction. The IMPEDDANS study aims to assess the usefulness of ICG for the screening of left ventricular diastolic dysfunction (LVDD) in patients with HT.

Methods

Patients with HT were assessed by echocardiography and ICG. Receiver-operating characteristic curve and the area under the curve were used to assess the discriminative ability of the parameters obtained by ICG to identify LVDD, as diagnosed by echocardiography.

Results

ICG derived pre-ejection period (PEP), left ventricle ejection time (LVET), systolic time ratio (STR) and D wave were associated (p < 0.001) with LVDD diagnosis, with good discriminative ability: PEP (AUC 0.81; 95% CI 0.74–0.89), LVET (AUC 0.82; 95% CI 0.75–0.88), STR (AUC 0.97; 95% CI 0.94–1.00) and presence of D wave (AUC = 0.87; 95% CI 0.82–0.93). STR ≥ 0.30 outperformed the other parameters (sensitivity of 98.0%, specificity of 90.2%, positive predictive value of 95.2%, and negative predictive value of 96.1%).

Conclusion

The ICG derived value of STR allows the accurate screening of LVDD in patients with HT. It might as well be used for follow up assessment.

Trial registration

The study protocol was retrospectively registered as IMPEDDANS on ClinicalTrials.gov (ID: NCT03209141) on July 6, 2017.

Good agreement between echocardiography and impedance cardiography in the assessment of left ventricular performance in hypertensive patients

BACKGROUND

Impedance cardiography (ICG) is a noninvasive hemodynamic monitoring tool which can define hypertensive patients' hemodynamic profiles and help to tailor antihypertensive therapy. This study assesses the concordance between ICG-derived indexes used to evaluate left ventricular performance and transthoracic echocardiography (TTE) in hypertensive patients.

METHODS

In this IMPEDDANS post-hoc analysis, the ICG-derived indexes are compared with TTE by Bland-Altman method. Statistical significance of the relationship between the values obtained was assessed by generalized linear mixed-effects models.

RESULTS

In supine position, Bland-Altman analysis showed good concordance for cardiac output (CO) (mean difference of 0.006 mL/min [-0.120; 0.133]), cardiac index (CI) (mean difference of 0.016 mL/min/m² [-0.471; 0.504]), pre-ejection period (PEP) (mean difference of -0.216 ms [-4.510; 4.077]), left ventricular ejection time (LVET) (mean difference of -0.140 ms [-6.573; 6.293]), and systolic time ratio (STR) (mean difference of -0.00004 [-0.008; 0.008]). In orthostatic position, good concordance was found for CO (mean difference 0.028 mL/min [-2.036; 1.980]), CI (mean difference -0.012 mL/min/m² [-1.063; 1.039]), and STR (mean difference -0.101 [0.296; 0.094]). No significant difference between methods was identified by the linear mixed-effects models.

CONCLUSION

The ICG-derived indexes CO, CI, PEP, LVET, and STR in supine position have good agreement with TTE. Therefore, ICG can be used to accurately evaluate left ventricular performance.