Ventricular–vascular coupling in hypertension

The Relationship of Renal Augmented Velocity Index With Ventricular-Arterial Coupling in Comparison to Renal Resistive Index: Analysis by Means of Arterial and Ventricular Elastances in Hypertensive Patients

OBJECTIVE

It's a well-known scientific statement that the heart and kidney functions are frequently tied together and the impairment of one directly alters the other. However, there exist knowledge gaps about this intricate pathophysiologic link and the exact unifying mechanism is not established. Herein, we aimed to investigate the presence of cardiorenal interaction at subclinical level while the conventional cardiac and renal clinical parameters are not disrupted yet in patients with hypertension.

METHODS

We chose a novel renal Doppler ultrasonographic parameter-augmented velocity index (Avi)-and an echocardiographic measure-ventriculoarterial coupling-which is complex to analyze but increasingly used after its acceptance about being a key determinant of cardiovascular efficiency. We recruited 137 patients without a previous history of antihypertensive medication use (47.4% women; median age, 49 years). Renal Avi, renal resistive index (RI), arterial elastance (Ea ), ventricular elastance (Ees ) and Ea /Ees (ventriculoarterial coupling) parameters were all examined.

RESULTS

Renal Avi, Ea , and Ea /Ees values were higher in females. Correlation analysis revealed that renal Avi was correlated with many hemodynamic variables including Ea and Ea /Ees . On multiple linear regression analysis, Ea and Ea /Ees remained as significant independent predictors of renal Avi but not of renal RI after adjustments for co-variables (β = 0.488, P < .001 for Ea ; β = 0.380, P < .001 for Ea /Ees ).

CONCLUSIONS

In comparison to renal RI, we suggest that renal Avi is a more reliable and promising index that can even measure subclinical changes in the cardiorenal circulation which needs to be elucidated.

Altered Aortic Hemodynamics and Relative Pressure in Patients with Dilated Cardiomyopathy

Ventricular-vascular interaction is central in the adaptation to cardiovascular disease. However, cardiomyopathy patients are predominantly monitored using cardiac biomarkers. The aim of this study is therefore to explore aortic function in dilated cardiomyopathy (DCM). Fourteen idiopathic DCM patients and 16 controls underwent cardiac magnetic resonance imaging, with aortic relative pressure derived using physics-based image processing and a virtual cohort utilized to assess the impact of cardiovascular properties on aortic behaviour. Subjects with reduced left ventricular systolic function had significantly reduced aortic relative pressure, increased aortic stiffness, and significantly delayed time-to-pressure peak duration. From the virtual cohort, aortic stiffness and aortic volumetric size were identified as key determinants of aortic relative pressure. As such, this study shows how advanced flow imaging and aortic hemodynamic evaluation could provide novel insights into the manifestation of DCM, with signs of both altered aortic structure and function derived in DCM using our proposed imaging protocol.

Predictive Value of Left Atrial and Ventricular Strain for the Detection of Atrial Fibrillation in Patients With Cryptogenic Stroke

Background and Aims

Cryptogenic stroke (CS) is associated with a high rate of recurrences and adverse outcomes at long-term follow-up, especially due to its unknown etiology that often leads to ineffective secondary prevention. Asymptomatic atrial fibrillation (AF) could play an important pathophysiological role. Some studies have pointed to left atrial (LA) and left ventricular (LV) systolic and diastolic dysfunction as surrogate markers of AF. The aim of the study is to evaluate the relationship between echocardiographic parameters of LA and LV function, and the occurrence of AF revealed by continuous ECG monitoring in a cohort of patients with CS.

Methods

Single-center prospective cohort study. Seventy-two patients with CS with insertable cardiac monitors (ICM) underwent transthoracic echocardiography (TTE). TTE was focused on LA and LV function, including both standard and longitudinal strain-derived parameters. All detected AF episodes lasting more than 2 min were considered.

Results

Continuous ECG monitoring revealed subclinical AF in 23 patients (32%) at an average of 6.5 months after ICM implantation. Many echocardiographic parameters, indicating LA volume and LV systolic/diastolic function, were significantly associated with the occurrence of AF, suggesting the worst atrial function in the AF group. Furthermore, multivariable regression analysis revealed that peak atrial contraction strain and left ventricular strain were independently associated with AF (adjusted OR = 0.72, CI 95% 0.48–0.90, p = 0.005, and adjusted OR = 0.69, CI 95% 0.46–0.95, p = 0.041, respectively).

Conclusion

In patients with CS, LA and LV strain analysis add predictive value for the occurrence of AF over clinical and morpho-functional echocardiographic parameters. Impaired booster pump strain and LV longitudinal strain are strong and independent predictors of AF.

Supplementation of cumin seed powder prevents oxidative stress, hyperlipidemia and non-alcoholic fatty liver in high fat diet fed rats

The present investigation was an attempt to evaluate the hypoglycemic, lipid-lowering, antioxidant and hepatoprotective effects of cumin (Cuminum cyminum family: Apiaceae) supplementation in high fat (HF) diet fed rats. Male Wistar rats were divided into four groups, such as control, control+ cumin, HF and HF+ cumin. Oral glucose tolerance test, plasma lipids, oxidative stress parameters, antioxidant enzymes activities, and liver dysfunction marker enzyme activities were evaluated. Additionally, histological staining of liver tissue was performed to evaluate the inflammatory cells infiltration, iron deposition and fibrosis. The current investigation demonstrated that 1% (w/w) supplementation of cumin powder significantly reduced HF diet-induced glucose intolerance, epididymal and mesenteric fat wet weights and lipid parameters like triglycerides, total cholesterol and low-density lipoproteins. Oxidative stress-related biomarkers including thiobarbituric acid reactive substances (TBARS), nitric oxide (NO) and advanced oxidation protein product (APOP) were also reduced by cumin supplementation. Moreover, HF-diet increased the activity of hepatic biomarker enzymes such as alanine transaminase (ALT) and alkaline phosphatase (ALP) activities which were significantly reduced by cumin powder supplementation. On the other hand, cumin powder supplementation was able to restore the reduced glutathione level with parallel augmentation of the antioxidant enzymes activities such as superoxide dismutase (SOD) and catalase in liver of HF diet-fed rats. Additionally, histological assessments confirmed that cumin powder supplementation also normalized the fat droplet deposition and inflammatory cells infiltration in the liver of HF diet-fed rats. This study suggests that cumin powder supplementation ameliorates dyslipidemia, oxidative stress and hepatic damage in HF diet-fed rats.

Arterial Hemodynamics in Prehypertensives

Compared to age-matched normotensive adults, those with essential hypertension have been shown to have distinct arterial hemodynamic abnormalities consisting of increased peripheral resistance, pulse wave velocity, and wave reflection magnitude as well as decreased wave reflection time and aortic compliance. These abnormalities are further exacerbated by beta-adrenergic blockade. To see if there are similar hemodynamic abnormalities that antedate the onset of fixed hypertension, we compared age-matched normotensives with prehypertensives selected from patients undergoing diagnostic cardiac catheterization. Ascending aortic pressure and flow were measured with a micromanometer and flow velocity sensor in the baseline state and after beta-adrenergic blockade. In the baseline state the prehypertensive compared to the normotensive group had elevated blood pressure, resistance, left ventricular end-diastolic pressure (LVEDP), and wave reflections. Beta-adrenergic blockade increased resistance, LVEDP, and wave reflections in both groups. Some of these findings are the same as those we previously reported in young persons with established, essential hypertension. The differences in LVEDP and wave reflections, both in the baseline state and after beta-blockade, were still present in subgroups with no differences in blood pressure. Hence, the elevated wave reflections in prehypertensives do not appear to be directly related to the level of blood pressure. These results support the notion that the elevated blood pressure in hypertension may represent a later manifestation of an already abnormal vascular system rather than the vascular abnormalities resulting from hypertension. Consequently, even before blood pressure becomes elevated, early diagnosis and treatment of the vascular abnormalities in prehypertensives may be warranted.

Arterial stiffness and mitral regurgitation in arterial hypertension: an intriguing pathophysiological link

BACKGROUND

We examined the relative impact of arterial stiffness on the presence and/or severity of chronic mitral regurgitation (MR) in hypertensive patients.

METHODS

We prospectively enrolled 141 untreated hypertensive patients (mean age 56.6 ± 11.5 years): 94 with MR, 47 without MR. As a measure of arterial stiffness, pulse wave velocity (PWV) was assessed by applanation tonometry. Assessment of MR severity was obtained through calculation of effective regurgitant orifice area (EROA) and vena contracta by standard two-dimensional transthoracic echocardiography.

RESULTS

PWV appears to progressively increase according to the presence and severity of MR (no MR = 7.3 ± 1.1 m/s, mild MR = 7.9 ± 1.3 m/s, moderate MR = 9.0 ± 1.7 m/s, severe MR = 13.3 ± 4.1 m/s; P < 0.001 for all comparisons). EROA was positively correlated with age (P = 0.011), left atrial volume index (P = 0.023), PWV (P < 0.001) and augmentation index (P < 0.001), and negatively correlated with left ventricular ejection fraction (P = 0.002) and heart rate (HR) (P = 0.018). On stepwise multivariate logistic regression analysis, only PWV (OR = 2.87, 95% CI 1.750-4.738, P < 0.001) and HR (OR = 0.94, 95% CI 0.895-0.994, P = 0.02) appeared to be independent predictors of severe MR. Receiver operating characteristic curves showed that a cutoff of 9 m/s for PWV provided the best sensitivity/specificity for predicting both the presence of any degree of MR (sensitivity 73%, specificity 87%, AUC = 0.863; P < 0.001) and MR severity (sensitivity 100%, specificity 81%, AUC = 0.954; P < 0.001).

CONCLUSION

Reduced arterial elasticity because of increased stiffness may be an important marker for the presence and severity of MR in hypertensive patients.

Left ventricular torsion rate and the relation to right ventricular function in pediatric pulmonary arterial hypertension

The right ventricle and left ventricle are physically coupled through the interventricular septum. Therefore, changes in the geometry and mechanics of one ventricle can directly affect the function of the other. In treatment of pediatric pulmonary arterial hypertension, the left ventricle is often overlooked, with clinical focus primarily on improving right ventricular function. Pediatric pulmonary arterial hypertension represents a disease distinct from adult pulmonary arterial hypertension based on etiology and survival rates. We aimed to assess left ventricular torsion rate in pediatric pulmonary arterial hypertension and its role in right ventricular dysfunction. Cardiac magnetic resonance images with tissue tagging were prospectively acquired for 18 pediatric pulmonary arterial hypertension (WHO class I) patients and 17 control subjects with no known cardiopulmonary disease. The pulmonary arterial hypertension cohort underwent cardiac magnetic resonance within 48 hours of clinically indicated right heart catheterization. Using right heart catheterization data, we computed single beat estimation of right ventricular end-systolic elastance (as a measure of right ventricular contractility) and ventricular vascular coupling ratio (end-systolic elastance/arterial afterload). Left ventricular torsion rate was quantified from harmonic phase analysis of tagged cardiac magnetic resonance images. Ventricular and pulmonary pressures and pulmonary vascular resistance were derived from right heart catheterization data. Right ventricular ejection fraction and interventricular septum curvature were derived from cardiac magnetic resonance. Left ventricular torsion rate was significantly reduced in pulmonary arterial hypertension patients compared to control subjects (1.40 ± 0.61° vs. 3.02 ± 1.47°, P < 0.001). A decrease in left ventricular torsion rate was significantly correlated with a decrease in right ventricular contractility (end-systolic elastance) ( r = 0.61, P = 0.007), and an increase in right ventricular systolic pressure in pulmonary arterial hypertension kids ( r = -0.54, P = 0.021). In both pulmonary arterial hypertension and control subjects, left ventricular torsion rate correlated with right ventricular ejection fraction (controls r = 0.45, P = 0.034) (pulmonary arterial hypertension r = 0.57, P = 0.032). In the pulmonary arterial hypertension group, interventricular septum curvature demonstrated a strong direct relationship with right ventricular systolic pressure ( r = 0.7, P = 0.001) and inversely with left ventricular torsion rate ( r = -0.57, P = 0.013). Left ventricular torsion rate showed a direct relationship with ventricular vascular coupling ratio ( r = 0.54, P = 0.021), and an inverse relationship with mean pulmonary arterial pressure ( r = -0.60, P = 0.008), and pulmonary vascular resistance ( r = -0.47, P = 0.049). We conclude that in pediatric pulmonary arterial hypertension, reduced right ventricular contractility is associated with decreased left ventricular torsion rate.

Management and Outcomes of Childhood Renal Artery Stenosis and Middle Aortic Syndrome

BACKGROUND

Renal artery stenosis (RAS) in isolation or in conjunction with middle aortic syndrome (MAS) are important vascular causes of childhood hypertension. Few longitudinal studies have assessed the risk of surgical or endovascular intervention, and outcomes by etiology or extent of vascular disease.

METHODS

In a retrospective study of 93 children seen over 30 years with RAS and/or MAS, data on vascular involvement (isolated RAS vs. RAS with MAS), etiology (unknown, inflammatory, or genetic), and management were collected. Time to first intervention (endovascular or surgical) was assessed by Cox regression. Mixed-effects analysis examined the longitudinal change in blood pressure after intervention compared to antihypertensive medications alone.

RESULTS

Children were 7.0 ± 5.4 years old. Etiology was unknown in 50%, genetic in 26% and inflammatory in 24% of children. Children had isolated RAS (49%) or MAS with or without RAS (51%). Overall, 70% were managed with surgical or endovascular intervention. After adjusting for age, sex, and systolic blood pressure, children with unknown etiology had a higher risk of intervention compared to those with genetic and inflammatory diseases (hazard ratio 3.1, 95% confidence interval [CI] 1.7, 5.6). Children with RAS and MAS were less likely to receive intervention (hazard ratio 0.4, 95% CI 0.2, 0.8) than isolated RAS. Over a median follow-up of 2 years, 65% remained hypertensive. The longitudinal changes in systolic blood pressure did not differ by etiology, or between interventional and medical management.

CONCLUSIONS

Hypertension persists despite endovascular or surgical management of childhood RAS and MAS highlighting the importance of close monitoring and ongoing medical management.

Cardiac amyloidosis is associated with increased aortic stiffness

OBJECTIVE

Cardiac amyloidosis (CA) is as an infiltrative disorder primarily caused by extracellular tissue deposition of amyloid fibrils in the myocardial interstitium. The current study was designed to test whether alterations in ascending aortic elastic properties could be detected by echocardiography in CA patients, and to compare their results to controls.

PATIENTS AND METHODS

We included 19 CA patients from which CA proved to be AL amyloidosis in 17 cases and transthyretin (TTR) amyloidosis in 2 cases. Their results were compared to 20 age-, gender-, and risk factor-matched controls.

RESULTS

There was significantly greater interventricular septum and left ventricular (LV) posterior wall thickness, lower LV ejection fraction and greater E/A in CA patients than in controls, suggesting systolic, and diastolic dysfunction. CA patients also showed significantly reduced aortic strain and pulsatile change in aortic diameter, and increased aortic stiffness index.

CONCLUSION

These results suggest increased aortic stiffness in CA patients.

Cardiovascular Structure and Function in Children With Middle Aortic Syndrome and Renal Artery Stenosis

Middle aortic syndrome (MAS) is a narrowing of the abdominal aorta, often in conjunction with renal artery stenosis (RAS). Structure and function of the cardiovascular system are not well understood. In a prospective cross-sectional study, 35 children with MAS or RAS or both (MAS/RAS) were compared with 140 age-, sex-, and body surface area–matched healthy children. Vascular assessment included carotid intima–media thickness and carotid distensibility using B-mode ultrasound and central and peripheral pulse wave velocities using applanation tonometry. Left ventricular structure and function were assessed by 2-dimensional and speckle-tracking echocardiography. Children with MAS or RAS were 12.5±3.0 years old at enrollment, and 50% were men. Carotid intima–media thickness (0.54±0.10 versus 0.44±0.05 mm; P <0.001) and central pulse wave velocities (5.58±1.83 versus 5.00±0.90 m/s; P =0.01) were significantly higher in children with disease compared with healthy children; however, after adjustment for systolic blood pressure z score, only carotid intima–media thickness remained significantly higher in the MAS/RAS group compared with the controls (β=0.07 [0.03, 0.10]). Peripheral pulse wave velocities and carotid distensibility were normal. Children with disease had significantly increased left ventricular mass and changes in diastolic function (lower E/a ratio and lower e′ velocities). Systolic parameters, including ejection fraction, global longitudinal and circumferential strain, were similar to controls. Our findings demonstrate that children with MAS or RAS have evidence of carotid and left ventricular remodeling, without peripheral arterial involvement, which suggests a localized disease process. Left ventricular systolic function is preserved; however, subtle changes in diastolic function are observed. Carotid vessel changes are consistent with a 5- to 10-year aging, which underscores the importance of blood pressure control.

Ankle-brachial index and physical function in older individuals: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

Most prior studies investigating the association of lower extremity peripheral artery disease (PAD) with physical function were small or analyzed selected populations (e.g., patients at vascular clinics or persons with reduced function), leaving particular uncertainty regarding the association in the general community.

METHODS

Among 5262 ARIC participants (age 71-90 years during 2011-2013), we assessed the cross-sectional association of ankle-brachial index (ABI) with the Short Physical Performance Battery (SPPB) score (0-12), its individual components (chair stands, standing balance, and gait speed) (0-4 points each), and grip strength after accounting for potential confounders, including a history of coronary disease, stroke, or heart failure.

RESULTS

There were 411 participants (7.8%) with low ABI ≤0.90 and 469 (8.9%) participants with borderline low ABI 0.91-1.00. Both ABI ≤0.90 and 0.91-1.00 were independently associated with poor physical function (SPPB score ≤6) compared to ABI 1.11-1.20 (adjusted odds ratio 2.10 [95% CI 1.55-2.84] and 1.86 [1.38-2.51], respectively). The patterns were largely consistent across subgroups by clinical conditions (e.g., leg pain or other cardiovascular diseases), in every SPPB component, and for grip strength. ABI >1.3 (472 participants [9.0%]), indicative of non-compressible pedal arteries, was related to lower physical function as well but did not necessarily reach significance.

CONCLUSIONS

In community-dwelling older adults, low and borderline low ABI suggestive of PAD were independently associated with poorer systemic physical function compared to those with normal ABI. Clinical attention to PAD as a potential contributor to poor physical function is warranted in community-dwelling older adults.

Flavonoids Extraction from Propolis Attenuates Pathological Cardiac Hypertrophy through PI3K/AKT Signaling Pathway

Propolis, a traditional medicine, has been widely used for a thousand years as an anti-inflammatory and antioxidant drug. The flavonoid fraction is the main active component of propolis, which possesses a wide range of biological activities, including activities related to heart disease. However, the role of the flavonoids extraction from propolis (FP) in heart disease remains unknown. This study shows that FP could attenuate ISO-induced pathological cardiac hypertrophy (PCH) and heart failure in mice. The effect of the two fetal cardiac genes, atrial natriuretic factor (ANF) and β-myosin heavy chain (β-MHC), on PCH was reversed by FP. Echocardiography analysis revealed cardiac ventricular dilation and contractile dysfunction in ISO-treated mice. This finding is consistent with the increased heart weight and cardiac ANF protein levels, massive replacement fibrosis, and myocardial apoptosis. However, pretreatment of mice with FP could attenuate cardiac dysfunction and hypertrophy in vivo. Furthermore, the cardiac protection of FP was suppressed by the pan-PI3K inhibitor wortmannin. FP is a novel cardioprotective agent that can attenuate adverse cardiac dysfunction, hypertrophy, and associated disorder, such as fibrosis. The effects may be closely correlated with PI3K/AKT signaling. FP may be clinically used to inhibit PCH progression and heart failure.