Factors associated with diastolic dysfunction in patients with resistant hypertension: resist-POL study

Spironolactone improves left atrial function and atrioventricular coupling in patients with resistant hypertension

To determine the blood pressure independent effects of spironolactone on left atrial (LA) size and function in patients with resistant hypertension (RHTN). Patients with RHTN (n = 36, mean age 55 ± 7) were prospectively recruited. Spironolactone was initiated at 25 mg/day and increased to 50 mg/day after 4 weeks. Other antihypertensives were withdrawn to maintain constant blood pressure. Cardiac magnetic resonance imaging was performed at baseline and after 6 months of spironolactone treatment and changes in LA functional metrics were assessed. LA size and function parameters were improved (p < 0.05) from baseline to month-6: LA volumes indexed to body surface area (LAVI) were reduced (LAVImaximum 41.4 ± 12 vs. 33.2±9.7 mL/m2; LAVIpre-A 32.6 ± 9.8 vs. 25.6 ± 8.1 mL/m2; median LAVIminimum 18.5 [13.9-24.8] vs. 14.1 [10.9-19.2] mL/m2); left atrioventricular coupling index was reduced (28.2 ± 11.5 vs. 22.7 ± 9.2%); LA emptying fractions (LAEF) were increased (median total LAEF 52.4 [48.7-60.3] vs. 55.9 [50.3-61.1] %; active LAEF 40.2 ± 8.6 vs. 43.1 ± 7.8%). LA global longitudinal strain in the active phase was increased (16.3 ± 4.1 vs. 17.8 ± 4.2%). The effect of spironolactone was similar in patients with high (N = 18) and normal (N = 18) aldosterone status (defined by plasma renin activity and 24-h urine aldosterone). Treatment of RHTN with spironolactone is associated with improvements in LA size and function, and atrioventricular coupling, regardless of whether aldosterone levels were normal or high at baseline. This study suggests the need for larger prospective studies examining effects of mineralocorticoid receptor antagonists on atrial function and atrioventricular coupling.

Obstructive sleep apnoea syndrome and left ventricular hypertrophy: a meta-analysis of echocardiographic studies

AIM

We investigated the association between obstructive sleep apnoea (OSA) and subclinical cardiac organ damage through a meta-analysis of echocardiographic studies that provided data on left ventricular hypertrophy (LVH), assessed as a categorical or continuous variable.

DESIGN

The PubMed, OVID-MEDLINE, and Cochrane library databases were systematically analyzed to search English-language articles published from 1 January 2000 to 15 August 2019. Studies were detected by using the following terms: 'obstructive sleep apnea', 'sleep quality', 'sleep disordered breathing', 'cardiac damage', 'left ventricular mass', 'left ventricular hypertrophy', and 'echocardiography'.

RESULTS

Meta-analysis included 5550 patients with OSA and 2329 non-OSA controls from 39 studies. The prevalence of LVH in the pooled OSA population was 45% (CI 35--55%). Meta-analysis of studies comparing the prevalence of LVH in participants with OSA and controls showed that OSA was associated with an increased risk of LVH (OR = 1.70, CI 1.44-2.00, P < 0.001). LV mass was significantly increased in patients with severe OSA as compared with controls (SMD 0.46 ± 0.08, CI 0.29-0.62, P < 0.001) or with mild OSA. This was not the case for studies comparing patients with unselected or predominantly mild OSA and controls (0.33 ± 0.17, CI -0.01 to 0.67, P = 0.057).

CONCLUSION

The present meta-analysis expands previous information on the relationship between OSA and echocardiographic LVH, so far based on individual studies. The overall evidence strongly suggests that the likelihood of LVH increases with the severity of OSA, thus exhibiting a continuous relationship.

Obstructive Sleep Apnea-Induced Neurogenic Nocturnal Hypertension: A Potential Role of Renal Denervation?

There is a bidirectional, causal relationship between obstructive sleep apnea (OSA) and hypertension. OSA-related hypertension is characterized by high rates of masked hypertension, elevated nighttime blood pressure, a nondipper pattern of nocturnal hypertension, and abnormal blood pressure variability. Hypoxia/hypercapnia-related sympathetic activation is a key pathophysiological mechanism linking the 2 conditions. Intermittent hypoxia also stimulates the renin-angiotensin-aldosterone system to promote hypertension development. The negative and additive cardiovascular effects of OSA and hypertension highlight the importance of effectively managing these conditions, especially when they coexist in the same patient. Continuous positive airway pressure is the gold standard therapy for OSA but its effects on blood pressure are relatively modest. Furthermore, this treatment did not reduce the cardiovascular event rate in nonsleepy patients with OSA in randomized controlled trials. Antihypertensive agents targeting sympathetic pathways or the renin-angiotensin-aldosterone system have theoretical potential in comorbid hypertension and OSA, but current evidence is limited and combination strategies are often required in drug resistant or refractory patients. The key role of sympathetic nervous system activation in the development of hypertension in OSA suggests potential for catheter-based renal sympathetic denervation. Although long-term, randomized controlled trials are needed, available data indicate sustained and relevant reductions in blood pressure in patients with hypertension and OSA after renal denervation, with the potential to also improve respiratory parameters. The combination of lifestyle interventions, optimal pharmacological therapy, continuous positive airway pressure therapy, and perhaps also renal denervation might improve cardiovascular risk in patients with OSA.

Longitudinal changes in maternal left atrial volume index and uterine artery pulsatility indices in uncomplicated pregnancy

BACKGROUND

Data on the relationship between longitudinal changes in maternal volume-dependent echocardiographic parameters and placentation in uncomplicated pregnancy are limited.

OBJECTIVE

This study aimed to evaluate changes in volume-dependent echocardiographic parameters in uncomplicated pregnancy to test the hypothesis of the existence of an association between volume-dependent echocardiographic parameters and Doppler ultrasound parameters of fetal circulation and the uterine artery in uncomplicated pregnancy and to establish which of the volume-dependent echocardiographic parameters best depicts volume changes and correlates best with Doppler ultrasound of fetal circulation and the uterine artery in healthy pregnancy.

STUDY DESIGN

Data from 60 healthy pregnant women were analyzed. A complete echocardiographic study was performed at 11 to 13, 20 to 22, and 30 to 32 weeks' gestation: left ventricular end-diastolic volume, early diastolic peak flow velocity, late diastolic peak flow velocity, left atrial area, and left atrial volume index were assessed. Obstetrical assessment was performed including fetal growth and uterine artery pulsatility index. Fetal well-being was assessed by umbilical and middle cerebral artery blood flow. Serum pregnancy-associated plasma protein A and free β-human chorionic gonadotropin were assessed during the routine first-trimester scan (11-13 weeks' gestation).

RESULTS

Left ventricular end-diastolic volume and left atrial area increased significantly between 11 to 13 and 20 to 22 weeks' gestation but not between 20 to 22 and 30 to 32 weeks' gestation. Left atrial volume index measured at 30 to 32 weeks' gestation correlated with uterine artery pulsatility indices in 3 trimesters. Changes in the left atrial volume index between the third and first trimesters correlated significantly with the uterine artery pulsatility index measured at 20 to 22 weeks' gestation (r=-0.345; P=.020) and at 30 to 32 weeks' gestation (r=-0.452; P=.002). Changes in the left atrial volume index between the second and first trimesters significantly correlated with the uterine artery pulsatility index measured in the first trimester (r=-0.316; P=.025).

CONCLUSION

Our study showed that in an uncomplicated pregnancy, among volume-dependent echocardiographic parameters, left atrial volume index increased between both the first and second trimesters and the second and third trimesters and correlated with parameters of Doppler ultrasound of the fetal circulation and the uterine artery. Our results expand on the previous observation on the relationship between maternal cardiovascular adaptation and placentation in women with heart diseases to the population of healthy women with uncomplicated pregnancy.

Targeting subclinical organ damage in obstructive sleep apnea: a narrative review

Subclinical abnormalities in cardiac and vascular structure reflect the adverse effects triggered by a variety of risk factors on the cardiovascular (CV) system thereby representing an intermediate step in the cardiovascular continuum; such alterations are recognized as reliable markers of increased cardiovascular risk in different clinical settings including obstructive sleep apnea (OSA). The mechanisms underlying subclinical organ damage (OD) in the OSA setting are multifactorial. Hypoxemia and hypercapnia, induced by repeated collapses of upper airways, have been suggested to trigger a cascade of events such as activation of the sympathetic tone, renin-angiotensin-aldosterone system leading to endothelial dysfunction, vasoconstriction, myocardial and vascular remodeling, and hypertension. Furthermore, coexisting non-haemodynamic alterations such as increased oxidative stress, release of inflammatory substances, enhanced lipolysis and insulin resistance have been reported to play a role in the pathogenesis of both cardiac and extra-cardiac OD. In this article we reviewed available evidence on the association between OSA and subclinical cardiac (i.e., left and right ventricular hypertrophy, left atrial dilatation) and extra-cardiac organ damage (i.e., carotid atherosclerosis, arterial stiffness, microvascular retinal changes, and microalbuminuria). This association is apparently stronger for cardiac and carotid subclinical damage than for other markers (i.e., arterial stiffness and retinal changes) and mostly evident in the setting of severe OSA.

On the search for the right definition of heart failure with preserved ejection fraction

The definition of heart failure with preserved ejection fraction (HFpEF) has evolved from a clinically based "diagnosis of exclusion" to definitions focused on objective evidence of diastolic dysfunction and/or elevated left ventricular filling pressures. Despite advances in our understanding of HFpEF pathophysiology and the development of more sophisticated imaging modalities, the diagnosis of HFpEF remains challenging, especially in the chronic setting, given that symptoms are provoked by exertion and diagnostic evaluation is largely conducted at rest. Invasive hemodynamic study, and in particular - invasive exercise testing, is considered the reference method for HFpEF diagnosis. However, its use is limited as opposed to the high number of patients with suspected HFpEF. Thus, diagnostic criteria for HFpEF should be principally based on non-invasive measurements. As no single non-invasive variable can adequately corroborate or refute the diagnosis, different combinations of clinical, echocardiographic, and/or biochemical parameters have been introduced. Recent years have brought an abundance of HFpEF definitions. Here, we present and compare four of them: 1) the 2016 European Society of Cardiology criteria for HFpEF; 2) the 2016 echocardiographic algorithm for diagnosing diastolic dysfunction; 3) the 2018 evidence-based H2FPEF score; and 4) the most recent, 2019 Heart Failure Association HFA-PEFF algorithm. These definitions vary in their approach to diagnosis, as well as sensitivity and specificity. Further studies to validate and compare the diagnostic accuracy of HFpEF definitions are warranted. Nevertheless, it seems that the best HFpEF definition would originate from a randomized clinical trial showing a favorable effect of an intervention on prognosis in HFpEF.

Targeting Concentric Left Ventricular Hypertrophy in Obstructive Sleep Apnea Syndrome. A Meta-analysis of Echocardiographic Studies

AIM

We assessed the association between obstructive sleep apnea (OSA) and left ventricular hypertrophy (LVH) subtypes (i.e., concentric and eccentric LVH) trough a meta-analysis of echocardiographic studies.

DESIGN

The PubMed, OVID-MEDLINE, and Cochrane library databases were systematically analyzed to search full papers published from 1st January 2000 to 31st August 2019. Studies were detected by using the following terms: "obstructive sleep apnea", "sleep disordered breathing", "left ventricular mass", "left ventricular geometry", "left ventricular hypertrophy", "echocardiography".

RESULTS

Meta-analysis included 1,760 patients with OSA and 1,284 non-OSA controls from 9 studies. The prevalence rates of concentric and eccentric LVH in the pooled OSA population were 24.0% (confidence interval [CI] 16.0-33.0%) and 16.0% (CI 12.0-23.0%), respectively. Meta-analysis of six studies comparing the prevalence of LVH subtypes in participants with OSA and controls showed that OSA was associated with an increased risk of both concentric (odds ratio [OR] = 1.62, CI: 1.27-2.07, P < 0.0001) and eccentric (OR = 1.34, CI: 1.07-1.67, P < 0.009) LVH, respectively.

CONCLUSIONS

Our findings suggest that in the OSA setting concentric LVH is more frequent than eccentric LVH. From a practical perspective, in consideration of the particularly adverse prognostic significance of concentric LVH, a comprehensive echocardiographic evaluation targeting LVH subtypes could improve cardiovascular risk stratification in patients with OSA.