Abstract
Aims
Hypertension is a well-established heart failure (HF) risk factor, especially in the context of adverse left ventricular (LV) remodelling. We aimed to use myocardial flow reserve (MFR) ...and global longitudinal strain (GLS), markers of subclinical microvascular and myocardial dysfunction, to refine hypertensive HF risk assessment.
Methods and results
Consecutive patients undergoing symptom-prompted stress cardiac positron emission tomography (PET)-computed tomography and transthoracic echocardiogram within 90 days without reduced left ventricular ejection fraction (<40%) or flow-limiting coronary artery disease (summed stress score ≥ 3) were included. Global MFR was quantified by PET, and echocardiograms were retrospectively analysed for cardiac structure and function. Patients were followed over a median 8.75 (Q1–3 4.56–10.04) years for HF hospitalization and a composite of death, HF hospitalization, MI, or stroke. Of 194 patients, 155 had adaptive LV remodelling while 39 had maladaptive remodelling, which was associated with lower MFR and impaired GLS. Across the remodelling spectrum, diastolic parameters, GLS, and N-terminal pro-B-type natriuretic peptide were independently associated with MFR. Maladaptive LV remodelling was associated with increased adjusted incidence of HF hospitalization and death. Importantly, the combination of abnormal MFR and GLS was associated with a higher rate of HF hospitalization compared to normal MFR and GLS adjusted hazard ratio (HR) 3.21, 95% confidence interval (CI) 1.09–9.45, P = 0.034), including in the adaptive remodelling subset (adjusted HR 3.93, 95% CI 1.14–13.56, P = 0.030).
Conclusion
We have demonstrated important associations between coronary microvascular dysfunction and myocardial mechanics that refine disease characterization and HF risk assessment of patients with hypertension based on subclinical target organ injury.
Aims
The present study aimed to assess the association between left atrial (LA) structure and function and the risk for cardiovascular (CV) death or heart failure (HF) hospitalization in a population ...with atrial fibrillation (AF).
Methods and results
In a prospective echocardiographic substudy of the Effective Anticoagulation with Factor Xa Next Generation in AF‐Thrombolysis in Myocardial Infarction 48 (ENGAGE AF‐TIMI 48) study, 971 patients underwent transthoracic echocardiography. The associations between LA structure (LA volume index LAVi) and function (LA emptying fraction LAEF and LA expansion index LAEi) and risk for the composite endpoint of CV death or HF hospitalization, and its components, were assessed. Over a median follow‐up of 2.5 years, 142 patients (14.6%) experienced CV death or HF hospitalization. Higher LAVi and lower LAEF and LAEi were each associated with a higher unadjusted risk for the composite outcome and its components. After adjustment for clinical and echocardiographic confounders, only measures of impaired LA function were predictive of the composite outcome (hazard ratio HR per 1 standard deviation SD decrease in LAEF: 1.35; 95% confidence interval CI 1.09–1.67 P = 0.005; HR per 1 SD decrease in LAEi: 1.34; 95% CI 1.06–1.69 P = 0.012). These findings were similar regardless of left ventricular ejection fraction, history of HF or whether patients were in AF or sinus rhythm at the time of the echocardiographic examination.
Conclusions
In patients with AF, LA dysfunction was significantly associated with an increased risk for CV death or HF hospitalization and was more predictive of these outcomes than LA size. These parameters may help to identify AF patients at greatest risk for the development of HF.
Clinical Trial Registration: ClinicalTrials.gov, NCT00781391.
Hypertensive disorders of pregnancy (HDP) are associated with long-term maternal risks for cardiovascular disease for reasons that remain incompletely understood.
The HCHS/SOL (Hispanic Community ...Health Study/Study of Latinos), a multi-center community-based cohort of Hispanic/Latino adults recruited 2008 to 2011, was used to evaluate the associations of history of de novo HDP (gestational hypertension, preeclampsia, eclampsia) with echocardiographic measures of cardiac structure and function in Hispanic/Latina women with ≥1 prior pregnancy and the proportion of association mediated by current hypertension (>140/90 mm Hg or antihypertensive therapy).
The study cohort included 5168 Hispanic/Latina women with an average age (SD) of 58.7 (9.7) years at time of echocardiogram. Prior de novo HDP was reported by 724 (14%) of the women studied and was associated with lower left ventricle (LV) ejection fraction -0.66 (95% confidence interval CI, -1.21 to -0.11), higher LV relative wall thickness 0.09 (95% CI, 0-0.18), and 1.39 (95% CI, 1.02-1.89) higher risk of abnormal LV geometry after adjusting for blood pressure and other confounders. The proportion of the association mediated by current hypertension between HDP and LV ejection fraction was 0.09 (95% CI, 0.03-0.45), LV relative wall thickness was 0.28 (95% CI, 0.16-0.51), abnormal LV geometry was 0.14 (95% CI, 0.12-0.48), concentric left ventricular hypertrophy was 0.31 (95% CI, 0.19-0.86), and abnormal LV diastolic dysfunction was 0.58 (95% CI, 0.26-0.79).
In a large cohort of Hispanic/Latina women those with history of de novo HDP had detectable and measurable subclinical alterations in cardiac structure and both systolic and diastolic dysfunction that were only partially mediated by current hypertension.
Communities throughout the Pacific Islands region have experienced, and will continue to experience, extensive non-economic loss and damage (NELD) from climate change. Assessments of loss and damage, ...however, often fall short on their coverage of these non-economic dimensions, which can distort our understanding of climate change impacts, discount the experiences of some and skew future decision-making. This paper explores how stakeholders in the Pacific Islands understand NELD and what they perceive to be the best ways of responding to it. An open-ended questionnaire was used to collect qualitative and quantitative data from representatives from governments, donors and development partners, civil society, intergovernmental organisations, and relevant others. This study found that NELD in the Pacific Islands is understood, perceived and experienced through the lens of intangible values, identity and cultural landscapes, and this is encapsulated by a typology with eight interconnected core dimensions. These eight dimensions include: health and wellbeing, ways of being, future ways of being, cultural sites and sacred places, Indigenous and local knowledge, life sustaining tools, biodiversity and ecosystem services, and connection to land and sea. NELD is complex, entangled and interconnected, thereby significantly undermining entire socio-ecological systems. Moving forward, responding to NELD in the Pacific Islands region will require a comprehensive approach that protects, conserves and restores complex socio-ecological systems, and provides opportunities to work through loss and damage by means of education and training, safeguarding knowledge systems, community activities, cultural connection and maintenance, and strong relationships with land and sea.
A series of novel polyhedral oligomelic silsesquioxane (POSS)-containing triblock copolymers that self-assemble into hexagonally-packed cylinders of the POSS domain in a polystyrene (PS) matrix was ...developed in this study. POSS-containing diblock copolymers prefer to form lamellae as the aggregation of the rigid rods of the POSS-containing polymer chains results in a zero interfacial curvature. Cylindrical structures of the POSS-containing domain could not be obtained even when the volume fraction of the POSS-containing domain was reduced. Therefore, to obtain the cylindrical structures which are desirable for nanofabrication purposes, we designed a novel triblock copolymer with short polyisoprene (PI) middle blocks inserted between PS and poly(polyhedral oligomeric silsesquioxane methacrylate) (PMAPOSS) blocks. Differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) analyses suggested that the short PI block does not form a separate domain but is miscible with the PS and PMAPOSS blocks. This intermixing of the PI block has led to the development of a controlled interfacial region (CIR) between the two domains and a non-zero interfacial curvature required for forming cylinders.
Abstract Climate-smart agriculture has emerged as a way of increasing food productivity, building resiliency to climate change and reducing carbon emissions. Despite rapid technical advances, ...research on climate-smart agriculture has arguably under-theorized the socio-political processes that continue to marginalize vulnerable groups such as smallholder farmers. This review discusses the potential usefulness of political ecology perspectives for improving climate-smart agriculture. Political ecology theory elucidates how three interrelated socio-political processes that perpetuate smallholder farmer vulnerability significantly influence climate-smart responses: inequality, unequal power relations and social injustice. The article discusses these three inter-connected political ecology factors using a number of examples from the Green Revolution, smallholder farming communities, and indigenous farmers. In comparison to conventional technical approaches, our article argues that Climate-Smart Agriculture needs to consider political ecology perspectives at different levels to explore the vulnerability of smallholder farmers to current and future climate change impacts. Interventions to support climate-smart agriculture should examine local risks, specificities and priorities of smallholder farmers. The article concludes with a renewed call for concepts of inequality, unequal power relations and social injustice to be embedded into both the policy and practice of climate smart agriculture. Keywords: climate-smart agriculture, equality, political ecology, power, smallholder, social justice
This study sought to assess the effects of neurohormonal therapies in preventing cardiotoxicity in patients receiving chemotherapy.
Various cardioprotective approaches have been evaluated to prevent ...chemotherapy-related cardiotoxicity; however, their overall utility remains uncertain.
This meta-analysis included randomized clinical trials of adult patients that underwent chemotherapy and neurohormonal therapies (β-blockers, mineralocorticoid receptor antagonists, or angiotensin-converting enzyme inhibitors/angiotensin receptor blockers) versus placebo with follow-up ≥4 weeks. The primary outcome was change in left ventricular ejection fraction (LVEF) from baseline to the end of the trial. Other outcomes of interest were measures of LV size, strain, and diastolic function. Pooled estimates for each outcome were reported as standardized mean difference and weighted mean difference between the neurohormonal therapy and placebo groups using random effects models.
We included 17 trials, collectively enrolling 1,984 participants. In pooled analysis, neurohormonal therapy (vs. placebo) was associated with significantly higher LVEF on follow-up (standardized mean difference: +1.04 95% confidence interval (CI): 0.57 to 1.50) but with significant heterogeneity in the pooled estimate (I2 = 96%). Compared with placebo-treated patients, those randomized to neurohormonal therapies experienced a 3.96% (95% CI: 2.90 to 5.02) less decline in LVEF estimated by weighted mean difference, but with significant heterogeneity (I2 = 98%). There was a trend toward lower adverse clinical events with neurohormonal therapy (vs. placebo) that did not meet statistical significance (risk ratio: 0.80 95% CI: 0.53 to 1.20; I2 = 71%).
Neurohormonal therapies are associated with higher LVEF in follow-up among cancer patients receiving chemotherapy, although absolute changes in LVEF are small and may be within inter-test variability. Furthermore, significant heterogeneity is observed in the treatment effects across studies highlighting the need for larger trials of cardioprotective strategies.
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Low cardiorespiratory fitness (CRF), high body mass index, and excess visceral adiposity are each associated with impairment in left ventricular (LV) peak circumferential strain (E
), an intermediate ...phenotype that precedes the development of clinical heart failure (HF). However, the association of regional fat distribution and CRF with E
independent of each other and other potential confounders is not known.
Participants from the Dallas Heart Study Phase 2 who underwent dual energy X-ray absorptiometry assessment of regional fat distribution, CRF assessment by submaximal treadmill test, and E
quantification by tissue-tagged cardiovascular magnetic resonance were included in the analysis. The cross-sectional associations of measures of regional adiposity, namely visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and lower-body fat (LBF) with E
after adjustment for CRF and other potential confounders (independent variables) were assessed using multivariable linear regression analysis.
The study included 1089 participants (55% female, 39% black). In the unadjusted analysis, higher VAT was associated with greater impairment in E
. After adjustment for baseline risk factors, CRF, parameters of LV structure and function, and other fat depots such as SAT and LBF, higher VAT remained associated with greater impairment in E
(β: 0.19, P = 0.002). SAT and LBF were not significantly associated with E
, however, CRF remained associated with E
in the fully adjusted model including all fat depots (β: - 0.15, P < 0.001).
VAT and CRF are each independently associated with impairment in E
, suggesting that higher VAT burden and low CRF mediate pathological cardiac remodeling through distinct mechanisms.
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