52 research outputs found
Chronic elevation of pulmonary microvascular pressure in chronic heart failure reduces bi-directional pulmonary fluid flux
Aims. Chronic heart failure leads to pulmonary vascular remodelling and thickening of the alveolarācapillary barrier. We examined whether this protective effect may slow resolution of pulmonary oedema consistent with decreased bi-directional fluid flux.
Methods and results. Seven weeks following left coronary artery ligation, we measured both fluid flux during an acute rise in left atrial pressure (n = 29) and intrinsic alveolar fluid clearance (n = 45) in the isolated rat lung. Chronic elevation of pulmonary microvascular pressure prevented pulmonary oedema and decreased lung compliance when left atrial pressure was raised to 20 cmH2O, and was associated with reduced expression of endothelial aquaporin 1 (P = 0.03). However, no other changes were found in mediators of fluid flux or cellular fluid channels. In isolated rat lungs, chronic LV dysfunction (LV end-diastolic pressure and infarct circumference) was also inversely related to alveolar fluid clearance (P ā¤ 0.001). The rate of pulmonary oedema reabsorption was estimated by plasma volume expansion in eight patients with a previous clinical history of chronic heart failure and eight without, who presented with acute pulmonary oedema. Plasma volume expansion was reduced at 24 h in those with chronic heart failure (P = 0.03).
Conclusions. Chronic elevation of pulmonary microvascular pressure in CHF leads to decreased intrinsic bi-directional fluid flux at the alveolarācapillary barrier. This adaptive response defends against alveolar flooding, but may delay resolution of alveolar oedema.A National Health and Medical Research Council (NHMRC) grant (#375129); Australian and New Zealand College of Anaesthetists (ANZCA) grant (#08/020); the Flinders Medical Centre Foundation
Long term prognostic importance of late gadolinium enhancement in first-presentation non-ischaemic dilated cardiomyopathy
Ā© 2019 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This author accepted manuscript is made available following 12 month embargo from date of publication (January 2019) in accordance with the publisherās archiving policyBackground
Presence of myocardial fibrosis in well-established non-ischaemic dilated cardiomyopathy (NIDCM) is associated with adverse clinical outcomes. However, the impact of myocardial fibrosis at first presentation in NIDCM, and its long-term association with left ventricular (LV) dysfunction, heart failure (HF) and ventricular arrhythmia (VA) remains unclear. We investigated whether the presence of myocardial fibrosis quantified by late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) at presentation, is independently associated with long-term major adverse cardiovascular events (MACE) in patients with first presentation NIDCM.
Methods
Consecutive patients with a first diagnosis of NIDCM were recruited. Patients underwent LGE-CMR at baseline. Replacement myocardial fibrosis by LGE-CMR was quantified by experienced observers blinded to patient outcome. MACE was defined as a composite end-point including cardiac death, HF rehospitalisation and the occurrence of sustained VA.
Results
Fifty-one patients with first presentation NIDCM were included, of which 49 (96%) had follow up and outcome data. Median follow up was 8.2āÆyears. Both the LGE positive and LGE negative groups had similar clinical characteristics at follow up. In univariate Cox regression analysis, positive LGE was associated with MACE (HR:3.44; 95% CI:1.89 to 6.24, p-valueāÆ<āÆ0.001) and HF rehospitalisation (HR:2.89; 95% CI:1.42 to 5.85, p-valueāÆ=āÆ0.003). In multivariate Cox regression, positive LGE-CMR was independently associated with MACE (HR:3.53; 95% CI:1.51 to 8.27, p-valueāÆ=āÆ0.004) and HF rehospitalisation (HR:3.07; 95% CI:1.24 to 7.59, p-valueāÆ=āÆ0.015).
Conclusions
The presence of myocardial fibrosis in first presentation NIDCM is independently associated with an increased risk of HF rehospitalisation, at long term follow-up
Perspectives in noninvasive imaging for chronic coronary syndromes
Both the latest European guidelines on chronic coronary syndromes and the American guidelines on chest pain have underlined the importance of noninvasive imaging to select patients to be referred to invasive angiography. Nevertheless, although coronary stenosis has long been considered the main determinant of inducible ischemia and symptoms, growing evidence has demonstrated the importance of other underlying mechanisms (e.g., vasospasm, microvascular disease, energetic inefficiency). The search for a pathophysiology-driven treatment of these patients has therefore emerged as an important objective of multimodality imaging, integrating "anatomical" and "functional" information. We here provide an up-to-date guide for the choice and the interpretation of the currently available noninvasive anatomical and/or functional tests, focusing on emerging techniques (e.g., coronary flow velocity reserve, stress-cardiac magnetic resonance, hybrid imaging, functional-coronary computed tomography angiography, etc.), which could provide deeper pathophysiological insights to refine diagnostic and therapeutic pathways in the next future
Quantitative assessment of paravalvular regurgitation following transcatheter aortic valve replacement
Paravalvular aortic regurgitation (PAR) following transcatheter aortic valve implantation (TAVI) is well acknowledged. Despite improvements, echocardiographic measurement of PAR largely remains qualitative. Cardiovascular magnetic resonance (CMR) directly quantifies AR with accuracy and reproducibility. We compared CMR and transthoracic echocardiography (TTE) analysis of pre-operative and post-operative aortic regurgitation in patients undergoing both TAVI and surgical aortic valve replacement (AVR).Gareth Crouch, Phillip J Tully, Jayme Bennetts, Ajay Sinhal, Craig Bradbrook, Amy L Penhall, Carmine G De Pasquale, Robert A Baker, and Joseph B Selvanayaga
Global disparities in surgeonsā workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study
: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSSĀ® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 Ā± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 Ā± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 Ā± 4.9 and 7.8 Ā± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 Ā± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI
Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTICāHF: baseline characteristics and comparison with contemporary clinical trials
Aims:
The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTICāHF) trial. Here we describe the baseline characteristics of participants in GALACTICāHF and how these compare with other contemporary trials.
Methods and Results:
Adults with established HFrEF, New York Heart Association functional class (NYHA)āā„āII, EF ā¤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokineticāguided dosing: 25, 37.5 or 50āmg bid). 8256 patients [male (79%), nonāwhite (22%), mean age 65āyears] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NTāproBNP 1971āpg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTICāHF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressureā<ā100āmmHg (n = 1127), estimated glomerular filtration rate <ā30āmL/min/1.73 m2 (n = 528), and treated with sacubitrilāvalsartan at baseline (n = 1594).
Conclusions:
GALACTICāHF enrolled a wellātreated, highārisk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
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