Vulnerability to environmental and climatic health provocations among women and men hospitalized with chronic heart disease: insights from the RESILIENCE TRIAL cohort

AIMS

We aimed to recruit a representative cohort of women and men with multi-morbid chronic heart disease as part of a trial testing an innovative, nurse-co-ordinated, multi-faceted intervention to lower rehospitalization and death by addressing areas of vulnerability to external challenges to their health.

METHODS AND RESULTS

The prospective, randomized open, blinded end-point RESILIENCE Trial recruited 203 hospital inpatients (mean age 75.7 ± 10.2 years) of whom 51% were women and 94% had combined coronary artery disease, heart failure, and/or atrial fibrillation. Levels of concurrent multi-morbidity were high (mean Charlson Index of Comorbidity Score 6.5 ± 2.7), and 8.9% had at least mild frailty according to the Rockwood Clinical Frailty Scale. Including the index admission, 19-20% of women and men had a pre-existing pattern of seasonally linked hospitalization (seasonality). Detailed phenotyping revealed that 48% of women and 40% of men had ≥3 physiological factors, and 15% of women and 16% of men had ≥3 behavioural factors likely to increase their vulnerability to external provocations to their health. Overall, 61-62% of women and men had ≥4 combined factors indicative of such vulnerability. Additional factors such as reliance on the public health system (63 vs. 49%), lower education (30 vs. 14%), and living alone (48 vs. 29%) were more prevalent in women.

CONCLUSION

We successfully recruited women and men with multi-morbid chronic heart disease and bio-behavioural indicators of vulnerability to external provocations to their health. Once completed, the RESILIENCE TRIAL will provide important insights on the impact of addressing such vulnerability (promoting resilience) on subsequent health outcomes.

REGISTRATION

ClinicalTrials.org: NCT04614428.

Renin Levels and Angiotensin II Responsiveness in Vasopressor-Dependent Hypotension

OBJECTIVES

The relationship between renin levels, exposure to renin-angiotensin system (RAS) inhibitors, angiotensin II (ANGII) responsiveness, and outcome in patients with vasopressor-dependent vasodilatory hypotension is unknown.

DESIGN

We conducted a single-center prospective observational study to explore whether recent RAS inhibitor exposure affected baseline renin levels, whether baseline renin levels predicted ANGII responsiveness, and whether renin levels at 24 hours were associated with clinical outcomes.

SETTING

An academic ICU in Melbourne, VIC, Australia.

PATIENTS

Forty critically ill adults who received ANGII as the primary agent for vasopressor-dependent vasodilatory hypotension who were included in the Acute Renal effects of Angiotensin II Management in Shock study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

After multivariable adjustment, recent exposure to a RAS inhibitor was independently associated with a relative increase in baseline renin levels by 198% (95% CI, 36-552%). The peak amount of ANGII required to achieve target mean arterial pressure was independently associated with baseline renin level (increase by 46% per ten-fold increase; 95% CI, 8-98%). Higher renin levels at 24 hours after ANGII initiation were independently associated with fewer days alive and free of continuous renal replacement therapy (CRRT) (-7 d per ten-fold increase; 95% CI, -12 to -1).

CONCLUSIONS

In patients with vasopressor-dependent vasodilatory hypotension, recent RAS inhibitor exposure was associated with higher baseline renin levels. Such higher renin levels were then associated with decreased ANGII responsiveness. Higher renin levels at 24 hours despite ANGII infusion were associated with fewer days alive and CRRT-free. These preliminary findings emphasize the importance of the RAS and the role of renin as a biomarker in patients with vasopressor-dependent vasodilatory hypotension.

Door-to-diuretic time and mortality in patients with acute heart failure: A systematic review and meta-analysis

Early decongestion therapy with intravenous diuretics may be associated with improved outcomes in acute heart failure (AHF), however data is conflicting. This meta-analysis sought to evaluate the impact of door-to-IV diuretic (D2D) time on mortality in patients with AHF. Pooled estimates from observational studies comprising 28,124 patients, early IV diuresis (reference time 30-105 minutes) was associated with a 23% reduction in 30-day mortality in AHF (OR 0.77; 95% CI 0.64-0.93), despite no significant in-hospital death reduction (OR 0.84; 95% CI 0.57-1.24).

Incidence and progression of atrial fibrillation in patients with and without heart failure using mineralocorticoid receptor antagonists: a meta-analysis

BACKGROUND

Mineralocorticoid receptor antagonists (MRAs) have emerged as potential therapy to target the underlying arrhythmogenic substrate in atrial fibrillation (AF). Nevertheless, there have been inconsistent results on the impact of MRAs on AF.

OBJECTIVE

We sought to evaluate the effect of MRAs on AF incidence and progression in patients with and without heart failure.

METHODS

Electronic databases were searched up to September, 2022 for randomized controlled trials (RCTs) that evaluated MRA use and reported AF outcomes. Primary outcome was a composite of new-onset or recurrent AF. Safety outcomes included hyperkalemia and gynecomastia risks. A random-effects meta-analysis estimated pooled odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

12 RCTs, comprising 11,419 patients treated with various MRAs were included [5960 (52%) on MRA]. On follow-up (6-39 months), 714 (5.5%) patients developed AF. MRA therapy was associated with a 32% reduction in the risk of new-onset or recurrent AF [OR 0.68 (95% CI 0.51-0.92), I2 = 40%]. On subgroup analysis, the greatest benefit magnitude was demonstrated in reducing AF recurrence [OR 0.50 (95% CI 0.30-0.83)] and among patients with left ventricular dysfunction [OR 0.59 (95% CI 0.40-0.85)]. Gynecomastia, but not hyperkalemia, was associated with MRA use. Meta-regression analysis demonstrated that therapy duration was a significant interaction factor driving the effect size (Pinteraction = 0.013).

CONCLUSION

MRA use is associated with a reduction in AF risk, especially AF progression. A prominent effect is seen in patients with heart failure, further augmented by therapy duration. Prospective trials are warranted to evaluate MRA use as upstream therapy for preventing this common arrhythmia.

Lifestyle management of hypertension: International Society of Hypertension position paper endorsed by the World Hypertension League and European Society of Hypertension

Hypertension, defined as persistently elevated systolic blood pressure (SBP) >140 mmHg and/or diastolic blood pressure (DBP) at least 90 mmHg (International Society of Hypertension guidelines), affects over 1.5 billion people worldwide. Hypertension is associated with increased risk of cardiovascular disease (CVD) events (e.g. coronary heart disease, heart failure and stroke) and death. An international panel of experts convened by the International Society of Hypertension College of Experts compiled lifestyle management recommendations as first-line strategy to prevent and control hypertension in adulthood. We also recommend that lifestyle changes be continued even when blood pressure-lowering medications are prescribed. Specific recommendations based on literature evidence are summarized with advice to start these measures early in life, including maintaining a healthy body weight, increased levels of different types of physical activity, healthy eating and drinking, avoidance and cessation of smoking and alcohol use, management of stress and sleep levels. We also discuss the relevance of specific approaches including consumption of sodium, potassium, sugar, fibre, coffee, tea, intermittent fasting as well as integrated strategies to implement these recommendations using, for example, behaviour change-related technologies and digital tools.

Renin-angiotensin-aldosterone system dynamics after targeted blood pressure control using angiotensin II or norepinephrine in cardiac surgery: mechanistic randomised controlled trial

BACKGROUND

The role of the renin-angiotensin-aldosterone axis in vasoplegia after cardiac surgery remains unclear. We tested the hypothesis that, compared with norepinephrine, infusion of angiotensin II titrated to achieve similar mean arterial pressure (MAP) would suppress plasma renin concentration (PRC) while maintaining aldosterone levels.

METHODS

In a double-blind, randomised controlled trial, subjects received either an infusion of angiotensin II or norepinephrine to maintain MAP 70-80 mm Hg from induction of anaesthesia. We compared PRC, aldosterone, dipeptidyl peptidase-3, and angiotensin-converting enzyme 2 activity between treatment groups, before surgery, on ICU admission, and 24 h after surgery.

RESULTS

In 60 patients (11.7% female; mean age 68 yr [11 yr]), norepinephrine increased median PRC at ICU admission (median difference [MD] 46 [inter-quartile range, IQR, 3-88] μU ml-1; P<0.001) but angiotensin II did not (MD -3 [IQR -62 to 35] μU ml-1; P=0.36). Aldosterone levels increased with both. The aldosterone:PRC ratio did not change with norepinephrine (MD -0.01 [IQR -0.14 to 0.03] μU ml-1 per ng dl-1, P=0.76) but increased with angiotensin II (MD 0.05 [IQR 0.004-0.26] μU ml-1 per ng dl-1, P<0.001). The upper quartile of PRC before surgery was associated with higher vasopressor requirements when norepinephrine was used to maintain MAP, but not angiotensin II. Dipeptidyl peptidase-3 levels and angiotensin-converting enzyme 2 activities were similar at all time points.

CONCLUSIONS

Angiotensin II suppressed renin release while maintaining aldosterone levels compared with norepinephrine. Higher plasma renin concentration before surgery was associated with greater vasopressor requirement for norepinephrine, but not angiotensin II.

CLINICAL TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry-ACTRN12621000195853 23/02/2021.

Global coagulation assays in patients with chronic kidney disease and their role in predicting thrombotic risk

BACKGROUND

Despite cardiovascular diseases and thrombosis being major causes of death in patients with chronic kidney disease (CKD), there remains no effective biomarker to predict thrombotic risk in this population.

OBJECTIVE

To evaluate global coagulation assays in patients with CKD and correlate the biomarkers to clinical outcomes.

MATERIAL AND METHODS

Patients with eGFR<30 mL/min/1.73m² were recruited (n = 90) in this prospective observational study. Blood samples were collected for global coagulation assays, including thromboelastography, calibrated automated thrombogram (CAT), overall hemostatic potential (OHP) and tissue factor pathway inhibitor (TFPI).

RESULTS

Following adjustment for age and gender, CKD subjects (mean age 66 years, 36 % female) had increased maximum amplitude on thromboelastography (70.1 vs 60.2 mm, p < 0.001), higher peak thrombin (233.2 vs 219.7 mm, p = 0.030) and increased OHP (16.1 vs 6.4 units, p < 0.001) compared to healthy controls (n = 153). TFPI was also increased in CKD patients (36.4 vs 14.5 ng/mL, p < 0.001). Compared to hemodialysis patients (n = 43), peritoneal-dialysis patients (n = 25) had more hypercoagulable parameters. Thirty-five CKD patients reported thrombotic complications - key predictors included dialysis, higher fibrinogen, reduced endogenous thrombin potential, elevated D-dimer and increased TFPI. Using the dialysis cohort, the predictive risk model based on the key predictors performed better than Framingham heart score and number of cardiovascular risk factors (Harrell's C-stat 0.862 vs 0.585 vs 0.565).

CONCLUSION

CKD appears to confer a hypercoagulable state compared to healthy controls. Interestingly, reduced thrombin generation and raised TFPI was paradoxically associated with increased thrombotic risks, highlighting possible complex compensatory mechanisms within the coagulation system, which may be important in predicting clinical outcomes.

Diminazene aceturate uses different pathways to induce relaxation in healthy and atherogenic blood vessels

Diminazene aceturate (DIZE), a putative angiotensin-converting enzyme 2 (ACE2) activator, elicits relaxation in various animal models. This study aimed to determine the relaxing mechanisms in internal iliac arteries utilised by DIZE in healthy and atherogenic rabbit models. Studies were conducted on internal iliac artery rings retrieved from male New Zealand White rabbits fed a 4-week healthy control (n = 24) or atherogenic diet (n = 20). To investigate pathways utilised by DIZE to promote arterial relaxation, a DIZE dose response [10^-9.0 M - 10^-5.0 M] was performed on pre-contracted rings incubated with pharmaceuticals that target: components of the renin-angiotensin system; endothelial- and vascular smooth muscle-dependent mechanisms; protein kinases; and potassium channels. ACE2 expression was quantified by immunohistochemistry analysis following a 2 hr or 4 hr DIZE incubation. DIZE significantly enhanced vessel relaxation in atherogenic rings at doses [10^-5.5 M] (p < 0.01) and [10^-5.0 M] (p < 0.0001), when compared to healthy controls. Comprehensive results from functional isometric studies determined that DIZE causes relaxation via different mechanisms depending on pathology. For the first time, we report that in healthy blood vessels DIZE exerts its direct relaxing effect through ACE2/AT₂R and NO/sGC pathways; however, in atherogenesis this switches to MasR, arachidonic acid pathway (i.e., COX1/2, EET and DHET), MCLP, Ca²⁺ activated voltage channels, AMPK and ERK1/2. Moreover, quantitative immunohistochemical analysis demonstrated that DIZE increases artery ACE2 expression in a time dependent manner. We provide a detailed investigation of DIZE's mechanisms and demonstrate for the first time that in healthy and atherogenic arteries DIZE provides beneficial effects through directly inducing relaxation, albeit via different pathways.

Corrigendum: Fc engineered ACE2-Fc is a potent multifunctional agent targeting SARS-CoV2

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Angiotensin receptor blockers for the treatment of covid-19: pragmatic, adaptive, multicentre, phase 3, randomised controlled trial

OBJECTIVE

To determine whether disrupting the renin angiotensin system with angiotensin receptor blockers will improve clinical outcomes in people with covid-19.

DESIGN

CLARITY was a pragmatic, adaptive, multicentre, phase 3, randomised controlled trial.

SETTING

17 hospital sites in India and Australia.

PARTICIPANTS

Participants were at least 18 years old, previously untreated with angiotensin receptor blockers, with a laboratory confirmed diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection who had been admitted to hospital for management of covid-19.

INTERVENTION

Oral angiotensin receptor blockers (telmisartan in India) or placebo (1:1) for 28 days.

MAIN OUTCOME MEASURES

The primary endpoint was covid-19 disease severity using a modified World Health Organization Clinical Progression Scale (WHO scale) at day 14. Secondary outcomes were WHO scale scores at day 28, mortality, intensive care unit admission, and respiratory failure. Analyses were evaluated on an ordinal scale in the intention-to-treat population.

RESULTS

Between 3 May 2020 and 13 November 2021, 2930 people were screened for eligibility, with 393 randomly assigned to angiotensin receptor blockers (of which 388 (98.7%) to telmisartan 40 mg/day) and 394 to the control group. 787 participants were randomised: 778 (98.9%) from India and nine (1.1%) from Australia. The median WHO scale score at day 14 was 1 (interquartile range 1-1) in 384 participants assigned angiotensin receptor blockers and 1 (1-1) in 382 participants assigned placebo (adjusted odds ratio 1.51 (95% credible interval 1.02 to 2.23), probability of an odds ratio of >1 (Pr(OR>1)=0.98). WHO scale scores at day 28 showed little evidence of difference between groups (1.02 (0.55 to 1.87), Pr(OR>1)=0.53). The trial was stopped when a prespecified futility rule was met.

CONCLUSIONS

In patients admitted to hospital for covid-19, mostly with mild disease, not requiring oxygen, no evidence of benefit, based on disease severity score, was found for treatment with angiotensin receptor blockers, using predominantly 40 mg/day of telmisartan.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04394117.

Effect of Myocardial Tissue Characterization Using Native T1 to Predict the Occurrence of Adverse Events in Patients With Chronic Kidney Disease and Severe Aortic Stenosis

Among patients with chronic kidney disease (CKD), aortic stenosis (AS) is associated with a significantly higher rate of mortality. We aimed to evaluate whether diffuse myocardial fibrosis, determined using native T1 mapping, has prognostic utility in predicting major adverse cardiovascular events (MACEs), including all-cause mortality or heart failure hospitalization, in patients with CKD and severe AS who are evaluated for transcatheter aortic valve implantation. Cardiac magnetic resonance with T1 mapping using the modified Look-Locker inversion recovery technique was performed in 117 consecutive patients with severe AS and CKD (stage ≥3). Patients were followed up to determine the occurrence of MACE. The mean age of the 117 patients in the cohort was 82 ± 8 years. Native T1 was 1,055 ms (25th- to 75th percentiles 1,031 to 1,078 ms), which is higher than previously reported in healthy controls. Patients with higher T1 times were more likely to have higher N-terminal pro-B-type natriuretic peptide levels (4,122 [IQR 1,578 to 7,980] pg/ml vs 1,678 [IQR 493 to 2,851] pg/ml, p = 0.005) and a history of heart failure (33% vs 9%, p = 0.034). After median follow-up of 3.4 years, MACE occurred in 71 patients (61%). The Society of Thoracic Surgeons predicted risk of mortality score (hazard ratio [HR] 1.07, 95% confidence interval [CI] 1.02 to 1.12, p = 0.006), native T1 >1,024 ms (HR 2.10, 95% CI 1.09 to 4.06, p = 0.028), and New York Heart Association class (HR 1.56, 95% 1.09 to 2.34, p = 0.016) were independent predictors of MACE. Longer native T1 was associated with MACE occurrence in patients with CKD and severe AS.

Fc engineered ACE2-Fc is a potent multifunctional agent targeting SARS-CoV2

Joining a function-enhanced Fc-portion of human IgG to the SARS-CoV-2 entry receptor ACE2 produces an antiviral decoy with strain transcending virus neutralizing activity. SARS-CoV-2 neutralization and Fc-effector functions of ACE2-Fc decoy proteins, formatted with or without the ACE2 collectrin domain, were optimized by Fc-modification. The different Fc-modifications resulted in distinct effects on neutralization and effector functions. H429Y, a point mutation outside the binding sites for FcγRs or complement caused non-covalent oligomerization of the ACE2-Fc decoy proteins, abrogated FcγR interaction and enhanced SARS-CoV-2 neutralization. Another Fc mutation, H429F did not improve virus neutralization but resulted in increased C5b-C9 fixation and transformed ACE2-Fc to a potent mediator of complement-dependent cytotoxicity (CDC) against SARS-CoV-2 spike (S) expressing cells. Furthermore, modification of the Fc-glycan enhanced cell activation via FcγRIIIa. These different immune profiles demonstrate the capacity of Fc-based agents to be engineered to optimize different mechanisms of protection for SARS-CoV-2 and potentially other viral pathogens.

The Need for Individualized Risk Assessment in Cardiovascular Disease

Cardiovascular disease remains the leading cause of death in the era of modern medicine despite major advancements in this field. Current available clinical surrogate markers and blood tests do not adequately predict individual risk of cardiovascular disease. A more precise and sophisticated tool that can reliably predict the thrombosis and bleeding risks at an individual level is required in order for clinicians to confidently recommend early interventions with a favorable risk–benefit profile. Critical to the development of this tool is the assessment and understanding of Virchow’s triad and its complex interactions between hypercoagulability, endothelial dysfunction and vessel flow, a fundamental concept to the development of thrombosis. This review explores the pathophysiology of cardiovascular disease stemming from the triad of factors and how individualized risk assessment can be improved through the multimodal use of tools such as global coagulation assays, endothelial biomarkers and vessel flow assessment.

Controlled evaLuation of Angiotensin Receptor Blockers for COVID-19 respIraTorY disease (CLARITY): statistical analysis plan for a randomised controlled Bayesian adaptive sample size trial

The CLARITY trial (Controlled evaLuation of Angiotensin Receptor Blockers for COVID-19 respIraTorY disease) is a two-arm, multi-centre, randomised controlled trial being run in India and Australia that investigates the effectiveness of angiotensin receptor blockers in addition to standard care compared to placebo (in Indian sites) with standard care in reducing the duration and severity of lung failure in patients with COVID-19. The trial was designed as a Bayesian adaptive sample size trial with regular planned analyses where pre-specified decision rules will be assessed to determine whether the trial should be stopped due to sufficient evidence of treatment effectiveness or futility. Here, we describe the statistical analysis plan for the trial and define the pre-specified decision rules, including those that could lead to the trial being halted. The primary outcome is clinical status on a 7-point ordinal scale adapted from the WHO Clinical Progression scale assessed at day 14. The primary analysis will follow the intention-to-treat principle. A Bayesian adaptive trial design was selected because there is considerable uncertainty about the extent of potential benefit of this treatment.

Trial registration

ClinicalTrials.gov NCT04394117. Registered on 19 May 2020Clinical Trial Registry of India CTRI/2020/07/026831

Version and revisions

Version 1.0. No revisions.

Immunological dysfunction persists for 8 months following initial mild-to-moderate SARS-CoV-2 infection

A proportion of patients surviving acute coronavirus disease 2019 (COVID-19) infection develop post-acute COVID syndrome (long COVID (LC)) lasting longer than 12 weeks. Here, we studied individuals with LC compared to age- and gender-matched recovered individuals without LC, unexposed donors and individuals infected with other coronaviruses. Patients with LC had highly activated innate immune cells, lacked naive T and B cells and showed elevated expression of type I IFN (IFN-β) and type III IFN (IFN-λ1) that remained persistently high at 8 months after infection. Using a log-linear classification model, we defined an optimal set of analytes that had the strongest association with LC among the 28 analytes measured. Combinations of the inflammatory mediators IFN-β, PTX3, IFN-γ, IFN-λ2/3 and IL-6 associated with LC with 78.5-81.6% accuracy. This work defines immunological parameters associated with LC and suggests future opportunities for prevention and treatment.

Retinal microvascular function predicts chronic kidney disease in patients with cardiovascular risk factors

BACKGROUND AND AIMS

Endothelial dysfunction is a precursor to atherosclerosis and is implicated in the coexistence between cardiovascular disease (CVD) and chronic kidney disease (CKD). We examined whether retinal microvascular dysfunction is present in subjects with renal impairment and predictive of long-term CKD progression in patients with CVD.

METHODS

In a single centre prospective observational study, 253 subjects with coronary artery disease and CVD risk factors underwent dynamic retinal vessel analysis. Retinal microvascular dysfunction was quantified by measuring retinal arteriolar and venular dilatation in response to flicker light stimulation. Serial renal function assessment was performed over a median period of 9.3 years using estimated GFR (eGFR).

RESULTS

Flicker light-induced retinal arteriolar dilatation (FI-RAD) was attenuated in patients with baseline eGFR <90 mL/min/1.73 m², compared to those with normal renal function (eGFR ≥90 mL/min/1.73 m²) (1.0 [0.4-2.1]% vs. 2.0 [0.8-3.6]%; p < 0.01). In patients with normal renal function, subjects with the lowest FI-RAD responses exhibited the greatest annual decline in eGFR. In uni- and multivariable analysis, among subjects with normal renal function, a 1% decrease in FI-RAD was associated with an accelerated decline in eGFR of 0.10 (0.01, 0.15; p = 0.03) and 0.07 mL/min/1.73 m² per year (0.00, 0.14; p = 0.06), respectively. FI-RAD was not predictive of CKD progression in subjects with baseline eGFR <90 mL/min/1.73 m².

CONCLUSIONS

Retinal arteriolar endothelial dysfunction is present in patients with CVD who have early-stage CKD, and serves as an indicator of long-term CKD progression in those with normal renal function.

No dynamic changes in plasma ACE2 activity in patients with acute coronary syndrome

Background

Angiotensin converting enzyme 2 (ACE2) is expressed in the human myocardium and blood vessels and degrades the vasoconstrictor peptide angiotensin (Ang) II. Plasma ACE2 activity is elevated in patients with cardiovascular disease (CVD) and is a predictor of major adverse cardiovascular events (MACE) in obstructive coronary artery disease. However, it is unknown whether acute coronary syndrome (ACS) causes dynamic changes in plasma ACE2 activity.

Purpose

We investigated dynamic changes in serial troponin-T and plasma ACE2 activity in patients presenting with ACS who underwent invasive coronary angiography (ICA).

Methods

Consecutive patients admitted with ACS from October-November 2019 were screened. Those meeting the Fourth Universal Definition of Myocardial Infarction who had both ICA and serial troponin-T testing were included. The study was approved by the hospitals Human Research Ethics Committee. All patients had routine plasma samples taken over 3 time-points for measurement of troponin-T; the same sample was used to measure plasma ACE2 activity. Catalytic ACE2 activity was measured using a validated, sensitive quenched fluorescent substrate-based assay. Serial median troponin and ACE2 activity levels were analysed using the Friedman test for repeated measures.

Results

Forty-nine patients were included. The mean age of participants was 63.9±11.0 years, and 36 (74%) patients were male. Overall, 16 (36%) patients presented with ST-elevation myocardial infarction (STEMI) and 29 (74%) with non-ST-elevation myocardial infarction (NSTEMI). Twenty-nine (59%) patients had a history of hypertension and 14 (29%) a history of ischaemic heart disease; 13 (27%) with priorMI, 11 (22%) had previous PCI and 2 (4%) had prior coronary artery bypass grafting. Over the 3 time points, there was a clear rise in median troponin-T levels representing myocardial injury (p&lt;0.001), with no change in median plasma ACE2 activity (p=0.23, table 1). There was no difference in median ACE2 activity in those presenting with STEMI vs. NSTEMI (6.9 [2.1–9.5] vs. 6.0 [1.8–12.1], p=0.87), nor in those who underwent PCI to a culprit lesion compared to those who did not have a culprit lesion stented (5.8 [0.9–10.5] vs. 7.3 [2.8–14.9], p=0.37).

Conclusions

Patients with ACS had higher plasma ACE2 levels compared to levels previously reported in healthy controls. There were no dynamic changes in ACE2 activity in the setting of ACS, despite a significant rise in troponin-T. These results suggest that plasma ACE2 levels reflect underlying endothelial dysfunction rather than acute myocardial injury or infarction. Studies are now underway to assess if plasma ACE2 activity in ACS predicts MACE.

Funding Acknowledgement

Type of funding sources: None. Table 1

Protocol for the Controlled evaLuation of Angiotensin Receptor blockers for COVID-19 respIraTorY disease (CLARITY): a randomised controlled trial

BACKGROUND

SARS-CoV-2 binds to membrane-bound angiotensin-converting enzyme 2 (ACE2) which may result in downregulation of membrane-bound ACE2. ACE2 is a key regulator of the renin-angiotensin system (RAS) and is responsible for degrading angiotensin II and thereby counteracting its pro-inflammatory, pro-fibrotic effects mediated through the angiotensin II type 1 receptor (AT1R). As AT1R is directly blocked by angiotensin receptor blockers (ARBs), these agents may offer a safe, low-cost solution for reducing COVID-19 respiratory outcomes.

METHODS AND DISCUSSION

CLARITY is a pragmatic, adaptive, two-arm, multi-centre, comparative effectiveness phase III randomised controlled trial that examines whether ARBs reduce COVID-19 severity among high-risk patients. Recruiting in India and Australia, the trial will compare treatment with a maximum tolerated daily dose of an ARB to standard of care. Treatment allocation is blinded in India but open-label in Australia due to interruptions to placebo supply in the latter. The primary endpoint is a 7-point ordinal scale of clinical states, ranging from no limitation of activities (category 1) to death (category 7), assessed on day 14. Secondary outcomes include the 7-point scale assessed at day 28 and 28- and 90-day mortality. The design adapts the sample size based on accumulating data via frequent interim analyses and the use of predictive probability to determine whether the current sample size is sufficient or continuing accrual would be futile. The trial commenced recruitment on 18 August 2020.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04394117 . Registered on 19 May 2020. Clinical Trial Registry of India: CTRI/2020/07/026831).

Angiotensin-Converting Enzyme 2 Activity Is Associated With Embolic Stroke of Undetermined Source

[Figure: see text].

Plasma ACE2 activity is persistently elevated following SARS-CoV-2 infection: implications for COVID-19 pathogenesis and consequences

Coronavirus disease 2019 (COVID-19) causes persistent endothelial inflammation, lung, cardiovascular, kidney and neurological complications, and thromboembolic phenomena of unclear pathogenesis [1]. Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) utilises the catalytic site of full-length membrane-bound angiotensin converting enzyme 2 (ACE2) for host cell entry [2], which is thought to downregulate membrane-bound ACE2, and thus contribute to ongoing inflammation due to loss of a degradative pathway for angiotensin II. In healthy individuals, ACE2 exists primarily in its membrane-bound form with very low levels of the catalytically active ectodomain of ACE2 present in the circulation [3]. However, in patients with cardiovascular disease, there is increased “shedding” of ACE2, and higher circulating levels are associated with downregulation of membrane-bound ACE2 [4].

Plasma ACE2 activity is persistently elevated in patients after COVID-19 infection. Larger studies are needed to determine if this identifies people at risk of prolonged illness following COVID-19.https://bit.ly/2XQlrYF

Novel Approach to Risk Stratification in Left Ventricular Non-Compaction Using A Combined Cardiac Imaging and Plasma Biomarker Approach

Background

Left ventricular non‐compaction remains a poorly described entity, which has led to challenges of overdiagnosis. We aimed to evaluate if the presence of a thin compacted myocardial layer portends poorer outcomes in individuals meeting cardiac magnetic resonance criteria for left ventricular non‐compaction .

Methods and Results

This was an observational, retrospective cohort study involving individuals selected from the Cleveland Clinic Foundation cardiac magnetic resonance database (N=26 531). Between 2000 and 2018, 328 individuals ≥12 years, with left ventricular non‐compaction or excessive trabeculations based on the cardiac magnetic resonance Petersen criteria were included. The cohort comprised 42% women, mean age 43 years. We assessed the predictive ability of myocardial thinning for the primary composite end point of major adverse cardiac events (composite of all‐cause mortality, heart failure hospitalization, left ventricular assist device implantation/heart transplant, ventricular tachycardia, or ischemic stroke). At mean follow‐up of 3.1 years, major adverse cardiac events occurred in 102 (31%) patients. After adjusting for comorbidities, the risk of major adverse cardiac events was nearly doubled in the presence of significant compacted myocardial thinning (hazard ratio [HR], 1.88 [95% CI, 1.18‒3.00]; P=0.016), tripled in the presence of elevated plasma B‐type natriuretic peptide (HR, 3.29 [95% CI, 1.52‒7.11]; P=0.006), and increased by 5% for every 10‐unit increase in left ventricular end‐systolic volume (HR, 1.01 [95% CI, 1.00‒1.01]; P=0.041).

Conclusions

The risk of adverse clinical events is increased in the presence of significant compacted myocardial thinning, an elevated B‐type natriuretic peptide or increased left ventricular dimensions. The combination of these markers may enhance risk assessment to minimize left ventricular non‐compaction overdiagnosis whilst facilitating appropriate diagnoses in those with true disease.

Excess mortality at Christmas due to cardiovascular disease in the HUNT study prospective population-based cohort in Norway

Background

Although it is known that winter inclusive of the Christmas holiday period is associated with an increased risk of dying compared to other times of the year, very few studies have specifically examined this phenomenon within a population cohort subject to baseline profiling and prospective follow-up. In such a cohort, we sought to determine the specific characteristics of mortality occuring during the Christmas holidays.

Methods

Baseline profiling and outcome data were derived from a prospective population-based cohort with longitudinal follow-up in Central Norway - the Trøndelag Health (HUNT) Study. From 1984 to 1986, 88% of the target population comprising 39,273 men and 40,353 women aged 48 ± 18 and 50 ± 18 years, respectively, were profiled. We examined the long-term pattern of mortality to determine the number of excess (all-cause and cause-specific) deaths that occurred during winter overall and, more specifically, the Christmas holidays.

Results

During 33.5 (IQR 17.1–34.4) years follow-up, 19,879 (50.7%) men and 19,316 (49.3%) women died at age-adjusted rate of 5.3 and 4.6 deaths per 1000/annum, respectively. Overall, 1540 (95% CI 43–45 deaths/season) more all-cause deaths occurred in winter (December to February) versus summer (June to August), with 735 (95% CI 20–22 deaths per season) of these cardiovascular-related. December 25th–27th was the deadliest 3-day period of the year; being associated with 138 (95% CI 96–147) and 102 (95% CI 72–132) excess all-cause and cardiovascular-related deaths, respectively. Accordingly, compared to 1st–21st December (equivalent winter conditions), the incidence rate ratio of all-cause mortality increased to 1.22 (95% CI 1.16–1.27) and 1.17 (95% 1.11–1.22) in men and women, respectively, during the next 21 days (Christmas/New Year holidays). All observed differences were highly significant (P < 0.001). A less pronounced pattern of mortality due to respiratory illnesses (but not cancer) was also observed.

Conclusion

Beyond a broader pattern of seasonally-linked mortality characterised by excess winter deaths, the deadliest time of year in Central Norway coincides with the Christmas holidays. During this time, the pattern and frequency of cardiovascular-related mortality changes markedly; contrasting with a more stable pattern of cancer-related mortality. Pending confirmation in other populations and climates, further research to determine if these excess deaths are preventable is warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10503-7.

Incidental Thoracic Aortic Dilation on Chest Computed Tomography in Patients With Atrial Fibrillation

Patients with atrial fibrillation (AF) have risk factors that predispose to thoracic aneurysmal disease (TAD) and atherosclerosis. In this study in patients with AF, we assessed the occurrence of incidental TAD and assessed if a validated predictive score used to predict AF, the CHARGE-AF score, was associated with greater aortic dimensions. We also assessed the prevalence of coronary calcification. We conducted a cross-sectional study of 1,000 consecutive patients with AF undergoing chest multidetector CT during evaluation for pulmonary vein isolation. A dilated aortic root or ascending aorta (AA, dimension/ body surface area >2.05 cm/m²) were found in 195 (20%). A total of 12 (1%) had significant aortic aneurysmal enlargement of > 5.0 cm. Advancing age, a bicuspid aortic valve, hypertension, and male gender were associated with increased aortic dimensions. Aortic root dimensions increased linearly (p < 0.001) and ascending aortic dimensions increased nonlinearly across CHARGE-AF deciles (p < 0.001). Nearly two-thirds (63%) had coronary calcification, 38% of whom were not on lipid-lowering therapy. In conclusion, in patients with AF undergoing gated chest CT, 1 in 5 had previously undetected TAD, with a small proportion having significantly aneurysmal dimensions approaching surgical thresholds. Risk factors previously established to increase the propensity to develop AF are also associated with increased TAD. These findings raise the need to consider a surveillance strategy for TAD in patients with AF, particularly in those with other risk factors for aortic disease. A high prevalence of coronary calcium was also detected, representing an opportunity to optimize statin therapy in patients with AF.

Systematic quantification of histologic ventricular fibrosis in isolated mitral valve prolapse and sudden cardiac death

BACKGROUND

Cardiac fibrosis in mitral valve prolapse (MVP) is implicated in the development of sudden cardiac death (SCD); however, the pattern remains poorly characterized.

OBJECTIVE

The purpose of this study was to systematically quantify left and right ventricular fibrosis in individuals with isolated MVP and SCD (iMVP-SCD), whereby other potential causes of death are excluded, compared to a control cohort.

METHODS

Individuals with iMVP-SCD were identified from the Victorian Institute of Forensic Medicine, Australia, and matched for age, sex, and body mass index to control cases with noncardiac death. Cardiac tissue sections were analyzed to determine collagen deposition in the left ventricular free wall (anterior, lateral, and posterior portions), interventricular septum, and right ventricle. Within the iMVP-SCD cases, the endocardial-to-epicardial distribution of fibrosis within the left ventricle was specifically characterized.

RESULTS

Seventeen cases with iMVP-SCD were matched 1:1 with 17 controls, yielding 149 samples and 1788 histologic regions. The iMVP-SCD group had increased left ventricular (anterior, lateral, and posterior; all P <.001) and interventricular septum fibrosis (P <.001), but similar amounts of right ventricular fibrosis (P = .62) compared to controls. In iMVP-SCD, left ventricular fibrosis was significantly higher in the lateral and posterior walls compared to the anterior wall and interventricular septum (all P <.001). Within the lateral and posterior walls, iMVP-SCD cases had a significant endocardial-to-epicardial gradient of cardiac fibrosis (P <.01) similar to other known conditions that cause cardiac remodeling.

CONCLUSION

Our study indicates that nonuniform left ventricular remodeling with both localized and generalized left ventricular fibrosis is important in the pathogenesis of SCD in individuals with MVP.

Hypertension and renin-angiotensin system blockers are not associated with expression of angiotensin-converting enzyme 2 (ACE2) in the kidney

AIMS

Angiotensin-converting enzyme 2 (ACE2) is the cellular entry point for severe acute respiratory syndrome coronavirus (SARS-CoV-2)-the cause of coronavirus disease 2019 (COVID-19). However, the effect of renin-angiotensin system (RAS)-inhibition on ACE2 expression in human tissues of key relevance to blood pressure regulation and COVID-19 infection has not previously been reported.

METHODS AND RESULTS

We examined how hypertension, its major metabolic co-phenotypes, and antihypertensive medications relate to ACE2 renal expression using information from up to 436 patients whose kidney transcriptomes were characterized by RNA-sequencing. We further validated some of the key observations in other human tissues and/or a controlled experimental model. Our data reveal increasing expression of ACE2 with age in both human lungs and the kidney. We show no association between renal expression of ACE2 and either hypertension or common types of RAS inhibiting drugs. We demonstrate that renal abundance of ACE2 is positively associated with a biochemical index of kidney function and show a strong enrichment for genes responsible for kidney health and disease in ACE2 co-expression analysis.

CONCLUSION

Our results indicate that neither hypertension nor antihypertensive treatment is likely to alter the expression of the key entry receptor for SARS-CoV-2 in the human kidney. Our data further suggest that in the absence of SARS-CoV-2 infection, kidney ACE2 is most likely nephro-protective but the age-related increase in its expression within lungs and kidneys may be relevant to the risk of SARS-CoV-2 infection.

Reduced urinary levels of angiotensin-converting enzyme 2 activity predict acute kidney injury in critically ill patients

Objective: Angiotensin-converting enzyme 2 activity reflects non-classical renin-angiotensin system upregulation. We assessed the association of urinary angiotensin-converting enzyme 2 (uACE2) activity with acute kidney injury (AKI). Design, setting and participants: A prospective observational study in which we measured uACE2 activity in 105 critically ill patients at risk of AKI. We report AKI stage 2 or 3 at 12 hours of urine collection (AKI12h) and AKI stage 2 or 3 at any time during intensive care unit stay in patients free from any stage of AKI at inclusion (AKIICU). AKI prediction was assessed using area under the receiver-operating characteristics curve (AUROC) and net reclassification indices (NRIs). Main outcome measure: AKI stage 2 or 3 at 12 hours of urine collection. Results: Within 12 hours of inclusion, 32 of 105 patients (30%) had developed AKI12h. Corrected uACE2 activity was significantly higher in patients without AKI12h compared with those with AKI12h (median [interquartile range], 13 [6-24] v 7 [4-10] pmol/min/mL per mmol/L of urine creatinine; P < 0.01). A 10-unit increase in uACE2 was associated with a 28% decrease in AKI12h risk (odds ratio [95% CI], 0.72 [0.46-0.97]). During intensive care unit admission, 39 of 76 patients (51%) developed AKIICU. uACE2 had an AUROC for the prediction of AKI12h of 0.68 (95% CI, 0.57-0.79), and correctly reclassified 28% of patients (positive NRI) to AKI12h. Patients with uACE2 > 8.7 pmol/min/mL per mmol/L of urine creatinine had a significantly lower risk of AKIICU on log-rank analysis (52% v 84%; P < 0.01). Conclusions: Higher uACE2 activity was associated with a decreased risk of AKI stage 2 or 3. Our findings support future evaluations of the role of the non-classical renin-angiotensin system during AKI.

Renin-angiotensin system inhibition and risk of infection and mortality in COVID-19: a systematic review and meta-analysis

Background

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the causative agent of COVID‐19, enters human cells by binding of its viral protein to the aminopeptidase angiotensin‐converting enzyme 2 (ACE2). This has led to speculation whether treatment with renin–angiotensin system (RAS) inhibitors was associated with an increased likelihood of a positive test for COVID‐19 and risk of mortality.

Aims

We performed a systematic review and meta‐analysis to investigate whether RAS inhibitors increased the likelihood of a positive test or death/severe illness in patients with COVID‐19.

Methods

A systematic search of MEDLINE, PubMed and EMBASE was conducted for studies stratified by the use of angiotensin‐converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB). Pooled analysis was performed using a random‐effects model.

Results

Seven trials of 73 122 patients were included. Overall, 16 624 (22.7%) patients had a positive COVID‐19 test and 7892 (10.8%) were on a RAS inhibitor. RAS inhibitors were not associated with higher likelihood of a positive COVID‐19 test result (odds ratio (OR) 0.97 (95% CI 0.97–1.05, P = 0.48) with low heterogeneity. This was comparable when stratifying by use of each medication class. The use of RAS inhibitors was also not associated with mortality or severe illness (OR 0.89, 95% CI 0.73–1.07, P = 0.21) with moderate heterogeneity.

Conclusion

Use of ACEI or ARB was not associated with a heightened susceptibility for a positive diagnosis of COVID‐19. Furthermore, they were not associated with increased illness severity or mortality due to COVID‐19. Randomised controlled trials are needed to address definitively the potential benefits or harms of RAS inhibitors in patients with COVID‐19.

Plasma Cortisol, Aldosterone, and Ascorbic Acid Concentrations in Patients with Septic Shock Do Not Predict Treatment Effect of Hydrocortisone on Mortality. A Nested Cohort Study

Rationale: Whether biomarkers can identify subgroups of patients with septic shock with differential treatment responses to hydrocortisone is unknown.Objectives: To determine if there is heterogeneity in effect for hydrocortisone on mortality, shock resolution, and other clinical outcomes based on baseline cortisol, aldosterone, and ascorbic acid concentrations.Methods: From May 2014 to April 2017, we obtained serum samples from 529 patients with septic shock from 22 ICUs in Australia and New Zealand.Measurements and Main Results: There were no significant interactions between the association with 90-day mortality and treatment with either hydrocortisone or placebo for total cortisol (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.02-1.16 vs. OR, 1.07; 95% CI, 1.00-1.13; P = 0.70), free cortisol (OR, 1.20; 95% CI, 1.04-1.38 vs. OR, 1.16; 95% CI, 1.02-1.32; P = 0.75), aldosterone (OR, 1.01; 95% CI, 0.97-1.05 vs. OR, 1.01; 95% CI, 0.98-1.04; P = 0.99), or ascorbic acid (OR, 1.11; 95% CI, 0.89-1.39 vs. OR, 1.05; 95% CI, 0.91-1.22; P = 0.70), respectively. Similar results were observed for the association with shock resolution. Elevated free cortisol was significantly associated with 90-day mortality (OR, 1.13; 95% CI, 1.00-1.27; P = 0.04), but total cortisol, aldosterone, and ascorbic acid were not.Conclusions: In patients with septic shock, there was no heterogeneity in effect of adjunctive hydrocortisone on mortality, shock resolution, or other clinical outcomes based on cortisol, aldosterone, and ascorbic acid concentrations. Plasma aldosterone and ascorbic acid concentrations are not associated with outcome.

May Measurement Month 2018: a pragmatic global screening campaign to raise awareness of blood pressure by the International Society of Hypertension

Aims

Raised blood pressure (BP) is the biggest contributor to mortality and disease burden worldwide and fewer than half of those with hypertension are aware of it. May Measurement Month (MMM) is a global campaign set up in 2017, to raise awareness of high BP and as a pragmatic solution to a lack of formal screening worldwide. The 2018 campaign was expanded, aiming to include more participants and countries.

Methods and results

Eighty-nine countries participated in MMM 2018. Volunteers (≥18 years) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, or taking antihypertensive medication. In total, 74.9% of screenees provided three BP readings. Multiple imputation using chained equations was used to impute missing readings. 1 504 963 individuals (mean age 45.3 years; 52.4% female) were screened. After multiple imputation, 502 079 (33.4%) individuals had hypertension, of whom 59.5% were aware of their diagnosis and 55.3% were taking antihypertensive medication. Of those on medication, 60.0% were controlled and of all hypertensives, 33.2% were controlled. We detected 224 285 individuals with untreated hypertension and 111 214 individuals with inadequately treated (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) hypertension.

Conclusion

May Measurement Month expanded significantly compared with 2017, including more participants in more countries. The campaign identified over 335 000 adults with untreated or inadequately treated hypertension. In the absence of systematic screening programmes, MMM was effective at raising awareness at least among these individuals at risk.

May Measurement Month 2018: an analysis of blood pressure screening results from Australia

May Measurement Month (MMM), originally initiated as a temporary solution to address the lack of blood pressure (BP) screening programs worldwide, emerged as an effective annual campaign to increase the awareness of hypertension. MMM18, a cross-sectional survey of volunteers aged ≥18 years was carried out during May 2018 predominantly in capital cities across Australia following the standard MMM protocol. Blood pressure screening along with additional information including anthropometric data and responses to questionnaires on demographic, lifestyle, and environmental factors were collected from 3 352 individuals across Australia. After multiple imputation, 1 026 (30.6%) adult Australians had hypertension. Of the 2 936 individuals not on antihypertensive treatment, 610 (20.8%) were hypertensive, and 237 (57.1%) of the 416 individuals receiving antihypertensive treatment had uncontrolled BP. In line with MMM17 results and other previous surveys, MMM18 revealed that close to one-third of the screened population (30.6%) had hypertension, 57.1% of individuals treated with BP-lowering medication remained uncontrolled indicating suboptimal management of the condition in the majority of patients. Most importantly, only 49.0% of those with hypertension were aware of their elevated BP, highlighting lack of awareness of elevated BP in nearly half of the affected population. Elevated BP was directly associated with alcohol consumption, overweight, and obesity. Our findings demonstrate the need for (i) continued efforts to increase BP awareness in the population, (ii) optimization of BP management strategies, and (iii) tackling some of the major contributors to BP elevation, including alcohol consumption and obesity.

Impaired retinal microvascular function predicts long-term adverse events in patients with cardiovascular disease

AIMS

Endothelial dysfunction is a precursor to the development of symptomatic atherosclerosis. Retinal microvascular reactivity to flicker light stimulation is a marker of endothelial function and can be quantified in vivo. We sought to determine whether retinal microvascular endothelial dysfunction predicts long-term major adverse cardiovascular events (MACE).

METHODS AND RESULTS

In a single-centre prospective observational study, patients with coronary artery disease (CAD) or cardiovascular risk factors underwent dynamic retinal vessel assessment in response to flicker light stimulation and were followed up for MACE. Retinal microvascular endothelial dysfunction was quantified by measuring maximum flicker light-induced retinal arteriolar dilatation (FI-RAD) and flicker light-induced retinal venular dilatation (FI-RVD). In total, 252 patients underwent dynamic retinal vessel assessment and 242 (96%) had long-term follow-up. Of the 242 patients, 88 (36%) developed MACE over a median period of 8.6 years (interquartile range 6.0-9.1). After adjustment for traditional risk factors, patients within the lowest quintile of FI-RAD had the highest risk of MACE [odds ratio (OR) 5.21; 95% confidence interval (CI) 1.78-15.28]. Patients with lower FI-RAD were also more likely to die (OR 2.09; 95% CI 1.00-4.40, per standard deviation decrease in FI-RAD). In Kaplan-Meier analysis, patients with FI-RAD responses below the cohort median of 1.4% exhibited reduced MACE-free survival (55.5 vs. 71.5%; log-rank P = 0.004). FI-RVD was not predictive of MACE.

CONCLUSION

Retinal arteriolar endothelial dysfunction is an independent predictor of MACE in patients with CAD or cardiovascular risk factors. Dynamic retinal vessel analysis may provide added benefit to traditional risk factors in stratifying patients at risk for cardiovascular events.

Imbalance of the renin-angiotensin system may contribute to inflammation and fibrosis in IBD: a novel therapeutic target?

OBJECTIVE

We evaluated the influence of the renin-angiotensin system (RAS) on intestinal inflammation and fibrosis.

DESIGN

Cultured human colonic myofibroblast proliferation and collagen secretion were assessed following treatment with angiotensin (Ang) II and Ang (1-7), their receptor antagonists candesartan and A779, and the ACE inhibitor captopril. Circulating and intestinal RAS components were evaluated in patients with and without IBD. Disease outcomes in patients with IBD treated with ACE inhibitors and angiotensin receptor blockers (ARBs) were assessed in retrospective studies.

RESULTS

Human colonic myofibroblast proliferation was reduced by Ang (1-7) in a dose-dependent manner (p<0.05). Ang II marginally but not significantly increased proliferation, an effect reversed by candesartan (p<0.001). Colonic myofibroblast collagen secretion was reduced by Ang (1-7) (p<0.05) and captopril (p<0.001), and was increased by Ang II (p<0.001). Patients with IBD had higher circulating renin (mean 25.4 vs 18.6 mIU/L, p=0.026) and ACE2:ACE ratio (mean 0.92 vs 0.69, p=0.015) than controls without IBD. RAS gene transcripts and peptides were identified in healthy and diseased bowels. Colonic mucosal Masson's trichrome staining correlated with Ang II (r=0.346, p=0.010) and inversely with ACE2 activity (r=-0.373, p=0.006). Patients with IBD who required surgery (1/37 vs 12/75, p=0.034) and hospitalisation (0/34 vs 8/68, p=0.049) over 2 years were less often treated with ACE inhibitors and ARBs than patients not requiring surgery or hospitalisation.

CONCLUSIONS

The RAS mediates fibrosis in human cell cultures, is expressed in the intestine and perturbed in intestinal inflammation, and agents targeting this system are associated with improved disease outcomes.

P5740ACE2 activity level is associated with embolic stroke of undetermined source

Background

ACE2 activity levels correlate with adverse left atrial remodelling in patients with atrial fibrillation (AF). Several biochemical and structural markers have been associated with embolic stroke of undetermined source (ESUS). The relationship between ACE2 activity and ESUS is unknown.

Purpose

Randomised controlled trials failed to demonstrate a clear benefit of oral anticoagulation in an unselected ESUS population. As selective use of oral anticoagulation guided by biomarker risk-profiling may benefit these patients, we evaluated the association between ACE2 activity and ESUS.

Methods

This prospective case control study compared patients with ESUS against a control group matched for vascular risk factors. ESUS was diagnosed following cerebral vascular imaging and 24 hours of cardiac monitoring to exclude AF. Blood samples were collected for measurement of ACE2 activity, D-Dimer and high sensitivity troponin T (hsTnT).

Results

A total of 51 patients in the ESUS group were compared with 47 patients in the Control group. ACE2 activity and D-Dimer levels were significantly higher in the ESUS group. There was a significant but weak positive correlation between ACE2 activity and hsTnT (r=0.20, p<0.05). Left atrial volume index (LAVI) on echocardiography was significantly higher in the ESUS group. On regression modelling adjusting for LAVI, only ACE2 activity remained significant for ESUS, with a 20% rise in odds for every 4 unit increase in ACE2 activity (OR 1.20; 95% CI: 1.01 - 1.36, p=0.04).

Participant characteristics Control (n=47) ESUS (n=51) P value Age (years) 65.65±6.78 67.20±6.89 0.26 Female gender 22 (45.8) 19 (38.0) 0.43 Hypertension 22 (45.8) 24 (48.0) 0.83 Diabetes mellitus 9 (18.8) 12 (24.0) 0.53 CHA2DS2VASc score 2 (1–3) 2 (1–3) 0.50 LA size & Biomarkers   LA volume index (ml/m2) 36.5 (32.6–42.5) 39.1 (36.2–46.0) 0.04   ACE2 (pmol/ml/min) 7.24 (2.66–14.64) 10.16 (4.54–18.80) 0.04   D-Dimer (mg/L) 0.35 (0.3–0.5) 0.40 (0.30–0.60) 0.02   hsTroponin T (ng/L) 7.0 (5–10) 9.00 (6.0–13.5) 0.05 Values are expressed as mean ± standard deviation, median (IQR), or n (%).

Median ACE2 activity

Conclusion(s)

ACE2 activity is associated with ESUS independent of left atrial volume and correlate with elevated Troponin. Further studies are warranted to investigate the utility of ACE2 activity in identifying ESUS patients that may benefit from oral anticoagulation.

Acknowledgement/Funding

This study received project funding from the Eastern Health Foundation

Plasma ACE2 Activity Predicts Mortality in Aortic Stenosis and Is Associated With Severe Myocardial Fibrosis

OBJECTIVES

This study investigated the relationship between plasma angiotensin-converting enzyme 2 (ACE2) activity levels and the severity of stenosis and myocardial remodeling in patients with aortic stenosis (AS) and determined if plasma ACE2 levels offered incremental prognostic usefulness to predict all-cause mortality.

BACKGROUND

ACE2 is an integral membrane protein that degrades angiotensin II and has an emerging role as a circulating biomarker of cardiovascular disease.

METHODS

Plasma ACE2 activity was measured in 127 patients with AS; a subgroup had myocardial tissue collected at the time of aortic valve replacement.

RESULTS

The median plasma ACE2 activity was 34.0 pmol/ml/min, and levels correlated with increased valvular calcification (p = 0.023) and the left ventricular (LV) mass index (r = 0.34; p < 0.001). Patients with above-median plasma ACE2 had higher LV end-diastolic volume (57 ml/m² vs. 48 ml/m²; p = 0.021). Over a median follow-up of 5 years, elevated plasma ACE2 activity was an independent predictor of all-cause mortality after adjustment for relevant clinical, imaging, and biochemical parameters (HR: 2.28; 95% CI: 1.03 to 5.06; p = 0.042), including brain natriuretic peptide activation (integrated discrimination improvement: 0.08; p < 0.001). In 22 patients with plasma and tissue, increased circulating ACE2 was associated with reduced myocardial ACE2 gene expression (0.7-fold; p = 0.033) and severe myocardial fibrosis (p = 0.027).

CONCLUSIONS

In patients with AS, elevated plasma ACE2 was a marker of myocardial structural abnormalities and an independent predictor of mortality with incremental value over traditional prognostic markers. Loss of ACE2 from the myocardium was associated with increased fibrosis and higher circulating ACE2 levels.

Winter Peaks in Heart Failure: An Inevitable or Preventable Consequence of Seasonal Vulnerability?

Climate change is a major contributor to annual winter peaks in cardiovascular events across the globe. However, given the paradoxical observation that cardiovascular seasonality is observed in relatively mild as well as cold climates, global warming may not be as positive for the syndrome of heart failure (HF) as some predict. In this article, we present our Model of Seasonal Flexibility to explain the spectrum of individual responses to climatic conditions. We have identified distinctive phenotypes of resilience and vulnerability to explain why winter peaks in HF occur. Moreover, we identify how better identification of climatic vulnerability and the use of multifaceted interventions focusing on modifiable bio-behavioural factors may improve HF outcomes.

May Measurement Month 2017: an analysis of blood pressure screening results from Australia-South-East Asia and Australasia

Increased blood pressure (BP) is the single biggest contributing risk factor to the global disease burden. May Measurement Month (MMM) is a global initiative of the International Society of Hypertension aimed at raising awareness of high BP. In Australia, hypertension affects around six million adults and continues to remain the greatest attributable cause of cardiovascular mortality and morbidity (48.3%), stroke deaths (28%), and kidney disease (14%). An opportunistic cross-sectional survey was carried out during May 2017 predominantly in capital cities across Australia which included adult volunteers. Blood pressure measurement, the definition of hypertension and statistical analysis followed the standard MMM protocol. Additional information obtained included anthropometric data and responses to questionnaires on demographic, lifestyle, and environmental factors. Data were collected from 3817 individuals. After multiple imputation, of the 3758 individuals for whom a mean of the second and third BP reading was available, 1188 (31.2%) had hypertension. Of 3213 individuals not receiving antihypertensive treatment, 591 (18.4%) were hypertensive, and 239 (40.1%) of the 596 individuals receiving treatment had uncontrolled BP. Adjusted BP was higher in association with antihypertensive medication, cerebrovascular disease, smoking, and alcohol consumption. Blood pressure was higher when measured on the right arm and on Tuesdays. MMM17 was one of the largest BP screening campaigns undertaken in Australia using standardized BP measurements. In line with previous surveys, around one-third of screened adults had hypertension and approximately 40% of treated individuals remained uncontrolled. These results suggest that opportunistic screening can identify significant numbers with raised BP.

Plasma endothelin-1 and adrenomedullin are associated with coronary artery function and cardiovascular outcomes in humans

BACKGROUND

Endothelin-1 (ET-1) is a vasoconstrictor associated with cardiovascular disease, whereas adrenomedullin (ADM) is a vasorelaxant with cardioprotective properties. We sought to determine the relationship between plasma ET-1 and ADM with coronary circulatory function and long-term major adverse cardiovascular events (MACE).

METHODS

Thirty-two patients undergoing coronary angiography for chest pain were recruited. Baseline plasma ET-1 and ADM levels were measured. The index of microcirculatory resistance (IMR), coronary flow mediated dilatation (cFMD) and coronary flow reserve (CFR) were measured in a non-obstructed coronary artery. Patients were assessed for MACE over a median period of 8.8 years.

RESULTS

Plasma ET-1 levels correlated with IMR (r = 0.57; p < 0.01) and ADM levels correlated with CFR (r = 0.50; p = 0.04) and cFMD (r = 0.62; p = 0.01). After adjustment for age, gender and cardiovascular risk factors, the association between ADM and cFMD (β = 0.79; p < 0.01) and between ET-1 and IMR (β = 5.7; p = 0.01) remained significant. IMR was higher, although not statistically significant, in patients with long-term MACE (17.9 ± 5.3 vs. 13.1 ± 6.0 units; p = 0.14). In patients free of MACE, cFMD (9.3 ± 7.6 vs. 2.8 ± 5.0%; p = 0.01) and plasma ADM levels (7.6 ± 5.3 vs. 4.0 ± 1.9 pmol/L; p = 0.07) were higher.

CONCLUSIONS

Plasma ET-1 and ADM were associated with measures of coronary microvascular and coronary conduit vessel function, respectively. Increased cFMD and elevated plasma ADM were associated with a cardioprotective effect.

Classic and Nonclassic Renin-Angiotensin Systems in the Critically Ill

Classic and nonclassic renin-angiotensin systems (RAS) are 2 sides of an ubiquitous endocrine/paracrine cascade regulating blood pressure and homeostasis. Angiotensin II and angiotensin-converting enzyme (ACE) levels are associated with severity of disease in the critically ill, and are central to the physiology and the pathogenesis of circulatory shock. Angiotensin (1-7) and ACE2 act as an endogenous counterregulatory arm to the angiotensin II/ACE axis. The tissue-based RAS has paracrine effects dissociated from those of the circulating RAS. Exogenous angiotensin II or ACE2 may improve the outcome of septic shock and acute respiratory distress syndrome, respectively.

Prevalence and profile of "seasonal frequent flyers" with chronic heart disease: Analysis of 1598 patients and 4588 patient-years follow-up

BACKGROUND

Peaks and troughs in cardiovascular events correlated with seasonal change is well established from an epidemiological perspective but not a clinical one.

METHODS

Retrospective analysis of the recruitment, baseline characteristics and outcomes during minimum 12-month exposure to all four seasons in 1598 disease-management trial patients hospitalised with chronic heart disease. Seasonality was prospectively defined as ≥4 hospitalisations (all-cause) AND >45% of related bed-days occurring in any one season during median 988 (IQR 653, 1394) days follow-up.

RESULTS

Patients (39% female) were aged 70 ± 12 years and had a combination of coronary artery disease (58%), heart failure (54%), atrial fibrillation (50%) and multimorbidity. Overall, 29.9% of patients displayed a pattern of seasonality. Independent correlates of seasonality were female gender (adjusted OR 1.27, 95% CI 1.01-1.61; p = 0.042), mild cognitive impairment (adjusted OR 1.51, 95% CI 1.16-1.97; p = 0.002), greater multimorbidity (OR 1.20, 95% CI 1.15-1.26 per Charlson Comorbidity Index Score; p < 0.001), higher systolic (OR 1.01, 95%CI 1.00-1.01 per 1 mmHg; p = 0.002) and lower diastolic (OR 0.99, 95% CI 0.98-1.00 per 1 mmHg; p = 0.002) blood pressure. These patients were more than two-fold more likely to die (adjusted HR 2.16, 95% CI 1.60-2.90; p < 0.001) with the highest and lowest number of deaths occurring during spring (31.7%) and summer (19.9%), respectively.

CONCLUSIONS

Despite high quality care and regardless of their diagnosis, we identified a significant proportion of "seasonal frequent flyers" with concurrent poor survival in this real-world cohort of patients with chronic heart disease.

Renin-angiotensin inhibitors reprogram tumor immune microenvironment: A comprehensive view of the influences on anti-tumor immunity

Renin-angiotensin system inhibitors (RASi) have shown potential anti-tumor effects that may have a significant impact in cancer therapy. The components of the renin-angiotensin system (RAS) including both, conventional and alternative axis, appear to have contradictory effects on tumor biology. The mechanisms by which RASi impair tumor growth extend beyond their function of modulating tumor vasculature. The major focus of this review is to analyze other mechanisms by which RASi reprogram the tumor immune microenvironment. These involve impairing hypoxia and acidosis within the tumor stroma, regulating inflammatory signaling pathways and oxidative stress, modulating the function of the non-cellular components and immune cells, and regulating the cross-talk between kalli krein kinin system and RAS.