Early outcomes following integration of computed tomography (CT) coronary angiography service in an established cardiology practice in disease management.

BACKGROUND: Computed tomography coronary angiography (CTCA) is an established modality for the diagnosis and assessment of cardiovascular disease. However, price and space pressure have mostly necessitated outsourcing CTCA to external radiology providers. Advara HeartCare has recently integrated CT services within local clinical networks across Australia. This study examined the benefits of the presence (integrated) or absence (pre-integrated) of this "in-house" CTCA service in real-world clinical practice. METHODS: De-identified patient data from electronic medical records were used to create an Advara HeartCare CTCA database. Data analysis included clinical history, demographics, CTCA procedure, and 30-day outcomes post-CTCA from two age-matched cohorts: integrated (n â€‹= â€‹495) and pre-integrated (n â€‹= â€‹456). RESULTS: Data capture was more comprehensive and standardised across the integrated cohort. There was a 21% increase in referrals for CTCA from cardiologists observed for the integration cohort vs. pre-integration [n â€‹= â€‹332 (72.8%) pre-integration vs. n â€‹= â€‹465 (93.9%) post-integration, p â€‹< â€‹0.0001] with a parallel increase in diagnostic assessments including blood tests [n â€‹= â€‹209 (45.8%) vs. n â€‹= â€‹387 (78.1%), respectively, p â€‹< â€‹0.0001]. The integrated cohort received lower total dose length product [Median 212 (interquartile range 136-418) mGy∗cm vs. 244 (141.5, 339.3) mGy∗cm, p â€‹= â€‹0.004] during the CTCA procedure. 30-days after CTCA scan, there was a significantly higher use of lipid-lowering therapies in the integrated cohort [n â€‹= â€‹133 (50.5%) vs. n â€‹= â€‹179 (60.6%), p â€‹= â€‹0.04], along with a significant decrease in the number of stress echocardiograms performed [n â€‹= â€‹14 (10.6%) vs. n â€‹= â€‹5 (11.6%), p â€‹= â€‹0.01]. CONCLUSION: Integrated CTCA has salient benefits in patient management, including increased pathology tests, statin usage, and decreased post-CTCA stress echocardiography utilisation. Our ongoing work will examine the effect of integration on cardiovascular outcomes.

Early vs. Late Readmission following Percutaneous Coronary Intervention: Predictors and Impact on Long-Term Outcomes.

BACKGROUND: Readmissions within 1 year after percutaneous coronary intervention (PCI) are common (18.6-50.4% in international series) and a burden to patients and health services, however their long-term implications are not well characterised. We compared predictors of 30-day (early) and 31-day to 1-year (late) unplanned readmission and the impact of unplanned readmission on long-term clinical outcomes post-PCI. METHODS: Patients enrolled in the GenesisCare Cardiovascular Outcomes Registry (GCOR-PCI) from 2008 to 2020 were included in the study. Multivariate logistic regression analysis was performed to identify predictors of early and late unplanned readmission. A Cox proportion hazards regression model was used to explore the impact of any unplanned readmission during the first year post-PCI on the clinical outcomes at 3 years. Finally, patients with early and late unplanned readmission were compared to determine which group was at the highest risk of adverse long-term outcomes. RESULTS: The study comprised 16,911 consecutively enrolled patients who underwent PCI between 2009-2020. Of these, 1422 patients (8.5%) experienced unplanned readmission within 1-year post-PCI. Overall, the mean age was 68.9 ± 10.5 years, 76.4% were male and 45.9% presented with acute coronary syndromes. Predictors of unplanned readmission included increasing age, female gender, previous CABG, renal impairment and PCI for acute coronary syndromes. Unplanned readmission within 1 year of PCI was associated with an increased risk of MACE (adjusted HR 1.84 (1.42-2.37), p < 0.001) and death over a 3-year follow-up (adjusted HR 1.864 (1.34-2.59), p < 0.001) compared with those without readmission within 1-year post-PCI. Late compared with early unplanned readmission within the first year of PCI was more frequently associated with subsequent unplanned readmission, MACE and death between 1 and 3 years post-PCI. CONCLUSIONS: Unplanned readmissions in the first year following PCI, particularly those occurring more than 30 days after discharge, were associated with a significantly higher risk of adverse outcomes, such as MACE and death at 3 years. Strategies to identify patients at high risk of readmission and interventions to reduce their greater risk of adverse events should be implemented post-PCI.

30-Day Outcomes With the Portico Transcatheter Heart Valve: Insights From a Multi-Centre Australian Observational Study.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is an established therapy for the treatment of aortic valve disease in appropriately selected patients. Previous studies using the self-expanding Portico transcatheter heart valve (THV), (Abbott Structural Heart, St Paul, MN, USA) have demonstrated the technical feasibility of this system albeit in the hands of relatively inexperienced Portico users. The objective of this study was to assess the real-world safety and efficacy of the Portico THV (with and without the FlexNav delivery system, Abbott Structural Heart) at the 30-day timepoint in an Australian cohort. METHODS AND RESULTS: This study was a retrospective real-world cohort analysis of 269 consecutive patients with severe aortic valve disease who underwent TAVI at multiple centres within Australia between February 2015 and April 2021. Of the 269 patients, 51.7% were female, mean Society of Thoracic Surgeons (STS) score was 5.2 (±6.8) and 98.5% had successful implantations. Thirty (30)-day post-implantation all-cause mortality was observed in one (0.4%) patient, major vascular complications in two (0.7%) patients, more-than-mild paravalvular leak in six (2.2%) patients and requirement for new permanent pacemaker implantation in 27 (10.2%) patients. Haemodynamic parameters at 30 days included mean effective orifice area (EOA) of 2.3 (±0.9) cm2 and mean aortic valve gradient (AVG) of 9.6 (±6.2) mmHg. CONCLUSION: This analysis of the Portico THV in a real-world setting suggested that the system is associated with satisfactory safety and efficacy parameters. Previously published datasets may not have found similar findings owing to lower operator experience with the Portico THV system.

Comorbidities and Symptom Status in Moderate and Severe Aortic Stenosis: A Multicenter Clinical Cohort Study.

Background: Symptoms associated with severe aortic stenosis (AS) are used to guide management. Objectives: The purpose of this study was to examine the pattern of symptoms, comorbidities, and cardiac damage in moderate and severe AS. Methods: A total of 846,198 echocardiographic investigations from 330,940 individuals aged >18 years were selected for the most recent echocardiogram, moderate or severe AS (mean gradient 20.0-39.9 mm Hg, aortic valve peak gradient 3.0-3.9 m/s and aortic valve area >1.0 cm2; or ≥ 40.0 mm Hg, ≥4.0 m/s or ≤1.0 cm2, respectively), and a cardiologist consultation. Natural Language Processing was applied to letters to extract comorbidities, dyspnea, chest pain, and syncope. Patients with prior aortic valve replacement were excluded. Results: 2,213 patients (0.7% overall, 32.8% females) had moderate and 3,416 (1.0%, 47.3% females) had severe AS. Comorbidities were common, including hypertension, (56.6% moderate AS, 53.1% severe AS, P = 0.01), coronary disease (46.0% and 46.8%, respectively, P = 0.58) and atrial fibrillation (29.6% and 34.8%, respectively, P < 0.001). Symptoms were also common in both moderate (n = 915, 41.3%) and severe (n = 1,630, 47.7%) AS (P < 0.001). Comorbidities were more likely in symptomatic vs asymptomatic patients (P < 0.001). Dyspnea was more likely in severe AS, whereas angina and syncope were similar in moderate vs severe AS. In multivariable analysis, only dyspnea was associated with severe (vs moderate) AS (OR: 1.73, 95% CI: 1.41-2.13, P < 0.001). In both adjusted and unadjusted models, the degree of cardiac damage did not relate to presence of any symptoms but was associated with AS severity. Conclusions: Dyspnea is common in both moderate and severe AS, is associated with comorbidities and is not related to the degree of cardiac damage. Symptom-guided management decisions in AS may need revision.

The Association of Sex with Unplanned Cardiac Readmissions following Percutaneous Coronary Intervention in Australia: Results from a Multicentre Outcomes Registry (GenesisCare Cardiovascular Outcomes Registry).

Background and aim: Unplanned cardiac readmissions in patients with percutaneous intervention (PCI) is very common and is seen as a quality indicator of in-hospital care. Most studies have reported on the 30-day cardiac readmission rates, with very limited information being available on 1-year readmission rates and their association with mortality. The aim of this study was to investigate the impact of biological sex at 1-year post-PCI on unplanned cardiac readmissions. Methods and results: Patients enrolled into the GenesisCare Cardiovascular Outcomes Registry (GCOR-PCI) from December 2008 to December 2020 were included in the study. A total of 13,996 patients completed 12 months of follow-up and were assessed for unplanned cardiac readmissions. All patients with unplanned cardiac readmissions in the first year of post-PCI were followed in year 2 (post-PCI) for survival status. The rate of unplanned cardiac readmissions was 10.1%. Women had a 29% higher risk of unplanned cardiac readmission (HR 1.29, 95% CI 1.11 to 1.48; p = 0.001), and female sex was identified as an independent predictor of unplanned cardiac readmissions. Any unplanned cardiac readmission in the first year was associated with a 2.5-fold higher risk of mortality (HR 2.50, 95% CI 1.67 to 3.75; p < 0.001), which was similar for men and women. Conclusion: Unplanned cardiac readmissions in the first year post-PCI was strongly associated with increased all-cause mortality. Whilst the incidence of all-cause mortality was similar between women and men, a higher incidence of unplanned cardiac readmissions was observed for women, suggesting distinct predictors of unplanned cardiac readmissions exist between women and men.

Changes in R-wave amplitude at implantation are associated with gender and orientation of insertable cardiac monitor: observations from the confirm Rx™ body posture and physical activity study.

BACKGROUND: Insertable cardiac monitors (ICMs) are small subcutaneously implanted devices that detect changes in R-wave amplitudes (RWAs), effective in arrhythmia-monitoring. Although ICMs have proven to be immensely successful, electrical artefacts are frequent and can lead to misdiagnosis. Thus, there is a growing need to sustain and increase efficacy in detection rates by gaining insight into various patient-specific factors such as body postures and activities. METHODS: RWAs were measured in 15 separate postures, including supine, lying on the right-side (RS) or left-side (LS) and sitting, and two separate ICM orientations, immediately after implantation of Confirm Rx™ ICM in 99 patients. RESULTS: The patients (53 females and 46 males, mean ages 66.62 ± 14.7 and 66.40 ± 12.25 years, respectively) had attenuated RWAs in RS, LS and sitting by ~ 26.4%, ~ 27.8% and ~ 21.2% respectively, compared to supine. Gender-based analysis indicated RWAs in RS (0.32 mV (0.09-1.03 mV), p < 0.0001) and LS (0.37 mV (0.11-1.03 mV), p = 0.004) to be significantly attenuated compared to supine (0.52 mV (0.20-1.03 mV) for female participants. Similar attenuation was not evident for male participants. Further, parasternally oriented ICMs (n = 44), attenuated RWAs in RS (0.37 mV(0.09-1.03 mV), p = 0.05) and LS (0.34 mV (0.11-1.03 mV), p = 0.02) compared to supine (0.48 mV (0.09-1.03 mV). Similar differences were not observed in participants with ICMs in the 45°-relative-to-sternum (n = 46) orientation. When assessing the combined effect of gender and ICM orientation, female participants demonstrated plausible attenuation in RWAs for RS and LS postures compared to supine, an effect not observed in male participants. CONCLUSION: This is the first known study depicting the effects on RWA due to body postures and activities immediately post-implantation with an overt impact by gender and orientation of ICM. Future work assessing the cause of gender-based differences in RWAs may be critical. TRIAL REGISTRATION: Clinical Trials, NCT03803969. Registered 15 January 2019 - Retrospectively registered, https://clinicaltrials.gov/NCT03803969.

Health-Related Quality of Life (HRQoL) and the Effect on Outcome in Patients Presenting with Coronary Artery Disease and Treated with Percutaneous Coronary Intervention (PCI): Differences Noted by Sex and Age.

Background and aim: poor quality of life (QoL) has been identified as an independent risk factor for mortality and major cardiac events (MACE) in patients with cardiovascular disease (CVD). The aim of this study was to assess health-related quality of life (HRQoL) at baseline and its association with outcome in patients with coronary artery disease presenting for percutaneous coronary intervention (PCI). The outcome was measured by mortality and MACE at 1-year, and whether there was any difference for sex and different age groups. Methods and results: all patients prospectively enrolled into the GenesisCare Outcome Registry (GCOR) over a 11-year period were included in the study. The EQ-5D-5L and VAS patient survey were used for assessment of baseline HRQoL. Of the 15,198 patients, only 6591 (43.4%) completed the self-assessment. Women had significantly more impairment of all five dimensions of the EQ-5D-5L survey, and their self-reported QoL was significantly lower than men (68.3 in women vs. 71.9 in men, p < 0.001). Poor QoL was strongly associated with increased mortality (HR 2.85; 95% CI 1.76 to 4.62, p < 0.001) and MACE (HR 1.40; 95% CI 1.10 to 1.79, p = 0.01). A similar trend was noted for women and men, but did not reach significance in women due to the smaller number of female patients. Conclusion: poor HRQoL is associated with subsequent mortality and MACE in patients undergoing PCI. By not assessing quality of life as a standard of care, an opportunity is lost to identify high-risk patients who may benefit from targeted interventions to improve health outcomes.

R-wave amplitude changes with posture and physical activity over time in an insertable cardiac monitor.

Background: Insertable cardiac monitors (ICMs) are accepted tools in cardiac arrhythmia management. Consistent R-wave amplitude (RWA) is essential for optimal detection. Objectives: Assess RWAs with posture/activities at insertion and at 30 days. Methods: Participants (n = 90) with Confirm Rx™ ICM had RWAs measured in different postures (supine, right-side [RS], left-side [LS], sitting, and standing) and defined physical activities (including isometric push [IPUSH] and pull) at 2 time points. ICMs were inserted in 45° to sternum and parasternal orientations. Results: There were significant reductions at insertion with RS, LS, sitting, or standing vs supine (reference position) (all P < .05). At 30 days, significant changes only occurred with LS and sitting (P < .05). Sex had an effect on RWAs, with females having significant variability at insertion (supine vs RS, LS, sitting, standing, and IPUSH; all P < .05). Males showed large RWA interpatient variabilities but minimal differences between positions vs supine. At 30 days, RS, LS, and sitting positions remained significant for females (P < .05), while in males RWAs were higher than at insertion for most postures and activities. The orientation 45° to sternum had consistently higher RWAs vs parasternal orientation at both time points (P < .0001). In females, ICM orientation had no significant effect on RWAs; however, in males the 45° to sternum produced higher RWAs. ICM movement from the insertion site showed no correlation with RWA changes. Conclusion: The mean RWAs were higher at 30 days with less interparticipant and interpostural variability; males had higher RWAs compared to females; 45° to sternum orientation had higher RWAs; and ICM migration from the insertion site did not affect RWAs.

Sex Differences in Baseline Characteristics Do Not Predict Early Outcomes after Percutaneous Coronary Intervention: Results from the Australian GenesisCare Cardiovascular Outcomes Registry (GCOR).

OBJECTIVE: The effect of baseline differences between men and women on early outcomes after percutaneous coronary intervention (PCI). DESIGN, SETTING, PARTICIPANTS: This is an observational study of all participants in the GenesisCare Cardiovascular Outcomes Registry, undergoing PCI. The registry holds data for both emergency and elective procedures. Data was collected on 10,989 consecutive patients from 12 Australian Private Hospitals, including baseline demographics, co-morbidities, risk factors, PCI procedures, and lesion characteristics. MAIN OUTCOME MEASURES: Outcome was measured for complications (in-hospital death, peri-procedural myocardial infarctions, and bleeding events), at discharge and at 30-days for death, myocardial infarction, target lesion revascularisation (TLR), major adverse cardiac events (MACE), and unplanned readmissions. RESULTS: Women represented 23% of the study population, were significantly older, with a higher rate of hypertension and hyperlipidaemia. Heart failure was more common in women and was associated with a significantly higher average ejection fraction than in men. Women had a lower rate of pre-existing coronary artery disease (CAD), had less complex CAD, and needed fewer stents. Periprocedural complications were similar, but major bleeding was more common in women. The 30-day outcome was similar between men and women for death, myocardial infarction, target lesion revascularisation (TLR), major adverse cardiovascular events (MACE), and unplanned readmissions. CONCLUSIONS: Although significant differences were observed between women and men in both clinical presentation and complexity of disease, the 30-day outcome was similar for death and MACE. Women had a higher rate of major bleeding events, and lower adherence to statins and dual antiplatelet therapy (DAPT).

Long-Term Outcomes of Contemporary Percutaneous Coronary Intervention with the Xience Drug-Eluting Stent: Results from a Multicentre Australian Registry.

Introduction: Several large registries have evaluated outcomes after percutaneous coronary intervention (PCI) in the USA, however there are no contemporary data regarding long-term outcomes after PCI, particularly comparing new generation drug-eluting stents (DES) with other stents in Australia. Additionally, approval of new-generation drug-eluting stents (DES) is almost exclusively based on non-inferiority trials comparing outcomes with early generation DES, and there are limited data comparing safety and efficacy outcomes of new-generation DES with bare metal stents (BMS). This study reports in-hospital and long-term outcomes after PCI with the Xience DES from a large national registry, the GenesisCare Outcomes Registry (GCOR). Methods: The first 1500 patients consecutively enrolled from January 2015 to January 2019 and treated exclusively with either Xience DES or BMS and eligible for 1-year follow-up were included. Baseline patient and procedural data, major adverse cardiovascular events (MACE) in-hospital, at 30 days and 1-year, and medications were reported and analysed with respect to Xience DES (n = 1000) or BMS (n = 500) use. Results: In this cohort the mean age was 68.4 ± 10.7 years, 76.9% were male, 24.6% had diabetes mellitus and 45.9% presented with acute coronary syndromes. Of the overall cohort of 4765 patients from this period including all DES types, and patients who received multiple DES or a combination of DES and BMS, DES were exclusively used in 3621 (76.0%) patients, and BMS were exclusively used in 596 (12.5%). In comparison to international cohorts, adverse clinical event rates were low at 30 days in terms of mortality (0.20%), target lesion revascularisation (TLR, 0.27%) and MACE (0.47%), and at 12 months for mortality (1.26%) TLR (1.16%) and MACE (1.78%). Conclusions: Clinical practice and long-term outcomes of PCI with the Xience DES in Australia are consistent with international series. Recent trends indicate DES use has increased in parallel with good outcomes despite an increasingly complex patient and lesion cohort.

Omega-3 fatty acids ameliorate vascular inflammation: A rationale for their atheroprotective effects.

BACKGROUND AND AIMS: Clinical trials have demonstrated reductions in major adverse cardiovascular events with purified high-dose eicosapentaenoic acid (EPA), independent of effects on lipids. We aimed to investigate whether omega-3 fatty acids reduce vascular inflammation, a critical mediator of atherosclerosis, and hypothesised that EPA is superior to docosahexaenoic acid (DHA). METHODS: In a double-blind randomised controlled trial and cell-culture study, 40 healthy volunteers were supplemented with 4 g daily of either EPA, DHA, fish oil (2:1 EPA:DHA), or placebo for 30 days. Serum was incubated with TNF-stimulated human umbilical vein endothelial cells (HUVECs), and markers of acute vascular inflammation (AVI) were measured. The effects of EPA, DHA (600 mg/kg/day), olive oil, or no treatment were also measured in preclinical models of [1] AVI using a periarterial collar (C57Bl/6J; n = 40 mice) and [2] atherosclerosis where ApoE-/- mice (n = 40) were fed a 16-week atherogenic diet. RESULTS: EPA supplementation reduced expression of C-C motif chemokine ligand 2 (CCL2) by 25% compared to placebo (p = 0.03). In the AVI model, EPA reduced vascular expression of VCAM1 by 43% (p = 0.02) and CCL2 by 41% (p = 0.03). Significant inverse correlations were observed between EPA levels and vascular expression of VCAM1 (r = -0.56, p = 0.001) and CCL2 (r = -0.56, p = 0.001). In ApoE-/- mice, EPA reduced aortic expression of Il1b by 44% (p = 0.04) and Tnf by 49% (p = 0.04), with similar inverse correlations between EPA levels and both Il1b (r = -0.63, p = 0.009) and Tnf (r = -0.50, p = 0.04). CONCLUSIONS: Supplementation with EPA, more so than DHA, ameliorates acute and chronic vascular inflammation, providing a rationale for the cardiovascular benefit observed with high dose omega-3 fatty acid administration.

Associations of ABCG1-mediated cholesterol efflux capacity with coronary artery lipid content assessed by near-infrared spectroscopy.

BACKGROUND: Although high-density lipoprotein (HDL) has atheroprotective properties, the association of HDL functionality with coronary plaques remains unclear. METHODS: We investigated the association between HDL-mediated cholesterol efflux capacity (CEC) and coronary lipid burden in 74 patients who underwent near-infrared spectroscopy (NIRS) imaging for acute coronary syndrome (ACS) or stable ischemic symptoms. We measured baseline HDL-mediated CEC, distinguishing the specific pathways, and stratified patients according to their median CEC values. Coronary lipid burden was assessed as lipid core burden index (LCBI) using NIRS at baseline (n=74) and on serial imaging (n=47). RESULTS: Patients with baseline ATP-binding cassette transporter G1 (ABCG1)-mediated CEC > median had a greater baseline LCBI {74 [20, 128] vs. 32 [5, 66]; P=0.04} or change in LCBI {-30 [-89, 0] vs. -3 [-16, 0]; P=0.048}. In addition to a negative association between baseline LCBI and change in LCBI (standardized ß=-0.31; P=0.02), multivariable analysis demonstrated a significant interaction effect between clinical presentation of coronary artery disease (CAD) and baseline ABCG1-mediated CEC on change in LCBI (P=0.003), indicating that baseline ABCG1-mediated CEC was inversely associated with change in LCBI in patients with ACS (standardized ß=-0.79, P=0.003), but not in those with stable ischemic symptoms (P=0.52). CONCLUSIONS: In this study, ABCG1-mediated CEC, but not ATP-binding cassette transporter A1 and scavenger receptor B type I, was associated with regression of coronary artery lipid content, especially in patients with high-risk phenotype. Further studies are required to determine the roles of ABCG1 pathway in the development coronary plaques.

A Novel Ruthenium-based Molecular Sensor to Detect Endothelial Nitric Oxide.

Nitric oxide (NO) is a key regulator of endothelial cell and vascular function. The direct measurement of NO is challenging due to its short half-life, and as such surrogate measurements are typically used to approximate its relative concentrations. Here we demonstrate that ruthenium-based [Ru(bpy)2(dabpy)]2+ is a potent sensor for NO in its irreversible, NO-bound active form, [Ru(bpy)2(T-bpy)]2+. Using spectrophotometry we established the sensor's ability to detect and measure soluble NO in a concentration-dependent manner in cell-free media. Endothelial cells cultured with acetylcholine or hydrogen peroxide to induce endogenous NO production showed modest increases of 7.3 ± 7.1% and 36.3 ± 25.0% respectively in fluorescence signal from baseline state, while addition of exogenous NO increased their fluorescence by 5.2-fold. The changes in fluorescence signal were proportionate and comparable against conventional NO assays. Rabbit blood samples immediately exposed to [Ru(bpy)2(dabpy)]2+ displayed 8-fold higher mean fluorescence, relative to blood without sensor. Approximately 14% of the observed signal was NO/NO adduct-specific. Optimal readings were obtained when sensor was added to freshly collected blood, remaining stable during subsequent freeze-thaw cycles. Clinical studies are now required to test the utility of [Ru(bpy)2(dabpy)]2+ as a sensor to detect changes in NO from human blood samples in cardiovascular health and disease.

Induction of obesity impairs reverse cholesterol transport in ob/ob mice.

OBJECTIVES: Obesity is an independent risk factor for cardiovascular disease. Reverse cholesterol transport (RCT) is an important cardioprotective mechanism. This study aimed to investigate RCT changes in a murine model of obesity. METHODS: Ob/ob and control mice were injected with [3H]-cholesterol-labelled macrophages and cholesterol accumulation quantified after 48 h. Ex vivo, cholesterol efflux and uptake were determined in hepatic and adipose tissues. RESULTS: Ob/ob mice had more labelled cholesterol in their plasma (86%, p<0.001), suggesting impaired RCT. SR-BI-mediated cholesterol efflux was elevated from ob/ob mice (serum, 33%; apoB-depleted plasma, 14%, p<0.01) and HDL-c were also higher (60%, p<0.01). Ex vivo it was found that cholesterol uptake was significantly lower into the livers and adipose tissue of ob/ob mice, compared to non-obese wildtype controls. Furthermore, ex vivo cholesterol efflux was reduced in ob/ob liver and adipose tissue towards apoA-I and HDL. Consistent with this, protein levels of SR-BI and ABCG1 were significantly lower in ob/ob hepatic and adipose tissue than in wildtype mice. Finally, labelled cholesterol concentrations were lower in ob/ob bile (67%, p<0.01) and faeces (76%, p<0.0001). CONCLUSION: Obesity causes impairment in RCT due to reduced plasma cholesterol uptake and efflux by hepatocytes and adipocytes. A reduction in the capacity for plasma cholesterol clearance may partly account for increased CVD risk with obesity.

Myeloperoxidase modification of high-density lipoprotein suppresses human endothelial cell proliferation and migration via inhibition of ERK1/2 and Akt activation.

BACKGROUND AND AIMS: Preclinical studies show high-density lipoproteins (HDL) have a protective and reparative effect on the endothelium. HDL is, however, susceptible to oxidation, which affects function. Myeloperoxidase (MPO)-induced modification of HDL results in loss of anti-apoptotic and anti-inflammatory functions, however, its effect on endothelial proliferation and migration has not been characterized. METHODS: HUVECs were co-incubated with MPO-oxidised- or native-HDL (nHDL) in proliferation and migration assays. Signalling proteins were assessed in Western blots. RESULTS: nHDL caused dose-dependent increases of endothelial proliferation and migration. Consistent with an increase in cellular proliferation, HDL also stimulated proliferative cellular nuclear antigen (PCNA) expression and ERK phosphorylation in a concentration-dependent manner, which did not occur with MPO-oxidised HDL. HDL increased Akt phosphorylation, a driver of cellular migration. Contrastingly, MPO-oxidised HDL was unable to increase Akt phosphorylation and extensively-oxidised HDL inhibited Akt phosphorylation. CONCLUSIONS: HDL promotes endothelial proliferation and migration, mediated in part via activation of ERK and Akt signalling. MPO-induced oxidative modification of HDL attenuates the endothelial-protective effects of HDL. These findings suggest that in an oxidative milieu, present in ageing and disease, HDL is likely to become ineffective. This has implications for HDL-raising therapies and emphasizes the need for strategies that prevent oxidation-related HDL dysfunction.

High-density lipoproteins attenuate high glucose-impaired endothelial cell signaling and functions: potential implications for improved vascular repair in diabetes.

BACKGROUND: Abnormalities of endothelial cell function are proposed to be a critical factor underlying adverse cardiovascular outcomes in the setting of hyperglycaemia. While high-density lipoproteins (HDL) have been demonstrated to be cardioprotective, the impact on the endothelium in hyperglycaemia has not been fully elucidated. METHODS: Human umbilical vein endothelial cells (HUVECs) were exposed to high-glucose conditions using dextrose, the main isoform of glucose, and native HDL. HUVEC proliferation and migration were determined. The key signalling pathways that regulate endothelial cell function were also characterized. RESULTS: Increasing concentrations of dextrose resulted in significant reductions in HUVEC proliferation, this was attenuated by coincubation with HDL. In support of this, HDL was also found to rescue dextrose impaired expression of PCNA and the activation (phosphorylation) of the key transcription factor for proliferation ERK. Dextrose also dose-dependently inhibited HUVEC migration, which was mitigated by co-incubation with HDL. Consistent with this, HDL prevented dextrose-induced inhibition of p38 phosphorylation, responsible for cell migration. Finally, phosphorylation of the pro-survival transcription factor Akt was dose-dependently inhibited by dextrose, however, this was completely rescued by co-administration with HDL. CONCLUSION: Dextrose-induced hyperglycaemia causes the impairment of endothelial cell proliferation and migration and inhibits the activation of ERK, p38 and Akt pathways. The protective effects of HDL in this milieu highlights the potential for HDL to improve vascular repair in patients with impaired glucose homeostasis.

Regression of coronary atherosclerosis with infusions of the high-density lipoprotein mimetic CER-001 in patients with more extensive plaque burden.

BACKGROUND: CER-001 is an engineered pre-beta high-density lipoprotein (HDL) mimetic, which rapidly mobilizes cholesterol. Infusion of CER-001 3 mg/kg exhibited a potentially favorable effect on plaque burden in the CHI-SQUARE (Can HDL Infusions Significantly Quicken Atherosclerosis Regression) study. Since baseline atheroma burden has been shown as a determinant for the efficacy of HDL infusions, the degree of baseline atheroma burden might influence the effect of CER-001. METHODS: CHI-SQUARE compared the effect of 6 weekly infusions of CER-001 (3, 6 and 12 mg/kg) vs. placebo on coronary atherosclerosis in 369 patients with acute coronary syndrome (ACS) using serial intravascular ultrasound (IVUS). Baseline percent atheroma volume (B-PAV) cutoff associated with atheroma regression following CER-001 infusions was determined by receiver-operating characteristics curve analysis. 369 subjects were stratified according to the cutoff. The effect of CER-001 at different doses was compared to placebo in each group. RESULTS: A B-PAV ≥30% was the optimal cutoff associated with PAV regression following CER-001 infusions. CER-001 induced PAV regression in patients with B-PAV ≥30% but not in those with B-PAV <30% (-0.45%±2.65% vs. +0.34%±1.69%, P=0.01). Compared to placebo, the greatest PAV regression was observed with CER-001 3mg/kg in patients with B-PAV ≥30% (-0.96%±0.34% vs. -0.25%±0.31%, P=0.01), whereas there were no differences between placebo (+0.09%±0.36%) versus CER-001 in patients with B-PAV <30% (3 mg/kg; +0.41%±0.32%, P=0.39; 6 mg/kg; +0.27%±0.36%, P=0.76; 12 mg/kg; +0.32%±0.37%, P=0.97). CONCLUSIONS: Infusions of CER-001 3 mg/kg induced the greatest atheroma regression in ACS patients with higher B-PAV. These findings identify ACS patients with more extensive disease as most likely to benefit from HDL mimetic therapy.

Clinical trials with cholesteryl ester transfer protein inhibitors.

PURPOSE OF REVIEW: Inhibition of cholesteryl ester transfer protein (CETP) has received considerable interest by virtue of its favorable effects on atherogenic and protective lipid parameters. The impact of CETP inhibitors in large clinical outcome trials will be reviewed. RECENT FINDINGS: Population and genetic studies demonstrate that low CETP activity associates with lower rates of cardiovascular events. Inhibiting CETP activity in animal models has a favorable impact on experimental atherosclerosis. Although the first CETP inhibitor to advance to an outcome trial proved to have adverse clinical effects and the next agent, a more modest inhibitor, was clinically futile, there continues to be immense interest in the potential to develop nontoxic, potent CETP inhibitors to reduce cardiovascular risk. SUMMARY: The current status of CETP inhibitors in the context of large outcomes trials will be reviewed.

CETP Inhibition in CVD Prevention: an Actual Appraisal.

By virtue of their effects on low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and cellular cholesterol efflux, there is considerable interest in the potential use of pharmacological inhibitors of cholesteryl ester transfer protein (CETP) as a novel approach for cardiovascular disease prevention. This is supported by observations from genetic and animal studies suggesting that less CETP activity has favorable cardiovascular effects. Despite the adverse effects of the first CETP inhibitor to move forward in clinical development, torcetrapib, there remains considerable interest in developing alternative CETP inhibitors without the off-target effects of torcetrapib. The clinical development programs leading to a number of promising CETP inhibitors will be reviewed.

HDL function and subclinical atherosclerosis in juvenile idiopathic arthritis.

BACKGROUND: Increasing evidence suggests that inflammation adversely impacts the protective properties of high-density lipoproteins (HDL) and progression of atherosclerosis. The impact of early chronic inflammatory conditions on HDL function and vascular risk has not been well investigated. METHODS: We compared measures of HDL particle distribution and functionality, in addition to measures of carotid intima-medial thickness (cIMT) in patients with juvenile idiopathic arthritis (JIA) and age matched controls. RESULTS: JIA patients demonstrated lower levels of HDL cholesterol [47.0 (40.0, 56.0) vs. 56.0 (53.0, 61.0) mg/dL, P=0.04], total HDL [29.5 (27.9, 32.3) vs. 32.9 (31.6, 36.3) mg/dL, P=0.05] and large HDL [5.1 (3.7, 7.3) vs. 8.0 (6.7, 9.7) mg/dL, P=0.04] particles. In association JIA patients demonstrated greater cholesterol efflux mediated via ATP binding cassette A1 (ABCA1) [17.3% (12.8, 19.7) vs. 10.0% (5.8, 16.0), P=0.05] and less efflux mediated via ATP binding cassette G-1 (ABCG1) [3.2% (2.0, 3.9) vs. 4.8% (3.5, 5.8), P=0.01] and SR-B1 [6.9% (6.0, 8.4) vs. 9.1% (8.6, 10.2), P=0.002] compared with controls. Exposure of macrophages to serum from JIA patients resulted in a smaller increase in mRNA expression of ABCA1 (2.0±0.95 vs. 7.1±5.7 fold increase, P=0.01) and greater increases in expression of ABCG1 [1.4 (0.9, 1.5) vs. 0.8 (0.7, 1.1) fold increase, P=0.04] and SR-B1 (1.3±0.47 vs. 0.7±0.3 fold increase, P=0.001) compared with controls. Arylesterase (128.9±27.6 vs. 152.0±45.2 umoles/min/mL, P=0.04) activity and endothelial cell migration (491.2±68.9 vs. 634.2±227.4 cells/field, P=0.01) were less in JIA patients. No differences in cIMT were observed between JIA patients and controls. CONCLUSIONS: The presence of JIA was associated with alterations in HDL particle distribution, cholesterol efflux and non-lipid transporting activities. The ultimate implication of these findings for cardiovascular risk requires further investigation.