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.

Colchicine exerts anti-atherosclerotic and -plaque-stabilizing effects targeting foam cell formation.

Colchicine is a broad-acting anti-inflammatory agent that has attracted interest for repurposing in atherosclerotic cardiovascular disease. Here, we studied its ability at a human equivalent dose of 0.5 mg/day to modify plaque formation and composition in murine atherosclerosis and investigated its actions on macrophage responses to atherogenic stimuli in vitro. In atherosclerosis induced by high-cholesterol diet, Apoe-/- mice treated with colchicine had 50% reduction in aortic oil Red O+ plaque area compared to saline control (p = .001) and lower oil Red O+ staining of aortic sinus lesions (p = .03). In vitro, addition of 10 nM colchicine inhibited foam cell formation from murine and human macrophages after treatment with oxidized LDL (ox-LDL). Mechanistically, colchicine downregulated glycosylation and surface expression of the ox-LDL uptake receptor, CD36, and reduced CD36+ staining in aortic sinus plaques. It also decreased macrophage uptake of cholesterol crystals, resulting in lower intracellular lysosomal activity, inhibition of the NLRP3 inflammasome, and reduced secretion of IL-1ß and IL-18. Colchicine's anti-atherosclerotic actions were accentuated in a mouse model of unstable plaque induced by carotid artery tandem stenosis surgery, where it decreased lesion size by 48% (p = .01), reduced lipid (p = .006) and necrotic core area (p = .007), increased collagen content and cap-to-necrotic core ratio (p = .05), and attenuated plaque neutrophil extracellular traps (p < .001). At low dose, colchicine's effects were not accompanied by the evidence of microtubule depolymerization. Together, these results show that colchicine exerts anti-atherosclerotic and plaque-stabilizing effects at low dose by inhibiting foam cell formation and cholesterol crystal-induced inflammation. This provides a new framework to support its repurposing for atherosclerotic cardiovascular disease.

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.

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).

Eukaryotic elongation factor 2 kinase regulates foam cell formation via translation of CD36.

Eukaryotic elongation factor 2 kinase (eEF2K) is an atypical protein kinase that controls protein synthesis in cells under stress. Although well studied in cancer, less is known about its roles in chronic inflammatory diseases. Here, we examined its regulation of macrophage cholesterol handling in the context of atherosclerosis. eEF2K mRNA expression and protein activity were upregulated in murine bone marrow-derived macrophages (BMDMs) exposed to oxidized low-density lipoprotein cholesterol (oxLDL). When incubated with oxLDL, BMDMs from eEF2K knockout (Eef2k-/- ) mice formed fewer Oil Red O+ foam cells than Eef2k+/+ BMDMs (12.5% ± 2.3% vs. 32.3% ± 2.0%, p < .01). Treatment with a selective eEF2K inhibitor, JAN-384, also decreased foam cell formation for C57BL/6J BMDMs and human monocyte-derived macrophages. Disabling eEF2K selectively decreased protein expression of the CD36 cholesterol uptake receptor, mediated by a reduction in the proportion of translationally active Cd36 mRNA. Eef2k-/- mice bred onto the Ldlr-/- background developed aortic sinus atherosclerotic plaques that were 30% smaller than Eef2k+/+ -Ldlr-/- mice after 16 weeks of high cholesterol diet (p < .05). Although accompanied by a reduction in plaque CD36+ staining (p < .05) and lower CD36 expression in circulating monocytes (p < .01), this was not associated with reduced lipid content in plaques as measured by oil red O staining. Finally, EEF2K and CD36 mRNA levels were higher in blood mononuclear cells from patients with coronary artery disease and recent myocardial infarction compared to healthy controls without coronary artery disease. These results reveal a new role for eEF2K in translationally regulating CD36 expression and foam cell formation in macrophages. Further studies are required to explore therapeutic targeting of eEF2K in atherosclerosis.

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.

Inflammation as a Therapeutic Target in Atherosclerosis.

Atherosclerotic coronary artery disease (CAD) results from build-up of cholesterol-rich plaques in the walls of the coronary arteries and is a leading cause of death. Inflammation is central to atherosclerosis. Uncontrolled inflammation makes coronary plaques "unstable" and vulnerable to rupture or erosion, leading to thrombosis and myocardial infarction (MI). As multiple inflamed plaques often co-exist in the coronary system, patients are at risk of repeated atherothrombotic cardiovascular events after MI, with rates of 10-12% at one year and 18-20% at three years. This is largely because current therapies for CAD, such as lipid-lowering statins, do not adequately control plaque inflammation. New anti-atherosclerotic agents are therefore needed, especially those that better target inflammation. The recent positive results for the anti-interleukin-1-beta (IL-1ß) monoclonal antibody, Canakinumab, in the Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS) clinical trial has provided a major stimulant to the field. It highlights that not only is inflammation important from a pathogenic and risk prediction perspective in CAD, but that reducing inflammation can be beneficial. The challenge is now to find the best strategies to achieve this in real-world practice. This review outlines the role that inflammation plays in atherosclerosis and provides an update on anti-inflammatory therapies currently being investigated to target atherosclerosis.

Clodronate-Liposome Mediated Macrophage Depletion Abrogates Multiple Myeloma Tumor Establishment In Vivo.

Multiple myeloma is a fatal plasma cell malignancy that is reliant on the bone marrow microenvironment. The bone marrow is comprised of numerous cells of mesenchymal and hemopoietic origin. Of these, macrophages have been implicated to play a role in myeloma disease progression, angiogenesis, and drug resistance; however, the role of macrophages in myeloma disease establishment remains unknown. In this study, the antimyeloma efficacy of clodronate-liposome treatment, which globally and transiently depletes macrophages, was evaluated in the well-established C57BL/KaLwRijHsd murine model of myeloma. Our studies show, for the first time, that clodronate-liposome pretreatment abrogates myeloma tumor development in vivo. Clodronate-liposome administration resulted in depletion of CD169+ bone marrow-resident macrophages. Flow cytometric analysis revealed that clodronate-liposome pretreatment impaired myeloma plasma cell homing and retention within the bone marrow 24 hours postmyeloma plasma cell inoculation. This was attributed in part to decreased levels of macrophage-derived insulin-like growth factor 1. Moreover, a single dose of clodronate-liposome led to a significant reduction in myeloma tumor burden in KaLwRij mice with established disease. Collectively, these findings support a role for CD169-expressing bone marrow-resident macrophages in myeloma disease establishment and progression and demonstrate the potential of targeting macrophages as a therapy for myeloma patients.

Vasculogenic properties of adventitial Sca-1+CD45+ progenitor cells in mice: a potential source of vasa vasorum in atherosclerosis.

The cellular origins of vasa vasorum are ill-defined and may involve circulating or local progenitor cells. We previously discovered that murine aortic adventitia contains Sca-1+CD45+ progenitors that produce macrophages. Here we investigated whether they are also vasculogenic. In aortas of C57BL/6 mice, Sca-1+CD45+ cells were localised to adventitia and lacked surface expression of endothelial markers (<1% for CD31, CD144, TIE-2). In contrast, they did show expression of CD31, CD144, TIE-2 and VEGFR2 in atherosclerotic ApoE-/- aortas. Although Sca-1+CD45+ cells from C57BL/6 aorta did not express CD31, they formed CD31+ colonies in endothelial differentiation media and produced interconnecting vascular-like cords in Matrigel that contained both endothelial cells and a small population of macrophages, which were located at branch points. Transfer of aortic Sca-1+CD45+ cells generated endothelial cells and neovessels de novo in a hindlimb model of ischaemia and resulted in a 50% increase in perfusion compared to cell-free control. Similarly, their injection into the carotid adventitia of ApoE-/- mice produced donor-derived adventitial and peri-adventitial microvessels after atherogenic diet, suggestive of newly formed vasa vasorum. These findings show that beyond its content of macrophage progenitors, adventitial Sca-1+CD45+ cells are also vasculogenic and may be a source of vasa vasorum during atherogenesis.

An organic fluorophore-nanodiamond hybrid sensor for photostable imaging and orthogonal, on-demand biosensing.

Organic fluorescent probes are widely used to detect key biomolecules; however, they often lack the photostability required for extended intracellular imaging. Here we report a new hybrid nanomaterial (peroxynanosensor, PNS), consisting of an organic fluorescent probe bound to a nanodiamond, that overcomes this limitation to allow concurrent and extended cell-based imaging of the nanodiamond and ratiometric detection of hydrogen peroxide. Far-red fluorescence of the nanodiamond offers continuous monitoring without photobleaching, while the green fluorescence of the organic fluorescent probe attached to the nanodiamond surface detects hydrogen peroxide on demand. PNS detects basal production of hydrogen peroxide within M1 polarised macrophages and does not affect macrophage growth during prolonged co-incubation. This nanosensor can be used for extended bio-imaging not previously possible with an organic fluorescent probe, and is spectrally compatible with both Hoechst 33342 and MitoTracker Orange stains for hyperspectral imaging.

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.

Infusional high-density lipoproteins therapies as a novel strategy for treating atherosclerosis.

High-density lipoproteins (HDL) have received considerable interest as a target for the development of novel anti-atherosclerotic agents beyond conventional approaches to lipid lowering. While a number of approaches have focused on modifying remodeling and expression pathways implicated in the regulation of HDL levels, an additional approach involves simply infusions of delipidated HDL. Several groups have advanced HDL infusions to clinical development with intriguing signs suggesting potentially favorable impacts at the level of the artery wall. The findings of early studies of infusional HDL therapies will be reviewed.

Rationally Designed Probe for Reversible Sensing of Zinc and Application in Cells.

Biologically compatible fluorescent ion sensors, particularly those that are reversible, represent a key tool for answering a range of fundamental biological questions. We report a rationally designed probe with a 6'-fluoro spiropyran scaffold (5) for the reversible sensing of zinc (Zn2+) in cells. The 6'-fluoro substituent overcomes several limitations normally associated with spiropyran-based sensors to provide an improved signal-to-background ratio and faster photoswitching times in aqueous solution. In vitro studies were performed with 5 and the 6'-nitro analogues (6) in HEK 293 and endothelial cells. The new spiropyran (5) can detect exogenous Zn2+ inside both cell types and without affecting the proliferation of endothelial cells. Studies were also performed on dying HEK 293 cells, with results demonstrating the ability of the key compound to detect endogenous Zn2+ efflux from cells undergoing apoptosis. Biocompatibility and photoswitching of 5 were demonstrated within endothelial cells but not with 6, suggesting the future applicability of sensor 5 to study intracellular Zn2+ efflux in these systems.

Cellular Therapy for Heart Failure.

The pathogenesis of cardiomyopathy and heart failure (HF) is underpinned by complex changes at subcellular, cellular and extracellular levels in the ventricular myocardium. For all of the gains that conventional treatments for HF have brought to mortality and morbidity, they do not adequately address the loss of cardiomyocyte numbers in the remodeling ventricle. Originally conceived to address this problem, cellular transplantation for HF has already gone through several stages of evolution over the past two decades. Various cell types and delivery routes have been implemented to positive effect in preclinical models of ischemic and nonischemic cardiomyopathy, with pleiotropic benefits observed in terms of myocardial remodeling, systolic and diastolic performance, perfusion, fibrosis, inflammation, metabolism and electrophysiology. To a large extent, these salubrious effects are now attributed to the indirect, paracrine capacity of transplanted stem cells to facilitate endogenous cardiac repair processes. Promising results have also followed in early phase human studies, although these have been relatively modest and somewhat inconsistent. This review details the preclinical and clinical evidence currently available regarding the use of pluripotent stem cells and adult-derived progenitor cells for cardiomyopathy and HF. It outlines the important lessons that have been learned to this point in time, and balances the promise of this exciting field against the key challenges and questions that still need to be addressed at all levels of research, to ensure that cell therapy realizes its full potential by adding to the armamentarium of HF management.